Isolation voltage and drive strength — the two numbers that decide fit
Its 5700Vrms isolation rating covers reinforced isolation requirements for motor drives, solar inverters, and industrial power supplies where the primary-to-secondary voltage differential exceeds 1kV.
30ns propagation delay — timing budget for dead-time management
In a 100kHz hard-switched half-bridge, 30ns of delay uncertainty forces you to pad the dead-time by at least 60ns, which directly eats into efficiency. The 6ns PWD means the on-times of the two channels stay well matched across temperature, reducing DC bus voltage imbalance in three-phase inverter stages.
100V/ns CMTI — the GaN/SiC enabler
Common-mode transient immunity of 100V/ns minimum is the spec that separates a gate driver that works from one that latches up or corrupts the output when the switching node slews at 80V/ns. This rating makes the UCC21521CDWR suitable for fast-switching GaN and SiC FETs where dV/dt routinely exceeds 50V/ns. If your design uses 650V GaN HEMTs in a totem-pole PFC stage, this driver will hold the gate drive clean through the hard commutation event.
Output supply range: 3V to 18V
The output supply accepts 3V to 18V, which covers both 5V-logic-level gate drives for low-voltage GaN and the 12V to 15V rails typical for IGBT gate drivers. The input side is separate and can run from 3.3V logic without a level shifter, answering the common question about 3.3V compatibility directly. The wide range also simplifies BOM consolidation across a product family that mixes Si MOSFETs and SiC devices.
Housed in a 16-SOIC wide-body (7.50mm width) package, the UCC21521CDWR meets the creepage distance required for reinforced isolation at working voltages up to 1kV.
ROHS3 compliant per the listing.