If peak current required for your application is too high to handle for MOSFET driver IC, you can use external totem-pole output or complementary MOSFET circuits. I'm rebuilding my circuit over again with single side prototype board, because I discovered the double-sided prototype board has issues with capacitance and shorting, even though the circuit works, which is adding to the heating. On the output side, the NPN and PNP totem pole stage does current amplification. TOTEM POLE OUTPUT USE AND APPLICATIONS NOTE: the current required to drive a MOSFET gate is very low but peak current somehow greater than average current. ![]() ![]() I'm building a TL494 based SEPEX motor controller that is switching huge 11X (eleven paralled) IRFP90N20D MOSFETS, with 10 ohm gate resistors on each MOSFET, and I'm using 6A darlington Sanken TO-220 drivers for them, and also smaller 5A TO-126 audio transistors driving one pair of IRFP90N20D Pin a typical NPN/PNP totem-pole arrangement. The totem pole output eliminates the need for a pull-up resistor and allows for direct drive of the current buffer. What bipolar transistors would you recommend for robust totem pole outputs at approximately 22khz or higher? Should I use heatsinking? Do I need TO247 sized bipolars to drive these massive MOSFETS? The ACPL-4800 fast-speed optocoupler contains a GaAsP LED and photo detector with built-in Schmitt trigger to provide logic-compatible waveforms, eliminating the need for additional wave shaping.
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