LTC Presents LTC3900/LTC3901 MOSFET Drivers

Linear Technology Corp. (LTC, Milpitas, CA) introduced two secondary-side, synchronous n-channel MOSFET drivers, the LTC3900 and LTC3901. Both devices have timer and current sense comparators to protect the external MOSFETs during normal and light load operation, power up/down, and when the driver supply voltage drops too low. Applications include 48V input, isolated, dc/dc converters, isolated telecom power supplies, industrial control, and automotive equipment.

A programmable timeout function disables the synchronous drivers when the synchronization signal between the primary and secondary sides is missing or incorrect, protecting the MOSFETs from over-voltage and electrical overstress. Additionally, the ICs turn off the MOSFETs if the negative inductor current exceeds a user-programmable level, preventing the buildup of excessive inductor energy and possible damage. Moreover, to ensure proper power-up and power-down, the drivers shut off the MOSFETs when the driver input voltage is below 4V.

The LTC3900 is offered in an eight-lead SO package. The LTC3901 is housed in a 16-lead SSOP. Both are rated for operation from -40°C to +85°C. The LTC3900 and LTC3901 are priced at $2.50 and $2.60, respectively, for 1,000-piece quantities.