Dual, 2-Phase, Synchronous Controller with Low Value DCR Sensing and Temperature Compensation

The LTC3875 is a dual output current mode synchronous step-down DC/DC controller that drives all N-channel power MOSFET stages. It employs a unique architecture that enhances the signal-to-noise ratio of the current sense signal, allowing the use of very low DC resistance (DCR) power inductors to maximize efficiency in high current applications. This feature also reduces the switching jitter commonly found in low DCR applications with current mode control.

The LTC3875 features two high speed differential amplifiers which can be used to compensate for the voltage drop from the LTC3875 to the load. Its DCR temperature compensated adjustable over current trip points from 10mV to 30mV limits the maximum output current precisely over temperature.

A unique thermal balancing function adjusts per phase current to minimize the thermal stress for multichip single output applications. The LTC3875 is available in the 40- lead 6mm × 6mm (0.5mm pitch) and 40-lead 5mm × 5mm (0.4mm pitch) QFN packages.

APPLICATIONS

* Servers and Instruments

* Telecom Systems

* DC Power Distribution Systems

* Low Value DCR Current Sensing

* Programmable DCR Temperature Compensation

* ±0.5% 0.6V Output Voltage Accuracy

* Dual True Remote Sensing Differential Amplifiers

* Phase-Lockable Fixed Frequency 250kHz to 720kHz

* Dual, 180° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise

* Dual N-Channel MOSFET Synchronous Drive

* Wide VIN Range: 4.5V to 38V Operation