Texas Instruments TPS65400RGZR

Overview

TPS65400RGZR from Texas Instruments is a 4-channel, PMBus/I²C-programmable power management unit (PMU) integrating four synchronous buck regulators - two 4-A (SW1/SW2) and two 2-A (SW3/SW4) - with integrated FETs, operating from 4.5 V to 18 V input. It delivers up to 95% efficiency per regulator, supports independent PWM frequency adjustment (275 kHz–2.2 MHz), and enables precise voltage sequencing for FPGA, DSP, and automotive infotainment systems.

For engineers reviewing the TPS65400RGZR datasheet, TPS65400RGZR pinout, TPS65400RGZR application, or TPS65400RGZR equivalent, this device offers runtime voltage positioning, programmable current limits, soft-start delay control, thermal/overvoltage/overcurrent protection, and EEPROM-stored configuration - critical for high-density, thermally constrained industrial and communications equipment.

Technical Context

The TPS65400RGZR implements four independent buck controllers with internal high- and low-side MOSFETs, each featuring adjustable current limit (SW1/SW2: 2–6 A; SW3/SW4: 0.5–3 A), 10-mV programmable VREF (0.6–1.87 V), and phase-aligned PWM outputs to minimize ripple. Its PMBus/I²C interface provides real-time monitoring of PGOOD status, fault flags, and output voltages, while enabling dynamic reconfiguration without hardware changes.

Sequencing is supported via both pin-strapped enable inputs (ENSW1–ENSW4) and EEPROM-configurable timing (fixed delays or PGOOD dependency). The device integrates three internal subregulators (VDDA, VDDD, VDDG) and uses a thermally enhanced 7-mm × 7-mm VQFN-48 package with exposed thermal pad tied to PGND, delivering R_θJA = 29.8°C/W and R_θJB = 6.3°C/W for high-ambient operation up to +125°C junction temperature.

Key Specifications

Pinout & Package

TPS65400RGZR is housed in a thermally enhanced 7-mm × 7-mm, 48-pin VQFN package (RGZ) with an exposed thermal pad that must be soldered to PCB ground for optimal thermal performance. Pin count and layout are optimized for four independent buck channels, analog/digital power domains, and full PMBus control.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-rail PMU applications.

Compared with TPS65400RGZR, TPS65400RGZT offers identical performance in a different packaging format, while MP2960GQ-0000-Z trades advanced PMBus telemetry and nonvolatile configuration for lower BOM cost and simpler firmware integration - making it viable only where EEPROM persistence and comprehensive fault diagnostics are unnecessary.

Availability

TPS65400RGZR is available at Aetrix Electronics and suitable for small cellular base stations, automotive infotainment systems, and Power-over-Ethernet infrastructure requiring stable component supply, long-lifecycle support, and AEC-Q100 Grade 1 qualification.

Supply support for TPS65400RGZR 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 experience in high-reliability industrial and automotive power solutions.

The TPS65400RGZR belongs to TI's high-density PMU product line, designed specifically for space-constrained, thermally demanding applications such as 5G small cells, automotive telematics, and industrial edge computing - where integration, efficiency, and digital configurability are critical.

FAQ

What is the maximum input voltage rating for the TPS65400RGZR?

The TPS65400RGZR has an absolute maximum input voltage rating of 20 V across PVIN1–PVIN4 and VIN pins, with recommended operation up to 18 V. Exceeding 18 V risks violating recommended operating conditions and may trigger undervoltage lockout (UVLO) release at 4.48 V or cause thermal stress under sustained load - always verify derating per application ambient temperature using R_θJA = 29.8°C/W.

Does the TPS65400RGZR support prebias start-up?

Yes, the TPS65400RGZR implements a dedicated prebias start-up algorithm that prevents output voltage dip when powering precharged loads. This feature actively controls gate drive timing during initial ramp-up, ensuring smooth transition even when output capacitors are already charged - critical for FPGA core rail stability and avoiding reset glitches in TPS65400RGZR-based systems.

Can the TPS65400RGZR operate without I²C communication?

Yes, the TPS65400RGZR supports full standalone operation using pin-strapped enable inputs (ENSW1–ENSW4), external feedback resistors, and RCLOCK_SYNC for frequency setting. All default configurations - including VREF, soft-start time, and sequencing order - are stored in on-chip EEPROM and loaded automatically at power-up, eliminating dependency on host I²C initialization for basic functionality of the TPS65400RGZR.

What thermal metrics define the TPS65400RGZR's cooling requirements?

The TPS65400RGZR's thermal performance is defined by R_θJA = 29.8°C/W (junction-to-ambient, JEDEC standard), R_θJB = 6.3°C/W (junction-to-board), and R_θJC(bot) = 0.8°C/W (junction-to-case bottom). These values assume proper soldering of the exposed thermal pad to a solid PGND plane - achieving ≤125°C junction temperature requires ≥4-layer PCB with ≥2 oz copper and thermal vias under the pad for the TPS65400RGZR.

How is current sharing implemented between SW1 and SW2 in the TPS65400RGZR?

Current sharing between SW1 and SW2 in the TPS65400RGZR is achieved by connecting COMP1 to COMP2 and configuring SW1's controller to drive both phases via internal logic. This forces matched duty cycles and phase alignment (≤5° error), enabling combined 8-A output capability with ±20% average current matching accuracy - verified under full 4-A-per-phase load with matched inductors and PCB layout for the TPS65400RGZR.