Texas Instruments UC3715D

Overview

UC3715D from Texas Instruments is a high-speed complementary switch FET driver IC designed for synchronous rectification and active clamp/reset circuits. It features independently programmable 50–500 ns delays between power (PWR) and auxiliary (AUX) outputs, 1-A source / 2-A sink PWR drive capability, 0.5-A source / 1-A sink AUX drive, and TTL-compatible INPUT/ENBL logic. It operates in 0°C to 70°C ambient and supports up to 1 MHz switching frequency in DC-DC converters.

For engineers reviewing the UC3715D datasheet, UC3715D pinout, UC3715D application, or UC3715D equivalent, key selection considerations include its dual-delay timing architecture, zero-voltage sensing via T1/T2 pins, ENBL-enabled 220-μA sleep mode, SOIC-8 package compatibility, and functional distinction from UC3714 (non-inverted AUX) and UC2715 (wider temperature range).

Technical Context

The UC3715D implements a two-output complementary driver architecture where the AUX output switches immediately on INPUT rising edge and after T2 delay on INPUT falling edge, while the PWR output activates after T1 delay on INPUT rising edge and turns off immediately on INPUT falling edge. Timing delays are set by external resistors to GND on T1 and T2 pins, with nominal internal voltage of 3 V and ±1 mA current limiting.

It uses true-zero-voltage-sensing capability on T1/T2 pins-pulling either below 2.5 V triggers immediate output activation-enabling adaptive dead-time control in resonant topologies. The PWR output remains active-low during ENBL ≤0.8 V regardless of VCC, ensuring safe gate-drive state in sleep mode.

Key Specifications

Pinout & Package

UC3715D is housed in an 8-pin SOIC (D) package with standard 1.27 mm pitch and gull-wing leads. Pin 1 is located at the top-left corner with notch or mark indicator; device orientation follows JEDEC MS-012.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar complementary FET driver applications.

Compared with UC3714D and UC2715D, UC3715D uniquely combines inverted AUX output, zero-voltage sensing on both T1/T2, and commercial-grade thermal specification-making it the preferred choice for compact, high-efficiency synchronous rectifier designs where p-channel gate drive and adaptive dead-time are required.

Availability

UC3715D is available at Aetrix Electronics and suitable for forward converters, LLC resonant supplies, isolated flyback active reset circuits, and synchronous rectifier modules requiring stable component supply across production volumes.

Supply support for UC3715D 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 power management technologies with over 50 years of innovation in power conversion solutions.

The UC37xx family was developed specifically for high-frequency, zero-voltage-switching power topologies-emphasizing precision timing control, integrated delay programming, and robust gate-drive strength for synchronous rectification and active clamp applications.

FAQ

What is the operating temperature range for UC3715D?

The UC3715D is specified for operation from 0°C to +70°C ambient temperature. This commercial-grade rating aligns with its intended use in thermally managed power supplies such as AC-DC adapters, USB-PD chargers, and enclosed DC-DC modules. It differs from the UC2715D, which supports –40°C to +85°C for industrial deployment. Always verify PCB layout thermal relief and local hotspot conditions when operating near the upper limit.

How does UC3715D implement zero-voltage sensing?

The UC3715D implements true zero-voltage sensing on the T1 and T2 pins: pulling either pin below 2.5 V (e.g., via resistor divider from resonant node) immediately triggers the corresponding output-T1 activation forces PWR on, T2 activation forces AUX on-bypassing programmed delay. This feature enables adaptive dead-time control without external comparators, directly supporting ZVS in LLC and forward converters. The nominal T1/T2 voltage is 3 V with ±1 mA current limiting.

What is the difference between UC3715D and UC3714D?

The core functional difference is AUX output polarity: UC3715D provides an inverted AUX output (suitable for driving p-channel MOSFETs directly), while UC3714D provides a non-inverted AUX output (aligned with INPUT). Both share identical delay programming, drive strength, pinout, and electrical specs. Selection depends on FET type-UC3715D eliminates level-shifters in p-channel synchronous rectifiers; UC3714D simplifies dual-N-channel complementary switching.

Does UC3715D support 1 MHz switching frequency?

Yes, UC3715D supports up to 1 MHz switching frequency, enabled by its typical 35–100 ns propagation delays and sub-100 ns rise/fall times (30–60 ns for PWR, 45–60 ns for AUX under specified loads). Its timing architecture-including independently programmable 50–500 ns delays and zero-voltage sensing-maintains timing integrity at high frequencies, making it suitable for GaN- and high-frequency Si-based converters where gate-drive jitter must remain <1% of switching period.

What happens to PWR output during ENBL sleep mode?

When ENBL is pulled ≤0.8 V, UC3715D enters 220-μA sleep mode and forces the PWR output active-low-regardless of VCC voltage or INPUT state. This fail-safe behavior ensures the main switch gate is held discharged, preventing unintended conduction during standby. The AUX output goes high-impedance. This design protects downstream FETs and simplifies system-level power sequencing in always-on or burst-mode power supplies.