® SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 ■ Ultra Low Quiescent Current: 10µA ■ Wide Input Voltage Range: 0.9V to 4.5V ■ 90mA I at 1.3V Input (SP6641A-3.3V) LX 1 5 VBATT OUT SP6641 ■ 500mA I at 2.6V Input (SP6641B-3.3V) OUT GND 2 ■ 100mA IOUT at 2.0V Input (SP6641A-5.0V) 5 Pin SOT-23 ■ 500mA IOUT at 3.3V Input (SP6641B-5.0V) VOUT 3 4 SHDN ■ Fixed 3.3V or 5.0V Output Voltage ■ Up to 87% Efficiency ■ 0.3Ω NFET RDSon APPLICATIONS ■ Startup Voltage Guaranteed at 0.9V ■ PDA's ■ 0.33A Inductor Current Limit (SP6641A) ■ DSC's ■ 1A Inductor Current Limit (SP6641B) ■ CD/MP3 Players ■ Logic Shutdown Control ■ Pagers ■ SOT-23-5 Package ■ Digital Cameras ■ Portable Handheld Medical Devices Now Available in Lead Free Packaging DESCRIPTION The SP6641 is an ultra-low quiescent current, high efficiency, DC-DC boost converter designed for single and dual cell alkaline, or Li-ion battery applications found in PDA’s, MP3 players, and other handheld portable devices. The SP6641 features a 10µA quiescent current, a 0.3Ω N- channel charging switch, 0.9V input startup, and a 0.33A or 1.0A inductor current limiting feature. The SP6641 is offered in a 5 pin SOT-23 package and provides an extremely small power supply footprint optimized for portable applications. The SP6641 is preset to 3.3V and can be controlled by a 1nA active LOW shutdown pin. L1 0.9V to 4.5V 700 VBATT 650 C1 600 1 LX VBATT 5 550 ®® D1 2 GND U1 455000 SP6641A 3 VOUT SHDN 4 SHDN mA) 345000 SSPP66664411BB,, 11..00AA,, 35.V3V R1 C3 I (OUT 235000 SSPP66664411AA,, 00..3333AA,, 35.V3V 200 VOUT 150 C2 +3.3V or 5V 100 50 SP6641A 3.3V & 5V: C1 = C2 = 22µF Ceramic, L1 = 22µH CDRH5D28, 0 D1 = MBR0520, C3 = Open, R1 = Shorted. 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 SP6641B 3.3V & 5V: C1 = C2 = 100µF POSCAP, L1 = 10µH CDRH5D28, D1 = ZHCS2000, C3 = 1µF Ceramic, R1 = 10Ω. VIN (V) Figure 1. Typical Application Schematic Figure 2. Maximum Load Current in Operation Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 1

ABSOLUTE MAXIMUM RATINGS These are stress ratings only and functional LX, V , SHDN, V to GND pin.......-0.3 to 6.0V OUT BATT operation of the device at these ratings or any other LX Current..........................................................1.5A above those indicated in the operation sections of Reverse V Current...................................220mA BATT the specifications below is not implied. Exposure to Storage Temperature........................-65°C to 150°C absolute maximum rating conditions for extended Operating Temperature.....................-40°C to +85°C periods of time may affect reliability. Lead Temperature (Soldering, 10 sec)..........300 °C ELECTRICAL SPECIFICATIONS VBATT = VSHDN = 1.3V, ILOAD = 0mA, -40°C <TA < +85°C, VOUT = +3.3V or +5.0V preset, typical values at 27°C unless otherwise noted. PARAMETER MIN TYP MAX UNITS CONDITIONS Input Voltage Operating Range, 0.5 4.5 V after startup V BATT Startup Voltage, VBATT 0.85 0.90 V RLOAD=3kΩ, TA =27°C 1.00 V RLOAD=3kΩ,-40°C <TA < +85°C Output Voltage, V 3.16 3.30 3.44 V 3.3V V preset OUT OUT 4.80 5.00 5.20 V 5.0V V preset OUT Quiescent Current into VOUT, 10 15 µA VOUT=3.5V, 3.3V VOUT preset I V =5.5V, 5.0V V preset Q(OUT) OUT OUT Quiescent Current into V , 250 500 nA V =3.5V, 3.3V V preset BATT OUT OUT I V =5.5V, 5.0V V preset QB OUT OUT Shutdown Current into V , 1 500 nA V =0V OUT SHDN I SHDN Shutdown Current into V , 20 100 nA V =0V BATT SHDN I SHDN Inductor Current Limit 280 330 380 mA (SP6641A) Inductor Current Limit 850 1000 1150 mA (SP6641B) Output Current (SP6641AEK-3.3) 90 mA V =1.3V BATT 190 mA V =2.6V BATT Output Current (SP6641BEK-3.3) 200 mA V =1.3V BATT 500 mA V =2.6V BATT Output Current (SP6641AEK-5.0) 100 mA V =2.0V BATT 175 mA V =3.3V BATT Output Current (SP6641BEK-5.0) 275 mA V =2.0V BATT 500 mA V =3.3V BATT Minimum Off-Time Constant 1.50 V*µs TOFF ≥ KOFF / (VOUT – VIN) K OFF NMOS Switch Resistance 0.3 0.75 Ω Inmos=100mA SHDN Input Voltage Vil 20 % % of V BATT Vih 80 % % of V BATT SHDN Input Current 1 100 nA Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 2

PIN DESCRIPTION PIN NO. PIN NAME DESCRIPTION 1 LX Inductor switching node. Connect one terminal of the inductor to the positive terminal of the battery. Connect the second terminal of the inductor to this pin. The inductor charging current flows into LX, through the internal charging N-channel FET, and out through the GND pin. 2 GND Ground pin. The internal regulator bias currents and the inductor charging current flows out of this pin. 3 V Output voltage sense pin, internal regulator voltage supply, and OUT minimum off-time one shot input. Kelvin connect this pin to the positive terminal of the output capacitor, but for SP6641B, use 10Ω series resistor and 1µF bypass per Figure 1 schematic. 4 SHDN Shutdown. Tie this pin to V for normal operation. Tie this pin the BATT ground to disable all circuitry inside the chip. In shutdown mode, the output voltage will float at a diode drop below the battery potential. 5 V Battery voltage pin. The startup circuitry runs off of this pin. The BATT regulating circuitry also uses this voltage to control the minimum off- time. TOFF ≥ KOFF / (VOUT – VIN). BLOCK DIAGRAM VBATT VOUT VBATT LX Internal VBATT VBATT VOUT LOAD SU SUGATE EN OSC IPK/M VOUT VBATT LX ITH +C ICHN R DRIVER - SHDN SHDN TMOinFF. TOFF QCHARGE NGATE VOUT M 1 VOUT GND REFREADY Internal SHDN BRloecfk Ground REF FB +-C VOUT(LOW) Qn S VOUT SP6641 Internal Supply Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 3

PERFORMANCE CHARACTERISTICS Refer to the circuit in Figure 1, T = +25°C AMB 100 100 95 VIN = 3.0V VIN = 1.3V 95 VIN = 3.0V VIN = 1.3V VIN = 2.6V VIN = 1.0V VIN = 2.6V VIN = 1.0V 90 VIN = 2.0V 90 VIN = 2.0V %) 85 %) 85 Efficiency ( 7850 Efficiency ( 7850 70 70 65 65 60 0.1 1.0 10.0 100.0 1000.0 600.1 1.0 10.0 100.0 1000.0 Iload (mA) Iload (mA) Figure 3. SP6641AEK - 3.3 Efficiency vs Load Current Figure 4. SP6641BEK - 3.3 Efficiency vs Load Current 3.400 3.400 3.380 VIN = 3.0V VIN = 1.3V 3.380 3.360 VIN = 2.6V VIN = 1.0V 3.360 3.340 VIN = 2.0V 3.340 3.320 3.320 VOUT 33..238000 VOUT 33..238000 VIN = 3.0V VIN = 1.3V 3.260 3.260 VIN = 2.6V VIN = 1.0V 3.240 3.240 VIN = 2.0V 3.220 3.220 3.200 3.200 0 50 100 150 200 250 0 200 400 600 800 Iload (mA) Iload (mA) Figure 5. SP6641AEK - 3.3 Line/Load Rejection vs Load Figure 6. SP6641BEK - 3.3 Line/Load Rejection vs Load Current Current 100 100 Vi=4.2V 95 95 Vi=3.6V Vi=3.3V 90 90 VVii==21..03VV %) 85 %) 85 Efficiency ( 7850 VVii==43..26VV Efficiency ( 7850 70 Vi=3.3V 70 Vi=2.0V 65 Vi=1.3V 65 60 60 0.1 1.0 10.0 100.0 1000.0 0.1 1.0 10.0 100.0 1000.0 Iload (mA) Iload (mA) Figure 7. SP6641AEK-5.0 Efficiency Vs Load Current Figure 8. SP6641BEK-5.0 Efficiency Vs Load Current Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 4

PERFORMANCE CHARACTERISTICS Refer to the circuit in Figure 1, T = +25°C AMB 5.200 5.100 5.180 Vi=4.2V 5.080 Vi=3.6V 5.160 Vi=3.3V 5.060 Vi=2.0V 5.140 5.040 Vi=1.3V 5.120 5.020 Vo (V) 5.100 Vo (V) 5.000 5.080 4.980 5.060 4.960 Vi=4.2V Vi=3.6V 5.040 4.940 Vi=3.3V Vi=2.0V 5.020 4.920 Vi=1.3V 5.000 4.900 0 50 100 150 200 250 0 200 400 600 800 Iload (mA) Iload (mA) Figure 9. SP6641AEK-5.0 Line/Load Rejection Vs Load Figure 10. SP6641BEK-5.0 Line/Load Rejection Vs Current Load Current 250 500 450 200 SP6641AEK-5.0 400 SP6641B-5.0 SP6641AEK-3.3 350 SP6641B-3.3 150 300 Iin (uA) 100 Iin (uA) 220500 150 50 100 50 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Vin (V) Vin (V) Figure 11. SP6641AEK-3.3 & SP6641AEK-5.0 No Load Figure 12. SP6641BEK-3.3 & SP6641AEK-5.0 No Load Battery Current Battery Current 250 700 600 200 500 150 A) A) 400 m m Io ( 100 Io ( 300 SP6641AEK-3.3, 22µH SP6641AEK-3.3, 10µH 200 SP6641BEK-3.3, 22µH 50 SP6641AEK-5.0, 22µH SSPP66664411BBEEKK--35..03,, 2120µµHH SP6641AEK-5.0, 10µH 100 SP6641BEK-5.0, 10µH 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Vin (V) Vin (V) Figure 13. SP6641AEK-3.3 & SP6641AEK-5.0 Figure 14. SP6641BEK-3.3 & SP6641BEK-5.0 Maximum Resistive Load Current in Startup Maximum Resistive Load Current in Startup Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 5

OPERATION General Overview The SP6641 is a high efficiency, low quiescent inductor to discharge through the rectifying current step-up DC-DC converter ideal for single diode for a minimum time defined by the one- and dual cell alkaline and single cell Lithium Ion shot duration. The end of the off-time pulse battery applications such as medical monitors, releases the SR latch, and its output state is once PDA’s, MP3 players, and other portable end again determined by the output of the loop products. The SP6641’s 10µA quiescent cur- comparator (VOUT(LOW)). Under light load con- rent, low 0.3Ω NFET switch, and unique PFM ditions, the output voltage will have been pulled control scheme combine to provide excellent above the regulation threshold during the mini- efficiency over a wide output power range. mum off-time, the signal V will be a OUT(LOW) logic “0”, and the NMOS charging switch will Other features include a logic level enable con- remain open. The inductor current discharges trol pin, guaranteed 0.9V startup, a tiny SOT23 until it reaches zero or the loop comparator 5 pin package, and precise inductor peak current triggers a new charge cycle. control. SP6641A sources up to 90mA at 1.3V, typ. and SP6641B sources up to 500mA at 2.6V, Under a heavy load, the output voltage will typ. by supporting different peak inductor current remain below the regulation point at the end of levels. Only two capacitors, an inductor, and a the off-time pulse. In this condition, V OUT(LOW) diode are required to build a power supply for has a logic value of 1 which immediately starts the SP6641A. The SP6641B, 1A peak current a new charge/discharge cycle defined by the requires an additional small resistor and capaci- peak inductor current and the minimum off- tor as a low pass filter for the V IC power pin. time. The inductor current will remain in a OUT continuous conduction mode until the loop com- Loop Regulation parator indicates the output voltage is above the The SP6641 combines a fixed inductor peak regulation threshold, and the inductor current current limit, a feed-forward minimum off-time will relax towards zero. one-shot, and a precision loop comparator to During continuous mode bursts, the inductor regulate the output voltage. Under light-load current frequency and ripple amplitude are con- conditions the loop operates as a standard PFM trolled by the minimum off-time one-shot and converter. The frequency of fixed amplitude the input and output voltage levels. The SP6641 inductor current triangles is modulated to regu- sets the minimum off-time to: late the load. Under heavy load conditions, the K converter adjusts the number of successive con- TOFF = OFF (V – V ), where: tinuous mode current pulses to regulate the load. OUT IN Refer to the block diagram for the following K = Off-time Constant, typically 1.5µs*V OFF explanation of operating modes in loop regulation. V = Output Voltage OUT The output voltage is internally divided down and V = Input Voltage fed to the negative terminal of the loop compara- IN tor. A +1.25V bandgap reference voltage is ap- Plugging the T expression into the boost OFF plied to the positive terminal of the comparator. As mode equations yields the maximum output the output voltage droops below the regulation current in regulation: threshold due to the load the loop comparator (V ) ( K ) output (signal V ) transitions to a logic IOUT(MAX) ≈ η IN IPK – OFF OUT(LOW) V 2L “1”. This sets the SR latch and initiates inductor OUT where: charging by pulling the signal NGATE high. In- ductor charging continues until the current reaches η = Efficiency, typically 0.80 to 0.90 the internally programmed limit, at which point, I = Programmed inductor peak current, typi- PK the off-time one-shot is triggered. cally 0.33A for the SP6641A, typically The off-time one-shot via signal T resets the 1.0A for the SP6641B. OFF SR latch regardless of the SET state (VOUT(LOW)), L = Inductor value opens the NMOS charge switch, and forces the Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 6

OPERATION Loop Regulation: continued The SP6641 feed forward off-time control de- Ignoring the conduction losses of V and V , D C livers more load current than constant off-time the burst frequency equation simplifies to: control because the input battery voltage drops (V – V )V F = OUT IN IN during its life cycle. The term (I – K /2L) is BURST PK OFF K V the average current delivered to the output ca- OFF OUT pacitor during the discharge phase. This is con- Startup stant with respect to input and output voltage. The internal regulator circuitry is bootstrapped With constant off-time control, the average dis- to the V pin. This requires a low voltage charge current term becomes OUT oscillator and charging switch powered from the (IPK-TOFF*(VOUT-VIN)/2L), VBATT pin to pump up the output voltage until which decreases as the input voltage drops. the reference is established. The reference pro- vides a REFREADY signal that determines when Table 1 illustrates the average inductor current output control is handed over to the regulator. delivered to the load during discharge versus the REFREADY shuts down the startup circuit and input voltage. The SP6641 feed forward off- enables the regulator when the reference is valid time control and the constant off-time control and V is above +1.9V. Once the regulator is are compared. For purposes of illustration, the OUT given control it will continue to pump up the off times of each control scheme are normalized output at full power until regulation is reached. at a typical two cell alkaline input voltage of 2.6V. The values used in Table 1 are: For two cell alkaline input voltages and above, I = 0.33A the output voltage will be pulled above +1.9V PK quickly through the rectifying diode before the L = 22µH reference has a chance to establish. In this sce- V = 3.3V OUT nario the startup circuit will coarsely regulate T (SP6641) = 1.5V*µs/(3.3-V ) OFF IN around +2.8V until the REFREADY signal as- T (constant) = 2.14µs OFF serts. This keeps the output from overshooting in startup with higher input voltages. SP6641A Constant TOFF Startup is guaranteed at +0.9V at room tempera- V T Avg I T Avg I ture with a 3kΩ load. Heavier loads will require IN OFF L OFF L a higher input voltage. 3.0 5.00µs 0.30A 2.14µs 0.32A 2.6 2.14µs 0.30A 2.14µs 0.30A Shutdown/Enable Control 2.0 1.15µs 0.30A 2.14µs 0.27A Pin 4 of the device is a VBATT referred control pin that shuts down the converter with the pin 1.3 0.75µs 0.30A 2.14µs 0.23A tied to ground, or enables the converter with the 1.0 0.65µs 0.30A 2.14µs 0.22A pin tied to VBATT. When the converter is shut- down the power switch is opened and all circuit Table 1- Average I vs. Input Voltage L biasing is extinguished leaving only junction leak- age currents on supply pins 3 and 5. The output The following equation defines the burst mode voltage will droop to one diode drop below the frequency under heavy load conditions: battery voltage through the rectifying diode. (V – V ) ( V – V ) After pin 4 is brought high, the startup circuit is F = OUT IN IN C BURST enabled and starts pumping up the output until K V + V –V OFF OUT D C REFREADY hands over control to the internal where: regulator. V = Forward schottky drop, (0.4V, typ) D V = Average charging switch drop, C Rnmos*I , typically 0.1V PK Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 7

APPLICATION INFORMATION Circuit Layout Printed circuit board layout is a critical part of a allow tantalum capacitors to exceed their ripple- power supply design. Poor designs can result in current ratings. For example, in the SP6641A a excessive EMI on the voltage gradients and 22µF, 6V, low-ESR, surface-mount tantalum feedback paths on the ground planes with appli- output filter capacitor typically provides 60mV cations involving high switching frequencies output ripple when stepping up from 1.3V to and large peak currents. Excessive EMI can 3.3V at 20mA. An input filter capacitor can result in instability or regulation errors. All reduce peak currents drawn from the battery and power components should be placed on the PC improve efficiency. Low-ESR aluminum elec- board as closely as possible with the traces kept trolytic capacitors are acceptable in some appli- short, direct, and wide (>50mils or 1.25mm). cations but standard aluminum electrolytic ca- Extra copper on the PC board should be inte- pacitors are not recommended. grated into ground as a pseudo-ground plane. In selecting an inductor, the saturation current On a multilayer PC board, route the star ground specified for the inductor needs to be greater using component-side copper fill, then connect then the SP6641A/B peak current to avoid satu- it to the internal ground plane using vias. For the rating the inductor, which would result in a loss SP6641A/6641B devices, input and output fil- in efficiency and could damage the inductor. ter capacitors should be soldered with their The SP6641A evaluation board uses a Sumida ground pins as close together as possible in a CDRH5D28 22µH inductor with an Isat value star-ground configuration. The VOUT pin must of 0.9A and a DCR of 0.095Ω, which easily be bypassed directly to ground as close to the handles the Ipeak of 0.33A of the SP6641A and SP6641A/6641B devices as possible (within will deliver high efficiencies. The SP6641B 0.2in or 5mm). The DC-DC converter and any evaluation board uses a Sumida CDRH5D28 digital circuitry should be placed on the oppo- 10µH inductor with an Isat value of 1.3A and a site corner of the PC board as far away from DCR of 0.065Ω, which easily handles the Ipeak sensitive RF and analog input stages. Noisy of 1.0A of the SP6641B and will deliver high traces, such as from the LX pin, should be kept efficiencies. Other inductors could be selected away from the voltage-feedback VOUT node provided their Isat is greater than the Ipeak of and separated from it using grounded copper to the SP6641A/SP6641B. minimize EMI. See the SP6641A/6641B Evalu- ation Board Manual for PC Board Layout de- Output Filter or LDO Regulator sign details. Designers could add LC pi filters, linear post- regulators, or shielding in applications necessary Component Selection to address excessive noise, voltage ripple, or EMI Selection of capacitors, inductors and schottky concerns. The LC pi filter’s cutoff frequency should diodes for SP6641A and SP6641B power sup- be at least a decade or two below the DC-DC ply circuits can be made through the use of converters’ switching frequency for the specified Table 1 component selection. Capacitor equiva- load and input voltage. The SP6201, a small SOT23- lent series resistance is a major contributor to 5pin 200mA Low Drop Out linear regulator can be output ripple, usually greater than 60%. Low used at the SP6641A/6641B output to reduce ESR capacitors are recommended. Ceramic ca- output noise and ripple. The schematic in figure 15 pacitors have the lowest ESR. Low-ESR tanta- illustrates this circuit on the SP6641A Evaluation lum capacitors may be a more acceptable solu- Board with the SP6641 3.3V output followed by tion having both a low ESR and lower cost than the Sipex SP6201 3.0V output Low Drop Out large ceramic capacitors. Designers should se- linear regulator. lect input and output capacitors with a rating exceeding the peak inductor current. Do not Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 8

APPLICATION INFORMATION: continued Maximum Startup Current It should be noted that for low input voltages the From the curves in Figures 13 and 14, you can SP6641 startup circuit can not support large see that for low input voltages, the 22µH induc- load currents at startup. In startup the SP6641 tor has more current capacity at startup than the needs to boost the output from zero volts using 10µH inductor, due to more energy per charge a charge pump which has a limited current cycle in the relationship 1/LI2. Thus for 1 cell 2 capacity. Once the output is greater than 1.7 to applications, 22µH is recommended for more 1.9V the operate circuit takes over and the startup current than 10µH. SP6641 can supply much more current. Curves For 1-cell battery applications, it is recommended of maximum resistive load current in startup for to apply any large load current after the SP6641 the SP6641A and SP6641B are shown in Fig- has started up, typically in a few millisecs. This ures 13 & 14 and can be compared with Figure is typically not a problem in many applications 2, maximum load current in operation. Also, where the load is a processor whose load current Table 2 provides SP6641A 3.3V resistive load is low until the processor voltage comes up. current in startup for some low cost 1812 size chip inductors. TABLE 1. COMPONENT SELECTION INDUCTORS - SURFACE MOUNT Inductor Specification Sipex Inductance Manufacturer/ Series R Isat Size LxWxH Inductor Manufacturer Part Number (µH) Part Number (Ω) (A) (mm) Type Website SP6641A Ipk = .33A 22 Sumida CDRH5D28-220 0.095 0.90 5.7x5.5x3 Shielded Ferrite Core www.sumida.com SP6641A Ipk = .33A 22 Coilcraft DO1608C-223 0.370 0.70 6.6x4.5x2.9 Unshielded Ferrite Core www.coilcraft.com SP6641A Ipk = .33A 22 TDK NLC453232T-220 0.900 0.37 4.4x3.2x3.2 Unshielded Ferrite Core www.tdk.com SP6641A Ipk = .33A 22 Murata LQH43C220K04 0.600 0.42 4.5x3.2x2.6 Unshielded Ferrite Core www.murata.com SP6641B Ipk = 1A 10 Sumida CDRH5D28-100 0.065 1.30 5.7x5.5x3 Shielded Ferrite Core www.sumida.com SP6641B Ipk = 1A 10 Coilcraft DO1608C-103 0.160 1.10 6.6x4.5x2.9 Unshielded Ferrite Core www.coilcraft.com SP6641B Ipk = 1A 10 Murata LQH55DN100M01 0.077 1.70 5x5x4.7 Unshielded Ferrite Core www.murata.com SP6641B Ipk = 1A 22 Sumida CDRH6D28-220 0.128 1.20 6.7x6.5x3 Shielded Ferrite Core www.sumida.com SP6641B Ipk = 1A 22 Murata LQH55DN220M01 0.160 1.20 5x5x4.7 Unshielded Ferrite Core www.murata.com CAPACITORS - SURFACE MOUNT & THRU-HOLE Capacitor Specification ESR Ripple Size Sipex Capacitance Manufacturer/ (max) Current LxWxH Voltage Capacitor Manufacturer Part Number (µF) Part Number (Ω) @ 45°C (A) (mm) (V) Type Website SP6641A Ipk = .33A 22 TDK C3225X5R0J226M 0.010 4.00 1210 6.3 SMT X5R Cer. www.tdk.com SP6641B Ipk = 1A 100 SANYO 10TPA100M 0.080 1.20 7343 6.3 SMT POSCAP Tant. www.sanyovideo.com SP6641B Ipk = 1A 100 SANYO 16SA100M 0.030 2.70 8Dx10L 16.0 Thru-hole OS-CON www.sanyovideo.com SCHOTTKY DIODE - SURFACE MOUNT Diode Specification Sipex Manufacturer/ VF @ IF IF(AV) Size LxWxH Reverse V Package Manufacturer Part Number Part Number (V) (A) (mm) (V) Type Website SP6641A Ipk = .33A STMicro STPS0520Z 0.39 0.50 3.9x1.7x1.3 20 SOD-123 www.st.com SP6641B Ipk = 1A Zetex ZCHS2000 0.42 2.00 3x3x1.4 40 SOT23-6 www.zetex.com Note: Components highlighted in bold are those used on the SP6641A or SP6641B Evaluation Board. Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 9

APPLICATION INFORMATION: continued +0.9V to +3.3V Input VBATT + C1 22µF L1 22µH VOUT +3.0V ®® 1LX U1VBATT 5 1 VIN ®® VOUT 5 D1 2GNDSP6641 1 2 GND SP6201 C1µ3F 3 VOUT SHDN 4 2 J1 3 ENABLE RESET 4 3 VOUT C2+ +3.3V 22µF Figure 15. SP6641A 3.3V Evaluation Board with SP6201 LDO Regulator SuperCap Application on the SP6641 Output cation circuit in figure 16 is recommended to When the battery input to SP6641A is removed, disconnect the SP6641 output from the SuperCap the SP6641A output will end up in the charge when the battery is removed. The small SOT23- mode and will slowly discharge a Supercap 3pin MOS switches are an inexpensive addition connected to the output. The typical Supercap to the SP6641 circuit and work well to maintain of 0.22F will go from fully charged at 3.3V to SuperCap voltage to retain Non-Volatile CMOS less than 2V in 5 minutes. The following appli- Memory while a battery is changed. TABLE 2. SP6641A Resistive Load Current in Startup - low cost inductors SP6641A APPLICATION CIRCUIT WITH PANASONIC INDUCTOR SP6641A APPLICATION CIRCUIT WITH TDK INDUCTOR L1 = ELJ-PB220KF 22µH, IDCmax = 300mA, DCR = 1.0Ω L1 = NLC453232T-220K 22µH, IDCmax = 370mA, DCR = 0.9Ω Startup VOUT IOUT Startup Startup VOUT IOUT Startup Load after after then Load after after then VIN ROUT (min) Startup Startup Load VIN ROUT (min) Startup Startup Load V Ω V mA mA (max) V Ω V mA mA (max) 0.86 16000 3.31 0.2 37 0.86 16000 3.30 0.2 42 0.88 1500 3.31 2 39 0.88 1500 3.30 2 43 0.90 800 3.30 4 40 0.90 900 3.30 4 44 0.95 230 3.30 14 44 0.95 260 3.30 13 48 1.00 125 3.30 26 48 1.00 126 3.30 26 52 1.10 73 3.29 45 56 1.10 66 3.29 50 60 1.20 58 3.29 57 63 1.20 49 3.29 67 69 1.30 50 3.28 66 71 1.30 43 3.29 77 77 1.40 43 3.28 76 78 1.40 39 3.29 84 84 1.50 39 3.28 84 86 1.50 36 3.29 91 91 Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 10

APPLICATION INFORMATION: continued Low Battery Circuit for SP6641 output, as shown. The small SOT23-3pin Application SPX432 and 2N3904 bipolar transistor and di- odes are small and inexpensive to add to the The circuit in figure 17 uses the Sipex SPX432 SP6641 circuit and work well to add a Battery shunt regulator as a reference and comparator Low detection circuit, with the addition of about circuit to detect a low battery condition and give a high level, typically 1.7V output. When the 130µA current from 3.3V out. As a bonus, the output of this circuit can be used to drive the battery is good, the SPX432 output is low, but SP6641 SHDN_N pin 3 to GND when the bat- not at ground but at 0.8V or about one Vbe tery is removed, which would reset the SP6641 below the 1.24V reference. To translate that and eliminate the need for the SuperCap Switch level to a CMOS Low of less than 0.4V, an NPN shown in figure 16. and 2 signal diodes can be added to the SPX432 VBATT C1 22µF L1 22µH 2.7V, 0.9Ω PMOS VOUT SOT23-3 IRLML6302 3.3V to ®® +3.3V 3 Q1 2 Nonvolatile Function 1 5 LX VBATT U1 R1 SP6641 SHDN 1M C3 2 J1 .22F Supercap GND Diode 1 1 Schottky 3 4 2 3 VOUT SHDN 3 1 Q2 SOT23-3 IRLML2402 2.7V NMOS C2 2 22µF Figure 16. SP6641A 3.3V with SuperCap Switch VBATT 1.8V THRES. VTHRES = 1.24V(1 + R1/R2) R1 C1 44k 22µF U2 1RESFPX432M A3 L1 2K SOT23-3 R2 22µH 100k BATT GOOD R4 D2 D3 2V = BATT GOOD 1 LX ®®VBATT5 Q2N23904 0V = LOW BATT 2 GND U1 100k 1N4148 1N4148 D1 SP6641 Diode 3 VOUT SHDN 4 R203k R1050k Schottky VOUT 3.3V C2 22µF Figure 17. SP6641A 3.3V with Low Battery Detection Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 11

PACKAGE: 5 Lead SOT23 b CL e E e1 D CL CL a 0.20 DATUM 'A' AA2 C E1 L A 2 A1 A .10 SYMBOL MIN MAX A 0.90 1.45 A1 0.00 0.15 A2 0.90 1.30 b 0.25 0.50 C 0.09 0.20 D 2.80 3.10 E 2.60 3.00 E1 1.50 1.75 L 0.35 0.55 e 0.95ref e1 1.90ref a 0O 10O Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 12

ORDERING INFORMATION Part Number TOP MARK Temperature Range Package Type SP6641AEK-3.3/TR.............K1...................... -40°C to 85°C........(Tape & Reel) 5-Pin SOT-23 SP6641BEK-3.3/TR.............L1...................... -40°C to 85°C........(Tape & Reel) 5-Pin SOT-23 SP6641AEK-5.0/TR.............P1...................... -40°C to 85°C........(Tape & Reel) 5-Pin SOT-23 SP6641BEK-5.0/TR.............Q1...................... -40°C to 85°C........(Tape & Reel) 5-Pin SOT-23 Available in lead free packaging. To order add “-L” suffix to part number. Example: SP6641AEK-3.3/TR = standard; SP6641AEK-L-3.3/TR = lead free, Top Mark “H4”. /TR = Tape and Reel Pack quantity is 2,500 for SOT23. Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation Headquarters and Sales Office 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: sales@sipex.com Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600 Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Rev. 5/26/05, *Patent Pending SP6641A/6641B 500mA Alkaline DC/DC Boost Regulator in SOT-23 © Copyright 2002 Sipex Corporation 13

Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: E xar: SP6641AEK-L-3-3/TR SP6641BEK-L-3-3/TR SP6641AEK-L-5-0/TR SP6641BKEB-5-0 SP6641AEK-L-3-3 SP6641AEK-L-5-0 SP6641AKEB-3-3 SP6641BEK-L-3-3 SP6641BEK-L-5-0 SP6641BKEB-3-3 SP6641EBLED SP6641AEK-L-3-3/MTR