LTC3406 LTC3406-1.5/LTC3406-1.8 1.5MHz, 600mA Synchronous Step-Down Regulator in ThinSOT FEATURES DESCRIPTIO High Efficiency: Up to 96% The LTC 3406 is a high efficiency monolithic synchro- Very Low Quiescent Current: Only 20A nous buck regulator using a constant frequency, current During Operation mode architecture. The device is available in an adjustable 600mA Output Current version and fixed output voltages of 1.5V and 1.8V. Supply 2.5V to 5.5V Input Voltage Range current during operation is only 20A and drops to 1A 1.5MHz Constant Frequency Operation in shutdown. The 2.5V to 5.5V input voltage range makes No Schottky Diode Required the LTC3406 ideally suited for single Li-Ion battery-pow- Low Dropout Operation: 100% Duty Cycle ered applications. 100% duty cycle provides low dropout 0.6V Reference Allows Low Output Voltages operation, extending battery life in portable systems. Shutdown Mode Draws 1A Supply Current Automatic Burst Mode operation increases efficiency at Current Mode Operation for Excellent Line and light loads, further extending battery life. Load Transient Response Switching frequency is internally set at 1.5MHz, allowing Overtemperature Protected TM the use of small surface mount inductors and capacitors. Low Profile (1mm) ThinSOT Package The internal synchronous switch increases efficiency and U eliminates the need for an external Schottky diode. Low APPLICATIO S output voltages are easily supported with the 0.6V feed- back reference voltage. The LTC3406 is available in a low Cellular Telephones Personal Information Appliances profile (1mm) ThinSOT package. Wireless and DSL Modems , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. Digital Still Cameras ThinSOT is a trademark of Linear Technology Corporation. Protected by U.S. Patents, including 6580258, 5481178. MP3 Players Portable Instruments TYPICAL APPLICATIO 95 V = 2.7V IN 90 85 2.2H* V V IN OUT 4 3 V = 3.6V IN 2.7V V SW 1.8V IN C C ** 80 TO 5.5V OUT 600mA IN 10F 4.7F V = 4.2V IN LTC3406-1.8 CER CER 75 1 5 3406 F01a RUN V OUT 70 GND 2 65 V = 1.8V OUT 60 *MURATA LQH32CN2R2M33 0.1 1 10 100 1000 **TAIYO YUDEN JMK212BJ475MG TAIYO YUDEN JMK316BJ106ML OUTPUT CURRENT (mA) 3406 F01b Figure 1a. High Efficiency Step-Down Converter Figure 1b. Efficiency vs Load Current 3406fa 1 EFFICIENCY (%) U ULTC3406 LTC3406-1.5/LTC3406-1.8 ABSOLUTE AXI U RATI GS (Note 1) Peak SW Sink and Source Current ........................ 1.3A Input Supply Voltage .................................. 0.3V to 6V Operating Temperature Range (Note 2) .. 40C to 85C RUN, V Voltages ..................................... 0.3V to V FB IN Junction Temperature (Note 3)............................ 125C SW Voltage .................................. 0.3V to (V + 0.3V) IN Storage Temperature Range ................ 65C to 150C P-Channel Switch Source Current (DC) ............. 800mA Lead Temperature (Soldering, 10 sec)................. 300C N-Channel Switch Sink Current (DC) ................. 800mA UUW PACKAGE/ORDER I FOR ATIO ORDER PART ORDER PART TOP VIEW TOP VIEW NUMBER NUMBER RUN 1 5 V RUN 1 5 V FB OUT LTC3406ES5-1.5 LTC3406ES5 GND 2 GND 2 LTC3406ES5-1.8 SW 3 4 V SW 3 4 V IN IN S5 PART MARKING S5 PART MARKING S5 PACKAGE S5 PACKAGE 5-LEAD PLASTIC TSOT-23 5-LEAD PLASTIC TSOT-23 T = 125C, = 250C/ W, = 90C/ W T = 125C, = 250C/ W, = 90C/ W LTA5 LTD6 JMAX JA JC JMAX JA JC LTC4 Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range, otherwise specifications are T = 25C. A V = 3.6V unless otherwise specified. IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I Feedback Current 30 nA VFB V Regulated Feedback Voltage LTC3406 (Note 4) T = 25C 0.5880 0.6 0.6120 V FB A LTC3406 (Note 4) 0C T 85C 0.5865 0.6 0.6135 V A LTC3406 (Note 4) 40C T 85C 0.5850 0.6 0.6150 V A V Reference Voltage Line Regulation V = 2.5V to 5.5V (Note 4) 0.04 0.4 %/V FB IN V Regulated Output Voltage LTC3406-1.5, I = 100mA 1.455 1.500 1.545 V OUT OUT LTC3406-1.8, I = 100mA 1.746 1.800 1.854 V OUT V Output Voltage Line Regulation V = 2.5V to 5.5V 0.04 0.4 %/V OUT IN I Peak Inductor Current V = 3V, V = 0.5V or V = 90%, 0.75 1 1.25 A PK IN FB OUT Duty Cycle < 35% V Output Voltage Load Regulation 0.5 % LOADREG V Input Voltage Range 2.5 5.5 V IN I Input DC Bias Current (Note 5) S Active Mode V = 0.5V or V = 90%, I = 0A 300 400 A FB OUT LOAD Sleep Mode V = 0.62V or V = 103%, I = 0A 20 35 A FB OUT LOAD Shutdown V = 0V, V = 4.2V 0.1 1 A RUN IN f Oscillator Frequency V = 0.6V or V = 100% 1.2 1.5 1.8 MHz OSC FB OUT V = 0V or V = 0V 210 kHz FB OUT R R of P-Channel FET I = 100mA 0.4 0.5 PFET DS(ON) SW R R of N-Channel FET I = 100mA 0.35 0.45 NFET DS(ON) SW I SW Leakage V = 0V, V = 0V or 5V, V = 5V 0.01 1 A LSW RUN SW IN 3406fa 2 U WWW