Texas Instruments TPS65261-1RHBR

Overview

TPS65261-1RHBR from Texas Instruments is a monolithic triple synchronous step-down DC/DC converter delivering 3-A, 2-A, and 2-A output currents across three independent buck channels. It operates from a 4.5-V to 18-V input supply, features a 0.6-V ±1% feedback reference, supports adjustable switching frequency (250 kHz–2 MHz), and implements forced continuous conduction mode (FCCM) for low-noise operation in set-top boxes and home gateways.

For engineers reviewing the TPS65261-1RHBR datasheet, TPS65261-1RHBR pinout, TPS65261-1RHBR application, or TPS65261-1RHBR equivalent, this page delivers verified electrical parameters, validated thermal performance (R_θJA = 31.6°C/W), confirmed FCCM light-load behavior, exact VQFN-32 (RHB) package mapping, and two rigorously cross-referenced alternative parts with documented functional distinctions.

Technical Context

The TPS65261-1RHBR uses constant-frequency peak-current-mode control per channel, with Buck1 operating 180° out-of-phase from Buck2/Buck3 to minimize input ripple and reduce bulk capacitor requirements. Each buck has dedicated EN, SS, FB, COMP, BST, and LX pins enabling independent sequencing, soft-start, loop compensation, and bootstrap management.

It integrates a 6.3-V internal LDO (V7V) for gate driver bias, monitors input voltage via VDIV for power-fail detection, asserts open-drain PGOOD when all outputs are within ±5% of regulation, and provides hiccup-mode overcurrent protection with 256-cycle wait time and 8192-cycle restart delay after thermal shutdown at 160°C.

Key Specifications

Pinout & Package

VQFN-32 (RHB) package: 5-mm × 5-mm, 0.5-mm pitch, exposed thermal pad soldered to PCB ground plane for optimal thermal performance (R_θJC(bot) = 0.9°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-buck DC/DC converter applications.

Compared with TPS65261RHBR and TPS65270RGET, the TPS65261-1RHBR uniquely balances FCCM noise suppression, integrated power-fail detection, and automatic sequencing-making it optimal for consumer-grade connected devices where EMI compliance and reliable cold/warm boot behavior are non-negotiable.

Availability

TPS65261-1RHBR is available at Aetrix Electronics and suitable for set-top box, home gateway, and surveillance camera applications requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.

Supply support for TPS65261-1RHBR 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 decades of expertise in high-reliability DC/DC conversion solutions.

The TPS6526x family was designed specifically for multi-rail consumer electronics power delivery-emphasizing integration, sequencing control, and FCCM/PSM mode flexibility to simplify design of DTV, gateway, and networking equipment.

FAQ

What is the key functional difference between TPS65261-1RHBR and TPS65261RHBR?

The TPS65261-1RHBR operates in Forced Continuous Conduction Mode (FCCM) at light loads, eliminating low-frequency switching noise and ensuring stable regulation under dynamic conditions. In contrast, the TPS65261RHBR uses Pulse Skipping Mode (PSM), which improves light-load efficiency but introduces variable-frequency artifacts that may interfere with RF or audio circuits. Both share identical pinout, package, and full-load specifications.

Does TPS65261-1RHBR support power sequencing across its three buck channels?

Yes, the TPS65261-1RHBR supports automatic power-up and power-down sequencing when the MODE pin is pulled high. This configures the device to stagger startup and shutdown of Buck1, Buck2, and Buck3 with a fixed 1024-cycle delay between channels, ensuring proper SoC or FPGA rail ordering without external controllers.

What is the purpose of the VDIV pin on the TPS65261-1RHBR?

The VDIV pin on the TPS65261-1RHBR serves as an input for power-fail detection. When connected to a resistor divider from the main input bus, it triggers the open-drain RESET signal when the input voltage falls below its 1.23-V threshold. This provides early brownout warning to system controllers before the buck regulators drop out of regulation.

Can TPS65261-1RHBR start up into a pre-biased output?

Yes, the TPS65261-1RHBR supports monotonic startup into pre-biased outputs. Its architecture prevents reverse current flow during initial ramp-up, making it suitable for hot-swap or modular systems where downstream circuitry may retain residual voltage on output rails prior to power application.

What thermal performance metrics are specified for TPS65261-1RHBR in the RHB package?

The TPS65261-1RHBR in the 5-mm × 5-mm VQFN-32 (RHB) package has a junction-to-ambient thermal resistance (R_θJA) of 31.6°C/W under standard JEDEC PCB conditions, and a junction-to-board resistance (R_θJB) of 6.1°C/W. The exposed thermal pad must be soldered to a solid copper pour for optimal heat dissipation and to maintain safe operation at full 3-A/2-A/2-A load.