Texas Instruments LP2954ISX/NOPB

Overview

LP2954ISX/NOPB from Texas Instruments is a fixed 5-V micropower low-dropout (LDO) linear regulator in an 8-pin SOIC package, delivering up to 250 mA output current with 90 µA typical quiescent current at 1 mA load and 470 mV dropout at full load-designed for battery-powered systems requiring stable voltage reference and extended runtime.

For engineers reviewing the LP2954ISX/NOPB datasheet, LP2954ISX/NOPB pinout, LP2954ISX/NOPB application, or LP2954ISX/NOPB equivalent, key selection criteria include guaranteed 5-V output accuracy (±1.2% over −40°C to +125°C), reverse-battery protection on IN, open-collector ERROR flag for dropout detection, logic-controlled shutdown, and tight line/load regulation (0.04% typical).

Technical Context

The LP2954ISX/NOPB implements a PNP pass transistor architecture enabling ultra-low dropout and minimal quiescent current increase during dropout (120 µA typical). Its internal 1.23-V bandgap reference feeds an error amplifier that compares feedback voltage against VREF to regulate output.

It integrates a dedicated dropout detection comparator with ±60 mV offset referenced to VREF, producing an open-collector ERROR signal that asserts low when output drops >5%-independent of programmed output voltage-and supports external pullup to VOUT for fault-safe logic-level signaling.

Key Specifications

Pinout & Package

LP2954ISX/NOPB is housed in an 8-pin SOIC (D package), 4.90 mm × 3.91 mm body size, with exposed pad not electrically connected. Pin functions are validated per TI SNVS096E Rev E (July 2016) datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP2954ISX/NOPB, LP2951ACN/NOPB trades guaranteed 5-V accuracy and integrated ERROR signaling for output adjustability, while TLV70033DBVR offers lower IQ but sacrifices voltage compatibility, reverse-battery protection, and fault diagnostics-making LP2954ISX/NOPB uniquely suited for legacy 5-V battery systems demanding reliability and simplicity.

Availability

LP2954ISX/NOPB is available at Aetrix Electronics and suitable for portable medical sensors, industrial data loggers, automotive body control modules, and smart utility meters requiring stable component supply with long-term manufacturability and consistent parametric performance.

Supply support for LP2954ISX/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 headquartered in Dallas, Texas, designing and manufacturing analog and embedded processing chips for industrial, automotive, and personal electronics markets.

The LP2954 product line delivers micropower, low-dropout linear regulators optimized for battery longevity and fault-aware operation in safety-critical portable and remote systems-emphasizing accuracy, protection, and diagnostic capability over raw efficiency.

FAQ

What is the guaranteed output voltage tolerance of LP2954ISX/NOPB over temperature?

The LP2954ISX/NOPB guarantees ±1.2% output voltage accuracy over the full operating junction temperature range of −40°C to +125°C, as specified in the LP2954AI grade electrical characteristics table. This tolerance applies to the fixed 5-V output and is verified across production lots using statistical quality control methods-not derived from room-temperature specs or extrapolated data.

Does LP2954ISX/NOPB require an external capacitor on the FEEDBACK pin?

No, LP2954ISX/NOPB does not require an external capacitor on the FEEDBACK pin. In its fixed-5V SOIC configuration, FEEDBACK is internally connected to SENSE and 5V TAP; the 100-pF capacitor between OUT and FEEDBACK cited in the datasheet applies only to adjustable variants using external resistors. For LP2954ISX/NOPB, only the mandatory 2.2 µF output capacitor is required for stability.

Can LP2954ISX/NOPB be used with a 3.7-V Li-ion battery?

Yes, LP2954ISX/NOPB can operate from a 3.7-V Li-ion battery, but only down to ~3.9 V under load due to its 470 mV dropout at 250 mA. At light loads (<10 mA), dropout drops to 60 mV, enabling regulation down to ~5.06 V input-so a single-cell Li-ion (nominal 3.7 V, max 4.2 V) cannot sustain 5-V output. It is suitable for two-cell alkaline (3.0–3.2 V) or LiFePO₄ (3.6 V nominal) only when paired with a boost stage or used in non-5V configurations via external feedback (not applicable to LP2954ISX/NOPB).

How is the ERROR pin of LP2954ISX/NOPB intended to be interfaced with a microcontroller?

The ERROR pin of LP2954ISX/NOPB is an open-collector output that must be pulled up to VOUT (recommended) or another logic-compatible supply via 100 kΩ–1 MΩ resistor. When asserted low (indicating >5% output drop), it sinks up to 400 µA. Connect directly to an MCU GPIO configured as interrupt-capable input with internal pullup disabled. Using VOUT as pullup ensures the ERROR signal remains below 1.2 V during deep brownout, avoiding invalid high states.

Is reverse-battery protection active when SHUTDOWN is asserted on LP2954ISX/NOPB?

Yes, reverse-battery protection on the IN pin remains fully active regardless of SHUTDOWN state-because it is implemented as a discrete series diode between IN and internal circuitry, independent of regulator enable logic. However, tying SHUTDOWN directly to IN (to avoid external pullup) disables this protection, per datasheet Section 7.4.1. For full protection, use a 20–100 kΩ pullup resistor from SHUTDOWN to IN.