LTC3525-3/ LTC3525-3.3/LTC3525-5 400mA Micropower Synchronous Step-Up DC/DC Converter with Output Disconnect U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The LTC®3525-3/LTC3525-3.3/LTC3525-5 are high efficiency synchronous step-up DC/DC converters with output disconnect that can start up with an input as low as 1V. They offer a compact, high efficiency alternative to charge pumps in single cell or dual cell alkaline or Li-ion applications. Only three small external components are required. The LTC3525 is offered in fixed output voltages of 3V, 3.3V or 5V. Up to 95% Efficiency Output Disconnect and Inrush Current Limit Fixed Output Voltages of 3V, 3.3V or 5V Delivers 65mA at 3V from a 1V Input Delivers 60mA at 3.3V from a 1V Input, or 140mA at 3.3V from a 1.8V Input Delivers 175mA at 5V from a 3V Input Burst Mode® Operation: IQ = 7µA Only Three External Components VIN > VOUT Operation <1µA Shutdown Current Antiringing Control Short-Circuit and Overtemperature Protection Very Low Profile of 1mm Tiny 6-Pin SC70 Package The device includes a 0.5Ω N-channel MOSFET switch and a 0.8Ω P-channel synchronous rectifier. Peak switch current ranges from 150mA to 400mA, depending on load, providing enhanced efficiency. Quiescent current is an ultralow 7µA, maximizing battery life in portable applications. Other features include <1µA shutdown current, antiringing control and thermal shutdown. The LTC3525 is available in a tiny 6-pin SC70 package. U APPLICATIO S ■ ■ ■ ■ , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Patents Pending MP3 Players Portable Instruments Glucose Meters Digital Cameras U TYPICAL APPLICATIO LTC3525-3.3 Efficiency and Power Loss vs Load Current L1* 10µH 100 100 90 SW OFF ON SHDN VOUT 3.3V 60mA GND VOUT GND 10µF 1µF EFFICIENCY (%) VIN 1V to 1.6V EFFICIENCY 70 1 60 POWER LOSS 50 0.1 40 3525 TA01 *MURATA LQH32CN100K53 VIN = 3V VIN = 2.4V VIN = 1.2V 30 20 0.01 POWER LOSS (mW) VIN 10 80 LTC3525-3.3 0.1 1 10 LOAD (mA) 100 0.01 1000 LT3525 • TA02 3525fa 1 LTC3525-3/ LTC3525-3.3/LTC3525-5 U W W W ABSOLUTE AXI U RATI GS U W U PACKAGE/ORDER I FOR ATIO (Note 1) VIN, VOUT Voltage ........................................ – 0.3V to 6V SW Voltage ................................................. – 0.3V to 6V SW Voltage < 100ns ................................... –0.3V to 7V ⎯S⎯H⎯D⎯N Voltage ............................................. –0.3V to 6V Operating Temperature Range (Notes 2, 5).......................................... –40°C to 85°C Storage Temperature Range................... –65°C to 125°C Lead Temperature (Soldering, 10 sec) .................. 300°C TOP VIEW SHDN 1 6 SW GND 2 5 GND VIN 3 4 VOUT SC6 PACKAGE 6-LEAD PLASTIC SC70 TJMAX = 125°C θJA = 256°C/W IN FREE AIR, θJA = 150°C/W ON BOARD OVER GROUND PLANE ORDER PART NUMBER SC6 PART MARKING LTC3525ESC6-3 LTC3525ESC6-3.3 LTC3525ESC6-5 LCDR LBTG LBWT Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS (LTC3525-3) The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 1.2V, V⎯S⎯H⎯D⎯N = 1.2V, VOUT = 3V unless otherwise noted. PARAMETER CONDITIONS MIN Input Start-Up Voltage ● 2.91 TYP MAX 0.85 1 UNITS V 3.00 3.09 V Output Voltage (Note 6) Quiescent Current, VOUT ⎯S⎯H⎯D⎯N = VIN (Note 4) 7 15 µA Quiescent Current, VIN ⎯S⎯H⎯D⎯N = VIN (Note 4) 0.5 3 µA Quiescent Current, VIN - Shutdown 0.1 1 µA NMOS Switch Leakage ⎯ ⎯H⎯D⎯N = 0V, VOUT = 0V S Not Including Switch Leakage VIN = VOUT = VSW = 5V, ⎯S⎯H⎯D⎯N = 0V 0.1 1 µA PMOS Switch Leakage VIN = VSW = 5V, VOUT = 0V, ⎯S⎯H⎯D⎯N = 0V 0.1 3 µA NMOS Switch On Resistance (Note 3) 0.6 Ω PMOS Switch On Resistance (Note 3) 0.9 Ω 0.45 A Peak Current Limit 0.4 ⎯S⎯H⎯D⎯N Threshold ⎯S⎯H⎯D⎯N Input Current 0.4 V⎯S⎯H⎯D⎯N = VIN or VOUT 0.6 1 V 0.01 1 µA 3525fa 2 LTC3525-3/ LTC3525-3.3/LTC3525-5 ELECTRICAL CHARACTERISTICS (LTC3525-3.3) The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 1.2V, V⎯S⎯H⎯D⎯N = 1.2V, VOUT = 3.3V unless otherwise noted. PARAMETER CONDITIONS MIN Input Start-Up Voltage ● 3.20 TYP MAX 0.85 1 UNITS V Output Voltage (Note 6) 3.30 3.40 V Quiescent Current, VOUT ⎯S⎯H⎯D⎯N = VIN (Note 4) 7 15 µA Quiescent Current, VIN ⎯S⎯H⎯D⎯N = VIN (Note 4) 0.5 3 µA Quiescent Current, VIN - Shutdown 0.1 1 µA NMOS Switch Leakage ⎯S⎯H⎯D⎯N = 0V, VOUT = 0V Not Including Switch Leakage ⎯ H ⎯ D ⎯ N ⎯ = 0V VIN = VOUT = VSW = 5V, S 0.1 1 µA PMOS Switch Leakage VIN = VSW = 5V, VOUT = 0V, ⎯S⎯H⎯D⎯N = 0V 0.1 3 µA NMOS Switch On Resistance (Note 3) 0.5 Ω PMOS Switch On Resistance (Note 3) 0.8 Ω Peak Current Limit 0.4 0.45 A ⎯S⎯H⎯D⎯N Threshold 0.4 0.6 1 V 0.01 1 µA ⎯S⎯H⎯D⎯N Input Current V⎯S⎯H⎯D⎯N = VIN or VOUT (LTC3525-5) The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 2.4V, V⎯S⎯H⎯D⎯N = 2.4V, VOUT = 5V unless otherwise noted. PARAMETER CONDITIONS MIN TYP 0.85 1 V 4.85 5.00 5.15 V Input Start-Up Voltage ● MAX UNITS Output Voltage (Note 6) Quiescent Current, VOUT ⎯S⎯H⎯D⎯N = VIN (Note 4) 8 18 µA Quiescent Current, VIN ⎯S⎯H⎯D⎯N = VIN (Note 4) 1.5 5 µA Quiescent Current, VIN - Shutdown 0.1 1 µA NMOS Switch Leakage ⎯S⎯H⎯D⎯N = 0V, VOUT = 0V Not Including Switch Leakage ⎯ H ⎯ D ⎯ N ⎯ = 0V VIN = VOUT = VSW = 5V, S 0.1 1 µA PMOS Switch Leakage VIN = VSW = 5V, VOUT = 0V, ⎯S⎯H⎯D⎯N = 0V 0.1 3 µA NMOS Switch On Resistance (Note 3) 0.4 Ω PMOS Switch On Resistance (Note 3) 0.7 Ω A Peak Current Limit 0.4 0.5 ⎯S⎯H⎯D⎯N Threshold 0.4 0.6 1 V 0.01 1 µA ⎯S⎯H⎯D⎯N Input Current V⎯S⎯H⎯D⎯N = VIN or VOUT Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTC3525E is guaranteed to meet performance specifications from 0°C to 85°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: Specification is guaranteed by design and not 100% tested in production. Note 4: Current Measurements are performed when the LTC3525 is not switching. Note 5: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125°C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. Note 6: Consult LTC Marketing for other output voltage options. 3525fa 3 LTC3525-3/ LTC3525-3.3/LTC3525-5 U W TYPICAL PERFOR A CE CHARACTERISTICS TA = 25°C unless otherwise noted. Maximum Output Current vs VIN (for VOUT to Drop 2.5%) 300 Maximum Startup Load vs VIN (Resistive Load) LTC3525-3.3 45 LTC3525-5 250 40 200 200 35 LTC3525-5 150 150 IIN (µA) LTC3525-3 LOAD (mA) IOUT (mA) No-Load Input Current vs VIN 50 250 LTC3525-3.3 100 100 30 25 LTC3525-5 20 15 LTC3525-3 10 50 50 LTC3525-3.3 5 0 0.5 1.5 2.0 2.5 3.0 VIN (V) 4.0 3.5 4.5 0.5 1.5 2.0 VIN (V) 1.0 100 100 100 10 0.1 40 30 1 10 LOAD (mA) 0.1 0.01 1000 100 EFFICIENCY (%) 1 60 POWER LOSS 50 0.1 40 VIN = 3V VIN = 2.4V VIN = 1.2V 30 VIN = 2.4V VIN = 1.2V 20 0.01 EFFICIENCY 70 20 0.01 1 10 LOAD (mA) 0.1 3525 G24 POWER LOSS 40 20 10 0 0.01 COUT = 22µF 0 COUT = 10µF –1.0 LTC3525-5 Load Regulation 2.5 1.5 1.0 0.5 COUT = 22µF 0 –0.5 COUT = 10µF –1.0 1.0 0.5 –1.0 –1.5 –2.0 –2.0 20 30 40 50 LOAD (mA) 60 70 80 3525 G06 –2.5 0 20 40 60 80 100 120 140 160 180 LOAD (mA) 3525 G07 COUT = 10µF –0.5 –2.0 10 COUT = 22µF 0 –1.5 0 VIN = 1.2V 2.0 –1.5 –2.5 1 10 LOAD (mA) 0.1 VIN = 3.6V 0.1 VIN = 2.4V VIN = 1.2V 0.01 100 1000 3525 G05 CHANGE IN VOUT (%) CHANGE IN VOUT (%) 1.0 1 30 1.5 –0.5 10 50 VIN = 2.4V 2.0 1.5 0.5 EFFICIENCY 60 LTC3525-3.3 Load Regulation 2.5 VIN = 1.2V 2.0 70 3525 G04 LTC3525-3.3 Load Regulation 2.5 0.01 1000 100 100 POWER LOSS (mW) POWER LOSS 50 4.5 1000 80 10 POWER LOSS (mW) 1 60 4.0 90 80 POWER LOSS (mW) EFFICIENCY 3.5 100 90 70 2.5 3.0 VIN (V) LTC3525-5 Efficiency and Power Loss vs Load EFFICIENCY (%) 90 80 2.0 3525 G03 LTC3525-3.3 Efficiency and Power Loss vs Load 100 1.5 3525 G02 LTC3525-3 Efficiency and Power Loss vs Load EFFICIENCY (%) 3.0 2.5 3525 G01 CHANGE IN VOUT (%) 0 1.0 0 1.0 –2.5 0 10 20 30 40 LOAD (mA) 50 60 3525 G08 3525fa 4 LTC3525-3/ LTC3525-3.3/LTC3525-5 U W TYPICAL PERFOR A CE CHARACTERISTICS TA = 25°C unless otherwise noted. LTC3525-5 Load Regulation LTC3525-5 Load Regulation 2.5 2.5 VIN = 2.4V 2.0 LTC3525-5 0.5 COUT = 22µF 0 –0.5 –1.0 COUT = 10µF 1000 1.0 0.5 FREQUENCY (kHz) 1.0 COUT = 22µF 0 COUT = 10µF –0.5 –1.0 900 800 700 –1.5 500 –2.0 –2.0 400 –2.5 0 20 40 60 80 100 LOAD (mA) 120 140 0 50 100 LOAD (mA) 150 35 0.3 30 0.2 COUT = 10µF 15 0.1 0 –0.1 1 LOAD (mA) 10 4.0 4.5 80 60 40 20 –0.3 0.1 3.5 100 COUT = 22µF 5 2.5 3.0 VIN (V) 120 –0.2 10 2.0 Startup Delay Coming Out of Shutdown SWITCHING DELAY (µs) 0.4 CHANGE IN VOUT (%) 40 20 1.5 3525 G11 VOUT Variation vs Temperature (Normalized to 25°C) Light Load Burst Frequency vs Load 0 300 1.0 200 3525 G10 3525 G09 25 LTC3525-3.3 600 –1.5 –2.5 L = 10µH 1100 1.5 CHANGE IN VOUT (%) CHANGE IN VOUT (%) VIN = 3.6V 2.0 1.5 BURST FREQUENCY (kHz) Switching Frequency vs VIN 1200 –0.4 –40–30–20–10 0 10 20 30 40 50 60 70 80 TEMPERATURE (°C) 0 1.0 1.5 2.0 2.5 3.0 VIN (V) 3525 G13 3525 G12 LTC3525-3.3 Input Current and VOUT at Startup 3.5 4.0 4.5 3525 G14 LTC3525-3.3 Output Voltage Ripple VIN = 1.2V IOUT = 5mA IOUT = 40mA VOUT 1V/DIV 50mV/DIV IOUT = 80mA INPUT CURRENT 100mA/DIV 500µs/DIV 3525 G15 VIN = 1.2V COUT = 10µF 50µs/DIV 3525 G16 3525fa 5 LTC3525-3/ LTC3525-3.3/LTC3525-5 U W TYPICAL PERFOR A CE CHARACTERISTICS TA = 25°C unless otherwise noted. LTC3525-3.3 Output Voltage Ripple LTC3525-3.3 Output Voltage Ripple IOUT = 5mA IOUT = 5mA IOUT = 40mA 50mV/DIV IOUT = 100mA IOUT = 80mA VIN = 1.2V COUT = 22µF 50µs/DIV 3525 G17 VIN = 2.4V COUT = 22µF 3525 G18 50µs/DIV LTC3525-5 Output Voltage Ripple LTC3525-5 Output Voltage Ripple IOUT = 20mA IOUT = 5mA IOUT = 50mA 50mV/DIV IOUT = 150mA IOUT = 100mA 50mV/DIV IOUT = 200mA VIN = 2.4V COUT = 22µF 50µs/DIV 3525 G19 VIN = 3.6V COUT = 22µF LTC3525-3.3 50mA Load Step Response OUTPUT RIPPLE 50mV/DIV LOAD CURRENT 20mA/DIV LOAD CURRENT 50mA/DIV 500µs/DIV 3525 G20 50µs/DIV LTC3525-3.3 100mA Load Step Response OUTPUT RIPPLE 50mV/DIV VIN = 1.2V COUT = 22µF 50mV/DIV IOUT = 190mA LTC3525-5 100mA Load Step Response OUTPUT RIPPLE 50mV/DIV LOAD CURRENT 50mA/DIV 3525 G21 VIN = 2.4V COUT = 22µF 500µs/DIV 3525 G22 VIN = 3.6V COUT = 22µF 500µs/DIV 3525 G23 3525fa 6 LTC3525-3/ LTC3525-3.3/LTC3525-5 U U U PI FU CTIO S ⎯S⎯H⎯D⎯N (Pin 1): Logic Controlled Shutdown Input. Connect to a voltage >1V to enable the LTC3525. Connect to a voltage <0.4V to disable the LTC3525. VOUT (Pin 4): Output Voltage Sense and the Output of the Synchronous Rectifier. Connect the output filter capacitor from VOUT to GND, close to the IC. A minimum value of 10µF ceramic is recommended. Use 22µF for reduced output ripple. The output disconnect feature disconnects VOUT from VIN when ⎯S⎯H⎯D⎯N is <0.4V. GND (Pins 2, 5): Ground. VIN (Pin 3): Input Voltage. The LTC3525 is powered from VIN until VOUT exceeds VIN. Once VOUT is greater than (VIN + 0.2V typical), it is powered from VOUT. Place a ceramic bypass capacitor from VIN to GND. A minimum value of 1µF is recommended. SW (Pin 6): Switch Pin. Connect an inductor from this pin to VIN. An internal antiringing resistor is connected across SW and VIN after the inductor current has dropped to zero to minimize EMI. W BLOCK DIAGRA SW VIN 6 3 VOUT VSEL VBEST WELL SWITCH VB 4 VOUT SHUTDOWN SHUTDOWN GATE DRIVERS AND ANTI-CROSS CONDUCTION + – OFFSET VREF UVLO ADJUST VREF IPK UVLO – + + IPK COMPARATOR STARTUP – ADJUST LOGIC IVAL + SHUTDOWN IVALLEY COMPARATOR TSD – WAKE + THERMAL SHUTDOWN OFFSET – SHDN 1 INTEGRATOR FB VREF SLEEP COMPARATOR ADJUST 5 2 GND GND 3525 BD 3525fa 7 LTC3525-3/ LTC3525-3.3/LTC3525-5 U OPERATIO The LTC3525 is a high performance Burst Mode operation only, synchronous boost converter requiring only three small external components. Its simplicity and small size make it a high efficiency alternative to charge pump designs. It is designed to start up from a single alkaline or nickel cell, with input voltages as low as 1V, or from two or three cells (or a Li-ion battery), with voltages as high as 4.5V. Once started, VIN can be as low as 0.5V (depending on load current) and maintain regulation. The output voltage is preset internally to either 3V, 3.3V or 5V. Peak switch current is 400mA minimum, providing regulation with load currents up to 150mA, depending on input voltage. Synchronous rectification provides high efficiency operation while eliminating the need for an external Schottky diode. True output disconnect eliminates inrush current at start-up, and allows VOUT to be disconnected from VIN, for zero shutdown current. The output disconnect feature also allows the LTC3525 to maintain regulation with an input voltage equal to or greater than VOUT. Note, however, that the synchronous rectifier is not enabled in this mode resulting in lower efficiency and reduced output current capability. The operating quiescent current is only 7µA typical, allowing the converter to maintain high efficiency at extremely light loads. Shutdown The LTC3525 is shut down by pulling ⎯S⎯H⎯D⎯N below 0.4V, and made active by raising it above 1V. Note that ⎯S⎯H⎯D⎯N can be driven as high as 6V, however, if it is more than 0.9V above the higher of VIN or VOUT, the ⎯S⎯H⎯D⎯N input current will increase from zero to 1.5µA. After the ⎯S⎯H⎯D⎯N pin rises, there is a short delay before switching starts. The delay is 20µs to 120µs, depending on input voltage (see Typical Performance Characteristics curve). Start-up A start-up oscillator allows the LTC3525 to start with input voltages as low as 1V. It remains in start-up mode until two conditions are met. VOUT must exceed VIN by at least 0.2V typical and either VIN or VOUT must be greater than 1.8V typical. During startup, the synchronous rectifier is not enabled, and the internal P-channel synchronous rectifier acts as a follower, causing the peak voltage on SW to reach (VIN + 1V) typical. This limits inrush current by maintaining control of the inductor current when VOUT is less than VIN. To reduce power dissipation in the P-channel synchronous rectifier when the output is shorted, a foldback feature is incorporated that reduces the peak inductor current when VIN is more than 1.7V greater than VOUT. Normal Operation Once VOUT has increased more than 0.2V typical above VIN, and either voltage is above 1.8V, normal operation begins, with synchronous rectification enabled. In this mode, the internal N-channel MOSFET connected between SW and GND stays on until the inductor current reaches a maximum peak value, after which it is turned off and the P-channel synchronous rectifier is turned on. It stays on, delivering current to the output, until the inductor current has dropped below a minimum value at which point it turns off and the cycle repeats. When the output voltage reaches its regulated value both switches are turned off and the LTC3525 goes to sleep, during which time the output capacitor supplies current to the load. Once the output voltage drops approximately 9mV below the regulation value the IC leaves sleep mode and switching is resumed. The LTC3525 has been designed for low output voltage ripple. The output voltage ripple is typically only 20mV peak-to-peak at light load and 60mV peak-to-peak at 3525fa 8 LTC3525-3/ LTC3525-3.3/LTC3525-5 U OPERATIO INDUCTOR CURRENT 100mA/DIV LOAD CURRENT 50mA/DIV 10µs/DIV 3525 F01 Figure 1. Inductor Current Changing as a Function of Load full load using the minimum recommended 10µF output capacitor for the LTC3525-3.3 and a 22µF capacitor for the LTC3525-5 (due to the capacitor’s DC bias effect). An antiring circuit damps any oscillation at the switch node when the inductor current falls to zero. Power Adjust Feature The LTC3525 incorporates a feature that maximizes efficiency at light load while providing increased power capability at heavy load by adjusting the peak and valley of the inductor current as a function of load. Lowering the peak inductor current to 150mA at light load optimizes efficiency by reducing conduction losses in the internal MOSFET switches. As the load increases, the peak inductor current is automatically increased to a maximum of 400mA. At intermediate loads, the peak inductor current may vary from 150mA to 400mA. Figure 1 shows an example of how the inductor current changes as the load increases. Please note that output capacitor values greater than 47µF will result in higher peak currents than necessary at light load. This will lower the light load efficiency. The valley of the inductor current is automatically adjusted as well, to maintain a relatively constant inductor ripple current. This keeps the switching frequency relatively constant. The maximum average load current that can be supported is given by: IO(MAX) = 0.3 • VIN • η Amps VO Where η is the efficiency (see Typical Performance Characteristics). The “burst” frequency (how often the LTC3525 delivers a burst of current pulses to the load) is determined by the internal hysteresis (output voltage ripple), the load current and the amount of output capacitance. All Burst Mode operation or hysteretic converters will enter the audible frequency range when the load is light enough. However, due to the low peak inductor current at light load, circuits using the LTC3525 do not typically generate any audible noise. 3525fa 9 LTC3525-3/ LTC3525-3.3/LTC3525-5 U OPERATIO Component Selection A ceramic input bypass capacitor should be located as close as possible to the VIN and GND pins of the IC. A minimum value of 1µF is recommended. If the battery is more than a few inches away, a bulk tantalum decoupling cap of at least 10µF is recommended on VIN. Inductor values between 4.7µH and 15µH are recommended. In most applications 10µH will yield the best compromise between size and efficiency. The inductor should be a low-loss ferrite design and must be rated for peak currents of at least 400mA without saturating. Inductors with lower DC resistance will improve efficiency. Note that the inductor value does not have a significant effect on ripple current, so while lower values will increase the operating frequency, they do not reduce output voltage ripple. The output capacitor should also be a ceramic, located close to the VOUT and GND pins. A minimum value of 10µF is recommended. Increasing the value of the output capacitor to 22µF will result in lower output ripple. Higher capacitor values will only offer a small reduction in output ripple, while reducing light load efficiency by causing the peak inductor current to increase above its minimum value of 150mA. The input and output capacitors should be X5R or X7R types, not Y5V. Some recommended inductor examples are Murata LQH32C and Coilcraft LPO4812, LPO3310, DO3314, DS1608 and MSS4020. Table 1. Inductor Vendor Information SUPPLIER PHONE FAX WEBSITE Murata USA: (814) 237-1431 USA: (814) 238-0490 www.murata.com Coilcraft (847) 639-6400 (847) 639-1469 www.coilcraft.com Sumida USA: (847) 956-0666 USA: (847) 956-0702 www.sumida.com Table 2. Capacitor Vendor Information SUPPLIER PHONE FAX WEBSITE Murata USA: (814) 237-1431 USA: (814) 238-0490 www.murata.com Taiyo Yuden (408) 573-4150 (408) 573-4159 www.t-yuden.com TDK (847) 803-6100 (847) 803-6296 www.component.tdk.com AVX (803) 448-9411 (803) 448-1943 www.avxcorp.com SHDN SHDN SW LTC3525 VIN GND GND VIN VOUT VOUT 3525 F02 Figure 2. Recommended Component Placement 3525fa 10 LTC3525-3/ LTC3525-3.3/LTC3525-5 U TYPICAL APPLICATIO S Single Cell to 3V Converter Using 1mm High Monolithic Inductor Single Alkaline or NiMH to 3.3V Converter with 1mm Profile 6.8µH* 6.8µH* 1V to 1.6V 3 1 2 LTC3525-3 VIN SHDN VOUT GND GND 1V to 1.6V 6 SW 3 VOUT 3V 65mA 4 5 1 2 10µF 4V 1µF LTC3525-3.3 6 SW VIN SHDN VOUT GND GND VOUT 3.3V 60mA 4 5 10µF** 6.3V 1µF 3525 TA04 3525 TA03 *COILCRAFT LPO3310-682MXD **MURATA GRM219R60J106KE191D *FDK MIP3226D6R8M 2-Alkaline or NiMH to 3.3V Li-Ion to 5V 10µH* 1.8V to 3.2V 3 1 2 10µH* LTC3525-3.3 SHDN VOUT GND GND 3V to 4.2V 6 SW VIN VOUT 3.3V 140mA 4 5 1µF 3 1 OFF ON Li-ion 2 LTC3525-5 VIN SW SHDN VOUT GND GND 6 VOUT 5V 175mA 4 5 1µF 10µF 10µF 3525 TA05 3525 TA06 *MURATA LQH32CN1002K53 *COILCRAFT MSS4020-103MXD U PACKAGE DESCRIPTIO SC6 Package 6-Lead Plastic SC70 (Reference LTC DWG # 05-08-1638) 0.10 – 0.40 0.47 MAX 0.65 REF 1.80 – 2.20 (NOTE 4) 1.16 REF 0.10 – 0.30 0.10 – 0.18 (NOTE 3) 3.26 MAX 2.1 REF 0.96 MIN INDEX AREA (NOTE 6) 1.80 – 2.40 1.15 – 1.35 (NOTE 4) 0.80 – 1.00 0.00 – 0.10 REF 1.00 MAX RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR PIN 1 0.65 BSC NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. DETAILS OF THE PIN 1 INDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE INDEX AREA 7. EIAJ PACKAGE REFERENCE IS EIAJ SC-70 0.15 – 0.30 6 PLCS (NOTE 3) SC6 SC70 0802 3525fa 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 LTC3525-3/ LTC3525-3.3/LTC3525-5 U TYPICAL APPLICATIO 3.3V TO 5V Converter with 1.4mm Profile 10µH* 3 3.3V 1 2 LTC3525-5 SW VIN SHDN VOUT GND GND 6 VOUT 5V 200mA 4 5 22µF** 6.3V 1µF 3525 TA07 *COILCRAFT DO3314-103MXD **MURATA GRM21BR60J226ME39L RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT®1615/LT1615-1 300mA/80mA (ISW), High Efficiency Step-Up DC/DC Converter VIN: 1V to 15V, VOUT(MAX) = 34V, IQ = 20µA, ISD <1µA, ThinSOT™ Package LTC1751-3.3/ LTC1751-5 100mA, 800kHz, Micropower, Regulated Charge Pump DC/DC Converters VIN: 2.5V to 5.5V, VOUT(MAX) = 3.3V/5V, IQ = 20µA, ISD <1µA, MS8 Package LT1930/LTC1930A 1A (ISW), 1.2MHz/2MHz, High Efficiency Step-Up DC/DC Converter High Efficiency, VIN: 2.6V to 16V, VOUT(MAX) = 34V, IQ = 4.2mA/5.5mA, ISD <1µA, ThinSOT Package LTC3200-5 100mA, 2MHz, Regulated 5V Charge Pump VIN: 2.7V to 4.5V, VOUT(MAX) = 5V, IQ = 2mA, ISD <1µA, ThinSOT Package LTC3400/LTC3400B 600mA (ISW), 1.2MHz, Synchronous Step-Up DC/DC Converter 92% Efficiency, VIN: 0.5V to 5V, VOUT(MAX) = 5V, IQ = 19µA/300µA, ISD <1µA, ThinSOT Package LTC3401 1A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter 97% Efficiency, VIN: 0.5V to 5V, VOUT(MAX) = 5.5V, IQ = 38µA, ISD <1µA, MS Package LTC3402 2A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter 97% Efficiency, VIN: 0.5V to 5V, VOUT(MAX) = 5.5V, IQ = 38µA, ISD <1µA, MS Package LTC3421 3A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter with Output Disconnect 95% Efficiency, VIN: 0.5V to 4.5V, VOUT(MAX) = 5.25V, IQ = 12µA, ISD <1µA, QFN-24 Package LTC3425 5A (ISW), 8MHz, 4-Phase Synchronous Step-Up DC/DC Converter with Output Disconnect 95% Efficiency, VIN: 0.5V to 4.5V, VOUT(MAX) = 5.25V, IQ = 12µA, ISD <1µA, QFN-32 Package LTC3429/LTC3429B 600mA, 500kHz Single/Dual Cell Micropower Synchronous Boost Converter with Output Disconnect 95% Efficiency, VIN: 1V to 4.5V, VOUT(MAX) = 5V, IQ = 20µA, ISD <1µA, SC70 Package LTC3458 1.4A (ISW), 1.5MHz, Synchronous Step-Up DC/DC Converter with Output Disconnect VIN: 1.5V to 6V, VOUT(MAX) = 7.5V, ISD <1µA, 3mm × 4mm DFN Package LTC3458L 1.7A (ISW), 1.5MHz, Synchronous Step-Up DC/DC Converter with Output Disconnect VIN: 1.5V to 6V, VOUT(MAX) = 6V, ISD <1µA, 3mm × 4mm DFN Package LTC3459 60mA, 10V Micro Power Synchronous Boost Converter 95% Efficiency, VIN: 1.5V to 6V, VOUT(MAX) = 10V, IQ =10µA, ISD <1µA, ThinSOT Package LT3464 85mA (ISW), High Efficiency Step-Up DC/DC Converter with Integrated Schottky and PNP Disconnect VIN: 2.3V to 10V, VOUT(MAX) = 34V, IQ = 25µA, ISD <1µA, ThinSOT Package ThinSOT is a trademark of Linear Technology Corporation. 3525fa 12 Linear Technology Corporation LT 0306 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2005