LTC3832/LTC3832-1 High Power Step-Down Synchronous DC/DC Controllers for Low Voltage Operation UFEATURESDESCRIPTIO ■ VOUT as Low as 0.6V The LTC®3832/LTC3832-1 are high power, high effi- ■ High Power Switching Regulator Controller ciency switching regulator controllers optimized for for 3.3V-5V to 0.6V-3.xV Step-Down Applications 3.3V-5V to 0.6V-3.xV step-down applications. A preci- ■ No Current Sense Resistor Required sion internal reference and feedback system provide ■ Low Input Supply Voltage Range: 3V to 8V ±1% output regulation over temperature, load current ■ Maximum Duty Cycle > 91% Over Temperature and line voltage variations. The LTC3832/LTC3832-1 use ■ All N-Channel External MOSFETs a synchronous switching architecture with N-channel ■ Excellent Output Regulation: ±1% Over Line, Load MOSFETs. Additionally, the chip senses output current and Temperature Variations through the drain-source resistance of the upper ■ High Efficiency: Over 95% Possible N-channel MOSFET, providing an adjustable current limit ■ Adjustable or Fixed 2.5V Output (LTC3832) without a current sense resistor. ■ Programmable Fixed Frequency Operation: 100kHz to The LTC3832/LTC3832-1 operate with an input supply 500kHz voltage as low as 3V and with a maximum duty cycle of ■ External Clock Synchronization >91% over temperature. They include a fixed frequency ■ Soft-Start PWM oscillator for low output ripple operation. The 300kHz ■ Low Shutdown Current: <10µA free-running clock frequency can be externally adjusted or ■ Overtemperature Protection synchronized with an external signal from 100kHz to 500kHz. ■ Available in SO-8 and SSOP-16 Packages In shutdown mode, the LTC3832 supply current drops to U <10µA. The LTC3832-1 is the SO-8 version without current APPLICATIO S limit, frequency adjustment and shutdown functions. ■ CPU Power Supplies , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Multiple Logic Supply Generator ■ Distributed Power Applications ■ High Efficiency Power Conversion UTYPICAL APPLICATIO VIN Efficiency 4.7µF 3V TO 7V 5.1Ω 100 + VOUT = 2.5V 0.1µF MBR0520T1 90 LTC3832-1 SS VCC/PVCC2 0.01µF 80 VOUT = 1V COMP G1 Si9426DY L1 15k 0.1µF 3.2µH V 70 OUT GND PVCC1 1V 9A 6.49k EFFICIENCY (%) 60 FB G2 Si9426DY + COUT 270µF 2V 50 4.32k 3832 F01 VIN = 3.3V 680pF L1: SUMIDA CDEP105-3R2MC-88 40 C 0 1 2 3 4 5 6 7 8 9 10 OUT: PANASONIC EEFUEOD271R LOAD CURRENT (A) Figure 1. High Efficiency 3.3V to 1V Power Converter 3832 F01b sn3832 3832fs 1