Texas Instruments UCC37321P

Overview

UCC37321P from Texas Instruments is an inverting 9-A peak low-side MOSFET driver with enable function, designed to interface PWM controllers with power N-channel MOSFETs in high-dV/dt switching applications. It delivers ±9 A peak current at the Miller plateau, supports 4.5–15 V supply, achieves 20-ns typical rise/fall times (10-nF load), and operates across –40°C to +105°C.

For engineers reviewing the UCC37321P datasheet, UCC37321P pinout, UCC37321P application, or UCC37321P equivalent, key selection criteria include its inverting logic configuration, true-drive bipolar-CMOS hybrid output stage, ENBL pin behavior (internally pulled up, active-high), thermal performance in PDIP-8 package, and suitability for synchronous rectification in buck-derived topologies.

Technical Context

The UCC37321P implements an inverting logic function: output goes low when input is high, and high when input is low. Its TrueDrive output stage combines bipolar and MOSFET transistors in parallel to deliver ±9 A peak current specifically during the Miller plateau region, minimizing switching losses in large gate-charge MOSFETs.

It features dual ground separation (AGND for control logic, PGND for power stage), internally pulled-up ENBL (100 kΩ to VDD) enabling active-high disable with forced-low output state, and TTL/CMOS-compatible inputs independent of supply voltage - ensuring robust operation across 4.5–15 V VDD with hysteresis-enhanced noise immunity.

Key Specifications

Pinout & Package

The UCC37321P is packaged in an 8-pin PDIP (Plastic Dual In-line Package) with body size 9.81 mm × 6.35 mm, lead pitch 2.54 mm, and Pb-free CU-Ni-Pd-Au (NiPdAu) finish. Thermal resistance θ_JA = 55.9°C/W (JEDEC std, 2S2P layout).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-side MOSFET driver applications.

Compared with UCC37321DR and UCC27321P, the UCC37321P provides guaranteed –40°C to +105°C operation and superior thermal margin in PDIP packaging - critical for high-reliability industrial power supplies where sustained 1.2-W dissipation occurs.

Availability

UCC37321P is available at Aetrix Electronics and suitable for switch mode power supplies, motor controllers, and Class-D switching amplifiers requiring stable component supply with long-term industrial temperature support and legacy through-hole assembly compatibility.

Supply support for UCC37321P 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 company specializing in analog, embedded processing, and power management ICs, with leadership in high-performance power conversion solutions.

The UCC3732x product line was engineered specifically for high-speed, high-current gate driving in industrial and telecom power systems - emphasizing Miller-region current delivery, noise-immune logic interfaces, and thermally robust packaging.

FAQ

What is the logic configuration of the UCC37321P?

The UCC37321P is an inverting low-side MOSFET driver: when the IN pin is high, the OUT pin goes low; when IN is low, OUT goes high. This matches synchronous rectifier requirements in buck-derived topologies where the controller outputs a high signal to turn off the low-side FET. The UCC37321P maintains this behavior across its full operating temperature and supply voltage range.

Does the UCC37321P require external pull-up or pull-down resistors on the ENBL pin?

No - the UCC37321P includes an internal 100-kΩ pull-up resistor from ENBL to VDD, making it active-high by default. Leaving ENBL unconnected enables normal operation. An external pull-down is only needed if active-low enable functionality is required, which would override the internal pull-up and force the driver into disabled (output low) state.

Can the UCC37321P drive GaN FETs effectively?

Yes - the UCC37321P's ±9-A peak output current, 20-ns rise/fall times, and low output impedance (0.4–1.5 Ω) make it suitable for driving enhancement-mode GaN FETs with Q_g ≤ 35 nC. Its Miller plateau current delivery ensures clean turn-on/turn-off transitions even under high dV/dt conditions common in GaN-based Class-D amplifiers and high-frequency DC-DC converters.

What is the maximum continuous power dissipation for the UCC37321P in PDIP package?

At T_A = 70°C, the UCC37321P (PDIP-8) has a power rating of 350 mW with a derating factor of 6.25 mW/°C above 70°C. This corresponds to a maximum junction temperature of 125°C. For applications dissipating >250 mW continuously, forced airflow or copper pour under the package is recommended to maintain reliability.

How does the dual-ground (AGND/PGND) design improve system performance in the UCC37321P?

The UCC37321P separates AGND (for input/enable logic) and PGND (for output stage return) to prevent high-di/dt switching noise from modulating input thresholds. This isolation reduces false triggering by >15 dB compared to single-ground drivers, especially critical in high-power motor drives and multi-phase VRMs where ground bounce exceeds 1 V peak-to-peak.