Texas Instruments UCC2540PWP

Overview

UCC2540PWP from Texas Instruments is a secondary-side synchronous buck PWM controller designed for high-current, low-voltage DC-DC post-regulation. It delivers dual ±3-A TrueDrive gate outputs, supports 1-MHz operation with 70-ns SYNCIN-to-G1 delay, and implements Predictive Gate Drive to eliminate body-diode conduction losses in synchronous rectifiers-enabling >95% efficiency in cascaded bus converter architectures.

For engineers reviewing the UCC2540PWP datasheet, UCC2540PWP pinout, UCC2540PWP application, or UCC2540PWP equivalent, key selection criteria include its thermally enhanced HTSSOP-20 PowerPAD package (θJC = 1.4°C/W), three-mode bias support (2.7–35 V), leading-edge modulation compatibility with primary-side controllers, and integrated reverse current protection for output stage reliability.

Technical Context

The UCC2540PWP integrates dual independent gate drivers (G1 high-side, G2 low-side) with predictive deadtime control using SWS and G2S sensing inputs to dynamically adjust timing based on SR MOSFET gate voltage and body-diode conduction detection. Its error amplifier architecture supports parallel average current mode control via CEA−/VEA− differential monitoring, enabling hiccup-mode overcurrent protection with programmable shutdown.

It operates across three supply modes: Mode 1 (VDD = 8.5–35 V), Mode 2 (VDRV = 4.75–8.0 V), and Mode 3 (REF = 3.0–3.6 V), each with distinct UVLO thresholds and hysteresis. Timing functions-including RAMP-based PWM modulation, G2C-controlled synchronous rectifier timeout, and SS-programmable soft-start-are all derived from a single RSET-programmed current source with precise gain ratios (e.g., 2× for RAMP/G2C, 1.33× for SS charge).

Key Specifications

Pinout & Package

UCC2540PWP is housed in a thermally enhanced 20-pin HTSSOP PowerPAD (PWP) package. The exposed PowerPAD (1.3 mm × 1.7 mm) is electrically connected to PGND and must be soldered to a dedicated PCB ground plane with multiple vias for optimal thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar secondary-side synchronous buck controller applications.

Compared with UCC2540PWP, UCC28220D offers lower integration and no predictive timing, limiting efficiency in high-current SSR applications, while LM5113SD shifts control responsibility to external circuitry - increasing BOM count and layout sensitivity but enabling full customization of protection thresholds and modulation behavior.

Availability

UCC2540PWP is available at Aetrix Electronics and suitable for telecom power supplies, server VRMs, and industrial DC transformer systems requiring stable component supply, extended temperature operation (−40°C to 105°C), and high-reliability thermal management.

Supply support for UCC2540PWP 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 ICs, with decades of expertise in high-efficiency power conversion solutions.

The UCC2540PWP belongs to TI's UCC secondary-side controller product line, engineered specifically for high-current, low-voltage post-regulation in isolated multi-output power systems - emphasizing thermal robustness, predictive timing, and seamless interoperability with bus converters and DC transformers.

FAQ

What is the maximum operating frequency supported by the UCC2540PWP?

The UCC2540PWP supports up to 1-MHz operation with a guaranteed 70-ns propagation delay from SYNCIN to G1 output. Its TrueDrive outputs maintain <25 ns rise/fall times into 2.2-nF loads, enabling stable high-frequency synchronous buck operation without external gate drivers. The RAMP timer and G2C timeout functions scale linearly with switching period, preserving timing integrity across the full frequency range.

How does the Predictive Gate Drive feature work in the UCC2540PWP?

The UCC2540PWP implements Predictive Gate Drive by continuously monitoring the SR MOSFET's gate voltage (via G2S) and drain voltage (via SWS) to detect body-diode conduction onset. When conduction is sensed, it dynamically adjusts G1/G2 deadtime in real time - turning off G2 before reverse current flows and turning on G1 earlier to clamp the node. This eliminates body-diode losses and improves efficiency by up to 3% in high-current SSR designs.

What are the thermal advantages of the UCC2540PWP's PowerPAD HTSSOP-20 (PWP) package?

The UCC2540PWP's PWP package delivers θJC = 1.4°C/W - over 10× better than standard TSSOP - due to its exposed PowerPAD thermally bonded to PGND. This allows sustained dual ±3-A driver operation at full load without derating, even in compact 2-layer PCBs. The 1.3 mm × 1.7 mm exposed pad must be soldered to a solid PGND copper area with ≥4 thermal vias to achieve rated thermal performance.

Can the UCC2540PWP operate without an external clock source?

Yes - the UCC2540PWP can accept a quasi-DC signal from bus converters or DC transformers on SYNCIN, eliminating need for a discrete clock generator. Its 1.5–1.8 V input threshold and internal hysteresis allow reliable synchronization to noisy or slowly rising waveforms. If SYNCIN is inactive, the RAMP timer enforces G1 pulse termination, preventing uncontrolled duty cycles during startup or fault conditions.

What protection features does the UCC2540PWP provide for overcurrent and reverse current conditions?

The UCC2540PWP provides parallel average current mode protection via CEA−/VEA− differential monitoring, triggering hiccup-mode shutdown when |CEA− − VEA−| exceeds 50 mV. It also includes reverse current protection that forces both G1 and G2 LOW if inductor current reverses, plus G2C timeout to prevent extended zero-duty operation. All protections are fully programmable via RSET and external capacitors - no firmware or external logic required.