LT1613 1.4MHz, Single Cell DC/DC Converter in 5-Lead SOT-23 U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The LT®1613 is the industry’s first 5-lead SOT-23 current mode DC/DC converter. Intended for small, low power applications, it operates from an input voltage as low as 1.1V and switches at 1.4MHz, allowing the use of tiny, low cost capacitors and inductors 2mm or less in height. Its small size and high switching frequency enables the complete DC/DC converter function to take up less than 0.2 square inches of PC board area. Multiple output power supplies can now use a separate regulator for each output voltage, replacing cumbersome quasi-regulated approaches using a single regulator and a custom transformer. Uses Tiny Capacitors and Inductor Internally Compensated Fixed Frequency 1.4MHz Operation Operates with VIN as Low as 1.1V 3V at 30mA from a Single Cell 5V at 200mA from 3.3V Input 15V at 60mA from Four Alkaline Cells High Output Voltage: Up to 34V Low Shutdown Current: <1µA Low VCESAT Switch: 300mV at 300mA Tiny 5-Lead SOT-23 Package U APPLICATIO S ■ ■ ■ ■ ■ ■ ■ ■ Digital Cameras Pagers Cordless Phones Battery Backup LCD Bias Medical Diagnostic Equipment Local 5V or 12V Supply External Modems PC Cards The LT1613 is available in the 5-lead SOT-23 package. , LTC and LT are registered trademarks of Linear Technology Corporation. U ■ A constant frequency, internally compensated current mode PWM architecture results in low, predictable output noise that is easy to filter. The high voltage switch on the LT1613 is rated at 36V, making the device ideal for boost converters up to 34V as well as for Single-Ended Primary Inductance Converter (SEPIC) and flyback designs. The device can generate 5V at up to 200mA from a 3.3V supply or 5V at 175mA from four alkaline cells in a SEPIC design. TYPICAL APPLICATIO L1 4.7µH Efficiency Curve D1 C1 15µF SHDN SW R1 37.4k LT1613 SHDN + 90 C2 22µF FB GND 95 R2 12.1k EFFICIENCY (%) + VIN 100 VOUT 5V 200mA VIN 3.3V VIN = 4.2V 85 80 VIN = 3.5V 75 VIN = 2.8V 70 65 L1: MURATA LQH3C4R7M24 OR SUMIDA CD43-4R7 C1: AVX TAJA156M010 C2: AVX TAJB226M006 D1: MBR0520 VIN = 1.5V 60 1613 TA01 Figure 1. 3.3V to 5V 200mA DC/DC Converter 55 50 0 50 100 150 200 250 300 350 400 LOAD CURRENT (mA) 1613 TA01a 1 LT1613 W U PACKAGE/ORDER INFORMATION U W W W (Note 1) VIN Voltage .............................................................. 10V SW Voltage ................................................– 0.4V to 36V FB Voltage ..................................................... VIN + 0.3V Current into FB Pin ............................................... ±1mA SHDN Voltage .......................................................... 10V Maximum Junction Temperature .......................... 125°C Operating Temperature Range Commercial ............................................. 0°C to 70°C Extended Commercial (Note 2) ........... – 40°C to 85°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U ABSOLUTE MAXIMUM RATINGS ORDER PART NUMBER LT1613CS5 TOP VIEW SW 1 5 VIN GND 2 4 SHDN FB 3 S5 PART MARKING S5 PACKAGE 5-LEAD PLASTIC SOT-23 LTED Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. Commercial grade 0°C to 70°C, VIN = 1.5V, VSHDN = VIN unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN Minimum Operating Voltage TYP MAX 0.9 1.1 V 10 V 1.255 V Maximum Operating Voltage Feedback Voltage ● FB Pin Bias Current 1.205 1.23 27 80 nA 3 4.5 mA VSHDN = 0V, VIN = 2V VSHDN = 0V, VIN = 5V 0.01 0.01 0.5 1.0 µA µA 1.5V ≤ VIN ≤ 10V 0.02 0.2 %/V 1.4 1.8 MHz ● Quiescent Current VSHDN = 1.5V Quiescent Current in Shutdown Reference Line Regulation Switching Frequency ● Maximum Duty Cycle ● Switch Current Limit (Note 3) Switch VCESAT ISW = 300mA Switch Leakage Current VSW = 5V SHDN Input Voltage High 1.0 82 86 % 550 800 mA 300 350 mV 0.01 1 µA 1 V SHDN Input Voltage Low SHDN Pin Bias Current VSHDN = 3V VSHDN = 0V Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 2 UNITS 25 0.01 0.3 V 50 0.1 µA µA Note 2: The LT1613C is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: Current limit guaranteed by design and/or correlation to static test. LT1613 U W TYPICAL PERFOR A CE CHARACTERISTICS Oscillator Frequency vs Temperature Switch VCESAT vs Switch Current 700 SWITCHING FREQUENCY (MHz) 1.75 500 400 300 200 100 50 TA = 25°C VIN = 5V SHDN PIN BIAS CURRENT (µA) TA = 25°C 600 1.50 VIN = 1.5V 1.25 1.00 0.75 0.50 40 30 20 10 0.25 0 –50 0 100 200 300 400 500 SWITCH CURRENT (mA) 600 700 0 –25 0 25 50 TEMPERATURE (°C) 75 1613 G01 100 0 1 2 3 4 SHDN PIN VOLTAGE (V) 1613 G02 Current Limit vs Duty Cycle 5 1613 G03 Feedback Pin Voltage 1000 1.25 900 FEEDBACK PIN VOLTAGE (V) 0 CURRENT LIMIT (mA) VCESAT (mV) SHDN Pin Current vs VSHDN 2.00 800 70°C 700 600 25°C 500 –40°C 400 1.24 VOLTAGE 1.23 1.22 1.21 300 200 10 20 30 40 50 60 DUTY CYCLE (%) 70 1.20 –50 80 1613 G04 –25 0 25 50 TEMPERATURE (°C) 75 100 1613 G05 Switching Waveforms, Circuit of Figure 1 VOUT 100mV/DIV AC COUPLED VSW 5V/DIV ISW 200mA/DIV ILOAD = 150mA 200ns/DIV 1613 G06 3 LT1613 U U U PIN FUNCTIONS SW (Pin 1): Switch Pin. Connect inductor/diode here. Minimize trace area at this pin to keep EMI down. SHDN (Pin 4): Shutdown Pin. Tie to 1V or more to enable device. Ground to shut down. GND (Pin 2): Ground. Tie directly to local ground plane. VIN (Pin 5): Input Supply Pin. Must be locally bypassed. FB (Pin 3): Feedback Pin. Reference voltage is 1.23V. Connect resistive divider tap here. Minimize trace area at FB. Set VOUT according to VOUT = 1.23V(1 + R1/R2). W BLOCK DIAGRAM VIN 5 VIN R5 40k R6 40k VOUT 1 SW + FB FB Q1 3 R2 (EXTERNAL) – A1 gm R1 (EXTERNAL) – Q2 x10 RC Σ RAMP GENERATOR + COMPARATOR A2 R FF S DRIVER Q3 Q + CC R3 30k R4 140k 0.15Ω – 1.4MHz OSCILLATOR SHDN 4 SHUTDOWN 2 GND 1613 • BD U OPERATIO The LT1613 is a current mode, internally compensated, fixed frequency step-up switching regulator. Operation can be best understood by referring to the Block Diagram. Q1 and Q2 form a bandgap reference core whose loop is closed around the output of the regulator. The voltage drop across R5 and R6 is low enough such that Q1 and Q2 do not saturate, even when VIN is 1V. When there is no load, FB rises slightly above 1.23V, causing VC (the error amplifier’s output) to decrease. Comparator A2’s output stays high, keeping switch Q3 in the off state. As increased output loading causes the FB voltage to decrease, A1’s output increases. Switch current is regulated directly on a cycle-by-cycle basis by the VC node. The flip flop is set at the beginning of each switch cycle, turning on the switch. When the summation of a signal representing switch current and a ramp generator (introduced to avoid 4 subharmonic oscillations at duty factors greater than 50%) exceeds the VC signal, comparator A2 changes state, resetting the flip flop and turning off the switch. More power is delivered to the output as switch current is increased. The output voltage, attenuated by external resistor divider R1 and R2, appears at the FB pin, closing the overall loop. Frequency compensation is provided internally by RC and CC. Transient response can be optimized by the addition of a phase lead capacitor CPL in parallel with R1 in applications where large value or low ESR output capacitors are used. As the load current is decreased, the switch turns on for a shorter period each cycle. If the load current is further decreased, the converter will skip cycles to maintain output voltage regulation. LT1613 U OPERATIO LAYOUT The LT1613 switches current at high speed, mandating careful attention to layout for proper performance. You will not get advertised performance with careless layouts. Figure 2 shows recommended component placement for a boost (step-up) converter. Follow this closely in your PCB layout. Note the direct path of the switching loops. Input capacitor C1 must be placed close (< 5mm) to the IC package. As little as 10mm of wire or PC trace from CIN to VIN will cause problems such as inability to regulate or oscillation. The ground terminal of output capacitor C2 should tie close to Pin 2 of the LT1613. Doing this reduces dI/dt in the ground copper which keeps high frequency spikes to a minimum. The DC/DC converter ground should tie to the PC board ground plane at one place only, to avoid introducing dI/dt in the ground plane. A SEPIC (single-ended primary inductance converter) schematic is shown in Figure 3. This converter topology produces a regulated output voltage that spans (i.e., can be higher or lower than) the output. Recommended component placement for a SEPIC is shown in Figure 4. C3 1µF L1A 22µH VIN 4V TO 7V + C1 15µF VIN L1B 22µH SW LT1613 SHDN D1 R1 100k SHDN FB GND + R2 32.4k C1, C2: AVX TAJA156M016 C3: TAIYO YUDEN JMK325BJ226MM D1: MOTOROLA MBR0520 L1, L2: MURATA LQH3C220 VOUT 5V/150mA C2 15µF 1613 F03 Figure 3. Single-Ended Primary Inductance Converter (SEPIC) Generates 5V from An Input Voltage Above or Below 5V L1B L1A + C1 VOUT VIN D1 C3 + 1 C2 5 2 3 4 SHUTDOWN VIAS TO GROUND PLANE R2 GROUND + L1 VOUT VIN Figure 4. Recommended Component Placement for SEPIC D1 + 1 C2 R1 1613 F04 C1 5 COMPONENT SELECTION 2 3 4 SHUTDOWN VIAS TO GROUND PLANE R2 GROUND R1 1613 F02 Figure 2. Recommended Component Placement for Boost Converter. Note Direct High Current Paths Using Wide PCB Traces. Minimize Area at Pin 3 (FB). Use Vias to Tie Local Ground Into System Ground Plane. Use Vias at Location Shown to Avoid Introducing Switching Currents Into Ground Plane Inductors Inductors used with the LT1613 should have a saturation current rating (where inductance is approximately 70% of zero current inductance) of approximately 0.5A or greater. DCR of the inductors should be 0.5Ω or less. For boost converters, inductance should be 4.7µH for input voltage less than 3.3V and 10µH for inputs above 3.3V. When using the device as a SEPIC, either a coupled inductor or two separate inductors can be used. If using separate inductors, 22µH units are recommended for input voltage above 3.3V. Coupled inductors have a beneficial mutual inductance, so a 10µH coupled inductor results in the same ripple current as two 20µH uncoupled units. 5 LT1613 U OPERATIO Table 1 lists several inductors that will work with the LT1613, although this is not an exhaustive list. There are many magnetics vendors whose components are suitable for use. Diodes A Schottky diode is recommended for use with the LT1613. The Motorola MBR0520 is a very good choice. Where the input to output voltage differential exceeds 20V, use the MBR0530 (a 30V diode). If cost is more important than efficiency, the 1N4148 can be used, but only at low current loads. lower ESR will result in lower output ripple. Ceramic capacitors can be used with the LT1613 provided loop stability is considered. A tantalum capacitor has some ESR and this causes an “ESR zero” in the regulator loop. This zero is beneficial to loop stability. The internally compensated LT1613 does not have an accessible compensation node, but other circuit techniques can be employed to counteract the loss of the ESR zero, as detailed in the next section. Some capacitor types appropriate for use with the LT1613 are listed in Table 2. Capacitors OPERATION WITH CERAMIC CAPACITORS The input bypass capacitor must be placed physically close to the input pin. ESR is not critical and in most cases an inexpensive tantalum is appropriate. Because the LT1613 is internally compensated, loop stability must be carefully considered when choosing an output capacitor. Small, low cost tantalum capacitors have some ESR, which aids stability. However, ceramic capacitors are becoming more popular, having attractive characteristics such as near-zero ESR, small size and reasonable cost. Simply replacing a tantalum output capacitor with a ceramic unit will decrease the phase margin, in some cases to unacceptable levels. With the addition of a phase lead capacitor (CPL) and isolating resistor (R3), the LT1613 can be used successfully with ceramic output capacitors as described in the following figures. The choice of output capacitor is far more important. The quality of this capacitor is the greatest determinant of the output voltage ripple. The output capacitor must have enough capacitance to satisfy the load under transient conditions and it must shunt the switched component of current coming through the diode. Output voltage ripple results when this switched current passes through the finite output impedance of the output capacitor. The capacitor should have low impedance at the 1.4MHz switching frequency of the LT1613. At this frequency, the impedance is usually dominated by the capacitor’s equivalent series resistance (ESR). Choosing a capacitor with A boost converter, stepping up 2.5V to 5V, is shown in Figure 5. Tantalum capacitors are used for the input and output (the input capacitor is not critical and has little Table 1. Inductor Vendors VENDOR PHONE URL PART COMMENT Sumida (847) 956-0666 www.sumida.com CLS62-22022 CD43-220 22µH Coupled 22µH Murata (404) 436-1300 www.murata.com LQH3C-220 LQH3C-100 LQH3C-4R7 22µH, 2mm Height 10µH 4.7µH Coiltronics (407) 241-7876 www.coiltronics.com CTX20-1 20µH Coupled, Low DCR Table 2. Capacitor Vendors 6 VENDOR PHONE URL PART COMMENT Taiyo Yuden (408) 573-4150 www.t-yuden.com Ceramic Caps X5R Dielectric AVX (803) 448-9411 www.avxcorp.com Ceramic Caps Tantalum Caps Murata (404) 436-1300 www.murata.com Ceramic Caps LT1613 U OPERATIO effect on loop stability, as long as minimum capacitance requirements are met). The transient response to a load step of 50mA to 100mA is pictured in Figure 6. Note the “double trace,” due to the ESR of C2. The loop is stable and settles in less than 100µs. In Figure 7, C2 is replaced by a 10µF ceramic unit. Phase margin decreases drastically, L1 10µH VIN 2.5V + C1 15µF VIN D1 VOUT 5V SW R1 37.4k LT1613 SHDN SHDN + C2 22µF FB GND R2 12.1k C1: AVX TAJA156M010R C2: AVX TAJA226M006R D1: MOTOROLA MBR0520 L1: MURATA LQH3C100 1613 F05 Figure 5. 2.5V to 5V Boost Converter with “A” Case Size Tantalum Input and Output Capacitors resulting in a severely underdamped response. By adding R3 and CPL as detailed in Figure 8’s schematic, phase margin is restored, and transient response to the same load step is pictured in Figure 9. R3 isolates the device FB pin from fast edges on the VOUT node due to parasitic PC trace inductance. Figure 10’s circuit details a 5V to 12V boost converter, delivering up to 130mA. The transient response to a load step of 10mA to 130mA, without CPL, is pictured in Figure␣ 11. Although the ringing is less than that of the previous example, the response is still underdamped and can be improved. After adding R3 and CPL, the improved transient response is detailed in Figure 12. Figure 13 shows a SEPIC design, converting a 3V to 10V input to a 5V output. The transient response to a load step of 20mA to 120mA, without CPL and R3, is pictured in Figure␣ 14. After adding these two components, the improved response is shown in Figure 15. L1 10µH VIN 2.5V + VOUT 20mV/DIV AC COUPLED C1 15µF VIN LT1613 SHUTDOWN 100mA 50mA 200µs/DIV 1613 F06 Figure 6. 2.5V to 5V Boost Converter Transient Response with 22µF Tantalum Output Capacitor. Apparent Double Trace on VOUT Is Due to Switching Frequency Ripple Current Across Capacitor ESR CPL 330pF SHDN R3 10k R1 37.4k C2 10µF FB R2 12.1k C1: AVX TAJA156M010R C2: TAIYO YUDEN LMK325BJ106MN D1: MBR0520 L1: MURATA LQH3C100K04 1613 F08 Figure 8. 2.5V to 5V Boost Converter with Ceramic Output Capacitor. CPL Added to Increase Phase Margin, R3 Isolates FB Pin from Fast Edges VOUT 20mV/DIV AC COUPLED VOUT 20mV/DIV AC COUPLED LOAD CURRENT VOUT 5V SW GND LOAD CURRENT D1 100mA 50mA LOAD CURRENT 200µs/DIV Figure 7. 2.5V to 5V Boost Converter with 10µF Ceramic Output Capacitor, No CPL 1613 F07 100mA 50mA 200µs/DIV 1613 F09 Figure 9. 2.5V to 5V Boost Converter with 10µF Ceramic Output Capacitor, 330pF CPL and 10k in Series with FB Pin 7 LT1613 U OPERATIO L1 10µH VIN 5V + VIN C1 22µF D1 SHUTDOWN CPL 200pF SW LT1613 VOUT 12V 130mA R3 10k R1 107k GND SW SHUTDOWN GND 1613 F10 L2 22µH CPL 330pF R3 10k FB SHDN R2 12.3k VOUT 100mV/DIV AC COUPLED R2 12.1k R1 37.4k C1: AVX TAJB226M010 C2: TAIYO YUDEN LMK325BJ106MN C3: TAIYO YUDEN LMK212BJ105MG D1: MOTOROLA MBR0520 L1, L2: MURATA LQH3C220 D1 VOUT 5V C2 10µF 1613 F13 Figure 13. 5V Output SEPIC with Ceramic Output Capacitor. CPL Adds Phase Margin VOUT 50mV/DIV AC COUPLED 130mA 10mA LOAD CURRENT 200µs/DIV 120mA 20mA 200µs/DIV 1613 F11 Figure 11. 5V to 12V Boost Converter with 4.7µF Ceramic Output Capacitor 1613 F14 Figure 14. 5V Output SEPIC with 10µF Ceramic Output Capacitor. No CPL. VIN = 4V VOUT 100mV/DIV AC COUPLED VOUT 50mV/DIV AC COUPLED 130mA 10mA LOAD CURRENT 200µs/DIV Figure 12. 5V to 12V Boost Converter with 4.7µF Ceramic Output Capacitor and 200pF Phase-Lead Capacitor CPL and 10k in Series with FB Pin 8 VIN LT1613 Figure 10. 5V to 12V Boost Converter with 4.7µF Ceramic Output Capacitor, CPL Added to Increase Phase Margin LOAD CURRENT C1 22µF C2 4.7µF C1: AVX TAJB226M010 C2: TAIYO YUDEN EMK325BJ475MN D1: MOTOROLA MBR0520 L1: MURATA LQH3C100 LOAD CURRENT VIN 3V TO 10V + FB SHDN C3 1µF L1 22µH 1613 F12 120mA 20mA 200µs/DIV Figure 15. 5V Output SEPIC with 10µF Ceramic Output Capacitor, 330pF CPL and 10k in Series with FB Pin 1613 F15 LT1613 U OPERATIO START-UP/SOFT-START When the LT1613 SHDN pin voltage goes high, the device rapidly increases the switch current until internal current limit is reached. Input current stays at this level until the output capacitor is charged to final output voltage. Switch current can exceed 1A. Figure 16’s oscillograph details start-up waveforms of Figure 17’s SEPIC into a 50Ω load without any soft-start. The output voltage reaches final value in approximately 200µs, while input current reaches 400mA. Switch current in a SEPIC is 2x the input current, so the switch is conducting approximately 800mA peak. time required to reach final value increases to 1.7ms. In Figure 19, CS is increased to 33nF. Input current does not exceed the steady-state current the device uses to supply power to the 50Ω load. Start-up time increases to 4.3ms. CS can be increased further for an even slower ramp, if desired. VOUT 2V/DIV IIN 200mA/DIV Soft-start reduces the inrush current by taking more time to reach final output voltage. A soft-start circuit consisting of Q1, RS1, RS2 and CS1 as shown in Figure 17 can be used to limit inrush current to a lower value. Figure 18 pictures VOUT and input current with RS2 of 33kΩ and CS of 10nF. Input current is limited to a peak value of 200mA as the VS 5V/DIV 500µs/DIV Figure 18. Soft-Start Components in Figure 17’s SEPIC Reduces Inrush Current. CSS = 10nF, RLOAD = 50Ω VOUT 2V/DIV VOUT 2V/DIV IIN 200mA/DIV IIN 200mA/DIV VSHDN 5V/DIV VS 5V/DIV 200µs/DIV 1ms/DIV 1613 F16 Figure 16. Start-Up Waveforms of Figure 17’s SEPIC Into 50Ω Load C1 22µF SOFT-START COMPONENTS VS CS 10nF/ 33nF C3 1µF + VIN SW LT1613 RS1 33k RS2 33k L2 22µH CPL 330pF D1 R3 10k VOUT 5V FB SHDN Q1 2N3904 1613 F18 Figure 19. Increasing CS to 33nF Further Reduces Inrush Current. RLOAD = 50Ω L1 22µH VIN 4V 1613 F18 GND R2 12.1k R1 37.4k RLOAD C2 10µF 1613 F17 C1: AVX TAJB226M006 C2: TAIYO YUDEN LMK325BJ106MN C3: TAIYO YUDEN LMK212BJ105MG D1: MOTOROLA MBR0520 L1, L2: MURATA LQH3C220 Figure 17. 5V SEPIC with Soft-Start Components 9 LT1613 U TYPICAL APPLICATIO S 4-Cell to 5V SEPIC DC/DC Converter + C3 1µF L1 22µH 6.5V TO 4V VIN C1 15µF SHDN VOUT 5V 175mA SW LT1613 4-CELL D1 374k L2 22µH + FB SHDN GND C2 22µF 121k L1, L2: MURATA LQH3C220 C3: AVX 1206YG105 CERAMIC D1: MBR0520 1613 • TA03 4-Cell to 15V/30mA DC/DC Converter L1 10µH + C1 22µF VIN VOUT 15V/30mA SW 1nF LT1613 10k SHDN SHDN Efficiency D1 85 R1 137k 1% + 75 C2 4.7µF FB GND VIN = 6.5V 80 EFFICIENCY (%) VIN 3.5V TO 8V R2 12.1k VIN = 3.6V VIN = 5V 70 65 60 C1: AVX TAJB226M016 C2: AVX TAJA475M025 D1: MOTOROLA MBR0520 L1: MURATA LQH3C100 55 1613 TA04 50 0 10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA) 1613 TA04a 3.3V to 8V/70mA, – 8V/5mA, 24V/5mA TFT LCD Bias Supply Uses All Ceramic Capacitors D2 VOFF – 8V 5mA 1µF D3 0.22µF 0.22µF 0.22µF: TAIYO YUDEN EMK212BJ224MG 1µF: TAIYO YUDEN LMK212BJ105MG 4.7µF: TAIYO YUDEN LMK316BJ475ML D1: MOTOROLA MBRO520 D2, D3, D4: BAT54S L1: SUMIDA CDRH5D185R4 L1 5.4µH VIN 3.3V VIN C1 4.7µF 1µF D4 0.22µF 1µF D1 AVDD 8V 70mA SW 274k LT1613 SHDN FB GND C2 4.7µF 48.7k 1613 TA05 10 VON 24V 5mA LT1613 U TYPICAL APPLICATIO S 4-Cell to 5V/50mA, 12V/10mA, 15V/10mA Digital Camera Power Supply D3 C1: TAIYO YUDEN JMK316BJ106ML C2, C3, C4: TAIYO YUDEN EMK212BJ105MG C5: TAIYO YUDEN JMK212BJ475MG D1: MOTOROLA MBR0520 D2, D3: BAT54 T1: COILCRAFT CCI8245A (847) 639-6400 15V/10mA 2 C3 1µF D2 12V/10mA 5 VIN 7V TO 3.6V C4 1µF D1 T1 6 5V/50mA 3 C5 4.7µF 1 4 SW C2 1µF C1 10µF VIN 270pF LT1613 102k SHDN SHUTDOWN FB GND 33.2k 1613 TA07 4-Cell to 5V/50mA, 15V/10mA, – 7.5V/10mA Digital Camera Power Supply D2 C1: TAIYO YUDEN JMK316BJ106ML C2, C3, C4: TAIYO YUDEN EMK212BJ105MG C5: TAIYO YUDEN JMK212BJ475MG D1: MOTOROLA MBR0520 D2, D3: BAT54 T1: COILCRAFT CCI8244A (847) 639-6400 VIN 7V TO 3.6V 15V/10mA 2 C3 1µF D1 5V/50mA 5 C5 4.7µF T1 6 3 1 4 SW C2 1µF C4 1µF D3 –7.5V/10mA C1 10µF VIN 270pF LT1613 102k SHUTDOWN SHDN FB GND 33.2k 1613 TA08 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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 11 LT1613 U TYPICAL APPLICATIONS Li-Ion to 16V/20mA Step-Up DC/DC Converter L1 2.2µH VIN 2.7V TO 4.5V + C1 4.7µF VIN D1 SW LT1613 SHDN 165k 1% FB SHDN GND 13.7k 1% C1: AVX TAJA4R7M010 C2: TAIYO YUDEN LMK212BJ105MG D1: BAT54S DUAL DIODE L1: MURATA LQH3C2R2 U PACKAGE DESCRIPTION 16V 20mA C2 1µF X5R CERAMIC 1613 TA06 Dimensions in inches (millimeters) unless otherwise noted. S5 Package 5-Lead Plastic SOT-23 (LTC DWG # 05-08-1633) 2.60 – 3.00 (0.102 – 0.118) 1.50 – 1.75 (0.059 – 0.069) 0.35 – 0.55 (0.014 – 0.022) 0.00 – 0.15 (0.00 – 0.006) 0.09 – 0.20 (0.004 – 0.008) (NOTE 2) 0.90 – 1.45 (0.035 – 0.057) 0.35 – 0.50 0.90 – 1.30 (0.014 – 0.020) (0.035 – 0.051) FIVE PLACES (NOTE 2) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DIMENSIONS ARE INCLUSIVE OF PLATING 3. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 4. MOLD FLASH SHALL NOT EXCEED 0.254mm 5. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ) 2.80 – 3.00 (0.110 – 0.118) (NOTE 3) 0.95 (0.037) REF 1.90 (0.074) REF S5 SOT-23 0599 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1307 Single Cell Micropower DC/DC 3.3V/75mA From 1V; 600kHz Fixed Frequency LT1317 2-Cell Micropower DC/DC 3.3V/200mA From Two Cells; 600kHz Fixed Frequency LTC1474 Low Quiescent Current, High Efficiency Step-Down Converter 94% Efficiency, 10µA IQ, 9V to 5V at 250µA LT1521 300mA Low Dropout Regulator with Micropower Quiescent Current and Shutdown 500mV Dropout, 300mA Output Current, 12µA IQ LTC1517-5 Micropower, Regulated Charge Pump 3-Cells to 5V at 20mA, SOT-23 Package, 6µA IQ LT1610 1.7MHz Single Cell Micropower DC/DC Converter 30µA IQ, MSOP Package, Internal Compensation LT1611 Inverting 1.4MHz Switching Regulator 5V to –5V at 150mA, Low Output Noise LT1615/LT1615-1 Micropower DC/DC Converter in 5-Lead SOT-23 20V at 12mA from 2.5V Input, Tiny SOT-23 Package 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com sn1613 1613fs LT/TP 1299 4K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1997