Power system slave controller allows up to 240A supplies

March 17, 2014 // By Graham Prophet
LTC3870 is a dual phase synchronous step-down slave controller that can generate currents up to 240A - when paired with a companion master controller - by extending the phase count in multiphase applications. Compatible master controllers include the LTC3880 and LTC3883 digital power system management controllers.

The LTC3870 is an alternative to Linear Technology’s full-featured controllers and provides the essential functions for multiphase slave designs. It operates over an input voltage range of 4.5V to 60V and produces a fixed output voltage up to 14V. Up to 12 phases can be paralleled and clocked out-of-phase to minimise filtering. Its peak current-mode architecture allows for accurate phase-to-phase current sharing even for dynamic loads. Applications include power distribution, redundant (n+1) supplies, industrial systems, DSP and ASIC power.

The LTC3870 has a fixed operating frequency from 250 kHz to 1 MHz, or it can be synchronised to an external clock. The powerful 1.1 Ohm onboard all N-channel gate drivers minimise MOSFET switching losses. Precise programmable current sense threshold limits from 50 mV to 72 mV minimise power loss and accurately set the overcurrent trip point. Additional features include selectable continuous or discontinuous light load operation, programmable phase shift control and overvoltage protection.

The LTC3870 comes in a 28-lead 4 x 5 mm QFN package and costs $2.35 (1000).

Linear Technology; www.linear.com/product/LTC3870