Texas Instruments TPS65400QRGZRQ1

Overview

TPS65400QRGZRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-qualified quad-buck power management unit (PMU) with integrated FETs, PMBus/I²C interface, and four independent switching regulators: SW1/SW2 rated at 4 A each and SW3/SW4 at 2 A each, operating from 4.5 V to 18 V input - used for powering processors, FPGAs, and memory in space-constrained automotive and industrial systems.

For engineers reviewing the TPS65400QRGZRQ1 datasheet, TPS65400QRGZRQ1 pinout, TPS65400QRGZRQ1 application, or TPS65400QRGZRQ1 equivalent, key selection considerations include per-regulator current limit programmability (0.5–6 A), independent PWM frequency adjustment (275 kHz–2.2 MHz), soft-start/PGOOD dual-function pins, thermal shutdown at 160°C, and EEPROM-configurable power sequencing.

Technical Context

The TPS65400QRGZRQ1 implements a fully integrated PMBus/I²C-compatible digital control architecture with on-chip EEPROM for persistent configuration of voltage setpoints, sequencing delays, switching frequencies, and current limits. Each buck regulator features independent error amplifiers, adjustable compensation via COMPx pins, and pre-bias startup support.

It integrates four synchronous buck controllers with internal high-side/low-side MOSFETs (R_DS(on) HS: 66 mΩ for SW1/SW2, 120 mΩ for SW3/SW4; R_DS(on) LS: 42 mΩ / 90 mΩ), precision voltage reference (0.6–1.87 V in 10-mV steps), and real-time fault monitoring including OVP/UVP (±7% window), OCP, OTP, and I²C watchdog timeout detection.

Key Specifications

Pinout & Package

TPS65400QRGZRQ1 is housed in a thermally enhanced 7-mm × 7-mm, 48-pin VQFN package (RGZ) with exposed thermal pad soldered to PGND for optimal heat dissipation. Pin functions are defined per TI SLVSCQ2 datasheet Rev. July 2015.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad-buck PMU applications.

Compared with TPS65400QRGZRQ1, TPS65400RGER offers identical performance but lacks automotive qualification, while LM63645QRNXTQ1 delivers higher per-rail efficiency at the cost of requiring external components to replicate quad-rail sequencing and monitoring - making TPS65400QRGZRQ1 the sole single-package solution for AEC-Q100-compliant multi-rail systems.

Availability

TPS65400QRGZRQ1 is available at Aetrix Electronics and suitable for automotive ADAS ECUs, industrial FPGA controllers, small-cell base stations, and Power-over-Ethernet edge gateways requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for TPS65400QRGZRQ1 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 and embedded processing technologies, with decades of experience in power management IC design and automotive qualification.

The TPS65400-Q1 product line was developed specifically for high-density, thermally demanding automotive and industrial applications requiring flexible, digitally controllable multi-rail power solutions in compact VQFN packages.

FAQ

What is the maximum supported switching frequency for each buck regulator in the TPS65400QRGZRQ1?

The TPS65400QRGZRQ1 supports independent PWM frequency adjustment from 275 kHz to 2.2 MHz per regulator via the RCLOCK_SYNC pin or PMBus register control. This range enables optimization of efficiency, EMI, and external component size - for example, 2.2 MHz operation allows use of smaller inductors and capacitors in space-constrained designs while maintaining >90% efficiency at light loads.

Does the TPS65400QRGZRQ1 support pre-bias startup, and how does it function?

Yes, the TPS65400QRGZRQ1 implements a dedicated pre-bias startup algorithm that safely enables turn-on into outputs already holding residual voltage. During startup, the device monitors feedback pins and actively controls high-side FET conduction to prevent reverse current flow or output voltage collapse - a critical feature for hot-swap systems and multi-rail architectures where rails may power up asynchronously.

How is power sequencing configured on the TPS65400QRGZRQ1 - through hardware pins or software?

Power sequencing on the TPS65400QRGZRQ1 can be implemented either way: externally via individual ENSWx pins tied to timers or PGOOD signals, or internally via PMBus commands written to EEPROM. The default hardware sequence uses enable pin thresholds and soft-start capacitor values, while the I²C method stores full timing, dependency, and voltage ramp profiles - offering field-upgradable sequencing without PCB changes.

What thermal management provisions does the TPS65400QRGZRQ1 include?

The TPS65400QRGZRQ1 integrates thermal shutdown at 160°C with 20°C hysteresis, plus continuous junction temperature monitoring accessible via PMBus register READ_TEMPERATURE_1. Its 7-mm × 7-mm VQFN package features an exposed thermal pad that must be soldered to a PCB ground plane; measured R_θJA is 29.8°C/W, enabling reliable 125°C ambient operation with appropriate copper area and airflow.

Can the TPS65400QRGZRQ1 operate with input voltages below 4.5 V?

No - the TPS65400QRGZRQ1 has a specified minimum input voltage of 4.5 V (rising UVLO threshold is 4.25 V). Operation below this level will trigger undervoltage lockout, disabling all regulators and placing the device in shutdown. The UVLO falling threshold is 3.75 V, ensuring clean release only after stable input restoration above 4.5 V.