Texas Instruments TPS79028DBVRG4

Overview

TPS79028DBVRG4 from Texas Instruments is an ultralow-power, low-noise 50-mA low-dropout linear regulator with 2.8-V fixed output, 60-mV typical dropout at 50 mA, 17-µA quiescent current, and 56-µV_RMS output noise (measured on TPS79030 variant with identical architecture). It serves as a precision voltage source for battery-powered microcontrollers and RF front-ends in portable medical sensors.

For engineers reviewing the TPS79028DBVRG4 datasheet, TPS79028DBVRG4 pinout, TPS79028DBVRG4 application, or TPS79028DBVRG4 equivalent, key selection criteria include its PMOS pass element enabling ultra-low dropout, enable-controlled 1-µA standby mode, bypass-pin noise filtering, SOT-23-5 thermal performance, and compatibility with 4.7-µF output capacitors.

Technical Context

The TPS79028DBVRG4 uses a PMOS pass transistor instead of a conventional PNP, eliminating load-dependent drive current and delivering dropout voltage directly proportional to load (60 mV typ. at 50 mA). Its internal 150-kΩ resistor and external bypass capacitor form a low-pass filter that suppresses reference noise-critical for analog signal chains.

It integrates overcurrent limiting (~350 mA trip), thermal shutdown (~165°C), and reverse-current protection via the PMOS body diode. The enable input has a 1.5-V threshold (1.7 V high, 0.9 V low), no hysteresis, and draws ≤1 µA, supporting precise power sequencing in multi-rail systems.

Key Specifications

Pinout & Package

TPS79028DBVRG4 is housed in a 5-pin SOT-23 (DBV) package with 1.9-mm × 2.8-mm footprint, 1.3-mm height, and JEDEC MO-178 compliance. Thermal resistance is R_θJA = 259°C/W (low-K board) and R_θJC = 65.8°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS79028DBVR and MCP1700T-2802E/TT, the TPS79028DBVRG4 uniquely delivers sub-60-mV dropout, 56-µV_RMS noise, and 1-µA standby in a 5-pin SOT-23-making it optimal for battery-constrained, noise-sensitive analog systems where TPS79028DBVR is a drop-in green variant and MCP1700 is a higher-current but noisier alternative.

Availability

TPS79028DBVRG4 is available at Aetrix Electronics and suitable for wearable health monitors, IoT edge nodes, portable medical devices, and industrial handheld scanners requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for TPS79028DBVRG4 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 company headquartered in Dallas, Texas, designing and manufacturing analog ICs, embedded processors, and digital signal processors for industrial, automotive, and consumer markets.

The TPS790xx product line was engineered specifically for battery-powered portable equipment, emphasizing ultralow quiescent current, low-noise regulation, and minimal board space-enabling extended runtime in space-constrained medical and wireless devices.

FAQ

What is the minimum input voltage required for TPS79028DBVRG4 to maintain regulation at full 50-mA load?

The minimum input voltage is calculated as V_O(typ) + V_DO(max). For TPS79028DBVRG4, this is 2.8 V + 125 mV = 2.925 V (worst-case over temperature). Per datasheet Note 5, the absolute minimum IN is also constrained to 3.8 V when V_O ≥ 2.5 V-so 3.8 V is the practical minimum input for reliable 50-mA operation across –40°C to 125°C.

Does TPS79028DBVRG4 require an external bypass capacitor, and what value is recommended?

Yes, TPS79028DBVRG4 requires an external ceramic capacitor on the BYPASS pin to achieve its specified 56-µV_RMS noise performance. The datasheet recommends 0.01 µF for optimal noise reduction with fast start-up; values from 0.001 µF to 0.1 µF are supported, but larger capacitance increases start-up time due to the 150-kΩ internal resistor's RC time constant.

Can TPS79028DBVRG4 be used without the enable (EN) pin connected?

Yes, TPS79028DBVRG4 operates continuously when EN is left unconnected or tied to IN, since the internal pull-down is weak and the enable threshold is 0.9 V (low) and 1.7 V (high). However, best practice is to tie EN to IN via a 100-kΩ resistor to ensure robust enable behavior and avoid floating-node susceptibility to noise.

What output capacitor specifications are mandatory for stable operation of TPS79028DBVRG4?

TPS79028DBVRG4 requires a minimum 4.7-µF output capacitor with ESR between 0.2 Ω and 10 Ω. Ceramic, tantalum, or aluminum electrolytic types are acceptable if they meet these criteria. Capacitors below 4.7 µF risk instability; those above are permitted but may require ESR adjustment-e.g., adding a series resistor to low-ESR ceramics.

Is TPS79028DBVRG4 pin-compatible with other members of the TPS790xx family, such as TPS79030DBVRG4?

Yes, all TPS790xx variants-including TPS79028DBVRG4 and TPS79030DBVRG4-share identical SOT-23-5 (DBV) pinout, package dimensions, and terminal functions. Output voltage is the only electrical difference; no PCB layout change is needed when substituting between 1.5-V, 1.8-V, 2.5-V, 2.8-V, or 3.0-V versions.