Texas Instruments TPS73125DBVRG4

Overview

TPS73125DBVRG4 from Texas Instruments is a capacitor-free, NMOS-based 150mA low-dropout linear regulator with reverse current protection and fixed 2.5V output. It operates from 1.7V to 5.5V input, delivers ultra-low 30mV typical dropout at full load, and achieves 0.5% initial accuracy and 30μVRMS output noise (10kHz–100kHz) - ideal for powering voltage-controlled oscillators in wireless infrastructure and test equipment.

For engineers reviewing the TPS73125DBVRG4 datasheet, TPS73125DBVRG4 pinout, TPS73125DBVRG4 application, or TPS73125DBVRG4 equivalent, this page provides verified specifications, SOT-23-5 pin functions, real-world use cases in medical and building automation systems, and two validated alternative LDOs with documented functional and parametric differences.

Technical Context

The TPS73125DBVRG4 uses an NMOS pass transistor with integrated 4MHz charge pump to drive the gate above VOUT, enabling stable regulation without output capacitance and delivering <100mV dropout at 150mA. Its voltage-follower topology ensures stability across capacitor types and values - including zero-output-capacitor operation.

It integrates reverse-current blocking via NMOS gate control, thermal shutdown at 160°C, foldback current limiting (150–500mA), and a dedicated NR pin for noise reduction (0.01μF to ground cuts output noise to ~8.5×VOUT μVRMS). Ground pin current remains near-constant over load (400–750μA at 10–150mA), supporting portable power budgeting.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.9mm × 2.8mm footprint, surface-mount, thermally enhanced with exposed pad (not electrically connected in DBV variant).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPS73125DBVRG4, TPS73225DBVR trades capacitor-free stability and noise reduction for slightly lower quiescent current, while MCP1700T-2502E/MB prioritizes ultra-low IQ over dropout, protection, and reverse-blocking - making both alternatives viable only in narrower operating envelopes.

Availability

TPS73125DBVRG4 is available at Aetrix Electronics and suitable for medical patient monitoring, wireless infrastructure baseband, smart grid AMI meters, and industrial building automation sensors requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for TPS73125DBVRG4 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 connectivity technologies with over 90 years of innovation in power management ICs.

The TPS731 family was designed for portable and noise-sensitive applications requiring capacitor-free LDOs with reverse-current protection, ultra-low dropout, and integrated enable/shutdown - targeting medical, telecom, and industrial edge devices.

FAQ

What is the minimum input voltage required for TPS73125DBVRG4 to regulate 2.5V output?

The TPS73125DBVRG4 requires a minimum input voltage of 2.53V to maintain regulation at full 150mA load, based on its 30mV typical dropout voltage. At lighter loads, it can operate down to 1.7V input, but regulation is only guaranteed when VIN ≥ VOUT + VDO - so 2.53V is the practical lower bound for full-load 2.5V output. This enables compatibility with aged LiFePO₄ cells and low-headroom industrial rails.

Does TPS73125DBVRG4 require an output capacitor for stability?

No, the TPS73125DBVRG4 does not require any output capacitor for stability due to its NMOS voltage-follower topology and internal compensation. It remains stable with zero output capacitance, 100nF ceramic, or 10μF tantalum - eliminating capacitor-related aging, microphonics, and board-space constraints. An optional 0.01μF NR capacitor further reduces noise but is not needed for loop stability.

How does the NR pin on TPS73125DBVRG4 reduce output noise?

The NR pin connects internally to a 27kΩ resistor tied to the bandgap reference. Adding a 0.01μF capacitor from NR to GND forms a low-pass filter that attenuates reference noise by ~3.2×, reducing total output noise from 30μVRMS to approximately 21.25μVRMS (for 2.5V output). This is critical for powering VCOs and precision ADCs where noise directly impacts phase jitter and ENOB.

What protection features are integrated into TPS73125DBVRG4?

The TPS73125DBVRG4 integrates thermal shutdown (trip at 160°C, reset at 140°C), foldback current limiting (150–500mA depending on VOUT), and reverse-current blocking (≤10μA leakage). These functions operate autonomously without external components, protecting against short-circuit faults, PCB overheating, and backfeed during hot-swap or multi-supply sequencing - enhancing system reliability in unattended deployments.

Can TPS73125DBVRG4 be used in automotive applications?

The TPS73125DBVRG4 is rated for –40°C to +125°C junction temperature and meets AEC-Q100 stress-test requirements for temperature cycling and HBM ESD (±2000V), but it is not officially qualified per AEC-Q100 Grade 2 or 1. It is suitable for under-hood-adjacent or cabin applications where ambient temperature stays within spec and qualification is not mandated - e.g., infotainment auxiliary rails or gateway module sensor interfaces.