4 A peak drive with 200 kV/µs CMTI
The Skyworks Solutions SI8271BBD-IS is a single-channel digital isolator from the Si827x series, purpose-built for driving power switches like MOSFETs and IGBTs. Its headline spec is the 4 A peak output current — enough to charge the gate capacitance of a large IGBT in tens of nanoseconds, which directly determines switching losses in a motor drive or inverter stage. The RF coupling isolation technology delivers 2500 Vrms of galvanic isolation, certified by CQC, CSA, UL, and VDE. That covers the basic insulation requirements for mains-connected power supplies and industrial drives up to the 250 Vrms working voltage class. Common-mode transient immunity (CMTI) is rated at 200 kV/µs minimum — this is the key parameter for surviving the fast voltage slewing at the switching node of a half-bridge. A poor CMTI isolator can latch or corrupt the output when the floating ground jumps several hundred volts in a few nanoseconds; 200 kV/µs gives comfortable margin for SiC and GaN switching edges.
Propagation delay and pulse fidelity
Maximum propagation delay is 75 ns in both directions (tpLH and tpHL), with a pulse-width distortion of just 8 ns max. That means the on and off edges stay within 8 ns of each other — important for dead-time control in a bridge leg where asymmetric delay would shift the effective duty cycle. Rise and fall times are 10.5 ns and 13.3 ns typical respectively. The asymmetric rise/fall is inherent to the output stage, but the 4 A peak sink (low-side) vs 1.8 A peak source (high-side) means the falling edge is faster — the gate discharges quicker than it charges, which helps prevent shoot-through during turn-off. The output supply range spans 4.2 V to 30 V, so the same isolator can drive a 5 V logic-level MOSFET or a 15 V IGBT gate without an external level shifter.
Package and board-fit note
The surface-mount package is compatible with standard reflow profiles — no exotic soldering requirements. Supplied in tube format, so pick-and-place feeders need tube-to-tape conversion or manual loading for low-volume builds.