Texas Instruments TPS78928DBVT

Overview

TPS78928DBVT from Texas Instruments is an ultralow-power, low-noise 100-mA low-dropout linear regulator with 2.8-V fixed output, 17 µA quiescent current at full load, 115 mV typical dropout voltage at 100 mA, and 56 µV_RMS output noise (measured on TPS78930 variant with identical architecture). It is used in battery-powered portable electronics requiring stable, quiet voltage regulation in space-constrained SOT-23 packages.

For engineers reviewing the TPS78928DBVT datasheet, TPS78928DBVT pinout, TPS78928DBVT application, or TPS78928DBVT equivalent, key selection criteria include its 2.8-V output accuracy (±2.8% over temperature), PMOS pass element enabling low dropout and constant quiescent current, enable-controlled 1-µA standby mode, bypass-pin noise filtering capability, and thermal/current protection for robust operation in handheld and IoT devices.

Technical Context

The TPS78928DBVT employs a PMOS pass transistor instead of conventional PNP, eliminating drive-current dependency on load and delivering dropout voltage directly proportional to load current. Its internal 150-kΩ resistor paired with an external bypass capacitor forms a configurable low-pass filter that suppresses reference noise-critical for RF and precision analog subsystems.

It integrates active-low enable logic with ~1.5-V threshold, current limiting (~350 mA), and thermal shutdown (~165°C trip, ~140°C recovery). The device operates across –40°C to 125°C junction temperature and requires ≥3.8 V input for 2.8-V output under full 100-mA load per recommended conditions.

Key Specifications

Pinout & Package

TPS78928DBVT is housed in a 5-pin SOT-23 (DBV) package-1.6 mm × 2.9 mm × 1.1 mm-with gull-wing leads, JEDEC MO-178 compliant, and rated for –40°C to 125°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS78928DBVR, the TPS78928DBVT offers identical performance in a smaller reel size for design validation; versus MCP1702T-2802E/MB, it delivers superior noise suppression and lower dropout at the expense of slightly higher quiescent current-making it the preferred choice for noise-critical, battery-limited systems.

Availability

TPS78928DBVT is available at Aetrix Electronics and suitable for wearable electronics, Bluetooth modules, industrial wireless sensors, and portable medical diagnostics requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for TPS78928DBVT 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.

The TPS789xx product line was engineered specifically for battery-powered portable equipment-prioritizing ultralow quiescent current, low output noise, and minimal board area through SOT-23 packaging.

FAQ

What is the minimum input voltage required for stable operation of the TPS78928DBVT?

The TPS78928DBVT requires a minimum input voltage of VO(typ) + 1 V = 3.8 V under full 100-mA load, per TI's recommended operating conditions. At lighter loads, dropout decreases proportionally-e.g., 57 mV at 50 mA-allowing operation down to ~2.857 V input. Input below 2.7 V is not supported, and exceeding 10 V violates absolute maximum ratings.

Does the TPS78928DBVT support reverse current protection?

The TPS78928DBVT does not include active reverse-current blocking. Its PMOS pass element contains an intrinsic back-gate diode that conducts from OUT to IN when V_IN < V_OUT, such as during power-down. This behavior is documented in the datasheet and may require external diode or MOSFET isolation in systems where reverse current must be prevented.

How does the BYPASS pin on the TPS78928DBVT reduce output noise?

The BYPASS pin connects internally to the voltage reference through a 150-kΩ resistor. Adding a 0.01–0.1 µF ceramic capacitor between BYPASS and GND creates an RC low-pass filter that attenuates reference noise before it modulates the output. This architecture enables the TPS78928DBVT to achieve ~56 µV_RMS noise (measured identically on TPS78930), critical for precision analog and RF circuits.

What output capacitor is required for stability with the TPS78928DBVT?

The TPS78928DBVT requires a minimum 4.7 µF output capacitor with ESR between 0.2 Ω and 10 Ω for guaranteed stability. Solid tantalum, aluminum electrolytic, or multilayer ceramic capacitors meeting these specifications are acceptable. Capacitors below 4.7 µF risk instability; ceramics with very low ESR may require a small series resistor to meet the minimum ESR requirement.

Is the TPS78928DBVT pin-compatible with other members of the TPS789xx family?

Yes-the TPS78928DBVT shares identical pinout, package (SOT-23 DBV), and terminal functions with all TPS789xx variants (e.g., TPS78915DBVT, TPS78930DBVT). Only the output voltage differs; all share the same enable logic, BYPASS functionality, protection features, and thermal characteristics-enabling easy voltage-scaling in existing PCB layouts.