Texas Instruments TPS51427ARHBT

Overview

TPS51427ARHBT from Texas Instruments is a dual synchronous step-down controller for notebook I/O and system bus rails, featuring two adjustable SMPS channels (0.7–5.9 V and 0.5–2.5 V), a programmable LDO (0.7–4.5 V), D-CAP™ control mode enabling <100 ns transient response, and wide 5.5–28 V input range.

For engineers reviewing the TPS51427ARHBT datasheet, TPS51427ARHBT pinout, TPS51427ARHBT application, or TPS51427ARHBT equivalent, key selection criteria include dual-channel adaptive on-time control, R_DS(on) current sensing, selectable PWM/OOA/Auto-Skip modes, integrated 3.3-V/5-V reference outputs, and thermal shutdown at +140°C.

Technical Context

The TPS51427ARHBT implements a dual-channel D-CAP™ architecture with independent feedback loops: SMPS1 uses VFB1 for 0.7–5.9 V output regulation with ±1% accuracy, while SMPS2 uses REFIN2 for 0.5–2.5 V output with ±1.2% accuracy. Each channel supports three operating modes-PWM-only, OOA™, and Auto-Skip-selected via SKIPSEL pin logic levels.

It integrates adaptive gate drivers with internal boost switches for high-side FET enhancement, temperature-compensated low-side R_DS(on) current sensing, and bootstrap charge auto-refresh. The LDO section provides 100 mA output with switchover between 5 V and 3.3 V based on VSW threshold detection, plus dedicated 3.3-V (VREF3) and 2-V (VREF2) reference outputs.

Key Specifications

Pinout & Package

TPS51427ARHBT is housed in a 32-pin, 5-mm × 5-mm QFN package (RHB) with exposed thermal pad, RoHS-compliant and lead-free.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-buck controller applications.

Compared with TPS51420RHLR and RT8205AZSP, the TPS51427ARHBT uniquely combines dual D-CAP™ buck control, integrated LDO with switchover, dual reference outputs, and R_DS(on) sensing - making it the only option among the three that satisfies full notebook power bus requirements without supplemental ICs.

Availability

TPS51427ARHBT is available at Aetrix Electronics and suitable for notebook system bus rails, graphics core supplies, PDA power management, and mobile communication baseband applications requiring stable component supply and long-term industrial lifecycle support.

Supply support for TPS51427ARHBT 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 expertise in power management IC design.

The TPS51427A product line targets high-efficiency, low-component-count power solutions for portable computing platforms, emphasizing fast transient response, flexible rail sequencing, and integration of references and LDOs alongside dual buck controllers.

FAQ

What is the maximum input voltage rating for the TPS51427ARHBT?

The TPS51427ARHBT has an absolute maximum input voltage rating of 30 V on the VIN pin, with recommended operation from 5.5 V to 28 V. Exceeding 30 V risks permanent damage. The device includes built-in overvoltage protection on auxiliary pins such as VBST1/2 (max 37 V) and DRVH1/2 (max 37 V w.r.t. LLx), but VIN remains the primary power input with strict 30 V ceiling.

How does the D-CAP™ control mode in the TPS51427ARHBT improve transient response?

The D-CAP™ mode in the TPS51427ARHBT achieves <100 ns transient response by eliminating external compensation components and directly sensing output voltage ripple to adjust on-time dynamically. This architecture avoids phase-margin limitations of traditional voltage-mode control, enabling immediate correction of load-induced voltage droop without waiting for error amplifier settling - critical for CPU/GPU burst-mode operation.

Can the TPS51427ARHBT generate both 3.3 V and 5 V simultaneously from its LDO and SMPS outputs?

Yes. The TPS51427ARHBT can deliver 3.3 V from its LDO (by connecting LDOREFIN to V5FILT) while simultaneously generating 5 V from SMPS1 (by setting VFB1 to GND). It also provides dedicated 3.3-V (VREF3) and 2-V (VREF2) reference outputs, enabling concurrent use of multiple fixed and adjustable rails without external regulators.

What are the thermal shutdown characteristics of the TPS51427ARHBT?

The TPS51427ARHBT activates thermal shutdown at +140°C junction temperature with +10°C hysteresis, returning to normal operation at +130°C. This protection is implemented internally and does not require external circuitry. The 32-pin QFN package (5 mm × 5 mm) features an exposed thermal pad designed for 2.32 W power dissipation at +25°C ambient, derating linearly to 0.93 W at +85°C.

Does the TPS51427ARHBT support power sequencing between its two SMPS channels?

Yes. The TPS51427ARHBT supports hardware-based sequencing: connecting EN2 to VREF2 causes SMPS2 to start only after SMPS1 reaches regulation, and vice versa for EN1-to-VREF2 connection. This eliminates need for external supervisors. Each channel also has independent PGOOD outputs with programmable fault thresholds, enabling robust system-level power sequencing and fault isolation.