DC/DC controller supports powertrain devices

Linear Technology Corp. has announced a dual output synchronous step-down DC/DC controller with multiphase operation, differential output voltage sensing and high frequency operation. The LTC3861works with external power train devices including power blocks and DrMOS, as well as discrete N-channel MOSFETs and associated gate drivers, enabling flexible design configurations, added the company.

The device boasts up to 12 phases that can be paralleled and clocked out-of-phase to minimize input and output filtering for very high current requirements (up to 300A). Applications for the LTC3861 include high current power distribution and industrial systems, DSP and ASIC supplies.

LTC3861's current sharing loop enables accurate current sharing between phases across multiple ICs, both DC and during a load transient. The device's voltage mode control architecture allows for selectable fixed operating frequency from 250kHz to 2.25MHz or it can be synchronized over the same range with its phased-lock loop (PLL). The differential amplifier provides true remote output voltage sensing of both V_OUT and ground terminals, enabling high accuracy regulation, described Linear Tech.

The step-down DC/DC controller operates with a V_CC voltage from 3-5.5V, a V_IN voltage (drain voltage for the high-side MOSFET) from 3-24V and it produces output voltages from 0.6-5V. The output current is sensed by monitoring the voltage drop across the output inductor (DCR) for maximum efficiency or using a sense resistor. Its adjustable current limit can be configured for very low sense voltages (up to 50mV) to minimize power loss.

Additional features include adjustable soft start or tracking, output overvoltage protection and two power good output signals. Furthermore, it maintains ±1% reference voltage accuracy from -40°C to 125°C.

The LTC3861 is housed in a 36-lead 5 x 6mm QFN package and is available from stock. The 1000-piece price starts at $2.88.