Works with DrMOS or power blocks providing up to 260A

Linear Technology Corporation announces the LTC7851/-1, a quad output multiphase synchronous step-down DC/DC controller with differential output voltage sensing and accurate current sharing between phases. The controller operates in conjunction with external power train devices such as DrMOS and power blocks, as well as discrete N-channel MOSFETs and associated gate drivers, allowing flexible design configurations.

Two ICs with up to eight phases can be configured in parallel and clocked out of phase to minimize input and output filtering for high current requirements up to 260 A. They are suitable for applications such as power distribution and industrial systems, FPGAs, DSPs, processors, and ASIC power supplies.

The LTC7851/-1's internal current sharing loop equalizes current between phases when paralleled, enabling accurate current sharing between multiple ICs during both steady state and transient conditions. This device operates from a VCC supply voltage in the range of 3 V to 5.5 V and is designed for step-down conversion from input voltages ranging from 3 V to 27 V, generating one to four independent output voltages ranging from 0.6 V to 5 V.

Selectable fixed operating frequency from 250kHz to 2.25MHz, synchronizing to external clock

The device's voltage-mode control architecture allows for a selectable fixed operating frequency from 250 kHz to 2.25 MHz, or can be synchronized to an external clock within the same range. The output current is sensed by monitoring the voltage drop across the output inductor (DCR) for maximum efficiency or by using a low-value sense resistor. An onboard differential amplifier provides true remote output voltage sensing for both the VOUT and ground terminals for high-precision regulation.

The LTC7851-1 is similar to the LTC7851, but offers a lower current sense amplifier gain, making it ideal for powertrain applications using DrMOS with integrated current sensing. Additional features for each phase include current monitoring, adjustable current limit, programmable soft-start or tracking, and a power-good signal. Additionally, this product maintains ±0.75% reference voltage accuracy over an operating temperature range of –20°C to 85°C.

The LTC7851/-1 is available immediately and is housed in a 58-pin 5mm x 9mm QFN package. Pricing starts at $4.27 each in 1,000-piece quantities. For more information, visit www.linear.com/product/LTC7851.