While it is possible to design a fully featured gate driver with discrete components, it is rarely the best approach in terms of parts cost, design effort, assembly time, and board area required. Integrated drivers are available from Toshiba that enable a reliable, high-performance gate driver covering all of the available switch technologies at any power level. Unlike discrete designs, off-the-shelf parts already hold relevant safety certifications, thereby avoiding costs and delays.
Toshiba offers a range of integrated ‘smart’ gate drivers and continually expands their range. The TLP5214 and TLP5214A are primarily intended for driving IGBTs at speeds up to 50kHz. With an appropriate choice of supply voltage, the parts can be used to drive silicon and / or silicon carbide (SiC) MOSFETs. Due to the lower gate capacitance and gate charge for SiC MOSFETs, PWM frequencies of up to 650kHz are possible. The parts are able to supply +/-4A peak gate current, with propagation delays of less than 150ns and with a common-mode transient immunity of +/-35kV/µs.
Both devices offer full protection features including DESAT monitoring and shutdown, along with an internal Miller clamp. The TLP5214A version has the same base characteristics, but with a longer DESAT blanking time and longer soft-duration shutdown time for systems with high peak loads and noise levels.
Another Toshiba part, the TLP5231, is similar to the TLP5214 parts but is intended to be a pre-driver, followed by a buffer of a P- and N-channel MOSFET. These can be scaled for any desired power rating, and separate drive signals are made available for the two external MOSFET gates for maximum flexibility. Under-voltage lock-out is included, along with DESAT protection, with an externally adjustable soft shutdown time. In this part, a drive is provided to an externally fitted Miller clamp MOSFET. There are also detail differences in the propagation delay, DESAT thresholds and blanking charging current and timing. Alternatively, the TLP5212 and TLP5214 could also be used as pre-drivers.
Toshiba has published a whitepaper on configuring the features of smart gate drivers, download your free copy below: