GaN power transistor drivers for military and high-rel
TDGD271 is a single channel driver in 8pad SOIC, while TDGD274 is a dual channel driver in 16pad SOIC.
“The TDGD27x family devices are ideal for isolated mosfet, IGBTand SiC or GaN HEMT gate drive applications, including driving Teledyne HiRel’s TDG family of GaN HEMTs,” according to the company. “Their small size and wide temperature range make them unique.”
For demanding use, they are available with 100% screening and from one diffusion lot, and are shipped from Teledyne’s DoD-trusted facility in California.
The dual version includes anti-overlap circuits allowing a single PWM waveform to drive both upper and lower transistors in a half-bridge – dead-time is adjustable across 10-200ns. Inputs are TTL compatible with >400mV hysteresis and there is a 3V under-voltage lock-out on the input-side logic supply.
The isolated outputs need a separate power supply, which can be suppled by boot-strapping for the upper channel of a half-bridge.
Inside, the isolation barrier is a Semiconductor type, with signals on-off modulated onto an RF carrier before crossing. 60ns max propagation delay is claimed along with 200ps peak-to-peak jitter.
“This RF on/off keying scheme is superior to pulse code schemes as it provides noise immunity, low power consumption and better immunity to magnetic fields,” according to the company – although magnetic immunity is not specified in the data sheet.
What is specified is electrical immunity: 200kV/µs common-mode transient and 400kV/µs latch-up.
Clearance and creepage are 4.7 and 3.9mm respectively, and minimum internal clearance is 8μm.
Operation is foreseen up to 1MHz, in applications including power supplies, dc-dc converters (including point-of-load), battery management and motor control.
The TDGD27x data sheet is here, and the product page is here. The latter also mentions TD99102, a 20MHz dual-channel non-isolated 100V part in the pipeline.