M48T201Y M48T201V ® 5.0 or 3.3 V TIMEKEEPER supervisor Features ■ Converts low power SRAM into NVRAMs ■ Year 2000 compliant SNAPHAT® (SH) ■ Battery low flag crystal/battery ■ Integrated real time clock, power-fail control circuit, battery and crystal ■ Watchdog timer ■ Choice of write protect voltages (V = power-fail deselect voltage): PFD – M48T201Y: V = 4.5 to 5.5 V CC 4.1V ≤ V ≤ 4.5 V PFD – M48T201V: V = 3.0 to 3.6 V CC 2.7 V ≤ VPFD ≤ 3.0 V ■ Microprocessor power-on reset (valid even during battery backup mode) 44 1 ■ Programmable alarm output active in the battery backed-up mode ■ Packaging includes a 44-lead SOIC and SNAPHAT® top (to be ordered separately) SOH44 (MH) 44-pin SOIC ■ SOIC package provides direct connection for a SNAPHAT® top which contains the battery and crystal ■ RoHS compliant – Lead-free second level interconnect March 2009 Rev 7 1/37 www.st.com 1

Contents M48T201Y, M48T201V Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.1 Address decoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.2 Read mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.3 Write mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.4 Data retention mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 Clock operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1 TIMEKEEPER® registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.2 Reading the clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.3 Setting the clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.4 Stopping and starting the oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.5 Setting the alarm clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.6 Watchdog timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.7 Square wave output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.8 Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.9 Reset inputs (RSTIN1 & RSTIN2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.10 Calibrating the clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.11 Battery low warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 3.12 Initial power-on defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.13 V noise and negative going transients . . . . . . . . . . . . . . . . . . . . . . . . . 26 CC 4 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 8 Environmental information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2/37

M48T201Y, M48T201V Contents 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3/37

List of tables M48T201Y, M48T201V List of tables Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Table 2. Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Table 3. Read mode AC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 4. Write mode AC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table 5. TIMEKEEPER® register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 6. Alarm repeat modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 7. Square wave output frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Table 8. Reset AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Table 9. Default values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Table 10. Absolute maximum ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table 11. DC and AC measurement conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 12. Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 13. DC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Table 14. Power down/up mode AC characteristic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Table 15. SOH44 – 44-lead plastic small outline, SNAPHAT®, pack. mech. data. . . . . . . . . . . . . . . 31 Table 16. SH – 4-pin SNAPHAT® housing for 48 mAh battery & crystal, pack. mech. data . . . . . . . 32 Table 17. SH – 4-pin SNAPHAT® housing for 120 mAh battery & crystal, pack. mech. data . . . . . . 33 Table 18. Ordering information scheme. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Table 19. SNAPHAT® battery table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Table 20. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4/37

M48T201Y, M48T201V List of figures List of figures Figure 1. Logic diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Figure 2. SOIC connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 3. Hardware hookup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Figure 4. G timing when switching between RTC and external SRAM . . . . . . . . . . . . . . . . . . . . 11 CON Figure 5. Read cycle timing: RTC and external RAM control signals . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 6. Write cycle timing: RTC and external RAM control signals. . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 7. Alarm interrupt reset waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 8. Backup mode alarm waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 9. RSTIN1 and RSTIN2 timing waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 10. Crystal accuracy across temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Figure 11. Calibration waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Figure 12. Supply voltage protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 13. AC testing load circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Figure 14. Power down/up mode AC waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Figure 15. SOH44 – 44-lead plastic small outline, SNAPHAT®, package outline . . . . . . . . . . . . . . . . 31 Figure 16. SH – 4-pin SNAPHAT® housing for 48 mAh battery & crystal, package outline. . . . . . . . . 32 Figure 17. SH – 4-pin SNAPHAT® housing for 120 mAh battery & crystal, pack. outline . . . . . . . . . . 33 Figure 18. Recycling symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 5/37

Description M48T201Y, M48T201V 1 Description The M48T201Y/V are self-contained devices that include a real time clock (RTC), programmable alarms, a watchdog timer, and a square wave output which provides control of up to 512 K x 8 of external low-power static RAM. Access to all RTC functions and the external RAM is the same as conventional bytewide SRAM. The 16 TIMEKEEPER® registers offer year, month, date, day, hour, minute, second, calibration, alarm, century, watchdog, and square wave output data. Externally attached static RAMs are controlled by the M48T201Y/V via the G and E signals. CON CON The 44-pin, 330 mil SOIC provides sockets with gold plated contacts at both ends for direct connection to a separate SNAPHAT® housing containing the battery and crystal. The unique design allows the SNAPHAT battery package to be mounted on top of the SOIC package after the completion of the surface mount process. Insertion of the SNAPHAT housing after reflow prevents potential battery damage due to the high temperatures required for device surface-mounting. The SNAPHAT housing is keyed to prevent reverse insertion. The SOIC and battery packages are shipped separately in plastic anti-static tubes or in tape & reel form. For the 44-lead SOIC, the battery/crystal package (e.g., SNAPHAT) part number is “M4Txx-BR12SH” (see Table19 on page34). Caution: Do not place the SNAPHAT battery/crystal top in conductive foam as this will drain the lithium button-cell battery. Figure 1. Logic diagram VCC 19 8 A0-A18 DQ0-DQ7 WDI IRQ/FT W RST M48T201Y E M48T201V GCON G ECON RSTIN1 SQW RSTIN2 VOUT VSS AI02240 6/37

M48T201Y, M48T201V Description Table 1. Signal names A0-A18 Address inputs DQ0-DQ7 Data inputs / outputs RSTIN1 Reset 1 input RSTIN2 Reset 2 Input RST Reset output (open drain) WDI Watchdog input E Chip enable input G Output enable Input W WRITE enable input E RAM chip enable output CON G RAM enable output CON IRQ/FT Interrupt / frequency test output (open drain) SQW Square wave output V Supply voltage output OUT V Supply voltage CC V Ground SS NC Not connected internally 7/37

Description M48T201Y, M48T201V Figure 2. SOIC connections RSTIN1 1 44 VCC RSTIN2 2 43 VOUT RST 3 42 SQW NC 4 41 IRQ/FT A18 5 40 A17 A16 6 39 A15 A14 7 38 A13 A12 8 37 A8 A7 9 36 A9 A6 10 35 A11 A5 11 34 G M48T201Y A4 12 33 W M48T201V A3 13 32 NC A2 14 31 A10 A1 15 30 E A0 16 29 ECON WDI 17 28 DQ7 GCON 18 27 DQ6 DQ0 19 26 DQ5 DQ1 20 25 DQ4 DQ2 21 24 DQ3 VSS 22 23 NC AI02241 8/37

M48T201Y, M48T201V Description Figure 3. Hardware hookup A0-A18 A0-Axx 32,768 Hz CRYSTAL VOUT VCC 0.1μF E2(1) LITHIUM M48T201Y/V 5V CELL VCC CMOS 0.1μF E SRAM W ECON E G W WDI GCON G RSTIN1 RST RSTIN2 IRQ/FT VSS SQW VSS DQ0-DQ7 DQ0-DQ7 AI00604 1. If the second chip enable pin (E2) is unused, it should be tied to V . OUT 9/37

Operation M48T201Y, M48T201V 2 Operation Automatic backup and write protection for an external SRAM is provided through V , OUT E , and G pins. (Users are urged to insure that voltage specifications, for both the CON CON supervisor chip and external SRAM chosen, are similar.) The SNAPHAT® containing the lithium energy source is used to retain the RTC and RAM data in the absence of V power CC through the V pin. The chip enable output to RAM (E ) and the output enable output OUT CON to RAM (G ) are controlled during power transients to prevent data corruption. The date CON is automatically adjusted for months with less than 31 days and corrects for leap years (valid until 2100). The internal watchdog timer provides programmable alarm windows. The nine clock bytes (7FFFFh-7FFF9h and 7FFF1h) are not the actual clock counters, they are memory locations consisting of BiPORT™ READ/WRITE memory cells within the static RAM array. Clock circuitry updates the clock bytes with current information once per second. The information can be accessed by the user in the same manner as any other location in the static memory array. Byte 7FFF8h is the clock control register. This byte controls user access to the clock information and also stores the clock calibration setting. Byte 7FFF7h contains the watchdog timer setting. The watchdog timer can generate either a reset or an interrupt, depending on the state of the watchdog steering bit (WDS). Bytes 7FFF6h-7FFF2h include bits that, when programmed, provide for clock alarm functionality. Alarms are activated when the register content matches the month, date, hours, minutes, and seconds of the clock registers. Byte 7FFF1h contains century information. Byte 7FFF0h contains additional flag information pertaining to the watchdog timer, the alarm condition, the battery status and square wave output operation. 4 bits are included within this register (RS0-RS3) that are used to program the square wave output frequency (see Table7 on page21). The M48T201Y/V also has its own power-fail detect circuit. This control circuitry constantly monitors the supply voltage for an out of tolerance condition. When V is out of CC tolerance, the circuit write protects the TIMEKEEPER® register data and external SRAM, providing data security in the midst of unpredictable system operation. As V falls below CC the battery backup switchover voltage (V ), the control circuitry automatically switches to SO the battery, maintaining data and clock operation until valid power is restored. 2.1 Address decoding The M48T201Y/V accommodates 19 address lines (A0-A18) which allow direct connection of up to 512 K bytes of static RAM. Regardless of SRAM density used, timekeeping, watchdog, alarm, century, flag, and control registers are located in the upper RAM locations. All TIMEKEEPER registers reside in the upper RAM locations without conflict by inhibiting the G (output enable RAM) signal during clock access. The RAM's physical locations CON are transparent to the user and the memory map looks continuous from the first clock address to the upper most attached RAM addresses. 10/37

M48T201Y, M48T201V Operation Table 2. Operating modes DQ7- Mode V E G W Power CC DQ0 Deselect V X X High-Z Standby IH 4.5 V to 5.5 V WRITE V X V D Active IL IL IN or READ V V V D Active 3.0 V to 3.6 V IL IL IH OUT READ V V V High-Z Active IL IH IH Deselect V to V (min)(1) X X X High-Z CMOS standby SO PFD Deselect ≤ V (1) X X X High-Z Battery backup SO 1. See Table14 on page30 for details. Note: X = V or V ; V = battery backup switchover voltage IH IL SO 2.2 Read mode The M48T201Y/V executes a READ cycle whenever W (WRITE enable) is high and E (chip enable) is low. The unique address specified by the address inputs (A0-A18) defines which one of the on-chip TIMEKEEPER® registers or external SRAM locations is to be accessed. When the address presented to the M48T201Y/V is in the range of 7FFFFh-7FFF0h, one of the on-board TIMEKEEPER registers is accessed and valid data will be available to the eight data output drivers within t after the address input signal is stable, providing that AVQV the E and G access times are also satisfied. If they are not, then data access must be measured from the latter occurring signal (E or G) and the limiting parameter is either t ELQV for E or t for G rather than the address access time. When one of the on-chip GLQV TIMEKEEPER registers is selected for READ, the G signal will remain inactive CON throughout the READ cycle. When the address value presented to the M48T201Y/V is outside the range of TIMEKEEPER registers, an external SRAM location will be selected. In this case the G signal will be passed to the G pin, with the specified delay times of t or t . CON AOEL OERL Figure 4. G timing when switching between RTC and external SRAM CON ADDRESS 7FFF0h - 7FFFFh 00000h - 7FFEFh 7FFF0h - 7FFFFh 00000h - 7FFEFh RTC External SRAM RTC External SRAM G GCON tAOEL tAOEH tOERL tRO E AI02333 11/37

Operation M48T201Y, M48T201V Figure 5. Read cycle timing: RTC and external RAM control signals READ READ WRITE tAVAV tAVAV tAVAV ADDRESS tELQV tAVQV tAVWL tWHAX E tELQX tGLQV G tRO GCON ECON tEPD tWLWH W tGLQX tAXQX tGHQZ DATA OUT DATA OUT DATA IN DQ0-DQ7 VALID VALID VALID AI02334 12/37

M48T201Y, M48T201V Operation Table 3. Read mode AC characteristics M48T201Y M48T201V Symbol Parameter(1) –70 –85 Unit Min Max Min Max t READ cycle time 70 85 ns AVAV t Address valid to output valid 70 85 ns AVQV t Chip enable low to output valid 70 85 ns ELQV t Output enable low to output valid 25 35 ns GLQV t (2) Chip enable low to output transition 5 5 ns ELQX t (2) Output enable low to output transition 0 0 ns GLQX t (2) Chip enable high to output Hi-Z 20 25 ns EHQZ t (2) Output enable high to output Hi-Z 20 25 ns GHQZ t Address transition to output transition 5 5 ns AXQX t External SRAM address to G low 20 30 ns AOEL CON t Supervisor SRAM address to G high 20 30 ns AOEH CON t E to E low or high 10 15 ns EPD CON t G low to G low 15 20 ns OERL CON t G high to G high 10 15 ns RO CON 1. Valid for ambient operating temperature: T = 0 to 70°C; V = 4.5 to 5.5 V or 3.0 to 3.6 V (except where A CC noted). 2. C = 5 pF. L 2.3 Write mode The M48T201Y/V is in the WRITE mode whenever W (WRITE enable) and E (chip enable) are low state after the address inputs are stable. The start of a WRITE is referenced from the latter occurring falling edge of W or E. A WRITE is terminated by the earlier rising edge of W or E. The addresses must be held valid throughout the cycle. E or W must return high for a minimum of t from chip enable or t from WRITE enable prior to the initiation EHAX WHAX of another READ or WRITE cycle. Data-in must be valid t prior to the end of WRITE DVWH and remain valid for t afterward. G should be kept high during WRITE cycles to avoid WHDX bus contention; although, if the output bus has been activated by a low on E and G a low on W will disable the outputs t after W falls. WLQZ When the address value presented to the M48T201Y/V during the WRITE is in the range of 7FFFFh-7FFF0h, one of the on-board TIMEKEEPER® registers will be selected and data will be written into the device. When the address value presented to M48T201Y/V is outside the range of TIMEKEEPER registers, an external SRAM location is selected. 13/37

Operation M48T201Y, M48T201V Figure 6. Write cycle timing: RTC and external RAM control signals WRITE WRITE READ tAVAV tAVAV tAVAV ADDRESS tAVEH tAVWH tAVEL tELEH tEHAX tWHAX tAVQV E tEPD ECON tEPD tGLQV G tRO tEHDX GCON tAVWL tWLWH tWHQX tWLQZ W tEHQZ tDVEH tDVWH tWHDX DATA OUT DATA IN DATA IN DATA OUT DQ0-DQ7 VALID VALID VALID VALID AI02336 14/37

M48T201Y, M48T201V Operation Table 4. Write mode AC characteristics M48T201Y M48T201V Symbol Parameter(1) –70 –85 Unit Min Max Min Max t WRITE cycle time 70 85 ns AVAV t Address valid to WRITE enable low 0 0 ns AVWL t Address valid to chip enable low 0 0 ns AVEL t WRITE enable pulse width 45 55 ns WLWH t Chip enable low to chip enable high 50 60 ns ELEH t WRITE enable high to address transition 0 0 ns WHAX t Chip enable high to address transition 0 0 ns EHAX t Input valid to WRITE enable high 25 30 ns DVWH t Input valid to chip enable high 25 30 ns DVEH t WRITE enable high to input transition 0 0 ns WHDX t Chip enable high to input transition 0 0 ns EHDX t (2)(3) WRITE enable low to output High-Z 20 25 ns WLQZ t Address valid to WRITE enable high 55 65 ns AVWH t Address valid to chip enable high 55 65 ns AVEH t (2)(3) WRITE enable high to output transition 5 5 ns WHQX 1. Valid for ambient operating temperature: T = 0 to 70°C; V = 4.5 to 5.5 V or 3.0 to 3.6 V (except where A CC noted). 2. C = 5 pF L 3. If E goes low simultaneously with W going low, the outputs remain in the high impedance state. 2.4 Data retention mode With valid V applied, the M48T201Y/V can be accessed as described above with READ CC or WRITE cycles. Should the supply voltage decay, the M48T201Y/V will automatically deselect, write protecting itself (and any external SRAM) when V falls between V CC PFD (max) and V (min). This is accomplished by internally inhibiting access to the clock PFD registers via the E signal. At this time, the reset pin (RST) is driven active and will remain active until V returns to nominal levels. External RAM access is inhibited in a similar CC manner by forcing E to a high level. This level is within 0.2 V of the V . E will CON BAT CON remain at this level as long as V remains at an out-of-tolerance condition. When V falls CC CC below the level of the battery (V ), power input is switched from the V pin to the BAT CC SNAPHAT® battery and the clock registers are maintained from the attached battery supply. External RAM is also powered by the SNAPHAT battery. All outputs except G , E , CON CON RST, IRQ/FT and V , become high impedance. The V pin is capable of supplying OUT OUT 100 µA of current to the attached memory with less than 0.3 V drop under this condition. On power up, when V returns to a nominal value, write protection continues for 200 ms (max) CC by inhibiting E . The RST signal also remains active during this time (see Figure14 on CON page30). 15/37

Operation M48T201Y, M48T201V Note: Most low power SRAMs on the market today can be used with the M48T201Y/V TIMEKEEPER® SUPERVISOR. There are, however some criteria which should be used in making the final choice of an SRAM to use. The SRAM must be designed in a way where the chip enable input disables all other inputs to the SRAM. This allows inputs to the M48T201Y/V and SRAMs to be “Don't care” once V falls below V (min). The SRAM should also guarantee data retention down to CC PFD V = 2.0 V. The chip enable access time must be sufficient to meet the system needs with CC the chip enable (and output enable) output propagation delays included. 16/37

M48T201Y, M48T201V Clock operation 3 Clock operation ® 3.1 TIMEKEEPER registers The M48T201Y/V offers 16 internal registers which contain TIMEKEEPER®, alarm, watchdog, flag, and control data (see Table5 on page18). These registers are memory locations which contain external (user accessible) and internal copies of the data (usually referred to as BiPORT™ TIMEKEEPER cells). The external copies are independent of internal functions except that they are updated periodically by the simultaneous transfer of the incremented internal copy. TIMEKEEPER and alarm registers store data in BCD. control, watchdog and flags (bits D0 to D3) registers store data in binary format. 3.2 Reading the clock Updates to the TIMEKEEPER registers should be halted before clock data is read to prevent reading data in transition. The BiPORT TIMEKEEPER cells in the RAM array are only data registers and not the actual clock counters, so updating the registers can be halted without disturbing the clock itself. Updating is halted when a '1' is written to the READ bit, D6 in the control register (7FFF8h). As long as a '1' remains in that position, updating is halted. After a halt is issued, the registers reflect the count; that is, the day, date, and time that were current at the moment the halt command was issued. All of the TIMEKEEPER registers are updated simultaneously. A halt will not interrupt an update in progress. Updating occurs approximately 1 second after the READ bit is reset to a '0.' 3.3 Setting the clock Bit D7 of the control register (7FFF8h) is the WRITE bit. Setting the WRITE bit to a '1,' like the READ bit, halts updates to the TIMEKEEPER registers. The user can then load them with the correct day, date, and time data in 24-hour BCD format (see Table5 on page18). Resetting the WRITE bit to a '0' then transfers the values of all time registers (7FFFFh- 7FFF9h, 7FFF1h) to the actual TIMEKEEPER counters and allows normal operation to resume. After the WRITE bit is reset, the next clock update will occur approximately one second later. Note: Upon power-up following a power failure, both the WRITE bit and the READ bit will be reset to '0.' 3.4 Stopping and starting the oscillator The oscillator may be stopped at any time. If the device is going to spend a significant amount of time on the shelf, the oscillator can be turned off to minimize current drain on the battery. The STOP bit is located at bit D7 within the seconds register (7FFF9h). Setting it to a '1' stops the oscillator. When reset to a '0,' the M48T201Y/V oscillator starts within one second. 17/37

Clock operation M48T201Y, M48T201V Note: It is not necessary to set the WRITE bit when setting or resetting the FREQUENCY TEST bit (FT) or the STOP bit (ST). Table 5. TIMEKEEPER® register map Data Function/range Address D7 D6 D5 D4 D3 D2 D1 D0 BCD format 7FFFFh 10 years Year Year 00-99 7FFFEh 0 0 0 10 M Month Month 01-12 7FFFDh 0 0 10 date Date: Day of month Date 01-31 7FFFCh 0 FT 0 0 0 Day Day 01-07 7FFFBh 0 0 10 hours Hours (24-hour format) Hours 00-23 7FFFAh 0 10 minutes Minutes Minutes 00-59 7FFF9h ST 10 seconds Seconds Seconds 00-59 7FFF8h W R S Calibration Control 7FFF7h WDS BMB4 BMB3 BMB2 BMB1 BMB0 RB1 RB0 Watchdog 7FFF6h AFE SQWE ABE Al.10M Alarm month Al. month 01-12 7FFF5h RPT4 RPT5 Al. 10 date Alarm date Al. date 01-31 7FFF4h RPT3 0 Al. 10 hours Alarm hours Al. hours 00-23 7FFF3h RPT2 Alarm 10 minutes Alarm minutes Al. minutes 00-59 7FFF2h RPT1 Alarm 10 seconds Alarm seconds Al. seconds 00-59 7FFF1h 1000 years 100 years Century 00-99 7FFF0h WDF AF 0 BL RS3 RS2 RS1 RS0 Flags Keys: S = Sign bit FT = Frequency test bit R = READ bit W = WRITE bit ST = Stop bit 0 = Must be set to '0' WDS = Watchdog steering bit AF = Alarm flag BL = Battery low flag SQWE = Square wave enable bit BMB0-BMB4 = Watchdog multiplier bits RB0-RB1 = Watchdog resolution bits AFE = Alarm flag enable flag ABE = Alarm in battery backup mode enable bit RPT1-RPT5 = Alarm repeat mode bits WDF = Watchdog flag RS0-RS3 = SQW frequency 18/37

M48T201Y, M48T201V Clock operation 3.5 Setting the alarm clock Registers 7FFF6h-7FFF2h contain the alarm settings. The alarm can be configured to go off at a prescribed time on a specific month, day of month, hour, minute, or second or repeat every month, day of month, hour, minute, or second. It can also be programmed to go off while the M48T201Y/V is in the battery backup to serve as a system wake-up call. Bits RPT5-RPT1 put the alarm in the repeat mode of operation. Table6 shows the possible configurations. Codes not listed in the table default to the once per second mode to quickly alert the user of an incorrect alarm setting. Note: User must transition address (or toggle chip enable) to see flag bit change. When the clock information matches the alarm clock settings based on the match criteria defined by RPT5-RPT1, the AF (alarm flag) is set. If AFE (alarm flag enable) is also set, the alarm condition activates the IRQ/FT pin. To disable alarm, write ’0’ to the alarm-date register and RPT1-5. The IRQ/FT output is cleared by a READ to the flags register as shown in Figure7. A subsequent READ of the flags register is necessary to see that the value of the alarm flag has been reset to '0.' The IRQ/FT pin can also be activated in the battery backup mode. The IRQ/FT will go low if an alarm occurs and both ABE (alarm in battery backup mode enable) and AFE are set. The ABE and AFE bits are reset during power-up, therefore an alarm generated during power-up will only set AF. The user can read the flag register at system boot-up to determine if an alarm was generated while the M48T201Y/V was in the deselect mode during power-up. Figure8 on page20 illustrates the backup mode alarm timing. Figure 7. Alarm interrupt reset waveforms A0-A18 ADDRESS 7FFF0h 15ns Min ACTIVE FLAG BIT IRQ/FT HIGH-Z AI02331 Table 6. Alarm repeat modes RPT5 RPT4 RPT3 RPT2 RPT1 Alarm setting 1 1 1 1 1 Once per second 1 1 1 1 0 Once per minute 1 1 1 0 0 Once per hour 1 1 0 0 0 Once per day 1 0 0 0 0 Once per month 0 0 0 0 0 Once per year 19/37

Clock operation M48T201Y, M48T201V Figure 8. Backup mode alarm waveforms tREC VCC VPFD (max) VPFD (min) VSO AFE bit/ABE bit AF bit in Flags Register IRQ/FT HIGH-Z HIGH-Z AI03520 3.6 Watchdog timer The watchdog timer can be used to detect an out-of-control microprocessor. The user programs the watchdog timer by setting the desired amount of timeout into the Watchdog Register, address 7FFF7h. Bits BMB4-BMB0 store a binary multiplier and the two lower order bits RB1-RB0 select the resolution, where 00 = 1/16 second, 01 = 1/4 second, 10 = 1 second, and 11 = 4 seconds. The amount of timeout is then determined to be the multiplication of the five-bit multiplier value with the resolution. (For example: writing 00001110 in the watchdog register = 3*1 or 3 seconds). Note: Accuracy of timer is within ± the selected resolution. If the processor does not reset the timer within the specified period, the M48T201Y/V sets the WDF (watchdog flag) and generates a watchdog interrupt or a microprocessor reset. WDF is reset by reading the flag register (address 7FFF0h). The most significant bit of the watchdog register is the watchdog steering bit (WDS). When set to a '0', the watchdog will activate the IRQ/FT pin when timed-out. When WDS is set to a '1,' the watchdog will output a negative pulse on the RST pin for t . The watchdog register REC and the AFE, SQWE, ABE, and FT bits will reset to a '0' at the end of a watchdog timeout when the WDS bit is set to a '1.' The watchdog timer can be reset by two methods: 1. a transition (high-to-low or low-to-high) can be applied to the watchdog input pin (WDI) or 2. the microprocessor can perform a WRITE of the watchdog register. The timeout period then starts over. The WDI pin should be tied to V if not used. The SS watchdog will be reset on each transition (edge) seen by the WDI pin. 20/37

M48T201Y, M48T201V Clock operation In order to perform a software reset of the watchdog timer, the original timeout period can be written into the watchdog register, effectively restarting the countdown cycle. Should the watchdog timer time out, and the WDS bit is programmed to output an interrupt, a value of 00h needs to be written to the watchdog register in order to clear the IRQ/FT pin. This will also disable the watchdog function until it is again programmed correctly. A READ of the flags register will reset the watchdog flag (bit D7; register 7FFF0h). The watchdog function is automatically disabled upon power-down and the watchdog register is cleared. If the watchdog function is set to output to the IRQ/FT pin and the frequency test function is activated, the watchdog or alarm function prevails and the frequency test function is denied. Note: The user must transition the address (or toggle chip enable) to see the flag bit change. 3.7 Square wave output The M48T201Y/V offers the user a programmable square wave function which is output on the SQW pin. RS3-RS0 bits located in 7FFF0h establish the square wave output frequency. These frequencies are listed in Table7. Once the selection of the SQW frequency has been completed, the SQW pin can be turned on and off under software control with the square wave enable bit (SQWE) located in register 7FFF6h. Table 7. Square wave output frequency Square wave bits Square wave RS3 RS2 RS1 RS0 Frequency Units 0 0 0 0 Hi-Z - 0 0 0 1 32.768 kHz 0 0 1 0 8.192 kHz 0 0 1 1 4.096 kHz 0 1 0 0 2.048 kHz 0 1 0 1 1.024 kHz 0 1 1 0 512 Hz 0 1 1 1 256 Hz 1 0 0 0 128 Hz 1 0 0 1 64 Hz 1 0 1 0 32 Hz 1 0 1 1 16 Hz 1 1 0 0 8 Hz 1 1 0 1 4 Hz 1 1 1 0 2 Hz 1 1 1 1 1 Hz 21/37

Clock operation M48T201Y, M48T201V 3.8 Power-on reset The M48T201Y/V continuously monitors V . When V falls to the power fail detect trip CC CC point, the RST pulls low (open drain) and remains low on power-up for t after V REC CC passes V (max). The RST pin is an open drain output and an appropriate pull-up resistor PFD to V should be chosen to control rise time. CC 3.9 Reset inputs (RSTIN1 & RSTIN2) The M48T201Y/V provides two independent inputs which can generate an output reset. The duration and function of these resets is identical to a reset generated by a power cycle. Figure9 and Table8 illustrate the AC reset characteristics of this function. Pulses shorter than t and t will not generate a reset condition. RSTIN1 and RSTIN2 are each internally R1 R2 pulled up to V through a 100 KΩ resistor. CC Figure 9. RSTIN1 and RSTIN2 timing waveforms RSTIN1 RSTIN2 tR2 Hi-Z Hi-Z RST tR1 tR1HRZ tR2HRZ AI01679 Table 8. Reset AC characteristics Symbol Parameter(1) Min Max Unit t RSTIN1 low to RST low 50 200 ns R1 t RSTIN2 low to RST low 20 100 ms R2 t (2) RSTIN1 high to RST Hi-Z 40 200 ms R1HRZ t (2) RSTIN2 high to RST Hi-Z 40 200 ms R2HRZ 1. Valid for ambient operating temperature: T = 0 to 70°C; V = 4.5 to 5.5 V or 3.0 to 3.6 V (except where A CC noted). 2. C = 5 pF (see Figure13 on page28). L 3.10 Calibrating the clock The M48T201Y/V is driven by a quartz controlled oscillator with a nominal frequency of 32,768 Hz. The devices are factory calibrated at 25°C and tested for accuracy. Clock accuracy will not exceed ±35 ppm (parts per million) oscillator frequency error at 25°C, which equates to about ±1.53 minutes per month. When the calibration circuit is properly employed, accuracy improves to better than +1/–2 ppm at 25°C. 22/37

M48T201Y, M48T201V Clock operation The oscillation rate of crystals changes with temperature (see Figure10 on page24). The M48T201Y/V design employs periodic counter correction. The calibration circuit adds or subtracts counts from the oscillator divider circuit at the divide by 256 stage, as shown in Figure11 on page24. The number of times pulses which are blanked (subtracted, negative calibration) or split (added, positive calibration) depends upon the value loaded into the five calibration bits found in the control register. Adding counts speeds the clock up, subtracting counts slows the clock down. The calibration bits occupy the five lower order bits (D4-D0) in the control register 7FFF8h. These bits can be set to represent any value between 0 and 31 in binary form. Bit D5 is a sign bit; '1' indicates positive calibration, '0' indicates negative calibration (see Figure11 on page24). Calibration occurs within a 64 minute cycle. The first 62 minutes in the cycle may, once per minute, have one second either shortened by 128 or lengthened by 256 oscillator cycles. If a binary '1' is loaded into the register, only the first 2 minutes in the 64 minute cycle will be modified; if a binary 6 is loaded, the first 12 will be affected, and so on. Therefore, each calibration step has the effect of adding 512 or subtracting 256 oscillator cycles for every 125,829,120 actual oscillator cycles, that is +4.068 or –2.034 ppm of adjustment per calibration step in the calibration register. Assuming that the oscillator is running at exactly 32,768 Hz, each of the 31 increments in the calibration byte would represent +10.7 or –5.35 seconds per month which corresponds to a total range of +5.5 or – 2.75 minutes per month. Two methods are available for ascertaining how much calibration a given M48T201Y/V may require. The first involves setting the clock, letting it run for a month and comparing it to a known accurate reference and recording deviation over a fixed period of time. Calibration values, including the number of seconds lost or gained in a given period, can be found in the STMicroelectronics application note AN934, “TIMEKEEPER® calibration.” This allows the designer to give the end user the ability to calibrate the clock as the environment requires, even if the final product is packaged in a non-user serviceable enclosure. The designer could provide a simple utility that accesses the calibration byte. The second approach is better suited to a manufacturing environment, and involves the use of the IRQ/FT pin. The pin will toggle at 512 Hz, when the stop bit (ST, D7 of 7FFF9h) is '0,' the frequency test bit (FT, D6 of 7FFFCh) is '1,' the alarm flag enable bit (AFE, D7 of 7FFF6h) is '0,' and the watchdog steering bit (WDS, D7 of 7FFF7h) is '1' or the watchdog register (7FFF7h=0) is reset. Note: A 4-second settling time must be allowed before reading the 512 Hz output. Any deviation from 512 Hz indicates the degree and direction of oscillator frequency shift at the test temperature. For example, a reading of 512.010124 Hz would indicate a +20 ppm oscillator frequency error, requiring a –10 (WR001010) to be loaded into the calibration byte for correction. Note that setting or changing the calibration byte does not affect the frequency test output frequency. The IRQ/FT pin is an open drain output which requires a pull-up resistor to V for proper CC operation. A 500-10 kΩ resistor is recommended in order to control the rise time. The FT bit is cleared on power-down. 23/37

Clock operation M48T201Y, M48T201V Figure 10. Crystal accuracy across temperature Frequency (ppm) 20 0 –20 –40 –60 –80 ΔF = -0.038 ppm(T - T)2 ± 10% –100 F C2 0 T = 25 °C –120 0 –140 –160 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 Temperature °C AI00999 Figure 11. Calibration waveform NORMAL POSITIVE CALIBRATION NEGATIVE CALIBRATION AI00594B 3.11 Battery low warning The M48T201Y/V automatically performs battery voltage monitoring upon power-up and at factory-programmed time intervals of approximately 24 hours. The battery low (BL) bit, bit D4 of flags register 7FFF0h, will be asserted if the battery voltage is found to be less than approximately 2.5 V. The BL bit will remain asserted until completion of battery replacement and subsequent battery low monitoring tests, either during the next power-up sequence or the next scheduled 24-hour interval. If a battery low is generated during a power-up sequence, this indicates that the battery is below approximately 2.5 V and may not be able to maintain data integrity in the SRAM. Data should be considered suspect and verified as correct. A fresh battery should be installed. 24/37

M48T201Y, M48T201V Clock operation If a battery low indication is generated during the 24-hour interval check, this indicates that the battery is near end of life. However, data is not compromised due to the fact that a nominal V is supplied. In order to insure data integrity during subsequent periods of CC battery backup mode, the battery should be replaced. The SNAPHAT® top may be replaced while V is applied to the device. CC Note: This will cause the clock to lose time during the interval the battery/crystal is removed. The M48T201Y/V only monitors the battery when a nominal V is applied to the device. CC Thus applications which require extensive durations in the battery backup mode should be powered-up periodically (at least once every few months) in order for this technique to be beneficial. Additionally, if a battery low is indicated, data integrity should be verified upon power-up via a checksum or other technique. 3.12 Initial power-on defaults Upon application of power to the device, the following register bits are set to a '0' state: WDS; BMB0-BMB4; RB0-RB1; AFE; ABE; SQWE; W; R; FT (see Table9). Table 9. Default values Watchdog Condition W R FT AFE ABE SQWE register(1) Initial power-up (Battery attach for 0 0 0 0 0 0 0 SNAPHAT)(2) RESET(3) 0 0 0 0 0 0 0 Power-down(4) 0 0 0 1 1 1 0 1. WDS, BMB0-BMB4, RB0, RB1. 2. State of other control bits undefined. 3. State of other control bits remains unchanged. 4. Assuming these bits set to '1' prior to power-down. 25/37

Clock operation M48T201Y, M48T201V 3.13 V noise and negative going transients CC I transients, including those produced by output switching, can produce voltage CC fluctuations, resulting in spikes on the V bus. These transients can be reduced if CC capacitors are used to store energy which stabilizes the V bus. The energy stored in the CC bypass capacitors will be released as low going spikes are generated or energy will be absorbed when overshoots occur. A ceramic bypass capacitor value of 0.1 µF (as shown in Figure12) is recommended in order to provide the needed filtering. In addition to transients that are caused by normal SRAM operation, power cycling can generate negative voltage spikes on V that drive it to values below V by as much as CC SS one volt. These negative spikes can cause data corruption in the SRAM while in battery backup mode. To protect from these voltage spikes, STMicroelectronics recommends connecting a schottky diode from V to V (cathode connected to V , anode to V ). CC SS CC SS Schottky diode 1N5817 is recommended for through hole and MBRS120T3 is recommended for surface mount. Figure 12. Supply voltage protection VCC VCC 0.1μF DEVICE VSS AI00605 26/37

M48T201Y, M48T201V Maximum ratings 4 Maximum ratings Stressing the device above the rating listed in the absolute maximum ratings table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 10. Absolute maximum ratings Symbol Parameter Value Unit T Ambient operating temperature 0 to 70 °C A SNAPHAT® –40 to 85 °C T Storage temperature STG SOH44 –55 to 125 °C T (1)(2) Lead solder temperature for 10 seconds 260 °C SLD V Input or output voltage –0.3 to V + 0.3 V IO CC M48T201Y –0.3 to 7.0 V V Supply voltage CC M48T201V –0.3 to 4.6 V I (2) Output current 20 mA O P Power dissipation 1 W D 1. For SOH44 package, standard (SnPb) lead finish: reflow at peak temperature of 225°C (the time above 220°C must not exceed 20 seconds). 2. For SOH44 package, lead-free (Pb-free) lead finish: Reflow at peak temperature of 260°C (the time above 255°C must not exceed 30 seconds). Caution: Negative undershoots below –0.3 V are not allowed on any pin while in the battery backup mode. Caution: Do NOT wave solder SOIC to avoid damaging SNAPHAT sockets. 27/37

DC and AC parameters M48T201Y, M48T201V 5 DC and AC parameters This section summarizes the operating and measurement conditions, as well as the DC and AC characteristics of the device. The parameters in the following DC and AC characteristic tables are derived from tests performed under the measurement conditions listed in Table11: DC and AC measurement conditions. Designers should check that the operating conditions in their projects match the measurement conditions when using the quoted parameters. Table 11. DC and AC measurement conditions Parameter M48T201Y M48T201V Unit V supply voltage 4.5 to 5.5 3.0 to 3.6 V CC Ambient operating temperature 0 to 70 0 to 70 °C Load capacitance (C ) 100 50 pF L Input rise and fall times ≤ 5 ≤ 5 ns Input pulse voltages 0 to 3 0 to 3 V Input and output timing ref. voltages 1.5 1.5 V Note: Output High Z is defined as the point where data is no longer driven. Figure 13. AC testing load circuit 645Ω DEVICE UNDER TEST CL = 100pF 1.75V CL includes JIG capacitance AI04764 Note: Excluding open-drain output pin; 50 pF for M48T201V. Table 12. Capacitance Symbol Parameter(1)(2) Min Max Unit C Input capacitance 10 pF IN C (3) Input/output capacitance 10 pF OUT 1. Effective capacitance measured with power supply at 5 V; sampled only, not 100% tested. 2. At 25°C; f = 1 MHz. 3. Outputs deselected. 28/37

M48T201Y, M48T201V DC and AC parameters Table 13. DC characteristics M48T201Y M48T201V Sym Parameter Test condition(1) –70 –85 Unit Min Typ Max Min Typ Max I (2) Input leakage current 0V ≤ V ≤ V ±1 ±1 µA LI IN CC Output leakage I (3) 0V ≤ V ≤ V ±1 ±1 µA LO current OUT CC I Supply current Outputs open 8 15 4 10 mA CC Supply current I E = V 5 3 mA CC1 (standby) TTL IH Supply current I E = V –0.2 3 2 mA CC2 (standby) CMOS CC Battery current OSC 575 800 575 800 nA ON I V = 0 V BAT CC Battery current OSC 100 100 nA OFF V Input low voltage –0.3 0.8 –0.3 0.8 V IL V Input high voltage 2.2 V + 0.3 2.0 V + 0.3 V IH CC CC Output low voltage I = 2.1 mA 0.4 0.4 V OL VOL Output low voltage I = 10 mA 0.4 0.4 V (open drain)(4) OL V Output high voltage I = –1.0 mA 2.4 2.4 V OH OH V (5) V battery backup I = –1.0 µA 2.0 3.6 2.0 3.6 V OHB OH OUT2 I (6) V current (active) V > V –0.3 100 70 mA OUT1 OUT OUT1 CC V current (battery I OUT V > V –0.3 100 100 µA OUT2 backup) OUT2 BAT Power-fail deselect V 4.1 4.35 4.5 2.7 2.9 3.0 V PFD voltage Battery backup V – V 3.0 PFD V SO switchover voltage 100 mV V Battery voltage 3.0 3.0 V BAT 1. Valid for ambient operating temperature: T = 0 to 70°C; V = 4.5 to 5.5 V or 3.0 to 3.6 V (except where noted). A CC 2. RSTIN1 and RSTIN2 internally pulled-up to V through 100 KΩ resistor. WDI internally pulled-down to V through CC SS 100 KΩ resistor. 3. Outputs deselected. 4. For IRQ/FT & RST pins (open drain). 5. Conditioned outputs (E - G ) can only sustain CMOS leakage currents in the battery backup mode. Higher leakage CON CON currents will reduce battery life. 6. External SRAM must match TIMEKEEPER® supervisor chip V specification. CC 29/37

DC and AC parameters M48T201Y, M48T201V Figure 14. Power down/up mode AC waveforms VCC VPFD (max) VPFD (min) VSO tF tR tFB tRB tREC INPUTS VALID DON'T CARE VALID HIGH-Z OUTPUTS VALID VALID RST AI03519 Table 14. Power down/up mode AC characteristic Symbol Parameter(1) Min Max Unit t (2) V (max) to V (min) V fall time 300 µs F PFD PFD CC M48T201Y 10 µs t (3) V (min) to V V fall time FB PFD SS CC M48T201V 150 µs t V (min) to V (max) V rise time 10 µs R PFD PFD CC t V (max) to RST high 40 200 ms REC PFD t V to V (min) V rise time 5 µs RB SS PFD CC 1. Valid for ambient operating temperature: T = 0 to 70°C; V = 4.5 to 5.5 V or 3.0 to 3.6 V (except where noted). A CC 2. V (max) to V (min) fall time of less than t may result in deselection/write protection not occurring until 200 µs after PFD PFD F V passes V (min). CC PFD 3. V (min) to V fall time of less than t may cause corruption of RAM data. PFD SS FB 30/37

M48T201Y, M48T201V Package mechanical data 6 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. Figure 15. SOH44 – 44-lead plastic small outline, SNAPHAT®, package outline A2 A C B e eB CP D N E H A1 α L 1 SOH-A Note: Drawing is not to scale. T able 15. SOH44 – 44-lead plastic small outline, SNAPHAT®, pack. mech. data mm inches Symb Typ Min Max Typ Min Max A 3.05 0.120 A1 0.05 0.36 0.002 0.014 A2 2.34 2.69 0.092 0.106 B 0.36 0.46 0.014 0.018 C 0.15 0.32 0.006 0.012 D 17.71 18.49 0.697 0.728 E 8.23 8.89 0.324 0.350 e 0.81 – – 0.032 – – eB 3.20 3.61 0.126 0.142 H 11.51 12.70 0.453 0.500 L 0.41 1.27 0.016 0.050 a 0° 8° 0° 8° N 44 44 CP 0.10 0.004 31/37

Package mechanical data M48T201Y, M48T201V Figure 16. SH – 4-pin SNAPHAT® housing for 48 mAh battery & crystal, package outline A2 A1 A A3 eA B L eB D E SHTK-A Note: Drawing is not to scale. T able 16. SH – 4-pin SNAPHAT® housing for 48 mAh battery & crystal, pack. mech. data mm inches Symb Typ Min Max Typ Min Max A 9.78 0.385 A1 6.73 7.24 0.265 0.285 A2 6.48 6.99 0.255 0.275 A3 0.38 0.015 B 0.46 0.56 0.018 0.022 D 21.21 21.84 0.835 0.860 E 14.22 14.99 0.560 0.590 eA 15.55 15.95 0.612 0.628 eB 3.20 3.61 0.126 0.142 L 2.03 2.29 0.080 0.090 32/37

M48T201Y, M48T201V Package mechanical data Figure 17. SH – 4-pin SNAPHAT® housing for 120 mAh battery & crystal, pack. outline A2 A1 A A3 eA B L eB D E SHTK-A Note: Drawing is not to scale. Table 17. SH – 4-pin SNAPHAT® housing for 120 mAh battery & crystal, pack. mech. data mm inches Symb Typ Min Max Typ Min Max A 10.54 0.415 A1 8.00 8.51 0.315 .0335 A2 7.24 8.00 0.285 0.315 A3 0.38 0.015 B 0.46 0.56 0.018 0.022 D 21.21 21.84 0.835 0.860 E 17.27 18.03 0.680 .0710 eA 15.55 15.95 0.612 0.628 eB 3.20 3.61 0.126 0.142 L 2.03 2.29 0.080 0.090 33/37

Part numbering M48T201Y, M48T201V 7 Part numbering Table 18. Ordering information scheme Example: M48T 201Y –70 MH 1 F Device type M48T Supply and write protect voltage 201Y = V = 4.5 to 5.5 V; V = 4.1 V to 4.5 V CC PFD 201V = V = 3.0 to 3.6 V; V = 2.7 V to 3.0 V CC PFD Speed –70 = 70 ns (for M48T201Y) –85 = 85 ns (for M48T201V) Package MH(1) = SOH44 Temperature range 1 = 0 to 70°C Shipping method for SOIC blank = tubes (not for new design - use E) E = ECOPACK® package, tubes F = ECOPACK® package, tape and reel TR = tape and reel (not for new design - use F) 1. The SOIC package (SOH44) requires the battery package (SNAPHAT®) which is ordered separately under the part number “M4Txx-BR12SH” in plastic tube or “M4Txx-BR12SHTR” in tape & reel form. Caution: Do not place the SNAPHAT battery package “M4Txx-BR12SH” in conductive foam as it will drain the lithium button-cell battery. For a list of available options (e.g., speed, package) or for further information on any aspect of this device, please contact the ST sales office nearest to you. Table 19. SNAPHAT® battery table Part number Description Package ® M4T28-BR12SH Lithium battery (48mAh) SNAPHAT SH ® M4T32-BR12SH Lithium battery (120mAh) SNAPHAT SH 34/37

M48T201Y, M48T201V Environmental information 8 Environmental information Figure 18. Recycling symbols This product contains a non-rechargeable lithium (lithium carbon monofluoride chemistry) button cell battery fully encapsulated in the final product. Recycle or dispose of batteries in accordance with the battery manufacturer's instructions and local/national disposal and recycling regulations. Please refer to the following web site address for additional information regarding compliance statements and waste recycling. Go to www.st.com/rtc, then select "Lithium Battery Recycling" from "Related Topics". 35/37

Revision history M48T201Y, M48T201V 9 Revision history Table 20. Document revision history Date Revision Changes Nov-1999 1 First issue 10-May-2001 2 Reformatted; added industrial temperature (Table10, 13, 3, 4, 14) 14-May-2001 2.1 Corrected table footnote (Table14) 30-May-2001 2.2 Change “controller” references to “supervisor” Formatting changes from recent document review findings; E2 01-Aug-2001 2.3 added to hookup (Figure3) 08-Aug-2001 2.4 Improve text in “Setting the alarm clock” section 18-Dec-2001 2.5 Added I values for industrial temperature device (Table13) BAT 13-May-2002 2.6 Modify reflow time and temperature footnote (Table10) 16-Jul-2002 2.7 Update DC characteristics, footnotes (Table13) 27-Mar-2003 3 v2.2 template applied; update test condition (Table13) Reformatted, remove industrial temperature (ambient operating) 24-Sep-2004 4 references (Table3, 4, 8, 10, 13, 14, 18) Reformatted; added lead-free second level interconnect information 12-Sep-2007 5 to cover page and Section6: Package mechanical data; updated Table10. 22-Apr-2008 6 Updated shipping method in Table18. Updated Table10, text in Section6: Package mechanical data; 23-Mar-2009 7 added Section8: Environmental information. 36/37

M48T201Y, M48T201V Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein. UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY, DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK. Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST. ST and the ST logo are trademarks or registered trademarks of ST in various countries. Information in this document supersedes and replaces all information previously supplied. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. © 2009 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com 37/37

Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: S TMicroelectronics: M48T201V-85MH1F M48T201V-85MH1E M48T201Y-70MH1E M48T201Y-70MH1F