Gate-drive isolator for automotive power stages
The Skyworks SI8261BBD-C-IS is a single-channel digital isolator with a 4 A peak output stage, designed to drive IGBTs and MOSFETs in automotive traction inverters, DC-DC converters, and on-board chargers. Its 5000 Vrms reinforced isolation (per the 6-SOIC wide-body package) creates a galvanic barrier between the low-voltage controller domain and the high-voltage power stage, meeting the creepage and clearance requirements for 400 V and 800 V battery systems. The capacitive coupling technology delivers 35 kV/µs common-mode transient immunity, which keeps the gate drive signal clean during fast switching events — a common failure mode in motor-drive applications where the power-stage dv/dt couples back into the control side.
Switching performance and drive capability
Propagation delay is 60 ns max for low-to-high and 50 ns max for high-to-low transitions, with a pulse-width distortion ceiling of 28 ns. This asymmetry matters in dead-time budgeting: the controller must account for the longer tpLH when calculating the minimum off-time between high-side and low-side switches to avoid shoot-through. Rise and fall times are 5.5 ns and 8.5 ns typical respectively, which means the output edge rate is fast enough to minimise switching losses in the power FETs without requiring an external booster stage. The output high/low current capability — 500 mA source, 1.2 A sink — allows direct drive of medium-power IGBTs (up to about 50 A collector current class) without a separate gate-driver buffer. The output supply range of 9.4 V to 30 V covers the typical gate-drive voltages for both silicon IGBTs (15 V nominal) and SiC MOSFETs (18-20 V recommended).
Package, approvals, and sourcing posture
The supplier device package is listed as 6-SDIP Gull Wing, which is the same physical footprint as the SOIC-6 wide body; the naming difference is a manufacturer-specific designation. Safety certifications include CQC (China), CSA (Canada), UR (UL Recognized, USA), and VDE (Germany), covering the major global regulatory jurisdictions for industrial and automotive equipment. No official second-source cross-reference is maintained by the manufacturer, but the SI8261 family shares the same pinout and functional characteristics across isolation voltage variants.