Vishay Intertechnology has unveiled three new high-speed, half-bridge MOSFET driver ICs that provide flexible gate drive levels. They are intended to optimise efficiency, reduce component count, and minimise expense in high-frequency, high-current DC/DC synchronous rectifier buck power supplies.
The new MOSFET drivers operate with external n-channel MOSFETs. They are designed to provide gate drive voltages of 8V or 12V, operate at switching frequencies up to 1MHz, and function in 5V to 48V systems, including power converters, and industrial and computing equipment. The high-side driver of each device has an internal bootstrap diode to reduce external component count.
In the SiP41109, the gate drive voltage is supplied to the high-side driver by an integrated 80-mA, 8-V regulator and to the low-side driver by the supply voltage. In the SiP41110, the regulator supplies both high-side and low-side voltages. In this way, designers can choose the gate drive voltage most suitable for achieving an optimal trade-off between MOSFET conduction and switching loss for the chosen operating frequency.
Adaptive shoot-through protection in the drivers prevents simultaneous conduction of the external MOSFETs. Under voltage lockout holds off operation of the circuits until their supply voltages reach valid operating levels, and over temperature protection disables the drivers if the die temperature exceeds 165°C.
Both the SiP41109 and SiP41110 have a three-state PWM input, which also provides for output shutdown.