STM1001 Reset circuit Features ■ Precision monitoring of 3 V, 3.3 V, and 5 V supply voltages ■ Open drain RST output ■ 30 ms or 140 ms reset pulse width (min) ■ Low supply current - 6 µA (typ) ■ Guaranteed RST assertion down to V = 1.0 V CC SOT23-3 (WX) ■ Operating temperature: – –40 °C to 85 °C (industrial grade) ■ Lead-free, small SOT23 package February 2010 Doc ID 10373 Rev 6 1/18 www.st.com 1

Contents STM1001 Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1 Reset output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2 Negative-going V transients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 CC 3 Typical operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 7 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2/18 Doc ID 10373 Rev 6

STM1001 List of tables List of tables Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Table 2. Absolute maximum ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Table 3. Operating and AC measurement conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Table 4. DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Table 5. SOT23-3 – 3-lead small outline transistor package mechanical data. . . . . . . . . . . . . . . . . 14 Table 6. Ordering information scheme. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table 7. Marking description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 8. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Doc ID 10373 Rev 6 3/18

List of figures STM1001 List of figures Figure 1. Logic diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 2. Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 3. Block diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Figure 4. Hardware hookup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Figure 5. Supply current vs. temperature, L/M/R/S/T (no load). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 6. Power-down reset delay vs. temperature - V = V – V (L/M). . . . . . . . . . . . . . . . . . . 8 OD TH CC Figure 7. Power-down reset delay vs. temperature - V = V – V (R/S/T) . . . . . . . . . . . . . . . . . 9 OD TH CC Figure 8. Power-up t vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 rec Figure 9. Normalized reset threshold vs. temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 10. Max transient duration not causing reset pulse vs. reset comparator overdrive. . . . . . . . . 10 Figure 11. AC testing input/output waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 12. SOT23-3 – 3-lead small outline transistor package outline . . . . . . . . . . . . . . . . . . . . . . . . 14 4/18 Doc ID 10373 Rev 6

STM1001 Description 1 Description The STM1001 microprocessor reset circuit is a low-power supervisory device used to monitor power supplies. It performs a single function: asserting a reset signal whenever the V supply voltage drops below a preset value and keeping it asserted until V has risen CC CC above the preset threshold for a minimum period of time (t ). rec Figure 1. Logic diagram VCC STM1001 RST VSS AI09116 Table 1. Signal names V Ground SS RST Active-low reset output (open drain) V Supply voltage CC Figure 2. Connections RST 1 3 V V 2 SS CC SOT23-3 AI09117 Doc ID 10373 Rev 6 5/18

Description STM1001 Figure 3. Block diagram VCC VRST COMPARE Gentreercator RST(1) AI09118 1. Open drain Figure 4. Hardware hookup VCC VCC (1) VCC MCU STM1001 RST(1) RESET Input VSS VSS AI09119 1. RST output requires pull-up resistor. 6/18 Doc ID 10373 Rev 6

STM1001 Operation 2 Operation 2.1 Reset output The STM1001 microprocessor reset circuit asserts a reset signal to the MCU whenever V CC goes below the reset threshold (V ). RST is guaranteed valid down to V =1 V (0° to RST CC 70 °C). During power-up, once V exceeds the reset threshold an internal timer keeps RST low for CC the reset time-out period, t . After this interval, RST returns high. rec If V drops below the reset threshold, RST goes low. Each time RST is asserted, it stays CC low for at least the reset time-out period. Any time V goes below the reset threshold, the CC internal timer clears. The reset timer starts when V returns above the reset threshold. The CC active-low reset (RST) is an open drain output. 2.2 Negative-going V transients CC The STM1001 is relatively immune to negative-going V transients (glitches). Figure10 on CC page10 shows typical transient duration versus reset comparator overdrive (for which the STM1001 will NOT generate a reset pulse). The graph was generated using a negative pulse applied to V , starting at 0.5 V above the actual reset threshold and ending below it CC by the magnitude indicated (comparator overdrive). The graph indicates the maximum pulse width a negative V transient can have without causing a reset pulse. As the magnitude of CC the transient increases (further below the threshold), the maximum allowable pulse width decreases. Any combination of duration and overdrive which lies under the curve will NOT generate a reset signal. Typically, a V transient that goes 100 mV below the reset CC threshold and lasts 20 µs or less will not cause a reset pulse. A 0.1 µF bypass capacitor mounted as close as possible to the V pin provides additional transient immunity. CC Doc ID 10373 Rev 6 7/18

Typical operating characteristics STM1001 3 Typical operating characteristics Note: Typical values are at T = 25 °C, V = 5 V for L/M versions, V = 3.3 V for T/S versions, A CC CC and V = 3.0 V for R versions. CC Figure 5. Supply current vs. temperature, L/M/R/S/T (no load) 8.0 6.0 A) µ nt ( e 1V urr 4.0 3V C 3.6V ply 5.5V p u S 2.0 0.0 –40 –20 0 20 40 60 80 Temperature (°C) AI07879 Figure 6. Power-down reset delay vs. temperature - V = V – V (L/M) OD TH CC 140.00 120.00 µs) ay (100.00 el D et 80.00 VOD = 20mV wn Res 60.00 VVOODD == 122050mmVV o D er- 40.00 w o P 20.00 0.00 –40 –20 0 20 40 60 80 Temperature (°C) AI07880 8/18 Doc ID 10373 Rev 6

STM1001 Typical operating characteristics Figure 7. Power-down reset delay vs. temperature - V = V – V (R/S/T) OD TH CC 100.00 80.00 µs) ay ( Del 60.00 et wn Res 40.00 VVVOOODDD === 21202005mmmVVV o D er- w Po 20.00 0.00 –40 –20 0 20 40 60 80 Temperature (°C) AI07878 Figure 8. Power-up t vs. temperature rec 250.00 240.00 up t (ms)rec 230.00 RL//MS/T er- 220.00 w o P 210.00 200.00 –40 –20 0 20 40 60 80 Temperature (°C) AI07881 Note: Valid for t = 210 ms (typ). rec Doc ID 10373 Rev 6 9/18

Typical operating characteristics STM1001 Figure 9. Normalized reset threshold vs. temperature 1.003 1.002 1.001 1.000 d ol 0.999 h s e d Tr 0.998 L/M alize 0.997 R/S/T m Nor 0.996 0.995 0.994 0.993 –40 –20 0 20 40 60 80 Temperature (°C) AI07882 Figure 10. Max transient duration not causing reset pulse vs. reset comparator overdrive 700.00 600.00 µs) 500.00 n ( o Durati 400.00 R/S/T nt L/M e 300.00 nsi a Tr m 200.00 u m axi 100.00 M 0.00 1 10 100 1000 Reset Comparator Overdrive, VRST – VCC (mV) AI07883 10/18 Doc ID 10373 Rev 6

STM1001 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 2. Absolute maximum ratings Symbol Parameter Value Unit T Storage temperature (V off) –55 to 150 °C STG CC T (1) Lead solder temperature for 10 seconds 260 °C SLD V Input or output voltage –0.3 to V +0.3 V IO CC V Supply voltage –0.3 to 7.0 V CC I Output current 20 mA O P Power dissipation 320 mW D 1. Reflow at peak temperature of 260 °C. The time above 255 °C must not exceed 30 seconds. Doc ID 10373 Rev 6 11/18

DC and AC parameters STM1001 5 DC and AC parameters This section summarizes the operating measurement conditions, and the DC and AC characteristics of the device. The parameters in the DC and AC characteristics tables that follow, are derived from tests performed under the measurement conditions summarized in Table3: Operating and AC measurement conditions. Designers should check that the operating conditions in their circuit match the operating conditions when relying on the quoted parameters. Table 3. Operating and AC measurement conditions Parameter STM1001 Unit V supply voltage 1.0 to 5.5 V CC Ambient operating temperature (T ) –40 to 85 °C A Input rise and fall times ≤ 5 ns Input pulse voltages 0.2 to 0.8 V V CC Input and output timing ref. voltages 0.3 to 0.7 V V CC Figure 11. AC testing input/output waveforms 0.8VCC 0.7VCC 0.3VCC 0.2VCC AI02568 12/18 Doc ID 10373 Rev 6

STM1001 DC and AC parameters Table 4. DC and AC characteristics Sym Description Test condition(1) Min Typ Max Unit T = –40 to +85 °C 1.2 5.5 V A V Operating voltage CC T = 0 to +70 °C 1.0 5.5 V A V < 3.6 V 5.5 10 µA CC I V supply current CC CC V < 5.5 V 7 15 µA CC I Open drain reset output VCC > VRST, –1 +1 µA LO leakage current Reset not asserted STM1001R/S/T only, I = 1.2 mA OL 0.3 V V = V (min) CC RST V RST output low voltage OL STM1001L/M only, I = 3.2 mA OL 0.4 V V = V (min) CC RST V RST output low voltage I = 50 µA; V > 1.0 V 0.3 V OL OL CC RESET thresholds 25 °C 4.56 4.63 4.70 V STM1001L –40 to 85 °C 4.50 4.75 V 25 °C 4.31 4.38 4.45 V STM1001M –40 to 85 °C 4.25 4.50 V 25 °C 3.04 3.08 3.11 V V Reset threshold STM1001T RST –40 to 85 °C 3.00 3.15 V 25 °C 2.89 2.93 2.96 V STM1001S –40 to 85 °C 2.85 3.00 V 25 °C 2.59 2.63 2.66 V STM1001R –40 to 85 °C 2.55 2.70 V V temperature coefficient V = 3.3 V 45 ppm/°C RST CC V = V to STM1001L/M 40 µs V to RST delay CC RST CC (VRST – 100 mV) STM1001R/S/T 20 µs Option B (refer to Table6) 20 30 40 t RST pulse width ms rec Option “Blank” (refer to Table6) 140 210 280 1. Valid for ambient operating temperature: T = –40 to 85 °C; V = 1.2 V to 5.5 V (except where noted). A CC Doc ID 10373 Rev 6 13/18

Package mechanical data STM1001 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 12. SOT23-3 – 3-lead small outline transistor package outline E E1 B 0.15MCAB A1 1 e e1 D 3X 0.20MCAB A 0.10C A2 3X b C A C θ L1 C L SOT23-3 Note: Drawing is not to scale. Table 5. SOT23-3 – 3-lead small outline transistor package mechanical data mm inches Symbol Typ Min Max Typ Min Max A 0.89 1.12 0.035 0.044 A1 0.01 0.10 0.001 0.004 A2 0.88 1.02 0.035 0.042 b 0.30 0.50 0.012 0.020 C 0.08 0.20 0.003 0.008 D 2.80 3.04 0.110 0.120 E 2.10 2.64 0.083 0.104 E1 1.20 1.40 0.047 0.055 e 0.89 1.03 0.035 0.041 e1 1.78 2.05 0.070 0.081 L 0.54 0.021 L1 0.40 0.60 0.016 0.024 Q 0° 8° 0° 8° N 3 3 14/18 Doc ID 10373 Rev 6

STM1001 Part numbering 7 Part numbering Table 6. Ordering information scheme Example: STM1001 S B WX 6 F Device type STM1001 Reset threshold voltage L = V = 4.50 V to 4.75 V RST M = V = 4.25 V to 4.50 V RST T = V = 3.00 V to 3.15 V RST S = V = 2.85 V to 3.00 V RST R = V = 2.55 V to 2.70 V RST RST pulse width (t ) rec B = 20 to 40 ms Blank = 140 to 280 ms Package WX = SOT23-3 Temperature range 6 = –40 to 85 °C Shipping method F = ECOPACK® package, tape & reel For other options, or for more information on any aspect of this device, please contact the ST sales office nearest you. Doc ID 10373 Rev 6 15/18

Part numbering STM1001 Table 7. Marking description Part number Reset threshold Output Topside marking(1) STM1001LWX6F 4.63 V Open drain RST 8BAx STM1001MWX6F 4.38 V Open drain RST 8BBx STM1001TWX6F 3.08 V Open drain RST 8BCx STM1001SWX6F 2.93 V Open drain RST 8BDx STM1001RWX6F 2.63 V Open drain RST 8BEx STM1001SBWX6F 2.93 V Open drain RST 8BMx 1. Lowercase “x” indicates date code. 16/18 Doc ID 10373 Rev 6

STM1001 Revision history 8 Revision history Table 8. Document revision history Date Revision Changes 09-Dec-2003 1 First edition 19-Feb-2004 2 Part number changed from STM6301 22-Mar-2004 2.1 Update DC characteristics (Table4) 09-Apr-2004 3 Device promoted; reformatted; marking updated (Table7) 19-Nov-2004 4 Update dimensions (Table5). 19-Sep-2005 5 Remove “Valid RST Output Down to V ...” text CC Updated Features; footnote in Table2; Table4; Table6; Table7; text in 17-Feb-2010 6 Section6; added note to Figure8; reformatted document. Doc ID 10373 Rev 6 17/18

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Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: S TMicroelectronics: STM1001LWX6F STM1001MWX6F STM1001RWX6F STM1001SWX6F STM1001TWX6F STM1001SBWX6F