Named TLP5814H, it is a “gate driver photocoupler suitable for driving silicon carbide mosfets in industrial equipment like inverters, uninterruptible power supplies and photovoltaic inverters which experience harsh thermal environments”, according to the company. “The Miller clamp circuit typically has a channel resistance of 0.69Ω, and a peak clamp sink rating of 6.8A.”
Such clamping can remove the need for a negative voltage rail in the gate circuit, and the devices output characteristics, including the clamp, are also suited to driving IGBTs, added Toshiba.
The clamp operates automatically when the LED is off and the voltage on the Vclamp pin is above ~2.5V.
The main output driver can operate rail-to-rail, delivering peaks of +6.8A and -4.8A.
All the currents so far have been absolute maximum values and, according to the data sheet, up to ±2A is the recommended operating condition.
Inside the package, linked by an optical path, is an infra-red LED and an an electrically-isolated photodetector.
Increase common-mode transient immunity to a minimum of ±70kV/µs, an internal Faraday shield is installed across the optical path – connected to the output ground pin.
Packaging is 5.85 x 10 x 2.1mm SO8L with 8mm minimum creepage and clearance. Overall isolation is a minimum of 5kVrms.
On the input side, a drive between 4.5 and 10mA (Vf = 1.43 to 1.7V at 10mA) is expected to turn on the output, and drive has to be below 0.8V to turn off the output.
On the secondary side, a supply of 13 to 23V is needed (25V abs max).
With 4.5mA drive, propagation delay either way is typically around 75ns, and rise and fall times are around 6ns.
Operation is over -40 to 125°C.
Find the TLP5814H on this Toshiba product page, and the company has prepared an app note on active miller clamping
Last year, Microchip included active Miller clamping in a 15kVA drive module for ‘more electric’ aircraft.
