Texas Instruments LP2951ACSDX-3.3/NOPB

Overview

LP2951ACSDX-3.3/NOPB from Texas Instruments is a micropower, low-dropout linear voltage regulator with fixed 3.3 V output, logic-controlled shutdown, and error flag output. It delivers up to 100 mA with 75 µA typical quiescent current, 380 mV dropout at full load, and ±0.5% initial output accuracy - designed for battery-powered systems requiring stable low-voltage supply and power-on reset capability.

For engineers reviewing the LP2951ACSDX-3.3/NOPB datasheet, LP2951ACSDX-3.3/NOPB pinout, LP2951ACSDX-3.3/NOPB application, or LP2951ACSDX-3.3/NOPB equivalent, this device supports precision 3.3 V regulation in space-constrained portable electronics, offers programmable enable/disable control via SHUTDOWN pin, and provides real-time output health monitoring through ERROR flag - critical for reliable embedded power management.

Technical Context

The LP2951ACSDX-3.3/NOPB integrates a high-accuracy 1.235 V bandgap reference, error amplifier, PNP pass transistor, and dedicated comparator circuitry for output undervoltage detection. Its architecture enables operation down to 2.3 V input while maintaining regulation across –40°C to +125°C ambient temperature.

It features dual-mode feedback: fixed-output configuration (pins SENSE and OUT tied) or adjustable mode (via external resistor divider on FEEDBACK), though the -3.3/NOPB variant is factory-trimmed for 3.3 V. The ERROR comparator triggers at ~5% output deviation (≈165 mV drop), referenced to internal 1.235 V, with 15 mV hysteresis.

Key Specifications

Pinout & Package

LP2951ACSDX-3.3/NOPB is housed in an 8-pin SOIC (D) package measuring 4.90 mm × 3.91 mm, with exposed thermal pad (DAP) connected to GND for enhanced heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV70733PDQNR and TPS7A2033PDBVR, LP2951ACSDX-3.3/NOPB uniquely combines fixed 3.3 V regulation, logic shutdown, and error flag in a single SOIC-8 package - eliminating need for external reset ICs or enable logic in cost-sensitive, space-constrained designs.

Availability

LP2951ACSDX-3.3/NOPB is available at Aetrix Electronics and suitable for portable medical sensors, industrial IoT edge nodes, smart metering modules, and automotive body control units requiring stable component supply and long-term production continuity.

Supply support for LP2951ACSDX-3.3/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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for industrial, automotive, and consumer markets.

The LP2951 series was designed specifically for micropower, low-dropout regulation in battery-operated equipment - emphasizing accuracy, ultra-low IQ, and integrated system-level functions like shutdown and fault reporting.

FAQ

What is the minimum input voltage required for LP2951ACSDX-3.3/NOPB to maintain regulation?

The LP2951ACSDX-3.3/NOPB requires a minimum input voltage of 3.68 V to sustain 3.3 V output at 100 mA load, based on its 380 mV typical dropout voltage. At lighter loads (100 µA), dropout drops to 50 mV, allowing operation from as low as 3.35 V - enabling deep discharge of single-cell Li-ion batteries while maintaining system functionality.

How does the ERROR pin on LP2951ACSDX-3.3/NOPB function in a power-on reset circuit?

The ERROR pin on LP2951ACSDX-3.3/NOPB is an open-collector output that pulls low when the regulated output falls more than ~5% (≈165 mV) below 3.3 V. In a power-on reset application, it can directly drive the reset input of most microcontrollers after adding a pull-up resistor - asserting reset until VOUT stabilizes within specification, ensuring deterministic boot behavior.

Can LP2951ACSDX-3.3/NOPB be used in adjustable-output configurations?

Yes - although LP2951ACSDX-3.3/NOPB is factory-configured for 3.3 V, its internal 1.235 V reference and FEEDBACK pin allow reconfiguration to any output between 1.24 V and 29 V using two external resistors. In such cases, SENSE remains connected to OUT, and VTAP is left unconnected per TI design guidelines.

What thermal considerations apply to LP2951ACSDX-3.3/NOPB in SOIC-8 packaging?

LP2951ACSDX-3.3/NOPB in SOIC-8 (D package) has a junction-to-ambient thermal resistance (RθJA) of 117.7°C/W on standard JEDEC High-K board. To avoid thermal shutdown above 125°C ambient, keep power dissipation below 212 mW - achievable at ≤100 mA load with ≤1 V input-output differential. Use the exposed DAP pad tied to PCB ground for improved thermal performance.

Is LP2951ACSDX-3.3/NOPB qualified for automotive applications?

LP2951ACSDX-3.3/NOPB is not AEC-Q200 qualified. While it operates across –40°C to +125°C junction temperature and withstands 30 V input transients, it lacks automotive-specific qualification testing (e.g., HTOL, ESD, mechanical shock). For automotive body electronics, TI recommends AEC-Q200 qualified alternatives like TPS7B6733QPWPRQ1.