Texas Instruments LP2951CSDX/NOPB

Overview

LP2951CSDX/NOPB from Texas Instruments is an 8-pin adjustable micropower low-dropout (LDO) voltage regulator with logic-controlled shutdown, error flag output, and programmable output (1.24 V to 29 V). It delivers 100 mA output current with 75 µA typical quiescent current, 380 mV dropout at full load, and ±0.5% initial output accuracy - optimized for battery-powered systems requiring precise regulation and power management.

For engineers reviewing the LP2951CSDX/NOPB datasheet, LP2951CSDX/NOPB pinout, LP2951CSDX/NOPB application, or LP2951CSDX/NOPB equivalent, key selection criteria include its integrated error comparator threshold (±5% VOUT), shutdown input compatibility (TTL/CMOS), feedback bias current (20–40 nA), stable operation with 10 mΩ–6 Ω ESR output capacitors, and SOIC-8 package thermal performance (RθJA = 117.7°C/W).

Technical Context

The LP2951CSDX/NOPB integrates a precision 1.235 V bandgap reference, error amplifier, PNP pass transistor, and dedicated comparator circuitry. Its feedback loop uses external resistors (R1/R2) to set output voltage, while the SENSE pin enables remote sensing for improved load regulation. The ERROR pin asserts low when VOUT drops >5% below nominal, and SHUTDOWN disables regulation with <10 µA standby current.

It operates across 2.3 V to 30 V input range and supports both fixed-output (3 V/3.3 V/5 V) and adjustable configurations. Thermal shutdown and foldback current limiting protect against overload, and its low temperature coefficient (20 ppm/°C) ensures stability over –40°C to +125°C junction temperature.

Key Specifications

Pinout & Package

LP2951CSDX/NOPB is housed in an 8-pin SOIC (D) package (4.90 mm × 3.91 mm), with exposed pad connected to GND for thermal enhancement. Pin 4 (GROUND) is the thermal and electrical ground reference for all internal circuits.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV70733PDQNR and TPS7A2033PDBVR, LP2951CSDX/NOPB uniquely combines adjustable output, integrated error flag, remote sensing, and logic-compatible shutdown in a single SOIC-8 package - making it optimal for battery-aware, multi-voltage, and fault-resilient embedded systems where flexibility and supervision are mandatory.

Availability

LP2951CSDX/NOPB is available at Aetrix Electronics and suitable for battery-powered sensor nodes, industrial I/O modules, medical wearables, automotive body control units, and portable instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for LP2951CSDX/NOPB 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 delivering analog and embedded processing solutions, with decades of expertise in precision power management ICs.

The LP2951CSDX/NOPB belongs to TI's LP295x-N series of micropower LDOs, designed specifically for battery-operated and low-power industrial systems demanding high accuracy, low dropout, and integrated supervision features.

FAQ

What output voltage options does the LP2951CSDX/NOPB support?

The LP2951CSDX/NOPB supports both fixed and adjustable outputs. As shipped, it is configured for 5 V output (no suffix code), but its FEEDBACK and VTAP pins allow programming from 1.24 V to 29 V using two external resistors. Fixed 3 V and 3.3 V versions exist as separate part numbers (e.g., LP2951CSX-3.0/NOPB), but LP2951CSDX/NOPB itself is the base adjustable variant.

How does the ERROR pin on the LP2951CSDX/NOPB function in practice?

The ERROR pin on the LP2951CSDX/NOPB is an open-drain output that pulls low when the regulated output drops more than approximately 5% below nominal (e.g., <4.75 V for a 5 V setup). It sinks up to 400 µA and is commonly wired to a microcontroller's interrupt pin or reset generator to trigger power-on reset or battery-low alerts without software polling.

Can the LP2951CSDX/NOPB be used with ceramic output capacitors?

Yes - the LP2951CSDX/NOPB is explicitly characterized for stability with ceramic capacitors having ESR between 10 mΩ and 6 Ω. A minimum 1 µF X7R/X5R ceramic capacitor is recommended at the OUT pin. This eliminates the need for larger, higher-ESR tantalum or aluminum electrolytic capacitors, saving board space and improving reliability.

What is the thermal performance of the LP2951CSDX/NOPB in its SOIC-8 package?

The LP2951CSDX/NOPB in SOIC-8 (D package) has a junction-to-ambient thermal resistance (RθJA) of 117.7°C/W under JEDEC High-K board conditions. With proper PCB copper area and thermal vias under the exposed pad, real-world dissipation can support ~350 mW continuous power. Derating is required above +70°C ambient to maintain TJ ≤125°C.

Does the LP2951CSDX/NOPB require input and output capacitors, and what values are recommended?

Yes - the LP2951CSDX/NOPB requires a 1 µF ceramic capacitor on the IN pin and at least 1 µF on the OUT pin for 5 V operation (2.2 µF for 3 V/3.3 V). These capacitors must be placed as close as possible to their respective pins. The device remains stable with output capacitor ESR from 10 mΩ to 6 Ω, enabling use of low-ESR ceramics without added series resistance.