Texas Instruments TPS73125DBVTG4

Overview

TPS73125DBVTG4 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 noise-sensitive VCOs in wireless infrastructure and medical equipment.

For engineers reviewing the TPS73125DBVTG4 datasheet, TPS73125DBVTG4 pinout, TPS73125DBVTG4 application, or TPS73125DBVTG4 equivalent, key selection criteria include its capacitor-free stability, sub-1μA shutdown current, reverse leakage <10µA, thermal-foldback current limit, and SOT-23-5 package compatibility with space-constrained portable and industrial designs.

Technical Context

The TPS73125DBVTG4 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 near-constant ground pin current across load and supports operation down to 1.7V input.

It integrates reverse current blocking via NMOS gate control, requires EN ≥1.7V for activation, and features an NR pin (pin 4) for noise reduction using a 0.01µF capacitor - reducing output noise to ~8.5×VOUT µVRMS (10Hz–100kHz). Thermal shutdown triggers at 160°C with 20°C hysteresis.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLS850F0TESKXUMA1 and MCP1826T-2502E/DB, the TPS73125DBVTG4 uniquely combines capacitor-free operation, 30mV dropout, and <10µA reverse leakage in a standard SOT-23-5 - making it optimal for space-constrained, battery-sensitive, and multi-rail isolation applications where those three traits are simultaneously required.

Availability

TPS73125DBVTG4 is available at Aetrix Electronics and suitable for wireless infrastructure, medical diagnostics, smart grid metering, and point-of-sale terminal designs requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for TPS73125DBVTG4 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 decades of LDO design expertise and broad industrial qualification.

The TPS731 family was engineered for portable, noise-sensitive, and capacitor-constrained applications - delivering ultra-low dropout, reverse current blocking, and integrated noise reduction without external compensation components.

FAQ

What is the minimum input voltage required for TPS73125DBVTG4 to regulate 2.5V output?

The TPS73125DBVTG4 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, VIN can be as low as 1.7V - but regulation is only guaranteed when VIN ≥ VOUT + VDO, where VDO increases with temperature and load. The device will not regulate below 1.7V input regardless of load.

Does TPS73125DBVTG4 require an output capacitor for stability?

No, the TPS73125DBVTG4 is explicitly designed for capacitor-free operation and remains stable with zero output capacitance due to its NMOS voltage-follower architecture. An optional output capacitor (e.g., 1µF ceramic) may be added to improve load transient response or PSRR, but it is never required for loop stability per TI's characterization and datasheet specifications.

How does the NR pin on TPS73125DBVTG4 reduce output noise?

The NR pin on TPS73125DBVTG4 connects internally to the bandgap reference through a 27kΩ resistor. Adding a 0.01µF capacitor from NR to GND forms a low-pass filter that attenuates reference noise, reducing total output RMS noise from 30µVRMS to approximately 21.25µVRMS (8.5 × 2.5V) over 10Hz–100kHz - a ~30% improvement critical for RF and precision analog circuits.

What happens to reverse current protection when EN is left floating or tied to IN?

If EN is tied to IN (common practice when shutdown is unused), the TPS73125DBVTG4 may retain gate charge on the NMOS pass transistor after VIN removal, compromising reverse current blocking. To ensure full <10µA reverse leakage, EN must be actively driven low before VIN is removed - otherwise, residual gate voltage permits backfeed from OUT to IN during power-down sequences.

Is TPS73125DBVTG4 compatible with lead-free reflow profiles and RoHS requirements?

Yes, the TPS73125DBVTG4 is manufactured in TI's RoHS-compliant, lead-free SOT-23-5 (DBV) package and qualified for standard JEDEC J-STD-020D reflow profiles, including peak temperatures up to 260°C. The "G4" suffix confirms green (halogen-free) packaging and compliance with EU RoHS Directive 2011/65/EU and China RoHS.