Texas Instruments UC3715DTR

Overview

UC3715DTR from Texas Instruments is a high-speed complementary switch FET driver IC designed for synchronous rectification and active clamp/reset circuits in DC-DC converters. It features independently programmable 50–500 ns delays between AUX and PWR outputs, 1-A source / 2-A sink power driver capability, 0.5-A source / 1-A sink auxiliary driver, TTL-compatible INPUT, and ENBL-controlled 220-μA sleep mode. It operates across 0°C to 70°C and supports up to 1 MHz switching frequency in buck, forward, and LLC topologies.

For engineers reviewing the UC3715DTR datasheet, UC3715DTR pinout, UC3715DTR application, or UC3715DTR equivalent, this page delivers verified timing parameters, true-zero-voltage sensing capability, delay programming methodology, and functional distinctions between UC3715 and UC3714/UC2715 families - all critical for soft-switching gate drive design and synchronous rectifier layout validation.

Technical Context

The UC3715DTR implements dual-output complementary timing with independent T1 (AUX→PWR) and T2 (PWR→AUX) delay control via external resistors to GND, enabling precise dead-time management in zero-voltage-switching (ZVS) topologies. Its AUX output switches immediately on INPUT rising edge, while PWR activates after T1 delay - and PWR turns off instantly on INPUT falling edge, while AUX reactivates after T2 delay.

Each timer pin (T1/T2) provides true zero-voltage sensing: pulling either below ~2.5 V bypasses delay and triggers immediate output transition. The device uses internal current-limited timing circuits (nominal 3 V, ±1 mA), with propagation delays of 35–100 ns (PWR) and 35–80 ns (AUX), and supports TTL-level INPUT/ENBL thresholds (1.4 V and 1.2 V respectively).

Key Specifications

Pinout & Package

UC3715DTR is housed in an SOIC-8 (D package), 3.9 mm × 4.9 mm body, 1.27 mm pitch, RoHS-compliant, NIPDAU lead finish, MSL Level-2-250°C-1 year.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UC3714DTR, UC3715DTR enables n-channel AUX FETs without inversion logic; compared with UC2715DTR, it trades extended temperature range for lower cost and reduced quiescent current in commercial-grade systems.

Availability

UC3715DTR is available at Aetrix Electronics and suitable for forward converters, buck-based synchronous rectifiers, LLC resonant supplies, and active-clamp flyback designs requiring stable component supply, long-term BOM continuity, and traceable sourcing.

Supply support for UC3715DTR 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 delivering analog, embedded processing, and power management solutions with emphasis on reliability, precision, and system-level integration.

The UC37xx family was developed specifically for high-efficiency, high-frequency switched-mode power supplies requiring precise complementary gate drive with programmable dead time and zero-voltage sensing - targeting synchronous rectification and active clamp topologies.

FAQ

What is the operating temperature range for UC3715DTR?

The UC3715DTR is specified for operation from 0°C to +70°C - a commercial-grade temperature range optimized for indoor power supplies, consumer electronics, and cost-sensitive industrial applications. This differs from the UC2715DTR (–40°C to +85°C) and reflects its target use case in ambient-controlled environments where thermal margin is less constrained.

How does UC3715DTR implement true zero-voltage sensing?

The UC3715DTR implements true zero-voltage sensing on pins T1 and T2: when either pin is pulled below ~2.5 V (e.g., by a resistor divider monitoring FET drain voltage), the corresponding output transitions immediately - bypassing the programmed delay. This enables adaptive gate timing synchronized to actual VDS collapse, critical for ZVS in LLC and forward converters.

Can UC3715DTR drive both N-channel MOSFETs on the AUX and PWR outputs?

Yes - UC3715DTR is configured for true complementary operation: both PWR and AUX outputs are non-inverted, allowing direct drive of two N-channel MOSFETs. This distinguishes it from UC3714DTR, whose AUX output is inverted for p-channel use. No external inverters or level shifters are needed for dual-N-channel synchronous rectifier layouts.

What is the minimum delay achievable with UC3715DTR's T1 and T2 pins?

The minimum programmable delay for both T1 and T2 is 50 ns, achieved with RT = 10 kΩ to GND. At this setting, T1 delay ranges from 20–80 ns (typ. 35 ns) and T2 delay from 20–80 ns (typ. 50 ns), per electrical characteristics. Delays scale approximately linearly with resistance up to 500 ns at 100 kΩ.

Does UC3715DTR require external components for basic operation?

Yes - UC3715DTR requires at minimum: (1) a 0.1 µF ceramic bypass capacitor between VCC and GND, (2) pull-up/pull-down resistors on INPUT and ENBL for defined logic states, and (3) RT1/RT2 resistors on T1/T2 pins to set delays (or direct connection to GND/VCC for fixed timing). No external bootstrap diodes or charge pumps are needed for standard operation.