Texas Instruments TPS76138DBVT

Overview

TPS76138DBVT from Texas Instruments is a 100-mA low-dropout linear regulator with fixed 3.8-V output, 170-mV typical dropout at full load, <1-µA quiescent current in shutdown, and operation from –40°C to 125°C junction temperature - designed for space-constrained battery-powered systems such as portable medical sensors and handheld instrumentation.

For engineers reviewing the TPS76138DBVT datasheet, TPS76138DBVT pinout, TPS76138DBVT application, or TPS76138DBVT equivalent, key selection criteria include its SOT-23-5 package footprint, enable-controlled low-power mode, thermal shutdown behavior, and compatibility with 4.7-µF output capacitors having 0.1–10-Ω ESR.

Technical Context

The TPS76138DBVT uses a BiCMOS process to achieve ultra-low quiescent current while maintaining stable regulation under dynamic load conditions. Its internal architecture integrates current limiting, thermal shutdown (trip at 160°C, recovery at 150°C), and an enable-controlled NMOS pass transistor with reverse-current protection via inherent body diode.

It requires a minimum 4.7-µF output capacitor with ESR between 0.1 Ω and 10 Ω for loop stability, and supports input voltages from 4.18 V to 16 V. The EN pin accepts logic-level control (high ≥2 V, low ≤0.8 V) and draws only ±1 µA when asserted or deasserted.

Key Specifications

Pinout & Package

TPS76138DBVT is housed in a 5-pin SOT-23 (DBV) package, 2.9 mm × 1.6 mm × 1.45 mm, with exposed pad not electrically connected. Pin 1 (IN) is located at the index area corner; pin orientation follows JEDEC MO-178 standard with Q3 quadrant assignment on tape.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator applications.

Compared with TPS76138DBVT, the DBVR variant offers identical performance with optimized logistics for mass production, while the MCP1700T-3802E/TT trades enable control and precise current limiting for lower quiescent current and higher output capability - requiring redesign of control logic and layout.

Availability

TPS76138DBVT is available at Aetrix Electronics and suitable for portable medical sensors, handheld test equipment, and industrial IoT edge nodes requiring stable component supply with guaranteed long-term sourcing and traceable manufacturing history.

Supply support for TPS76138DBVT 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 expertise in power management ICs.

The TPS761xx family was engineered for ultra-low-power, space-constrained battery-operated systems - emphasizing minimal quiescent current, small SOT-23 packaging, and robust thermal protection without external components.

FAQ

What is the minimum input voltage required for stable regulation of the TPS76138DBVT?

The TPS76138DBVT requires a minimum input voltage of 4.18 V to maintain regulation across its full 100-mA load range and temperature specification. This value accounts for the 170-mV typical dropout voltage at full load, ensuring the output remains within ±2.5% of 3.8 V even under worst-case conditions. Below 4.18 V, the device enters dropout and output voltage drops linearly with input.

Does the TPS76138DBVT require an external pull-up resistor on the EN pin?

No, the TPS76138DBVT does not require an external pull-up resistor on the EN pin. When unused, EN should be directly connected to IN to ensure continuous operation. The EN input draws only ±1 µA, so it can be driven directly by microcontroller GPIO without additional biasing. Leaving EN floating is prohibited and may cause erratic enable behavior.

Can the TPS76138DBVT be used with a 2.2-µF output capacitor?

No - the TPS76138DBVT requires a minimum 4.7-µF output capacitor with ESR between 0.1 Ω and 10 Ω for guaranteed loop stability. Using a 2.2-µF capacitor violates the datasheet-specified minimum and risks oscillation or poor transient response. Multilayer ceramic capacitors must meet the 4.7-µF minimum capacitance value across the full –40°C to 125°C operating range.

What is the thermal shutdown behavior of the TPS76138DBVT?

The TPS76138DBVT activates thermal shutdown when junction temperature exceeds 160°C, disabling the pass transistor and reducing output current to near zero. It automatically recovers and resumes regulation once the junction cools below 150°C. This hysteresis prevents cycling during marginal thermal conditions and protects both the TPS76138DBVT and downstream circuitry from sustained overheating.

Is the NC pin (Pin 4) on the TPS76138DBVT safe to connect to ground?

No - Pin 4 (NC) on the TPS76138DBVT has no internal connection and must remain unconnected on the PCB. Connecting it to ground, V_IN, or any other net may compromise package integrity, induce parasitic coupling, or violate TI's recommended layout. The NC designation is explicit: no routing, no solder mask opening, no copper pour beneath this pad.