UCC21521Q-Q1 - 4A/6A 5.7kVRMS Dual Gate Driver | Texas Instruments
MPN: UCC21521Q-Q1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1 | $1.00 |
| 10 | $1 | $10.00 |
| 100 | $1 | $100.00 |
| 500 | $1 | $500.00 |
| 1,000 | $1 | $1,000.00 |
UCC21521Q-Q1 Overview
An isolated gate driver is a power management IC that provides galvanic isolation between the low-voltage controller side and the high-voltage power stage, allowing a microcontroller to safely drive power semiconductor switches such as MOSFETs, SiC FETs, and IGBTs. Gate drivers form the interface layer of the power-conversion hierarchy: controller -> signal isolator -> gate driver -> power switch.
Key features include capacitive-coupled isolation rated at 5700 Vrms, high CMTI (common-mode transient immunity) for fast-switching wide-bandgap applications, a UVLO (undervoltage lockout) on both input and output supplies that prevents erratic gate drive during power-up, and an enable pin that places both outputs low for safety interlocks. The 4-A/6-A asymmetrical drive strength provides strong turn-off capability that minimizes switching losses and improves dv/dt immunity against parasitic turn-on.
The Q1 grade guarantees operation from -40C to +125C ambient under AEC-Q100 automotive qualification, making the device suited to traction inverters, on-board chargers, and 48V systems. The universal channel configuration lets a single bill-of-material position cover half-bridge, dual low-side, and dual high-side designs, reducing qualification overhead across platforms.
Typical applications include automotive traction inverters, OBC PFC and LLC power stages, DC fast-charger modules, solar string inverters, and industrial motor drives driving SiC or IGBT switches. The wide-body creepage and clearance of the SOIC-16 (DW) package supports reinforced isolation designs.
Design consideration: size the gate-loop resistance to balance switching speed against ringing, and place the driver close to the power switch to minimize loop inductance; always verify CMTI margin against the fastest dv/dt in the system.
Pricing data as of 2026-08-29; see tiers below for quantity pricing.
Drop-in alternatives for UCC21521Q-Q1 — 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 UCC21521Q-Q1 (same form factor and footprint) — differing in Isolation Rating, Package, Operating Temperature, Enable Pin, Isolation Technology.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
UCC21521DW
✅ Drop-In📋 Reference alternative (not in catalog)
UCC21520QDWRQ1
✅ Drop-In📋 Reference alternative (not in catalog)
UCC21521CDW
✅ Drop-In📋 Reference alternative (not in catalog)
UCC21520DW
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
UCC21540DWR
⚡ Same Package ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
UCC21521Q-Q1 Maximum Ratings & Electrical Characteristics
| Isolation Type | Capacitive coupling, reinforced isolation |
| Isolation Rating | 5700 Vrms |
| Channels | 2 (dual low-side, dual high-side, or half-bridge) |
| Peak Source Current | 4 A |
| Peak Sink Current | 6 A |
| Enable Pin | Yes |
| UVLO | Yes, on input and output supplies |
| AEC-Q100 | Qualified (automotive grade Q1) |
| Operating Temperature | -40C to +125C |
| Package | 16-SOIC (DW) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lifecycle Status | Active |
UCC21521Q-Q1 Pin Configuration
| Pin 1 | VCCI — Input-side supply voltage |
| Pin 2 | GND — Input-side ground |
| Pin 3 | INH — Input, channel H |
| Pin 4 | INL — Input, channel L |
| Pin 5 | EN — Enable (forces both outputs low when low) |
| Pin 8 | VDDA — Output channel A supply |
| Pin 9 | OUTA — Gate drive output, channel A |
| Pin 10 | GNDA — Output channel A ground return |
| Pin 12 | VDDB — Output channel B supply |
| Pin 13 | OUTB — Gate drive output, channel B |
| Pin 14 | GNDB — Output channel B ground return |
| Pin 16 | NC/GND — [DATA_NEEDED: verify pin 16 function against datasheet] |
Typical Applications
UCC21521Q-Q1 is suitable for 6 applications: Automotive Traction Inverter, On-Board Charger (OBC) Power Stage, DC Fast Charger Power Modules, Solar String Inverter, Industrial Motor Drives, 48V Automotive and Datacenter Power Systems.
Automotive Traction Inverter
The UCC21521Q-Q1's AEC-Q100 qualification, 5.7-kVRMS reinforced isolation, and 6-A sink current make it a strong fit for SiC- and IGBT-based traction-inverter gate stages, where -40C to +125C ambient and high CMTI are mandatory. Placed between the inverter MCU (e.g., C2000 PWM outputs through the enable-controlled inputs) and the power module gates, it translates logic-level PWM into isolated 4-A/6-A gate drive; the enable pin provides a hardware safety interlock for fault conditions.
Recommended
On-Board Charger (OBC) Power Stage
In OBC PFC and LLC stages, the UCC21521Q-Q1 drives the primary-side power switches with 5.7-kVRMS isolation meeting reinforced-isolation creepage requirements in the 16-SOIC (DW) package. Its universal half-bridge configuration lets one part number cover both the PFC leg and the LLC half-bridge, simplifying qualification; the UVLO on both supplies prevents operating the switches with insufficient gate voltage, protecting against operation in the linear region during startup.
Recommended
DC Fast Charger Power Modules
DC fast-charger modules use three-phase PFC and high-power DC/DC stages where the UCC21521Q-Q1 provides isolated 4-A/6-A gate drive for SiC super-junction switches. The high isolation rating (5700 Vrms) and robust CMTI withstand the large dv/dt of fast switching, while the automotive Q1 grade supports charger-to-vehicle communication and safety requirements. Strong 6-A turn-off current reduces switching losses, directly improving converter efficiency at hundreds of kilowatts.
Recommended
Solar String Inverter
Grid-tied solar inverters require isolated gate drivers for their boost and inverter legs; the UCC21521Q-Q1's 5.7-kVRMS isolation and enable-based shutdown support the safety architecture of string inverters up to 1500V DC bus. In half-bridge or full-bridge topologies, the interlock-free universal channel configuration lets designers map high-side and low-side channels as needed. The device's UVLO ensures the SiC/IGBT gates are never driven weakly, avoiding hot-switching failures during panel-side transients.
Recommended
Industrial Motor Drives
Servo and industrial motor drives use the UCC21521Q-Q1 to isolate the controller from IGBT power stages in the 16-SOIC (DW) package. The 4-A/6-A drive current supports IGBT modules up to several hundred amperes, and the enable pin allows the drive to gate off quickly during overcurrent faults detected by current sensors. The universal configuration serves both the three-phase inverter bridge and the brake chopper with a single component type, reducing inventory and board variants.
Recommended
48V Automotive and Datacenter Power Systems
In 48V mild-hybrid DC/DC converters and datacenter 48V power shelves, the UCC21521Q-Q1 provides isolated drive for the primary-side switches of LLC and phase-shifted full-bridge converters. The automotive grade covers vehicle requirements while the same design serves telecom power. Its capacitive isolation has no aging-related degradation of CMTI like optocoupler alternatives, and the 5.7-kVRMS rating gives margin for functional-isolation designs, improving long-term reliability in continuous-operation power systems.
Recommended
Recommended Products Summary
Engineering reference data for UCC21521Q-Q1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | UCC21521DW | UCC21520QDWRQ1 | UCC21521CDW |
|---|---|---|---|---|
| Package | 16-SOIC (DW) | 16-SOIC (DW) - same | 16-SOIC (DW) - same | 16-SOIC (DW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Isolation Rating | 5700 Vrms | 5700 Vrms | 5700 Vrms | 5700 Vrms |
| Peak Output Current | 4 A source / 6 A sink | 4 A / 6 A | 4 A / 6 A | 4 A / 6 A |
| AEC-Q100 Qualified | Yes (Q1) | No | Yes | No |
| Enable Pin | Yes | Yes | No (dual input configuration) | Yes |
| Configuration | Universal (dual low/high-side, half-bridge) | Universal | Universal, dual input | Universal |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C |
Key Differentiators
- Automotive AEC-Q100 qualification with enable interlock (vs UCC21520QDWRQ1)
- Q1 grade over commercial grade (vs UCC21521DW)
- Asymmetrical 4-A source / 6-A sink drive (vs UCC21520DW)
Design Notes
Minimize the gate drive loop: place UCC21521Q-Q1 within 10-15 mm of the power switch gate, use short wide gate traces, and place a low-ESR decoupling capacitor (e.g., 1uF ceramic) directly across each VDDA-GNDA and VDDB-GNDB pair within 3 mm of the pins. Route the OUTA/OUTB traces away from switching nodes to avoid dv/dt coupling into the gate loop.
Size each output-side bias supply (VDDA, VDDB) to deliver the average gate charge current plus device quiescent current. For a high-frequency SiC design, use an isolated bias such as TI UCC25800-Q1 push-pull transformer driver. Ensure the supply exceeds the UVLO threshold with margin so the driver never disables during supply ripple; TI datasheet layout and application sections give reference bias circuits.
Do not leave the EN pin floating - tie it to VCCI through a pull-up resistor if enable control is unused, otherwise the outputs may stay disabled. Also confirm CMTI margin: the external dv/dt of the power switch must remain below the device's specified CMTI, especially with fast SiC FETs. Verify all pin assignments against the TI UCC21521 datasheet (Rev. B) before PCB release.
Compliance Information
AEC-Q100 qualified (Q1 automotive grade) per TI product listings. RoHS compliant per DigiKey/TI product data. REACH, halogen-free, and conflict-minerals statements should be confirmed via TI's official compliance certificates for the exact orderable part number.