Texas Instruments TPS627451DSST

Overview

TPS627451DSST from Texas Instruments is an ultra-low-quiescent-current synchronous step-down converter optimized for low-power wireless and energy-harvesting systems. It delivers up to 300 mA output current with 400 nA typical IQ, supports 1.3 V to 2.8 V output in 100-mV steps via four VSEL pins, and operates from 3.3 V to 10 V input-enabling dual Li-ion, Li-primary, or USB/solar sources. It integrates DCS-Control™ topology, open-drain power-good output, and internal VOUT discharge.

For engineers reviewing the TPS627451DSST datasheet, TPS627451DSST pinout, TPS627451DSST application, or TPS627451DSST equivalent, key selection criteria include its 400 nA quiescent current, 12-pin WSON (3 mm × 2 mm) package, 1.3–2.8 V programmable output range, integrated VIN_SW switch, and RF-friendly PFM/PWM seamless transition behavior under microampere-to-300 mA loads.

Technical Context

The TPS627451DSST implements TI's DCS-Control™ topology, combining a fast AC loop for transient response and a DC voltage feedback loop for precise regulation-enabling stable operation with small ceramic capacitors and no external compensation. It operates in PWM mode at medium/high loads (up to 2.5 MHz) and transitions seamlessly into PFM mode at light loads to sustain >90% efficiency down to 15 µA.

Its functional architecture includes integrated high-side/low-side MOSFETs (R_DS(ON) = 0.6–0.98 Ω / 0.5–0.85 Ω), a 400-nA quiescent current path, EN-controlled shutdown (130 nA), VOUT discharge circuit (25–60 Ω), and a dedicated VIN_SW switch (85–160 Ω, 5 mA max) controlled by EN_VIN_SW for ADC scaling-each validated across –40°C to 125°C junction temperature.

Key Specifications

Pinout & Package

The TPS627451DSST is housed in a 12-pin WSON package (3 mm × 2 mm) with an exposed thermal pad connected to GND for optimal thermal performance. Pin numbering follows top-view orientation with Pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with TPS62745DSST, the TPS627451DSST offers lower output voltage headroom (1.3 V min) essential for next-gen ultra-low-voltage SoCs, while retaining identical quiescent current and RF-friendly regulation. Against TPS62840DRVR, it trades 340 nA higher IQ for 100 mA more output current, integrated discharge, and VIN_SW-critical for robust industrial and energy-harvesting deployments.

Availability

TPS627451DSST is available at Aetrix Electronics and suitable for Bluetooth Low Energy sensor nodes, industrial metering systems, and energy-harvesting wireless transceivers requiring stable component supply across long-lifecycle deployments.

Supply support for TPS627451DSST 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and personal electronics markets.

The TPS627451DSST belongs to TI's ultra-low-power DC/DC converter product line, designed specifically for battery- and energy-harvesting–powered IoT edge devices demanding multi-year operation, RF coexistence, and minimal bill-of-materials.

FAQ

What is the minimum input voltage required for TPS627451DSST to regulate a 1.3 V output?

The TPS627451DSST requires VIN ≥ VOUT + 0.7 V for regulation, so for 1.3 V output, minimum input is 2.0 V. However, the device's undervoltage lockout activates below 2.9 V (typical), and recommended operating VIN starts at 3.3 V. Therefore, stable regulation at 1.3 V output is guaranteed only when VIN is ≥3.3 V per datasheet specifications.

How does the TPS627451DSST achieve 400 nA quiescent current while maintaining regulation accuracy?

The TPS627451DSST achieves 400 nA IQ by integrating a high-impedance (50 MΩ) internal feedback divider and shutting down most internal circuits-including error amplifier and gate drivers-during PFM sleep periods. Regulation accuracy (±2.5%) is preserved via precise bandgap reference and comparator-based DCS-Control™ architecture that wakes only when output droop exceeds threshold, minimizing active time.

Can the VSEL pins of TPS627451DSST be reconfigured dynamically during operation?

Yes, the VSEL1–VSEL4 pins of TPS627451DSST support dynamic reconfiguration during operation. Changing their logic states adjusts the output voltage in real time with a defined slew rate; the device ramps VOUT smoothly to the new target without interruption, enabling adaptive power management for mixed-voltage SoCs or process-voltage scaling.

What is the purpose of the EN_VIN_SW pin on the TPS627451DSST, and how should it be used?

The EN_VIN_SW pin controls an internal MOSFET switch connecting VIN to the VIN_SW output terminal. When pulled high, it enables a low-leakage (±20 nA), 5 mA-capable path for scaling VIN-e.g., feeding a resistor divider to an ADC. If unused, EN_VIN_SW must be tied to GND to prevent unintended conduction and ensure zero static current through the switch.

Does the TPS627451DSST include overcurrent protection, and how does it behave under short-circuit conditions?

Yes, the TPS627451DSST includes cycle-by-cycle overcurrent protection on both high-side and low-side MOSFETs. Under short-circuit, the high-side current limit (480–720 mA) triggers immediate turn-off; the low-side then conducts until current falls below its limit (600 mA). This hiccup-mode behavior limits power dissipation and prevents thermal runaway while maintaining safe operation across –40°C to 125°C.