Texas Instruments UCC21521CDW

Overview

UCC21521CDW from Texas Instruments is a reinforced-isolated dual-channel gate driver optimized for high-speed switching of SiC MOSFETs, IGBTs, and power MOSFETs in high-voltage topologies. It delivers 4-A peak source and 6-A peak sink output current, features 12-V UVLO thresholds on VDDA/VDDB, supports up to 25-V output supply, and achieves 19-ns typical propagation delay with ≤6-ns pulse-width distortion. It enables half-bridge, dual high-side, or dual low-side configurations in isolated DC–DC converters and solar inverters.

For engineers reviewing the UCC21521CDW datasheet, UCC21521CDW pinout, UCC21521CDW application, or UCC21521CDW equivalent, key selection criteria include its 12-V VDD UVLO version, 5.7-kVRMS reinforced isolation barrier, ≥100 V/ns CMTI, programmable dead time via external resistor, and SOIC-16 (DW) package with functional isolation between secondary-side drivers.

Technical Context

The UCC21521CDW implements capacitive isolation with two independent secondary-side drivers, each supporting up to 1500 VDC working voltage across VSSA–VSSB. Its input logic accepts TTL/CMOS-compatible signals (INA/INB), while EN enables simultaneous shutdown and DT configures dead time from 0 ns (overlap) to 240 ns (R_DT = 20 kΩ).

It integrates dual UVLO protection: 2.55–2.85 V on VCCI and 12.5–14.5 V (rising) / 11.5–13.5 V (falling) on VDDA/VDDB - specific to the CDW variant. All outputs are actively pulled low during primary-side logic failure, ensuring fail-safe operation in critical power stages.

Key Specifications

Pinout & Package

UCC21521CDW uses a wide-body SOIC-16 (DW) package with 10.30 mm × 7.50 mm nominal footprint and reinforced isolation barrier. Pin 1 (INA) to Pin 16 (VDDA) follow TI's standard DW top-view layout, with internal functional isolation separating primary (pins 1–8) and secondary (pins 9–16) sides.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel isolated gate driver applications.

Compared with UCC21521DW and Si8273BD-D-IS, the UCC21521CDW provides the highest VDD UVLO threshold (12.5–14.5 V), full reinforced isolation certification, and superior CMTI (>100 V/ns), making it the only option qualified for 1500 VDC working voltage and medical-grade 2-MOPP systems.

Availability

UCC21521CDW is available at Aetrix Electronics and suitable for isolated AC–DC power supplies, solar inverters, and industrial motor drives requiring stable component supply, long-term lifecycle support, and traceable sourcing for safety-certified designs.

Supply support for UCC21521CDW includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and high-reliability power management solutions.

The UCC21521 family is designed for high-performance isolated gate driving in industrial, automotive, and renewable energy systems - emphasizing timing precision, safety certification, and robustness in high-dV/dt environments.

FAQ

What is the VDD under-voltage lockout (UVLO) threshold for UCC21521CDW?

The UCC21521CDW has a 12-V UVLO version: VDDA and VDDB rising threshold is 12.5–14.5 V, and falling threshold is 11.5–13.5 V. This ensures the driver remains disabled until secondary-side supplies stabilize above 12.5 V, preventing unreliable gate drive during power-up or brownout. The hysteresis is 1.0 V. This differs from the ADW (5-V) and DW (8-V) variants.

How does the DT pin configure dead time on UCC21521CDW?

The DT pin on UCC21521CDW accepts an external resistor to GND to set dead time from 0 ns (overlap mode, DT tied to VCCI) to 240 ns (with 20-kΩ resistor). The relationship is DT (ns) = 10 × R_DT (kΩ). A ceramic capacitor ≥2.2 nF should be placed in parallel with R_DT for noise immunity. Leaving DT floating is not recommended.

Does UCC21521CDW support half-bridge configuration?

Yes, UCC21521CDW supports half-bridge configuration by routing OUTA to the high-side switch gate and OUTB to the low-side switch gate, with shared VSSB as the low-side return. Its programmable DT pin and matched propagation delays (≤5 ns matching) prevent shoot-through. Independent VSSA/VSSB references allow flexible PCB layout without requiring level shifters.

What safety certifications apply to UCC21521CDW?

UCC21521CDW holds VDE-reinforced isolation (DIN V VDE V 0884-11:2017-01), UL 1577 (5700 VRMS), CSA/IEC 62368-1, IEC 60950-1, IEC 61010-1, IEC 60601-1 (2 MOPP), and CQC GB4943.1-2011. These cover industrial, medical, and test equipment applications requiring reinforced insulation and high surge immunity (12.8 kV).

Can UCC21521CDW drive silicon carbide (SiC) MOSFETs?

Yes, UCC21521CDW is explicitly rated for SiC MOSFETs: its 4-A source / 6-A sink peak current, 19-ns propagation delay, ≤6-ns pulse-width distortion, and >100 V/ns CMTI meet the demanding gate-drive requirements of high-frequency SiC switches. The 25-V VDD capability supports gate drive voltages up to 20 V needed for full enhancement of SiC devices.