Gate Drive Transformer Tutorial

The larger ones may come in a 5 pin to 220 package.

Gate drive transformer tutorial. They also are used for voltage isolation and impedance matching. For more information see the overview for mosfet and igbt gate drivers product page. A gate drive transformer is needed in a smps to control the timing of the circuit. This gate drive transformer gdt circuit allows the drive signal to the mosfet to range from 50 down to 0 while still offering a fast turn off that cannot be accomplished with a simple load.

Gate drive transformers are not suitable for dc and can be used only for ac signals time varying signals. A special section deals with the gate drive requirements of the mosfets in synchronous rectifier applications. These devices provide electri cal pulses for turning on and off semiconductors such as high voltage power mosfets or igbts. Gate drive ics the simplest way to drive a gate is to use a gate drive ic.

Designed is the gate drive transformer in a switch mode power supply smps. Procedure for ground referenced and high side gate drive circuits ac coupled and transformer isolated solutions are described in great details. Large duty ratios more than 50 cannot be handled by the transformer without being saturated due to the transformers operating only at ac signals the core flux must be reset each half cycle in order to maintain a volt second balance unless ac coupling capacitors and zener diodes are employed. A gate drive transformer isolates the controlling gate drive circuit from the switch node when driving the mosfet gate and may also scale the output voltage via an appropriate primary to secondary turns ratio.

The gate drive transformer provides both the floating supply as well as the level shifting of the switching signal to the power semiconductor thereby eliminating a separate floating power supply.