LTC3400/LTC3400B 600mA, 1.2MHz Micropower Synchronous Boost Converter in ThinSOT FEATURES DESCRIPTIO n Up to 92% Efficiency The LTC 3400/LTC3400B are synchronous, fixed fre- n Generates 3.3V at 100mA from a Single AA Cell quency, step-up DC/DC converters delivering high effi- n Low Start-Up Voltage: 0.85V ciency in a 6-lead ThinSOT package. Capable of supplying n 1.2MHz Fixed Frequency Switching 3.3V at 100mA from a single AA cell input, the devices n Internal Synchronous Rectifier contain an internal NMOS switch and PMOS synchronous n 2.5V to 5V Output Range rectifier. n Automatic Burst Mode Operation (LTC3400) A switching frequency of 1.2MHz minimizes solution n Continuous Switching at Light Loads (LTC3400B) footprint by allowing the use of tiny, low profile inductors n Logic Controlled Shutdown (<1A) and ceramic capacitors. The current mode PWM design is n Antiringing Control Minimizes EMI internally compensated, reducing external parts count. n Tiny External Components The LTC3400 features automatic shifting to power saving n Low Profile (1mm) SOT-23 Package Burst Mode operation at light loads, while the LTC3400B U features continuous switching at light loads. Antiringing APPLICATIO S control circuitry reduces EMI concerns by damping the n inductor in discontinuous mode, and the devices feature Pagers n low shutdown current of under 1A. MP3 Players n Digital Cameras Both devices are available in the low profile (1mm) n LCD Bias Supplies SOT-23 package. n Handheld Instruments , LTC, LT and Burst Mode are registered trademarks of Linear Technology Corporation. n ThinSOT is a trademark of Linear Technology Corporation. Wireless Handsets n GPS Receivers TYPICAL APPLICATIO Efficiency L1 100 4.7H V = 2.4V IN 1 + SINGLE 90 C1 AA CELL 4.7F SW V OUT 6 5 V V 3.3V IN OUT 80 V = 1.5V IN R1 100mA LTC3400 1.02M 1% 4 3 C2 70 OFF ON SHDN FB 4.7F R2 GND 604k 60 2 1% 3400 F01 FIGURE 1 CIRCUIT 50 C1, C2: TAIYO-YUDEN X5R EMK316BJ475ML WITH OPTIONAL SCHOTTKY DIODE L1: COILCRAFT DO160C-472 (SEE APPLICATIONS INFORMATION) 40 0.1 1 10 100 1000 LOAD CURRENT (mA) Figure 1. Single Cell to 3.3V Synchronous Boost Converter 3400 F01a 3400fa 1 EFFICIENCY (%) U ULTC3400/LTC3400B UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART V Voltage ................................................. 0.3V to 6V IN TOP VIEW NUMBER SW Voltage ................................................. 0.3V to 6V SW 1 6 V IN SHDN, FB Voltage ....................................... 0.3V to 6V LTC3400ES6 GND 2 5 V OUT V ........................................................... 0.3V to 6V LTC3400BES6 OUT FB 3 4 SHDN Operating Temperature Range (Note 2) .. 30C to 85C S6 PACKAGE S6 PART MARKING Storage Temperature Range ................... 65C to 125 6-LEAD PLASTIC SOT-23 LTWK Lead Temperature (Soldering, 10 sec).................. 300C T = 125C, = 102C/W JMAX JC LTUN Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. V = 1.2V, V = 3.3V, unless otherwise specified. A IN OUT PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Start-Up Voltage I = 1mA 0.85 1 V LOAD Minimum Operating Voltage SHDN = V (Note 4) 0.5 0.65 V IN Output Voltage Adjust Range 2.5 5 V Feedback Voltage l 1.192 1.23 1.268 V Feedback Input Current V = 1.25V (Note 3) 1 nA FB Quiescent Current (Burst Mode Operation) V = 1.4V (Note 5), LTC3400 Only 19 30 A FB Quiescent Current (Shutdown) V = 0V, Not Including Switch Leakage 0.01 1 A SHDN Quiescent Current (Active) Measured On V 300 500 A OUT NMOS Switch Leakage V = 5V 0.1 5 A SW PMOS Switch Leakage V = 0V 0.1 5 A SW NMOS Switch On Resistance V = 3.3V 0.35 OUT V = 5V 0.20 OUT PMOS Switch On Resistance V = 3.3V 0.45 OUT V = 5V 0.30 OUT NMOS Current Limit 600 850 mA Burst Mode Operation Current Threshold LTC3400 Only (Note 3) 3 mA Current Limit Delay to Output (Note 3) 40 ns Max Duty Cycle V = 1.15V l 80 87 % FB Switching Frequency 0.95 1.2 1.5 MHz l 0.85 1.2 1.5 MHz SHDN Input High 1V SHDN Input Low 0.35 V SHDN Input Current V = 5.5V 0.01 1 A SHDN Note 1: Absolute Maximum Ratings are those values beyond which the life Note 3: Specification is guaranteed by design and not 100% tested in of a device may be impaired. production. Note 2: The LTC3400E/LTC3400BE are guaranteed to meet performance Note 4: Minimum V operation after start-up is only limited by the IN specifications from 0C to 70C. Specifications over the 30C to 85C batterys ability to provide the necessary power as it enters a deeply operating temperature range are assured by design, characterization and discharged state. correlation with statistical process controls. Note 5: Burst Mode operation I is measured at V . Multiply this value Q OUT by V /V to get the equivalent input (battery) current. OUT IN 3400fa 2 U WWW