UCC21521ADWR - 5.7kVrms 4A/6A Isolated Gate Driver | TI
MPN: UCC21521ADWR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.44 | $3.44 |
| 10 | $3.17 | $31.70 |
| 100 | $2.89 | $289.00 |
| 500 | $2.64 | $1,320.00 |
| 1,000 | $2.41 | $2,410.00 |
UCC21521ADWR Overview
An isolated gate driver is a power management IC that transfers control signals across a galvanic isolation barrier, allowing a controller on the low-voltage side to switch power transistors such as MOSFETs, IGBTs, and SiC or GaN devices connected to a high-voltage rail. Isolated gate drivers sit within the broader gate driver and power management IC hierarchy and are essential wherever the gate-referenced potential differs from the logic-referenced potential.
Key differentiating specifications include the 5.7-kVRMS reinforced isolation rating per the capacitive isolation technology, the asymmetric 4-A source / 6-A sink drive strength that favors fast turn-off for switch protection, and a wide supply range with an 8-V UVLO threshold suited to SiC MOSFET gate driving. The enable pin supports system-level safety interlocks, and the dead-time control eases half-bridge design.
Architecturally, the UCC21521 uses a capacitive isolation barrier with on-chip signal isolation across a silicon-dioxide dielectric, providing high CMTI performance for switching noise immunity. The two output channels share a common topology with independent inputs, supporting inverting or non-inverting configurations depending on the ordering variant and input polarity.
Typical applications include motor drives and industrial inverters, solar string inverters and MPPT power stages, and on-board chargers or DC-DC power stages in industrial power systems. The 4-A/6-A drive strength matches medium-power SiC and IGBT modules where fast gate charge delivery reduces switching losses.
Design consideration: verify the input-side supply (VCCI) logic threshold matches the MCU or DSP bank voltage, and route the high-voltage side with adequate creepage and clearance per the reinforced-isolation footprint of the DW-16 package.
This page synthesizes verified distributor pricing, drop-in alternatives, and practical design notes not consolidated in the manufacturer datasheet alone.
Drop-in alternatives for UCC21521ADWR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with UCC21521ADWR (same form factor and footprint) — differing in Package, Configuration, Disable Function, Isolation Technology, Dead Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
UCC21520DW
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
UCC21521QDWQRQ1
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
UCC21550ADWR
✅ Drop-In✓ In Stock
$1.19 / Unit
View Datasheet →UCC21550BDWR
✅ Drop-In✓ In Stock
$0.88 / Unit
View Datasheet →UCC21550AQDWKRQ1
✅ Drop-In✓ In Stock
$2.2 / Unit
View Datasheet →UCC21521ADWR Maximum Ratings & Electrical Characteristics
| Product Type | Isolated dual-channel gate driver |
| Channels | 2 |
| Peak Source Current | 4 A |
| Peak Sink Current | 6 A |
| Isolation Rating | 5700 Vrms (reinforced) |
| Isolation Technology | Capacitive coupling |
| UVLO Threshold Option | 8 V |
| Enable Pin | Yes |
| Input Configuration | Dual input, inverting / non-inverting |
| Driver Configuration | Dual low-side, dual high-side, or half-bridge |
| Dead Time Control | Programmable |
| Package | 16-SOIC (DW) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Marking Code | UCC21521A |
UCC21521ADWR 16-soic (dw) Pin Configuration Guide
Pin configuration for UCC21521ADWR (16-soic (dw) package). This power device features gate, drain, and source terminals. For non-polarized packages, refer to the manufacturer datasheet for exact pin 1 orientation and footprint details. Common applications include power supply design, motor driving, and load switching.
No detailed pinout data available for UCC21521ADWR.
Refer to the datasheet for full pin configuration.
Typical Applications
UCC21521ADWR is suitable for 6 applications: Industrial Motor Drives, Solar String Inverters, On-Board Chargers and DC-DC Converters, SiC MOSFET Power Stages, Industrial Power Supplies and UPS, Battery Management and High-Voltage Discharge Circuits.
Industrial Motor Drives
Three-phase motor inverters place the UCC21521ADWR between the MCU or DSP PWM outputs and the gate terminals of six power switches. Its 4-A source / 6-A sink peak current delivers the gate charge of medium-power IGBT and SiC modules quickly, reducing switching losses at typical 5-20 kHz PWM frequencies, while the 5700-Vrms reinforced isolation barrier separates the control electronics from the DC bus. The programmable dead-time feature helps prevent shoot-through in each half-bridge leg, and the enable pin supports safe-torque-off interlocks. Placed close to the module gate pins with a minimized gate loop, the 6-A sink capability suppresses dv/dt-induced spurious turn-on in hard-switching legs.
Recommended
Solar String Inverters
In solar string inverters, the UCC21521ADWR drives the half-bridge power stages of the DC-DC boost and DC-AC inverter stages, where the power side floats hundreds of volts above the MPPT controller ground. The 5700-Vrms reinforced capacitive isolation provides the safety barrier required between the user-accessible control side and the PV bus. Its 8-V UVLO option is well matched to SiC MOSFET gate drives, preventing operation in the high-RDS(on) region during startup. The 6-A sink current reduces turn-off losses in high-frequency (50-100 kHz) boost stages, directly improving conversion efficiency and thermal headroom in sealed outdoor enclosures.
Recommended
On-Board Chargers and DC-DC Converters
OBC and auxiliary DC-DC power stages in industrial and vehicle systems use the UCC21521ADWR to drive LLC and phase-shifted full-bridge primaries. The reinforced isolation rating supports the safety separation between the grid-referenced primary and the battery-referenced secondary, and the capacitive isolation barrier's high CMTI tolerates the steep dv/dt of resonant topologies operating at 100-500 kHz. The asymmetric 4-A/6-A drive minimizes turn-off tail losses of the primary switches. Designers should keep the secondary gate loop short and use matched VDDA/VDDB decoupling to exploit the full sink current without gate ringing at high frequency.
Recommended
SiC MOSFET Power Stages
Silicon-carbide MOSFETs require gate drivers with UVLO thresholds above ~8 V and fast turn-off to avoid operation in elevated-RDS(on) regions and to limit dv/dt-induced shoot-through. The UCC21521ADWR's 8-V UVLO option and 6-A sink peak current align with these requirements: the strong pull-down discharges the SiC gate quickly, shortening the overlap of high voltage and high current at turn-off. Its capacitive isolation maintains signal integrity across the high dv/dt transients typical of SiC half-bridges. The enable pin allows a hardware fault interlock to disable both gates within microseconds, complementing software-level protection in the controller.
Recommended
Industrial Power Supplies and UPS
High-power AC-DC rectifier front ends and UPS inverter stages benefit from the UCC21521ADWR's universal configuration: the same device serves as a dual low-side driver for PFC stages or a half-bridge driver for the inverter bridge. The 5700-Vrms reinforced isolation satisfies the reinforced insulation requirement between mains-referenced power circuitry and user-accessible control logic in UPS and telecom rectifier architectures. The programmable dead-time control eases design of PFC half-bridge legs, while the 4-A/6-A drive keeps switching losses manageable at 20-100 kHz, reducing heatsink size in fanless or constrained-airflow industrial power systems.
Recommended
Battery Management and High-Voltage Discharge Circuits
High-voltage battery systems use contactors, pre-charge relays, and active discharge MOSFETs whose gates sit on the high-voltage domain while the BMS controller resides on the low-voltage domain. The UCC21521ADWR bridges this barrier with 5700-Vrms reinforced isolation, and its enable pin allows the BMS to open the gate-drive path immediately on a fault detection interrupt from current-sense amplifiers. The 6-A sink current ensures rapid gate discharge so that discharge or pre-charge switches turn off decisively under fault conditions. The dual channels allow one device to control both a main contactor driver and a pre-charge path from a single isolated component.
Recommended
Recommended Products Summary
Engineering reference data for UCC21521ADWR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | UCC21520DW | UCC21521QDWQRQ1 | UCC21550ADWR | UCC21550BDWR |
|---|---|---|---|---|---|
| Package | SOIC-16 (DW) | SOIC-16 (DW) - same | SOIC-16 (DW) - same | SOIC-16 (DW) - same | SOIC-16 (DW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Isolation Rating | 5700 Vrms (reinforced) | 5700 Vrms | 5700 Vrms | 5700 Vrms | 5700 Vrms |
| Enable Pin | Yes | Yes | Yes | Yes | Yes |
| UVLO Option | 8 V | 8 V (A-option) | 8 V (A-option) | A-option UVLO | B-option UVLO |
| Automotive Grade (AEC-Q100) | No | No | Yes | No | No |
Key Differentiators
- Asymmetric 4-A source / 6-A sink drive for fast turn-off (vs UCC21520DW)
- Enable pin for system-level safety interlock (vs UCC21550ADWR)
- Automotive drop-in path on identical footprint (vs UCC21521QDWQRQ1)
Design Notes
Preserve the reinforced isolation barrier in layout: do not route any copper traces or planes in the area directly beneath the isolation barrier region of the SOIC-16 (DW) footprint, and maintain the package's creepage and clearance envelope to the board. Keep primary-side VCCI decoupling (0.1 uF ceramic close to the pin plus a bulk capacitor) tight to the input-side supply pins. Group the input-side INA/INB/EN traces away from the output-side gate traces to prevent capacitive coupling across the board.
Minimize the secondary-side gate loop to exploit the 6-A sink current: place the driver as close as possible to the power switch, use wide gate traces (at least 20-30 mil for typical currents), and route the gate return (source or Kelvin-emitter) as a dedicated trace rather than sharing the power ground path. Estimate: with 10 nH of loop inductance and a 6-A/20-ns sink edge, induced L di/dt ringing can reach several volts - a dedicated Kelvin return is essential to avoid spurious turn-on in half-bridge legs.
Verify the ordering suffix polarity: the UCC21521 family includes inverting and non-inverting input variants, and swapping an inverting variant into a non-inverting design will invert the PWM logic and can cause shoot-through at power-up. Also confirm that the 8-V UVLO (A-option) matches the secondary gate-drive supply rail - a driver powered from a 12-V rail with 8-V UVLO works for SiC, but a rail that sags below UVLO during transients will interrupt gate drive mid-pulse. Add hysteresis margin on the bias rail.
Estimated: gate-drive average dissipation is P = Qg * fsw * (VDD - 0) per channel; for a SiC MOSFET with 60-nC gate charge at 100 kHz and 15-V drive, this is roughly 90 mW per channel, negligible in the SOIC-16 package. The dominant loss is usually in the internal pull-up/pull-down resistance during switching transitions - keep fsw within datasheet thermal guidelines and use the datasheet theta-JA with the DW-16 package for verification above approximately 200 kHz.
Compliance Information
RoHS compliance per TI product family standard. Not AEC-Q100 qualified - select UCC21521Q variants for automotive applications. REACH and halogen-free status not stated in verified data.