LTC3406B 1.5MHz, 600mA Synchronous Step-Down Regulator in ThinSOT FEATURES DESCRIPTIO High Efficiency: Up to 96% The LTC 3406B is a high efficiency monolithic synchro- 600mA Output Current at V = 3V nous buck regulator using a constant frequency, current IN 2.5V to 5.5V Input Voltage Range mode architecture. The device is available in an adjustable 1.5MHz Constant Frequency Operation version and fixed output voltages of 1.5V and 1.8V. Supply No Schottky Diode Required current with no load is 300A and drops to <1A in Low Dropout Operation: 100% Duty Cycle shutdown. The 2.5V to 5.5V input voltage range makes the Low Quiescent Current: 300A LTC3406B ideally suited for single Li-Ion battery-powered 0.6V Reference Allows Low Output Voltages applications. 100% duty cycle provides low dropout op- Shutdown Mode Draws < 1A Supply Current eration, extending battery life in portable systems. PWM Current Mode Operation for Excellent Line and pulse skipping mode operation provides very low output Load Transient Response ripple voltage for noise sensitive applications. Overtemperature Protected TM Switching frequency is internally set at 1.5MHz, allowing Low Profile (1mm) ThinSOT Package the use of small surface mount inductors and capacitors. U The internal synchronous switch increases efficiency and APPLICATIO S eliminates the need for an external Schottky diode. Low Cellular Telephones output voltages are easily supported with the 0.6V feed- Personal Information Appliances back reference voltage. The LTC3406B is available in a low Wireless and DSL Modems profile (1mm) ThinSOT package. Refer to LTC3406 for Digital Still Cameras applications that require Burst Mode operation. MP3 Players , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. Portable Instruments ThinSOT is a trademark of Linear Technology Corporation. Protected by U.S. Patents, including 6580258, 5481178. TYPICAL APPLICATIO 100 V = 1.8V OUT 90 80 2.2H* 70 V V IN OUT 4 3 V = 3.6V IN 2.7V V SW 1.8V IN 60 C TO 5.5V C ** OUT 600mA IN V = 2.7V 10F 4.7F IN LTC3406B-1.8 50 CER CER 1 5 3406B F01a 40 RUN V OUT GND 30 2 V = 4.2V IN 20 10 *MURATA LQH32CN2R2M33 0.1 1000 1 10 100 **TAIYO YUDEN JMK212BJ475MG OUTPUT CURRENT (mA) TAIYO YUDEN JMK316BJ106ML 3406B F01b Figure 1a. High Efficiency Step-Down Converter Figure 1b. Efficiency vs Load Current 3406bfa 1 EFFICIENCY (%) U ULTC3406B 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 (Notes 3, 6) ...................... 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 LTC3406BES5-1.5 LTC3406BES5 GND 2 GND 2 LTC3406BES5-1.8 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 LTE2 LTE3 JMAX JA JC JMAX JA JC LTE4 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. V = 3.6V unless otherwise specified. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I Feedback Current 30 nA VFB V Regulated Feedback Voltage LTC3406B (Note 4) T = 25C 0.5880 0.6 0.6120 V FB A LTC3406B (Note 4) 0C T 85C 0.5865 0.6 0.6135 V A LTC3406B (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 LTC3406B-1.5 1.455 1.500 1.545 V OUT LTC3406B-1.8 1.746 1.800 1.854 V V Output Overvoltage Lockout V = V V , LTC3406B 20 50 80 mV OVL OVL OVL FB V = V V , LTC3406B-1.5/LTC3406B-1.8 2.5 7.8 13 % OVL OVL OUT V Output Voltage Line Regulation V = 2.5V to 5.5V 0.04 0.4 % 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 %/V LOADREG V Input Voltage Range 2.5 5.5 V IN I Input DC Bias Current (Note 5) S V = 0.5V or V = 90% 300 400 A FB OUT 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 3406bfa 2 U WWW