LT1307 LINER
Document overview
- Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 20
Technical content
current with a voltage drop of just 295mV. tance and require only 1µF of input bypassing. Burst Mode is a trademark of Linear Technology Corporation. , LTC and LT are registered trademarks of Linear Technology Corporation.
1307 TA01
1307 F01
Figure 1. Single Cell to 3.3V Boost Converter
A UGWA WU WARBSOLUTEX I T I S IN + 1V Operating Temperature Range WU UPACKAGE/ORDER I FOR ATIO TJMAX = 125°C, θJA = 160°C/W ORDER PART NUMBER ORDER PART NUMBER V C FB SHDN GND LBO LBI V IN SW TOP VIEW MS8 PACKAGE 8-LEAD PLASTIC MSOP TOP VIEW LBO LBI V IN SW VC FB SHDN GND N8 PACKAGE 8-LEAD PDIP S8 PACKAGE 8-LEAD PLASTIC SO LT1307CMS8 LT1307BCMS8 LT1307CN8 LT1307CS8 LT1307IS8 LT1307BCS8 LT1307BIS8 TJMAX = 125°C, θJA = 100°C/W (N8) TJMAX = 125°C, θJA = 120°C/W (S8) S8 PART MARKING 1307 1307B 1307I 1307BI MS8 PART MARKING Consult factory for Military grade parts. Commercial Grade 0°C to 70°C. VIN = 1.1V, VSHDN = VIN, TA = 25°C, LT1307/LT1307B unless otherwise noted. ELECTRICAL C CHARA TERISTICS SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS IQ Quiescent Current Not Switching (LT1307) l 50 90 µA Not Switching (LT1307B) l 1.0 1.5 mA VSHDN = 0V l 13 µA VFB Feedback Voltage l 1.20 1.22 1.24 V IB FB Pin Bias Current (Note 2) V FB = VREF l 27 60 nA Reference Line Regulation 1V ≤ VIN ≤ 2V (25°C, 0°C) 0.6 1.1 %/V 1V ≤ VIN ≤ 2V (70°C) 1.5 %/V 2V ≤ VIN ≤ 5V l 0.3 0.8 %/V Minimum Input Voltage 0.92 1 V Input Voltage Range l 15 V gm Error Amp Transconductance ΔI = 5µA l 25 35 65 µmhos AV Error Amp Voltage Gain 25 °C, 0°C 35 100 V/V 70°C 30 V/V fOSC Switching Frequency l 550 600 750 kHz BU BF
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Maximum Duty Cycle 25 °C, 0°C8 0 8 4 % 70°C7 6 % Switch Current Limit (Note 3) DC = 40% l 0.6 1.25 A DC = 75% 0.5 A Switch VCESAT ISW = 500mA (25°C, 0°C) 295 350 mV ISW = 500mA (70°C) 400 mV Burst Mode Operation Switch Current Limit L = 10 µH 100 mA (LT1307 Only) L = 22 µH5 0 m A Shutdown Pin Current V SHDN = VIN l 2.5 4.0 µA VSHDN = 0V l –1.5 –2.5 µA LBI Threshold Voltage l 190 200 210 mV LBO Output Low I SINK = 10µA l 0.1 0.25 V LBO Leakage Current V LBI = 250mV, VLBO = 5V l 0.01 0.1 µA LBI Input Bias Current (Note 4) V LBI = 150mV l 52 5n A Low-Battery Detector Gain 1M Ω Load (25°C, 0°C) 1000 3000 V/V 1MΩ Load (70°C) 500 V/V Switch Leakage Current V SW = 5V l 0.01 3 µA Reverse Battery Current (Note 5) 750 mA Commercial Grade 0°C to 70°C. VIN = 1.1V, VSHDN = VIN, TA = 25°C unless otherwise noted. ELECTRICAL C CHARA TERISTICS Commercial Grade TA = –20 °C, VIN = 1.1V, VSHDN = VIN, unless otherwise noted (Note 1). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS IQ Quiescent Current V FB = 1.3V, Not Switching (LT1307) 50 100 µA VFB = 1.3V, Not Switching (LT1307B) 1.1 1.6 mA VSHDN = 0V 1 3 µA VFB Feedback Voltage 1.195 1.22 1.245 V gm Error Amp Transconductance ΔI = 5µA2 5 3 5 6 5 µmhos AV Error Amp Voltage Gain 35 100 V/V fOSC Switching Frequency 500 600 750 kHz Maximum Duty Cycle 80 84 % Switch VCESAT ISW = 500mA, VIN = 1.2V 250 350 mV Shutdown Pin Current V SHDN = VIN 2.5 4.0 µA VSHDN = 0V – 1.5 – 2.5 µA LBI Threshold Voltage 186 200 210 mV
ELECTRICAL C CHARA TERISTICS Industrial Grade – 40°C to 85°C. VIN = 1.1V, VSHDN = VIN, LT1307/LT1307B unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS IQ Quiescent Current V FB = 1.3V, Not Switching (LT1307) l 50 100 µA VFB = 1.3V, Not Switching (LT1307B) l 1 1.8 mA VSHDN = 0V l 13 µA VFB Feedback Voltage l 1.195 1.22 1.245 V IB FB Pin Bias Current (Note 2) V FB = VREF l 10 27 100 nA Reference Line Regulation 1V ≤ VIN ≤ 2V (–40 °C) 0.6 1.1 %/V 1V ≤ VIN ≤ 2V (85°C) 3.2 %/V 2V ≤ VIN ≤ 5V l 0.3 0.8 %/V Minimum Input Voltage –40 °C 1.1 1.2 V 85°C 0.8 1.0 V Input Voltage Range l 5V gm Error Amp Transconductance ΔI = 5µA l 25 35 65 µmhos AV Error Amp Voltage Gain –40 °C 35 V/V 85°C 30 V/V fOSC Switching Frequency l 500 600 750 kHz Maximum Duty Cycle –40 °C8 0 8 4 % 85°C7 5 8 0 % Switch Current Limit (Note 3) DC = 40% l 0.6 1.25 A DC = 75% 0.5 A Switch VCESAT ISW = 500mA, VIN = 1.2V (–40 °C) 250 350 mV ISW = 500mA (85°C) 330 400 mV Burst Mode Operation Switch Current Limit L = 10 µH 100 mA (LT1307 Only) L = 22 µH5 0 m A Shutdown Pin Current V SHDN = VIN l 2.5 4.0 µA VSHDN = 0V l – 1.5 – 2.5 µA LBI Threshold Voltage l 186 200 210 mV LBO Output Low I SINK = 10µA l 0.1 0.25 V LBO Leakage Current V LBI = 250mV, VLBO = 5V l 0.1 0.3 µA LBI Input Bias Current (Note 4) V LBI = 150mV l 53 0n A Low-Battery Detector Gain 1M Ω Load (– 40°C) 1000 6000 V/V 1MΩ Load (85°C) 400 V/V Switch Leakage Current V SW = 5V l 0.01 3 µA Note 2: Bias current flows into FB pin. Note 3: Switch current limit guaranteed by design and/or correlation to static tests. Duty cycle affects current limit due to ramp generator. Note 4: Bias current flows out of LBI pin. Note 5: The LT1307 will withstand continuous application of 1.6V applied to the GND pin while VIN and SW are grounded. The l denotes specifications which apply over the full operating temperature range. Note 1: Specifications for commercial (C) grade devices are guaranteed but not tested at –20 °C. MS8 package devices are designed for and intended to meet commercial temperature range specifications but are not tested at – 20°C or 0°C.
TYPICAL PERFORMANCE CHARACTERISTICS UW LOAD CURRENT (mA) EFFICIENCY (%) 2000.1 1 10 100 LT1307 • G01 VIN = 1.00V VIN = 1.25V VIN = 1.5V 3.3V Output Efficiency, Circuit of Figure 1 (LT1307B) 5V Output Efficiency, Circuit of Figure 1 (LT1307B) LOAD CURRENT (mA) 0.1 EFFICIENCY (%) 11 0 LT1307 • TPC03 100 VIN = 1V VIN = 1.5V VIN = 1.25V Quiescent Current vs Temperature Feedback Bias Current vs Temperature LBI Bias Current vs Temperature 5V Output Efficiency, Circuit of Figure 1 (LT1307) TEMPERATURE (°C) –50 QUIESCENT CURRENT (µA) 25 75 LT1307 • TPC04 –25 0 50 100 TEMPERATURE (°C) –50 FEEDBACK BIAS CURRENT (nA)10 –25 02 5 5 0 LTC1307 • TPC05 75 100 VIN = 1.1V TEMPERATURE (°C) –50 LBI BIAS CURRENT (nA) 25 75 LT1307 • TPC06 –25 0 50 100 Quiescent Current in Shutdown Shutdown Pin Bias Current vs Input Voltage Switch VCESAT vs Current INPUT VOLTAGE (V) QUIESCENT CURRENT (µA) LT1307 • TPC07 1 2 3 5 INPUT VOLTAGE (V) SHUTDOWN PIN CURRENT (µA) LT1307 • TPC08 1 2 3 5 SWITCH CURRENT (mA) VCESAT (mV) 100 200 300 400 500 100 200 300 400 LT1307 • TPC09 500 600 TA = 25°C LOAD CURRENT (mA) 0.1 EFFICIENCY (%) 100101
1307 G02
VIN = 1.25V VIN = 1.5V VIN = 1V
TYPICAL PERFORMANCE CHARACTERISTICS UW Feedback Voltage vs Temperature LBI Reference vs Temperature Oscillator Frequency vs Input Voltage TEMPERATURE (°C) –50 FEEDBACK VOLTAGE (V) 1.230 1.225 1.220 1.215 1.210 1.205 1.200 –25 02 5 5 0 LT1307 • TPC10 75 100 VIN = 1.25V 500 µs/DIV 1307 G13 VOUT = 3.3V Transient Response (LT1307) IL 200mA/DIV VOUT 200mV/DIV AC COUPLED 55mA 5mAILOAD VIN = 0.92V I LOAD 10mA/DIV 1307 G15 VOUT = 3.3V Load Regulation (LT1307) VOUT 50mV/DIV DC COUPLED OFFSET ADDED TEMPERATURE (°C) –50 REFERENCE VOLTAGE (mV) –25 0 25 50 LT1307 • TPC11 210 208 206 204 202 200 198 196 194 192 190 100 VIN = 1.25V 500 µs/DIV 1307 G14 VOUT = 3.3V Transient Response (LT1307B) IL 200mA/DIV VOUT 200mV/DIV AC COUPLED 55mA 5mA VIN = 1.15V I LOAD 20mA/DIV 1307 G17 VOUT = 3.3V Load Regulation (LT1307) VIN = 1V I LOAD 10mA/DIV 1307 G18 VOUT = 5V Load Regulation (LT1307) VOUT 50mV/DIV DC COUPLED OFFSET ADDED VOUT 50mV/DIV DC COUPLED OFFSET ADDED VIN = 1V I LOAD 20mA/DIV 1307 G16 VOUT = 3.3V Load Regulation (LT1307) VOUT 50mV/DIV DC COUPLED OFFSET ADDED Load Regulation (LT1307) ILOAD VIN = 1.25V 100 µs/DIV 1307 G21 VOUT = 5V ILOAD = 1.5mA IL 100mA/DIV VSW 5V/DIV VOUT 50mV/DIV AC COUPLED VOUT 50mV/DIV AC COUPLED VIN = 1.25V 100 µs/DIV 1307 G20 VOUT = 5V ILOAD = 1.5mA IL 100mA/DIV VSW 5V/DIV VOUT 50mV/DIV DC COUPLED OFFSET ADDED VIN = 1.15V I LOAD 10mA/DIV 1307 G19 VOUT = 5V Circuit Operation, L = 22 µH (LT1307) Circuit Operation, L = 10µH (LT1307) INPUT VOLTAGE (V) FREQUENCY (kHz) 600 700 LT1307 • TPC12 500 400 2 3 4 900 800 85°C –40°C 25°C
FB (Pin 2): Feedback Pin. Reference voltage is 1.22V. OUT according to: VOUT = 1.22V(1 + R1/R2). switcher. Do not float the SHDN pin. SW (Pin 5): Switch Pin. Connect inductor/diode here. Minimize trace area at this pin to keep EMI down. capacitor right at the pin, connected directly to ground. tor, can sink 10µA. A 1MΩ pull-up is recommended. Figure 2. LT1307/LT1307B Block Diagram
ing frequency (nominal switching frequency is 600kHz). Note, however, the absence of significant energy at 455kHz. further reduced, the Burst Mode frequency decreases. load step from 5mA to 45mA with a 1.5V input. made more conservative (increased C, decreased R). Figure 5. Increasing L to 100µH, Along with RC = 36k, pulling down VC to 0.3V or less externally. causing low frequency ripple to appear at the output.
1307 F06
Figure 6. Spectral Noise Plot of 3.3V Converter Delivering
1307 F07
Figure 7. Span Centered at 455kHz Shows – 55dBmVRMS
Burst Mode operation spectral components are gone. load is applied to the circuit. Figure 10 shows the setup. Figure 10. Boost Converter with Simulated Load do better. Reducing C to 2nF gives Figure 11c’s response. Figure 9. LT1307B at 5mA Load Shows No Audio Components
1307 F08
Figure 8. With Converter Delivering 20mA, Low Frequency
not get advertised performance with careless layouts. Figure 12 shows recommended component placement. in these cases. This capacitor need not have low ESR. ing. This places a lower limit on the physical size of the unit. nents are listed in Table 1. Table 1. Inductors Suitable for Use with the LT1307 Mode can be reduced by increasing output capacitance. For 2- and 3-cell applications, more than 10µF is needed. 594D series are both good choices for low ESR capacitors.
1306 F12
Figure 12. Recommended Component Placement. Traces
Table 2. Vendor Telephone Numbers the Motorola MBR0520L surface mount Schottky diode. Figure 13. Shutdown Circuit
1307 F13
ence can also be accessed as shown in Figure 15.
1307 F14
Figure 14. Setting Low-Battery Detector Trip Point
1307 F15
Figure 15. Accessing 200mV Reference
The LT1307 is built on a junction-isolated bipolar process.
- When the battery polarity is reversed, these diodes
AAA cell, several hundred milliamperes flow in the circuit. reverse voltage across the LT1307 to a single diode drop. Figure 18. 1N4001 Diode Protects LT1307 from Excessive Power
1307 F18
2 OR 3
1307 F16
1 CELL
Figure 16. LT1307 Showing Internal Substrate Diodes D1 and D2.
1307 F17
Figure 17. When Cell Is Reversed Current Flows through
Externally Controlled Burst Mode Operation This circuit overcomes the limitation of load-based transitioning between Burst Mode operation and constant switching mode by adding external control. If M1’s gate is grounded by an external open-drain signal, the converter functions normally in constant switching mode, delivering 3.3V. Output noise is low, however efficiency at loads less than 1mA is poor due to the 1mA supply current of the LT1307B. If M1’s gate is allowed to float, the low-battery detector now drives the V C pin. R3 and R2 set the output to 3V by allowing M1’s gate to go to VOUT until the output voltage drops below 3V. R1 adds hysteresis, resulting in low-frequency Burst Mode operation ripple voltage at the output. By pulling the V C pin below a V BE, quiescent current of the LT1307B drops to 60µA, resulting in accept- able efficiency at loads in the 100µA range. VIN VC SW FB LBO LBI LT1307B 10µH MBR0520 100k2 CELLS 1nF 1µF CERAMIC
1307 F19
GNDSHDN C2* 10µF CERAMIC 698k 499k 590k 10M +C1 100µF V OUT 3.3V 200mA 300k VOUT 2N7002 GROUND = HIGH POWER/LOW NOISE FLOAT = Burst Mode OPERATION SHUTDOWN 3.0V IN LOW-POWER Burst Mode OPERATION C1 = AVX TPSC107K006R0150 L1 = COILCRAFT DO1608-103 SUMIDA CD43-100 C2 OPTIONAL: REDUCES OUTPUT RIPPLE CAUSED BY C1'S ESR 0.2s/DIV 1307 F20 This photo details output voltage as the circuit is switched between the two modes. Load current is 100µA in Burst Mode operation; 10mA in constant switching mode. This photo shows transient response in constant switch- ing mode with a 10mA to 100mA stepped load. Output ripple at the switching frequency can be reduced consid- erably by adding a 10µF ceramic capacitor in parallel with the 100µF tantalum. 10mA 100µA IL VOUT 500mV/DIV 2ms/DIV 1307 F21 VOUT 100mV/DIV 100mA 10mA IL
Constant Current NiCd Battery Charger with Overvoltage Protection for Acknowledge-Back Pagers Step-Up/Step-Down Converter Low Cost 2-Cell to 5V VIN VC SW FB LT1307 10µH L1* MBR0520VIN 2.1V TO 4.8V 100k CELLS 608k 1.02M 3.3V 100mA 1000pF L1: COILTRONICS CTX10-1 OR 2 MURATA ERIE LQH3C100 EFFICIENCY ≈70% TO 73%
1307 TA03
1µF CERAMIC 2.2µF CERAMIC GNDSHDN SHDN 10µF CERAMIC VIN VC SW FB LBO LBI LT1307 10µH VIN 1.8V TO 1V • MBR0520L 47k 1µF L1: COILTRONICS CTX10-1
1307 TA04
–100mV
3 CELLS
2.2µF CERAMIC GNDSHDN 1 = CHARGE 0 = SHUTDOWN 323k 280k 6.7Ω OVERVOLTAGE PROTECTION 1µF CERAMIC 30k VIN SW FB LT1307 VIN 1.4V TO 3.3V 10µH 1N5818 SHDN 100k 323k 100mA 4700pF C1, C2: PANASONIC ECA0JFQ221 (DIGI-KEY P5604-ND) L1: SUMIDA CD43-100
1307 TA02
C1* 220µF 6.3V 0.1µF GND 0.1µF 220µF 6.3V
Single Cell Powered Constant Current LED Driver 1µF CERAMIC 10µH D1VIN
1307 TA05
5.1Ω100k ON/OFF VIN 22k 100k 1µF CERAMIC 2N3906 AA CELL 22µF L1: MURATA-ERIE LQH3C100K04 D1: 1N4148 C1, C2: CERAMIC D2, D3: LUMEX SSL-X100133SRC/4 "MEGA-BRITE" RED LED OR PANASONIC LNG992CF9 HIGH BRIGHTNESS BLUE LED VIN SW FB LT1307B LBI LBO SHDN VC GND Flash Memory VPP Supply VIN SW FB LT1307 10µH D1 47k 232k
1307 TA09
0.33µF CERAMIC 12V/30mA FROM 3V 12V/60mA FROM 5V ~250mV P-P RIPPLE0.33µF VC GND SHDNSHUTDOWN D1: MOTOROLA MBR0520L L1: MURATA-ERIE LQH3C100K04 1µF TANTALUM 2000pF 1N4148 VIN 3V TO 5.5V + 10pF High Voltage Flyback Converter VIN VIN 1V TO 5V SW 1N4148 LT1307 FBSHDNSHUTDOWN VC 100k 1000pF GND 240k OUT VOUT 0.1µF 1µF CERAMIC 0.01µF 0.1µF
1307 TA06
1:12 T1: DALE LPE3325-A190, n = 12 (605) 665-9301 MAXIMUM DUTY CYCLE: ≈80% FOR FLYBACK, VOUT = n(V IN – VSW) VOUT = 1.22V 1 +() DC 1 – DC FOR 1VIN, MAXIMUM VOUT = FOR 2VIN, MAXIMUM VOUT ≈ 85V. HIGHER VOLTAGES ACHIEVED WITH CAPACITIVE DOUBLER OR TRIPLER NO SNUBBER REQUIRED WITH SPECIFIED TRANSFORMER AND VIN < 5V 1 – 0.8
Single Cell CCFL Power Supply VIN VC 100Ω CCFL 1.5V
1307 TA08
0.1µF 0.1µF CELL 1.5V 1.5V 33µH LT1307B 1 = OPERATE 0 = SHUTDOWN C1: WIMA MKP-20 D1: MOTOROLA MBR0520L L1: SUMIDA CD54-330 T1: COILTRONICS CTX110611 Q1, Q2: ZETEX FZT-849 GND SHDN 10k DIMMING 0.1µF 1N4148 1N4148 1µF CERAMIC 10k 47pF 3kV Q1 Q2 Dimensions in inches (millimeters) unless otherwise noted.PACKAGE DESCRIPTIONU 8-Lead Plastic MSOP (LTC DWG # 05-08-1660) MSOP08 0596 * DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE 12 3 4 0.192 – 0.004 (4.88 – 0.10) 8 7 6 5 0.118 – 0.004* (3.00 – 0.10) 0.118 – 0.004** (3.00 – 0.10) 0.021 – 0.004 (0.53 – 0.01) 0° – 6° TYP SEATING PLANE 0.007 (0.18) 0.040 – 0.006 (1.02 – 0.15) 0.012 (0.30) 0.006 – 0.004 (0.15 – 0.10) 0.025 (0.65) TYP
Dimensions in inches (millimeters) unless otherwise noted.PACKAGE DESCRIPTIONU 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 1 2 3 4 0.150 – 0.157** (3.810 – 3.988) 8 7 6 5 0.189 – 0.197* (4.801 – 5.004) 0.228 – 0.244 (5.791 – 6.197) 0.016 – 0.050 0.406 – 1.270 0.010 – 0.020 0°– 8° TYP 0.008 – 0.010 (0.203 – 0.254) SO8 0695 0.053 – 0.069 (1.346 – 1.752) 0.014 – 0.019 (0.355 – 0.483) 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSCDIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) N8 0695 0.005 (0.127) MIN 0.100 – 0.010 (2.540 – 0.254) 0.065 (1.651) TYP 0.045 – 0.065 (1.143 – 1.651) 0.130 – 0.005 (3.302 – 0.127) 0.015 (0.380) MIN 0.018 – 0.003 (0.457 – 0.076) 0.125 (3.175) MIN 12 3 4 87 6 5 0.255 – 0.015* (6.477 – 0.381) 0.400* (10.160) MAX 0.009 – 0.015 (0.229 – 0.381) 0.300 – 0.325 (7.620 – 8.255) 0.325 +0.025 –0.015 +0.635 –0.3818.255() *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
LINEAR TECHNOLOGY CORPORATION 1 995 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 l FAX: (408) 434-0507 l TELEX: 499-3977 TYPICAL APPLICATIONU LCD Bias Generator LT/GP 1196 7K • PRINTED IN THE USA PART NUMBER DESCRIPTION COMMENTS LTC 1163 Triple High Side Driver for 2-Cell Inputs 1.8V Minimum Input, Drives N-Channel MOSFETs LTC1174 Micropower Step-Down DC/DC Converter 94% Efficiency, 130 µA IQ, 9V to 5V at 300mA LT1302 High Output Current Micropower DC/DC Converter 5V/600mA from 2V, 2A Internal Switch, 200 µA IQ LT1304 2-Cell Micropower DC/DC Converter Low-Battery Detector Active in Shutdown LTC1440/1/2 Ultralow Power Single/Dual Comparators with Reference 2.8 µA IQ, Adjustable Hysteresis LTC1516 2-Cell to 5V Regulated Charge Pump 12 µA IQ, No Inductors, 5V at 50mA from 3V Input LT1521 Micropower Low Dropout Linear Regulator 500mV Dropout, 300mA Current, 12 µA IQ RELATED PARTS VIN VC SW FB LT1307 L1 D3 100k 1, 2 OR 3 CELLS 100k PWM IN 3.3V, 0% TO 100% 215k 3.3M VOUT 16V TO 24V 5mA FROM 1 CELL 15mA FROM 2 CELLS 35mA FROM 3 CELLS OUT 4700pF 10pF L1: 3.3µH (1 CELL) 4.7 µH (2 CELLS) 1 0 µH (3 CELLS) SUMIDA CD43 MURATA-ERIE LQH3C COILCRAFT D01608 C1: 1µF FOR +OUTPUT 0.01 µF FOR –OUTPUT D1 TO D3: MBR0530 OR 1N4148
1307 TA07
1µF 3.3µF 0.1µF GNDSHDN SHUTDOWN 1µF