100 Mbps capacitive isolator with 85 kV/µs CMTI — the motor-drive choice
The Texas Instruments ISO7731FQDBQRQ1 is a three-channel, unidirectional digital isolator built on capacitive coupling technology, rated for 100 Mbps data rate and 3000 Vrms isolation. The standout spec for inverter and motor-drive applications is the 85 kV/µs common-mode transient immunity — that's the margin that keeps data intact when a 600 V IGBT switches off in a few nanoseconds. The 2/1 input-side/side-2 channel split (two inputs on side 1, one on side 2) suits it for isolating a three-wire interface like SPI's SCLK, MOSI, and MISO where the chip-select stays on the controller side.
AEC-Q100 grade and 125°C operation
That covers under-hood electronics, engine control modules, and any board that lives near a heat source.
Timing margins that matter
Propagation delay is 16 ns max in both directions (tpLH and tpHL), with a pulse-width distortion ceiling of 4.9 ns. That's tight enough for 100 Mbps SPI or general-purpose isolation without worrying about duty-cycle skew accumulating over a long frame. Rise and fall times are 1.3 ns and 1.4 ns typical — fast edges mean clean signal integrity into a standard CMOS input, but they also mean the layout should keep the output trace short and avoid long stubs. No isolated power is provided on-chip; you supply the secondary-side Vcc separately.
Package and footprint
Housed in a 16-pin SSOP with 0.154" body width and 3.90 mm width. It's a hand-solderable pitch — about 0.635 mm lead pitch — so a hobbyist with a fine-tip iron and some flux can mount it on a breakout board. Surface-mount only, naturally. The base product number is ISO7731, so the datasheet and app notes for that family apply directly.