High Power Step-Down Synchronous DC/DC Controllers for Low Voltage Operation

The LTC3832/LTC3832-1 are high power, high efficiency switching regulator controllers optimized for 3.3V-5V to 0.6V-3.xV step-down applications. A precision internal reference and feedback system provide ±1% output regulation over temperature, load current and line voltage variations. The LTC3832/LTC3832-1 use a synchronous switching architecture with N-channel MOSFETs. Additionally, the chip senses output current through the drain-source resistance of the upper N-channel MOSFET, providing an adjustable current limit without a current sense resistor.

The LTC3832/LTC3832-1 operate with an input supply voltage as low as 3V and with a maximum duty cycle of >91% over temperature. They include a fixed frequency PWM oscillator for low output ripple operation. The 300kHz free-running clock frequency can be externally adjusted or synchronized with an external signal from 100kHz to 500kHz. In shutdown mode, the LTC3832 supply current drops to <10µA. The LTC3832-1 is the SO-8 version without current limit, frequency adjustment and shutdown functions.

Applications

* CPU Power Supplies

* Multiple Logic Supply Generator

* Distributed Power Applications

* High Efficiency Power Conversion

* VOUT as Low as 0.6V

* High Power Switching Regulator Controller for 3.3V-5V to 0.6V-3.xV Step-Down Applications

* No Current Sense Resistor Required

* Low Input Supply Voltage Range: 3V to 8V

* Maximum Duty Cycle >91% Over Temperature

* All N-Channel External MOSFETs

* Excellent Output Regulation: ±1% Over Line, Load and Temperature Variations

* High Efficiency: Over 95% Possible

* Adjustable or Fixed 2.5V Output (LTC3832)

* Programmable Fixed Frequency Operation: 100kHz to 500kHz

* External Clock Synchronization

* Soft-Start

* Low Shutdown Current: <10µA

* Overtemperature Protection

* Available in SO-8 and SSOP-16 Packages