Texas Instruments TPS79401DGNRG4

Overview

TPS79401DGNRG4 from Texas Instruments is a 250mA, fixed-output (1.225V) low-dropout linear regulator in HVSSOP-8 package, featuring 155mV typical dropout at full load, 60dB PSRR at 10kHz, and fast 50µs startup. It delivers stable, low-noise power to noise-sensitive analog circuitry in portable RF electronics and high-resolution ADC/DAC signal chains.

For engineers reviewing the TPS79401DGNRG4 datasheet, TPS79401DGNRG4 pinout, TPS79401DGNRG4 application, or TPS79401DGNRG4 equivalent, key selection criteria include its 1.225V fixed output, HVSSOP-8 thermal performance (R_θJA = 51.9°C/W), 2.2µF minimum ceramic output capacitance requirement, and active discharge capability in the new-chip revision.

Technical Context

The TPS79401DGNRG4 implements a PMOS pass transistor architecture with internal 1.225V bandgap reference and undervoltage lockout (UVLO) threshold of 1.32–1.6V (rising). Its feedback loop is internally compensated for stability with ≥2.2µF ceramic output capacitors, eliminating need for external compensation components.

It supports active discharge via an internal pulldown MOSFET when disabled, and features hybrid brickwall-foldback current limiting (320–460mA I_CL, 175mA I_SC) with thermal shutdown activation at ~165°C and recovery at ~140°C.

Key Specifications

Pinout & Package

HVSSOP-8 (DGN) package: 3mm × 4.9mm body with exposed PowerPad for enhanced thermal performance. Requires soldering the PowerPad to PCB ground plane for optimal R_θJB = 25.3°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, fixed-output LDO applications.

Compared with TPS7A20125PDQNR and MCP1700T-1202E/MB, the TPS79401DGNRG4 uniquely combines 1.225V precision, active discharge, and 60dB PSRR in HVSSOP-8 - making it optimal for noise-sensitive, sequenced power domains where rapid, controlled power-down is mandatory.

Availability

TPS79401DGNRG4 is available at Aetrix Electronics and suitable for portable RF transceivers, high-resolution sensor signal chains, low-voltage microcontroller cores, and USB-powered peripherals requiring stable component supply across production lifecycles.

Supply support for TPS79401DGNRG4 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 LDO design expertise and broad automotive, industrial, and personal electronics portfolios.

The TPS794 family was engineered for noise-sensitive analog and RF applications demanding ultra-low dropout, high PSRR, and fast transient response - targeting portable communications, precision measurement, and high-fidelity audio systems.

FAQ

What is the output voltage tolerance of the TPS79401DGNRG4?

The TPS79401DGNRG4 provides a fixed 1.225V output with ±3% accuracy over temperature and load (–40°C to +125°C, 0–250mA). This tolerance is specified under conditions where V_IN ≥ V_OUT + 1V and 2.7V ≤ V_IN ≤ 5.5V. The internal 1.225V reference has a typical value of 1.225V with min/max of 1.201V/1.25V, directly defining the output voltage range of the TPS79401DGNRG4.

Does the TPS79401DGNRG4 require an external noise-reduction capacitor?

No - the TPS79401DGNRG4 is a "new-chip" revision and does not use the NR pin for noise filtering. Pin 4 (NR/NC) is unconnected internally; TI recommends tying it to GND for thermal improvement or leaving it floating. Unlike legacy TPS794 variants, the TPS79401DGNRG4 achieves low output noise (32–71µV_RMS) without external CNR capacitors, simplifying layout and reducing BOM count.

What is the minimum output capacitance required for stability with the TPS79401DGNRG4?

The TPS79401DGNRG4 is stable with a minimum 2.2µF ceramic output capacitor (X5R or X7R dielectric) for the new-chip revision. If a feed-forward capacitor is omitted, this 2.2µF value is mandatory. The effective capacitance must remain ≥0.47µF across temperature and bias; using a 2.2µF, 0603-size, 6.3V-rated X7R MLCC meets this requirement while fitting compact layouts. This specification applies specifically to the TPS79401DGNRG4 in HVSSOP-8.

How does the enable functionality work on the TPS79401DGNRG4?

The TPS79401DGNRG4 features an active-high enable pin (EN, Pin 6) with a logic threshold of 0.85V to V_IN for turn-on and 0–0.425V for shutdown. When enabled, it regulates with 500µs startup time; when disabled, it enters ultra-low shutdown current (<1µA) and activates internal active discharge to pull V_OUT to GND. This behavior is confirmed for the TPS79401DGNRG4's new-chip silicon revision.

Can the TPS79401DGNRG4 be used in place of adjustable TPS794 variants?

No - the TPS79401DGNRG4 is a fixed-output device (1.225V) with FB/NC and NR/NC pins internally disconnected. It cannot be reconfigured for other voltages. Adjustable versions (e.g., TPS79433) require external resistor dividers on the FB pin and have different pin functions. Substituting the TPS79401DGNRG4 for an adjustable variant would result in incorrect output voltage and potential system malfunction.