Gate Drive Transformer

Gate drive transformers are used to deliver the controlling gate-voltage pulses between the drain and source of a MOSFET, while providing isolation between the MOSFET and the controlling drive circuit. Gate-driver circuits need an isolated (floating) bias supply to maintain the required turn-on bias when the FET source rises to the input voltage. 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.
 
Coilcraft’s off-the-shelf gate drive transformers simplify the design of your gate-drive circuit and shorten design cycle time. Our designs typically utilize high-permeability ferrite cores to maximize magnetizing inductance and minimize magnetizing current. The required transformer size is determined by the volt-time product of the application. Therefore the first selection criterion for a gate drive transformer is the volt-time product (V-µsec) rating as shown on the transformer datasheet. This must be greater than or equal to the highest applied voltage-time product expected to avoid core saturation.
 
Check out our Guide to Gate Drive Transformers for a more detailed discussion of gate drive transformers.