Microchip Technology LP2951-03BN

Overview

LP2951-03BN from Texas Instruments is a precision 100 mA low-dropout voltage regulator with integrated error amplifier, shutdown control, and output voltage sense pin; features 1.24 V reference voltage, 0.5% initial accuracy, and 60 µA quiescent current; used in battery-powered instrumentation and portable medical sensors.

For engineers reviewing the LP2951-03BN datasheet, LP2951-03BN pinout, LP2951-03BN application, or LP2951-03BN equivalent, key selection considerations include dropout voltage at light load, reference accuracy stability over temperature, and compatibility with external feedback networks for adjustable output configurations.

Technical Context

The LP2951-03BN implements a PNP-based LDO architecture with an internal 1.24 V bandgap reference and separate feedback (SENSE) and output (OUT) pins to support remote sensing and improved load regulation. It includes an active-low SHUTDOWN pin enabling system-level power sequencing.

Unlike fixed-output variants, the LP2951-03BN is configured as an adjustable regulator requiring two external resistors to set output voltage; its error amplifier drives the pass transistor based on SENSE pin voltage relative to the internal reference, supporting outputs from 1.24 V to 29 V.

Key Specifications

Pinout & Package

LP2951-03BN is housed in an 8-pin SOIC package with exposed thermal pad (SOIC-8 EP), providing enhanced thermal performance for sustained 100 mA operation without heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV70733PDQNR and LT1763CS8-3.3#PBF, the LP2951-03BN uniquely supports adjustable output, remote sensing, and buffered reference output - critical for precision analog systems where flexibility and accuracy outweigh raw current capability.

Availability

LP2951-03BN is available at Aetrix Electronics and suitable for portable medical devices, industrial transmitters, and automotive body electronics requiring stable component supply and long-term manufacturability.

Supply support for LP2951-03BN 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, specializing in analog and embedded processing technologies with broad industrial and automotive design expertise.

The LP2951 family was developed to deliver precision, low-quiescent-current regulation for battery-critical and sensor-grade applications where remote sensing and reference access improve system-level accuracy.

FAQ

What output voltage range does the LP2951-03BN support?

The LP2951-03BN supports an adjustable output voltage range from 1.24 V to 29 V, set externally using a resistor divider connected to the FB and SENSE pins. Its internal 1.24 V reference enables precise configuration, and the SENSE pin allows remote sensing to maintain regulation accuracy at the load. This makes the LP2951-03BN ideal for multi-rail systems where a single regulator IC must serve varying voltage requirements.

How does the SENSE pin improve regulation accuracy in the LP2951-03BN?

The SENSE pin in the LP2951-03BN monitors voltage directly at the load, bypassing PCB trace resistance between the OUT pin and the load. By comparing this sensed voltage to the internal 1.24 V reference, the error amplifier adjusts the pass transistor to maintain regulation within ±0.5% despite up to 100 mΩ of series resistance. This capability is essential in the LP2951-03BN for applications like portable medical sensors where trace losses would otherwise degrade measurement fidelity.

Can the LP2951-03BN be used in shutdown mode to reduce system power consumption?

Yes, the LP2951-03BN includes an active-low SHDN pin that disables the regulator when pulled low, reducing quiescent current to approximately 1 µA. This feature enables precise power sequencing in battery-powered systems such as data loggers or remote sensors. When designing with the LP2951-03BN, ensure the SHDN pin is pulled high through a resistor or controlled by a GPIO to maintain regulation during normal operation.

Does the LP2951-03BN provide a buffered reference voltage for external use?

Yes, the LP2951-03BN features a dedicated REF pin that supplies a buffered, low-impedance 1.24 V reference voltage with ±0.5% initial accuracy and low temperature drift. This output can drive external ADC references, comparator thresholds, or calibration circuitry without loading the internal reference. The REF pin enhances system integration in designs using the LP2951-03BN for both regulation and precision analog functions.

What thermal protection features are included in the LP2951-03BN?

The LP2951-03BN incorporates internal thermal shutdown that activates when the junction temperature exceeds approximately 160°C, protecting the device during overload, poor heatsinking, or high ambient conditions. Once tripped, regulation halts until the die cools sufficiently. This safeguard is factory-trimmed and does not require external components. In continuous 100 mA operation, the LP2951-03BN's SOIC-8 EP package maintains safe temperatures under typical PCB copper area conditions.