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| 1 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation 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 10 a quiescent current, a 0.3 ? 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. 500ma alkaline dc/dc boost regulator in sot-23 ? ultra low quiescent current: 10 a wide input voltage range: 0.9v to 4.5v 90ma i out at 1.3v input (sp6641a-3.3v) 500ma i out at 2.6v input (sp6641b-3.3v) 100ma i out at 2.0v input (sp6641a-5.0v) 500ma i out at 3.3v input (sp6641b-5.0v) fixed 3.3v or 5.0v output voltage up to 87% efficiency 0.3 ? nfet r ds on startup voltage guaranteed at 0.9v 0.33a inductor current limit (sp6641a) 1a inductor current limit (sp6641b) logic shutdown control sot-23-5 package v out gnd shdn v batt lx sp6641 5 pin sot-23 1 2 3 5 4 applications pda's dsc's cd/mp3 players pagers digital cameras portable handheld medical devices sp6641a/6641b figure 1. typical application schematic figure 2. maximum load current in operation i out (ma) 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 v in (v) sp6641b, 1.0a, 3.3v sp6641b, 1.0a, 5v sp6641a, 0.33a, 3.3v sp6641a, 0.33a, 5v gnd lx v batt shdn l1 0.9v to 4.5v u1 sp6641a v out shdn v batt ? ? c2 v out +3.3v or 5v d1 1 2 3 c1 5 4 c3 r1 sp6641a 3.3v & 5v: c1 = c2 = 22 f ceramic, l1 = 22 h cdrh5d28, d1 = mbr0520, c3 = open, r1 = shorted. sp6641b 3.3v & 5v: c1 = c2 = 100 f poscap, l1 = 10 h cdrh5d28, d1 = zhcs2000, c3 = 1 f ceramic, r1 = 10 ? . now available in lead free packaging
2 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation absolute maximum ratings these are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. electrical specifications v batt = v shdn = 1.3v, i load = 0ma, -40 c 4 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation performance characteristics refer to the circuit in figure 1, t amb = +25 c 60 65 70 75 80 85 90 95 100 0.1 1.0 10.0 100.0 1000.0 iload (ma) v in = 3.0v v in = 2.6v v in = 2.0v v in = 1.3v v in = 1.0v efficiency (%) 60 65 70 75 80 85 90 95 100 0.1 1.0 10.0 100.0 1000.0 iload (ma) efficiency (%) v in = 3.0v v in = 2.6v v in = 2.0v v in = 1.3v v in = 1.0v 3.200 3.220 3.240 3.260 3.280 3.300 3.320 3.340 3.360 3.380 3.400 iload (ma) 0 50 100 150 200 250 v out v in = 3.0v v in = 2.6v v in = 2.0v v in = 1.3v v in = 1.0v 3.220 3.240 3.260 3.280 3.300 3.320 3.340 3.360 3.380 3.400 0 200 400 600 800 3.200 iload (ma) v out v in = 3.0v v in = 2.6v v in = 2.0v v in = 1.3v v in = 1.0v figure 3. sp6641aek - 3.3 efficiency vs load current figure 4. sp6641bek - 3.3 efficiency vs load current figure 5. sp6641aek - 3.3 line/load rejection vs load current figure 6. sp6641bek - 3.3 line/load rejection vs load current figure 7. sp6641aek-5.0 efficiency vs load current figure 8. sp6641bek-5.0 efficiency vs load current iload ( ma ) efficiency (%) 60 65 70 75 80 85 90 95 100 0.1 1.0 10.0 100.0 1000.0 vi=4.2v vi=3.6v vi=3.3v vi=2.0v vi=1.3v iload ( ma ) efficiency (%) 60 65 70 75 80 85 90 95 100 0.1 1.0 10.0 100.0 1000.0 vi=4.2v vi=3.6v vi=3.3v vi=2.0v vi=1.3v 5 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation figure 9. sp6641aek-5.0 line/load rejection vs load current figure 10. sp6641bek-5.0 line/load rejection vs load current performance characteristics refer to the circuit in figure 1, t amb = +25 c figure 11. sp6641aek-3.3 & sp6641aek-5.0 no load battery current figure 12. sp6641bek-3.3 & sp6641aek-5.0 no load battery current figure 13. sp6641aek-3.3 & sp6641aek-5.0 maximum resistive load current in startup figure 14. sp6641bek-3.3 & sp6641bek-5.0 maximum resistive load current in startup iload ( ma ) vo (v) 5.000 5.020 5.040 5.060 5.080 5.100 5.120 5.140 5.160 5.180 5.200 050 100 150 200 250 vi=4.2v vi=3.6v vi=3.3v vi=2.0v vi=1.3v iload (ma) vo (v) 4.900 4.920 4.940 4.960 4.980 5.000 5.020 5.040 5.060 5.080 5.100 0 200 400 600 800 vi=4.2v vi=3.6v vi=3.3v vi=2.0v vi=1.3v vin ( v ) iin (ua) 0 50 100 150 200 250 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 sp6641aek-5.0 sp6641aek-3.3 vin (v) iin (ua) 0 50 100 150 200 250 300 350 400 450 500 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 sp6641b-5.0 sp6641b-3.3 vin ( v ) io (ma) 0 50 100 150 200 250 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 sp6641aek-3.3, 22 h sp6641aek-3.3, 10 h sp6641aek-5.0, 22 h sp6641aek-5.0, 10 h vin ( v ) io (ma) 0 100 200 300 400 500 600 700 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 sp6641bek-3.3, 22 h sp6641bek-3.3, 10 h sp6641bek-5.0, 22 h sp6641bek-5.0, 10 h 6 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation i out(max) ( v in ) ( i pk k off ) v out 2l operation general overview the sp6641 is a high efficiency, low quiescent current step-up dc-dc converter ideal for single and dual cell alkaline and single cell lithium ion battery applications such as medical monitors, pda?, mp3 players, and other portable end products. the sp6641? 10 a quiescent cur- rent, low 0.3 ? nfet switch, and unique pfm control scheme combine to provide excellent efficiency over a wide output power range. other features include a logic level enable con- trol pin, guaranteed 0.9v startup, a tiny sot23 5 pin package, and precise inductor peak current control. sp6641a sources up to 90ma at 1.3v, typ. and sp6641b sources up to 500ma at 2.6v, typ. by supporting different peak inductor current levels. only two capacitors, an inductor, and a diode are required to build a power supply for the sp6641a. the sp6641b, 1a peak current requires an additional small resistor and capaci- tor as a low pass filter for the v out ic power pin. loop regulation the sp6641 combines a fixed inductor peak current limit, a feed-forward minimum off-time one-shot, and a precision loop comparator to regulate the output voltage. under light-load conditions the loop operates as a standard pfm converter. the frequency of fixed amplitude inductor current triangles is modulated to regu- late the load. under heavy load conditions, the converter adjusts the number of successive con- tinuous mode current pulses to regulate the load. refer to the block diagram for the following explanation of operating modes in loop regulation. the output voltage is internally divided down and fed to the negative terminal of the loop compara- tor. a +1.25v bandgap reference voltage is ap- plied to the positive terminal of the comparator. as the output voltage droops below the regulation threshold due to the load the loop comparator output (signal v out(low) ) transitions to a logic ?? this sets the sr latch and initiates inductor charging by pulling the signal ngate high. in- ductor charging continues until the current reaches the internally programmed limit, at which point, the off-time one-shot is triggered. the off-time one-shot via signal t off resets the sr latch regardless of the set state (v out(low) ), opens the nmos charge switch, and forces the inductor to discharge through the rectifying diode for a minimum time defined by the one- shot duration. the end of the off-time pulse releases the sr latch, and its output state is once again determined by the output of the loop comparator (v out(low) ). under light load con- ditions, the output voltage will have been pulled above the regulation threshold during the mini- mum off-time, the signal v out(low) will be a logic ?? and the nmos charging switch will remain open. the inductor current discharges until it reaches zero or the loop comparator triggers a new charge cycle. under a heavy load, the output voltage will remain below the regulation point at the end of the off-time pulse. in this condition, v out(low) has a logic value of 1 which immediately starts a new charge/discharge cycle defined by the peak inductor current and the minimum off- time. the inductor current will remain in a continuous conduction mode until the loop com- parator indicates the output voltage is above the regulation threshold, and the inductor current will relax towards zero. during continuous mode bursts, the inductor current frequency and ripple amplitude are con- trolled by the minimum off-time one-shot and the input and output voltage levels. the sp6641 sets the minimum off-time to: t off = k off (v out ?v in ), where: k off = off-time constant, typically 1.5 s*v v out = output voltage v in = input voltage plugging the t off expression into the boost mode equations yields the maximum output current in regulation: where: = efficiency, typically 0.80 to 0.90 i pk = programmed inductor peak current, typi- cally 0.33a for the sp6641a, typically 1.0a for the sp6641b. l= inductor value 7 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation the sp6641 feed forward off-time control de- livers more load current than constant off-time control because the input battery voltage drops during its life cycle. the term (i pk ?k off /2l) is the average current delivered to the output ca- pacitor during the discharge phase. this is con- stant with respect to input and output voltage. with constant off-time control, the average dis- charge current term becomes (i pk -t off *(v out -v in )/2l), which decreases as the input voltage drops. table 1 illustrates the average inductor current delivered to the load during discharge versus the input voltage. the sp6641 feed forward off- time control and the constant off-time control are compared. for purposes of illustration, the off times of each control scheme are normalized at a typical two cell alkaline input voltage of 2.6v. the values used in table 1 are: i pk = 0.33a l = 22 h v out = 3.3v t off (sp6641) = 1.5v* s/(3.3-v in ) t off (constant) = 2.14 s sp6641a constant t off v in t off avg i l t off avg i l 3.0 5.00 s 0.30a 2.14 s 0.32a 2.6 2.14 s 0.30a 2.14 s 0.30a 2.0 1.15 s 0.30a 2.14 s 0.27a 1.3 0.75 s 0.30a 2.14 s 0.23a 1.0 0.65 s 0.30a 2.14 s 0.22a table 1- average i l vs. input voltage the following equation defines the burst mode frequency under heavy load conditions: where: v d = forward schottky drop, (0.4v, typ) v c = average charging switch drop, rnmos*i pk , typically 0.1v ignoring the conduction losses of v d and v c , the burst frequency equation simplifies to: f burst = (v out ?v in )v in k off v out startup the internal regulator circuitry is bootstrapped to the v out pin. this requires a low voltage oscillator and charging switch powered from the v batt pin to pump up the output voltage until the reference is established. the reference pro- vides a refready signal that determines when output control is handed over to the regulator. refready shuts down the startup circuit and enables the regulator when the reference is valid and v out is above +1.9v. once the regulator is given control it will continue to pump up the output at full power until regulation is reached. for two cell alkaline input voltages and above, the output voltage will be pulled above +1.9v quickly through the rectifying diode before the reference has a chance to establish. in this sce- nario the startup circuit will coarsely regulate around +2.8v until the refready signal as- serts. this keeps the output from overshooting in startup with higher input voltages. startup is guaranteed at +0.9v at room tempera- ture with a 3k ? load. heavier loads will require a higher input voltage. shutdown/enable control pin 4 of the device is a v batt referred control pin that shuts down the converter with the pin tied to ground, or enables the converter with the pin tied to v batt . when the converter is shut- d own the power switch is opened and all circuit biasing is extinguished leaving only junction leak- age currents on supply pins 3 and 5. the output voltage will droop to one diode drop below the battery voltage through the rectifying diode. after pin 4 is brought high, the startup circuit is enabled and starts pumping up the output until refready hands over control to the internal regulator. operation loop regulation: continued f burst = ( v out ?v in ) ( v in ?v c ) k off v out + v d ? c 8 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation application information circuit layout printed circuit board layout is a critical part of a power supply design. poor designs can result in excessive emi on the voltage gradients and feedback paths on the ground planes with appli- cations involving high switching frequencies and large peak currents. excessive emi can result in instability or regulation errors. all power components should be placed on the pc board as closely as possible with the traces kept short, direct, and wide (>50mils or 1.25mm). extra copper on the pc board should be inte- grated into ground as a pseudo-ground plane. on a multilayer pc board, route the star ground using component-side copper fill, then connect it to the internal ground plane using vias. for the sp6641a/6641b devices, input and output fil- ter capacitors should be soldered with their ground pins as close together as possible in a star-ground configuration. the vout pin must be bypassed directly to ground as close to the sp6641a/6641b devices as possible (within 0.2in or 5mm). the dc-dc converter and any digital circuitry should be placed on the oppo- site corner of the pc board as far away from sensitive rf and analog input stages. noisy traces, such as from the lx pin, should be kept away from the voltage-feedback vout node and separated from it using grounded copper to minimize emi. see the sp6641a/6641b evalu- ation board manual for pc board layout de- sign details. component selection selection of capacitors, inductors and schottky diodes for sp6641a and sp6641b power sup- ply circuits can be made through the use of table 1 component selection. capacitor equiva- lent series resistance is a major contributor to output ripple, usually greater than 60%. low esr capacitors are recommended. ceramic ca- pacitors have the lowest esr. low-esr tanta- lum capacitors may be a more acceptable solu- tion having both a low esr and lower cost than large ceramic capacitors. designers should se- lect input and output capacitors with a rating exceeding the peak inductor current. do not allow tantalum capacitors to exceed their ripple- current ratings. for example, in the sp6641a a 22 f, 6v, low-esr, surface-mount tantalum output filter capacitor typically provides 60mv output ripple when stepping up from 1.3v to 3.3v at 20ma. an input filter capacitor can reduce peak currents drawn from the battery and improve efficiency. low-esr aluminum elec- trolytic capacitors are acceptable in some appli- cations but standard aluminum electrolytic ca- pacitors are not recommended. in selecting an inductor, the saturation current specified for the inductor needs to be greater then the sp6641a/b peak current to avoid satu- rating the inductor, which would result in a loss in efficiency and could damage the inductor. the sp6641a evaluation board uses a sumida cdrh5d28 22 h inductor with an isat value of 0.9a and a dcr of 0.095 ? , which easily handles the ipeak of 0.33a of the sp6641a and will deliver high efficiencies. the sp6641b evaluation board uses a sumida cdrh5d28 10 h inductor with an isat value of 1.3a and a dcr of 0.065 ? , which easily handles the ipeak of 1.0a of the sp6641b and will deliver high efficiencies. other inductors could be selected provided their isat is greater than the ipeak of the sp6641a/sp6641b. output filter or ldo regulator designers could add lc pi filters, linear post- regulators, or shielding in applications necessary to address excessive noise, voltage ripple, or emi concerns. the lc pi filter? cutoff frequency should be at least a decade or two below the dc-dc converters?switching frequency for the specified load and input voltage. the sp6201, a small sot23- 5pin 200ma low drop out linear regulator can be used at the sp6641a/6641b output to reduce output noise and ripple. the schematic in figure 15 illustrates this circuit on the sp6641a evaluation board with the sp6641 3.3v output followed by the sipex sp6201 3.0v output low drop out linear regu lator. 9 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation application information: continued table 1. component selection inductors - surface mount inductor specification sipex inductance manufacturer/ series r isat size lxwxh inductor manufacturer part number ( h) part number ( ? ) (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 ( f) part number ( ? )@ 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. maximum startup current it should be noted that for low input voltages the sp6641 startup circuit can not support large load currents at startup. in startup the sp6641 needs to boost the output from zero volts using a charge pump which has a limited current capacity. once the output is greater than 1.7 to 1.9v the operate circuit takes over and the sp6641 can supply much more current. curves of maximum resistive load current in startup for the sp6641a and sp6641b are shown in fig- ures 13 & 14 and can be compared with figure 2, maximum load current in operation. also, table 2 provides sp6641a 3.3v resistive load current in startup for some low cost 1812 size chip inductors. from the curves in figures 13 and 14, you can see that for low input voltages, the 22 h induc- tor has more current capacity at startup than the 10 h inductor, due to more energy per charge cycle in the relationship 1 / 2 li 2 . thus for 1 cell applications, 22 h is recommended for more startup current than 10 h. for 1-cell battery applications, it is recommended to apply any large load current after the sp6641 has started up, typically in a few millisecs. this is typically not a problem in many applications where the load is a processor whose load current is low until the processor voltage comes up. 10 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation application information: continued table 2. sp6641a resistive load current in startup - low cost inductors gnd lx v batt j1 l1 22 h u1 sp6641 v out shdn ? ? c2 22 f v out +3.3v d1 1 2 3 c1 22 f 5 4 1 2 3 v batt +0.9v to +3.3v input + + gnd enable v out sp6201 v in ? ? reset 1 2 3 5 4 v out +3.0v c3 1 f figure 15. sp6641a 3.3v evaluation board with sp6201 ldo regulator sp6641a application circuit with panasonic inductor sp6641a application circuit with tdk inductor l1 = elj-pb220kf 22 h, idcmax = 300ma, dcr = 1.0 ? l1 = nlc453232t-220k 22 h, idcmax = 370ma, dcr = 0.9 ? startup v out i out startup startup v out i out startup load after after then load after after then v in r out (min) startup startup load v in r out (min) startup startup load v ? vm a ma (max) v ? vm a 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 supercap application on the sp6641 output when the battery input to sp6641a is removed, the sp6641a output will end up in the charge mode and will slowly discharge a supercap connected to the output. the typical supercap of 0.22f will go from fully charged at 3.3v to less than 2v in 5 minutes. the following appli- cation circuit in figure 16 is recommended to disconnect the sp6641 output from the supercap when the battery is removed. the small sot23- 3pin mos switches are an inexpensive addition to the sp6641 circuit and work well to maintain supercap voltage to retain non-volatile cmos memory while a battery is changed. 11 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation low battery circuit for sp6641 application the circuit in figure 17 uses the sipex spx432 shunt regulator as a reference and comparator circuit to detect a low battery condition and give a high level, typically 1.7v output. when the battery is good, the spx432 output is low, but not at ground but at 0.8v or about one vbe below the 1.24v reference. to translate that level to a cmos low of less than 0.4v, an npn and 2 signal diodes can be added to the spx432 figure 17. sp6641a 3.3v with low battery detection application information: continued output, as shown. the small sot23-3pin spx432 and 2n3904 bipolar transistor and di- odes are small and inexpensive to add to the sp6641 circuit and work well to add a battery low detection circuit, with the addition of about 130 a current from 3.3v out. as a bonus, the output of this circuit can be used to drive the sp6641 shdn_n pin 3 to gnd when the bat- tery is removed, which would reset the sp6641 and eliminate the need for the supercap switch shown in figure 16. gnd lx v batt l1 22 h 100k u1 sp6641 v out shdn ? ? c2 22 f r3 20k diode schottky 1 2 3 c1 22 f 5 4 v batt r5 100k batt good d2 d3 1n4148 r2 100k r1 44k 1n4148 v out 3.3v q2 2n3904 2v = batt good 0v = low batt r4 1 2 3 ref k a 1.8v thres. vthres = 1.24v(1 + r1/r2) u2 spx432m sot23-3 d1 gnd lx v batt shdn j1 l1 22 h 2.7v, 0.9 ? pmos sot23-3 irlml6302 q1 u1 sp6641 v out shdn ? ? c2 22 f v out +3.3v diode schottky 1 2 3 c1 22 f 5 4 1 2 3 v batt c3 .22f supercap 3.3v to nonvolatile function 32 1 3 1 2 q2 sot23-3 irlml2402 2.7v nmos r1 1m figure 16. sp6641a 3.3v with supercap switch 12 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation p ackage: 5 lead sot23 symbol a a1 a2 b c d e e1 l e e1 a 1.45 0.15 1.30 0.50 0.20 3.10 3.00 1.75 0.55 10 o 0.90 0.00 0.90 0.25 0.09 2.80 2.60 1.50 0.35 0 o min max 0.95ref 1.90ref e a e c l b e1 d c l a2 a1 a a .10 c l e1 l 2 0.20 datum 'a ' c a 13 rev. 5/26/05, *patent pending sp6641a/6641b 500ma alkaline dc/dc boost regulator in sot-23 ? copyright 2002 sipex corporation 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 corporation signal processing excellence sipex corporation reserves the right to make changes to any products described herein. sipex does not assume any liability aris ing out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor t he rights of others. 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 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. mouser electronics authorized distributor click to view pricing, inventory, delivery & lifecycle information: exar: ? sp6641bek-l-5-0/tr |
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