Texas Instruments TPS65279RHHT

Overview

TPS65279RHHT from Texas Instruments is a dual-channel synchronous step-down DC/DC converter with integrated 5-A N-channel MOSFETs per channel, operating from 4.5 V to 18 V input and delivering up to 5 A continuous output current per buck stage. It supports current sharing (up to 10 A), 180° out-of-phase operation, and programmable switching frequency (200 kHz–1.6 MHz) for EMI reduction and layout optimization in point-of-load power systems.

For engineers reviewing the TPS65279RHHT datasheet, TPS65279RHHT pinout, TPS65279RHHT application, or TPS65279RHHT equivalent, this device is selected for high-density dual-rail power delivery requiring independent enable/soft-start control, pulse-skipping mode efficiency at light load, and robust thermal protection in telecom, DTV, and tablet PC designs.

Technical Context

The TPS65279RHHT implements constant-frequency peak-current-mode control with dedicated COMP pins for each buck stage, enabling simple Type-II compensation. Its 180° phase shift between channels reduces input ripple current by ~70%, lowering required input capacitance and easing EMI filter design.

It integrates a 6.3-V internal LDO (V7V) for gate drive biasing, supports external synchronization via ROSC pin with PLL lock, and features bidirectional low-side overcurrent protection plus hiccup-mode thermal shutdown (trip at 160°C, 20°C hysteresis) for reliable fault handling in industrial environments.

Key Specifications

Pinout & Package

TPS65279RHHT is housed in a 36-pin VQFN package (6.00 mm × 6.00 mm, 0.5-mm pitch) with exposed thermal pad soldered to PGND for enhanced heat dissipation. Pin functions are validated per TI SLVSC85C Rev C datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual synchronous buck converter applications.

Compared with MP8770GQ-Z and RTQ2132B-QT, the TPS65279RHHT uniquely combines current sharing, independent enable/soft-start, and robust thermal protection in a production-proven 6 mm × 6 mm VQFN-making it optimal for high-reliability dual-rail systems where sequencing, fault resilience, and scalability matter.

Availability

TPS65279RHHT is available at Aetrix Electronics and suitable for telecom infrastructure, DTV, and tablet PC applications requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.

Supply support for TPS65279RHHT 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 DC/DC conversion and automotive-grade reliability.

The TPS65279RHHT belongs to TI's high-current dual buck converter product line, designed specifically for compact, thermally demanding point-of-load applications in consumer, telecom, and industrial equipment where dual-rail flexibility and fault tolerance are essential.

FAQ

What is the maximum continuous output current per channel for the TPS65279RHHT?

The TPS65279RHHT delivers up to 5 A continuous output current per buck channel under recommended operating conditions (T_J ≤ 125°C, proper PCB thermal design). When configured in current-sharing mode using the ISHARE pin, the two channels combine to deliver up to 10 A to a single output rail. This capability is validated across the full 4.5 V to 18 V input range and requires appropriate external components (inductors, output capacitors) rated for the combined current.

How does the TPS65279RHHT achieve high efficiency at light load?

The TPS65279RHHT achieves high light-load efficiency through its pulse-skipping mode (PSM), activated by configuring the MODE pin to V7V. In PSM, the device monitors peak switch current and disables switching entirely when load drops below ~1 A, eliminating switching losses. This results in >85% efficiency at 10 mA output (e.g., 12 V_IN/3.3 V_OUT), significantly outperforming forced PWM mode at sub-100 mA loads. The TPS65279RHHT automatically resumes PWM operation when load increases.

Can the TPS65279RHHT be synchronized to an external clock signal?

Yes, the TPS65279RHHT supports external clock synchronization via the ROSC pin. Applying a square-wave clock (200–1600 kHz, 20–80% duty cycle, 0.8 V low / 2 V high thresholds) to ROSC engages the internal PLL, locking the switching cycles to the falling edge of the external clock. This feature overrides the resistor-based frequency setting and is used to reduce beat frequencies and improve EMI performance in multi-converter systems. The TPS65279RHHT automatically detects and switches between resistor and sync modes.

What thermal protection mechanisms does the TPS65279RHHT include?

The TPS65279RHHT incorporates thermal shutdown with a trip point of 160°C (rising junction temperature) and 20°C hysteresis. Upon exceeding the trip point, the device enters hiccup mode: it shuts down for 16384 switching cycles (~100 ms at 160 kHz), then attempts automatic restart via the soft-start circuit. If overheating persists, the cycle repeats. This protects against sustained overload or inadequate PCB cooling while minimizing thermal stress. The TPS65279RHHT's R_θJA = 30.8°C/W (RHH package) ensures reliable operation with standard 2-oz copper and thermal vias.

Does the TPS65279RHHT support power supply sequencing for multiple rails?

Yes, the TPS65279RHHT supports precise power supply sequencing through independent SS1 and SS2 pins. Each pin accepts an external capacitor to program soft-start time (e.g., 6 ms per nF), allowing staggered ramp-up of Buck1 and Buck2 outputs. Additionally, separate EN1 and EN2 pins enable hardware-controlled enable timing, while PGOOD1 and PGOOD2 open-drain outputs provide status signals for downstream logic or microcontroller monitoring. This makes the TPS65279RHHT suitable for complex SoC or FPGA power trees requiring strict voltage ordering.