Gate controlled to withstand ±300V and maintain forward voltage drop for low power operation

Linear Technology Korea has announced the launch of the LTC4371, a highly comprehensive diode OR controller for dual feed high-power telecom and datacom boards. The LTC4371 provides seamless handoff between redundant power supplies and replaces the heatsink associated with power Schottky diodes with an N-channel MOSFET, reducing power loss, voltage drop, and solution size.

This controller is designed to withstand ±300V or higher transient voltages generated during lightning surges, load switching, or power short-circuit periods for the most robust diode OR solution. The integrated shunt-regulated power supply features a low standby current of 350µA and high-impedance drain pin that allows large external resistors to safely limit device current during such high-voltage transients. External transient voltage suppressors are no longer required, saving cost and board area.


The LTC4371 controls the gate to maintain a low 15mV forward voltage drop across the ideal diode MOSFET to minimize power dissipation in high-current applications. Linear servo techniques enable smooth current transitions during power supply switching while preventing reverse DC current. During input power short-circuit periods, transient reverse current is minimized by a strong 2A gate turn-off current.

The strong 5mA gate pull-up current ensures fast MOSFET turn-on and enables AC rectification applications. The large gate current provides sufficient drive capability when multiple MOSFETs are paralleled in high-current 50A and 100A applications. The operating voltage range is extended to hundreds of volts by the thermal shunt regulator, while the 4.5V minimum supply accommodates low-voltage −5V and −12V ORing applications. Open-circuit faults or series fuses in the MOSFET are detected and signaled to the fault status output.

The LTC4371 is specified to operate over the commercial temperature range of 0°C to 70°C and industrial temperature range of −40°C to 85°C, and is available in 10-pin MSOP and 3mm x 3mm DFN plastic packages. Priced at $2.50 per unit in quantities of 1,000. Device samples and evaluation circuit boards are available online or through Linear Technology sales offices. For more information, refer to www.linear.com/product/LTC4371