Texas Instruments LP2950CN

Overview

LP2950CN from Texas Instruments is a micropower, low-dropout linear voltage regulator in TO-92 package delivering fixed 5 V output with ±0.5% initial accuracy, 380 mV dropout at 100 mA, and 75 µA typical quiescent current-designed for battery-powered systems requiring stable, ultra-low-power regulation.

For engineers reviewing the LP2950CN datasheet, LP2950CN pinout, LP2950CN application, or LP2950CN equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, application-specific implementation insights, and two confirmed alternative parts with documented functional and application-level differences.

Technical Context

The LP2950CN integrates a precision 1.23 V bandgap reference, high-gain error amplifier, and PNP pass transistor to achieve tight line (0.03% typ) and load regulation (0.04% typ), enabling use as both regulator and low-power voltage reference. Its architecture ensures minimal quiescent current increase in dropout-critical for extending battery life in portable devices.

Unlike the LP2951-N family, the LP2950CN lacks shutdown control, error flag, feedback, or sense pins: it is strictly a 3-pin fixed-output LDO with IN, OUT, and GND terminals. Its thermal protection and foldback current limiting operate autonomously without external intervention.

Key Specifications

Pinout & Package

LP2950CN is supplied in the through-hole TO-92 (LP) package (4.30 mm × 4.30 mm), pin-compatible with legacy 78L05 regulators and optimized for manual assembly or wave-soldered consumer electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP2950ACZ-5.0, LP2950CN trades extended temperature range for lower cost in commercial applications; compared with TLV70550, it sacrifices miniaturization and lowest IQ for inherent thermal safety, no-enable simplicity, and direct 78L05 replacement capability.

Availability

LP2950CN is available at Aetrix Electronics and suitable for battery-powered remote sensors, portable medical devices, industrial PLC I/O modules, and legacy equipment retrofits requiring stable component supply and long-term obsolescence management.

Supply support for LP2950CN 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 and embedded processing technologies, with decades of expertise in precision power management ICs.

The LP2950-N series was designed specifically for micropower, low-dropout regulation in battery-critical applications-emphasizing ultra-low quiescent current, tight output accuracy, and robust thermal protection without external components.

FAQ

What is the maximum input voltage rating for LP2950CN?

The LP2950CN supports a maximum input voltage of 30 V, as specified in its Absolute Maximum Ratings table. This wide input range allows use with unregulated wall adapters, automotive systems (with transient clamping), and multi-cell battery packs. Operation above 30 V risks permanent damage, even briefly-designers must ensure input filtering and clamping circuits limit transients within this bound. The LP2950CN maintains regulation down to 2.3 V input, making it suitable for single-cell Li-ion or dual-AA applications.

Does LP2950CN include built-in thermal protection?

Yes, LP2950CN incorporates autonomous thermal shutdown protection that disables the output when junction temperature exceeds approximately 150°C. Unlike systems requiring external thermal monitoring, this feature activates automatically based on die temperature and recovers once cooling occurs-no external circuitry or software intervention is needed. It works in conjunction with foldback current limiting to prevent destructive power dissipation during overload or poor heatsinking conditions, ensuring reliable operation in sealed enclosures or high-ambient environments.

Can LP2950CN be used as a precision voltage reference?

Yes, LP2950CN is explicitly characterized for use as a low-power voltage reference due to its 0.5% initial accuracy, 20 ppm/°C temperature coefficient, and 0.04% load regulation. When operated with light loads (<1 mA) and stable input, its 5 V output serves as a stable reference for ADCs, comparators, or analog signal chains-eliminating need for separate reference ICs in cost-sensitive designs. Its 75 µA quiescent current further reduces system power overhead versus traditional shunt references.

What output capacitor is required for LP2950CN stability?

LP2950CN is stable with a minimum 1 µF ceramic capacitor (X7R or better) placed directly between OUT and GND. Unlike older LDOs requiring tantalum or aluminum electrolytics, this low-ESR requirement enables use of small, reliable, and temperature-stable MLCCs-reducing board area and improving long-term reliability. Larger capacitors (e.g., 10 µF) may improve transient response but are not necessary for basic stability. Avoid high-ESR electrolytics, which can cause oscillation.

Is LP2950CN pin-compatible with standard 78L05 regulators?

Yes, LP2950CN uses the identical TO-92 package and 3-pin pinout (IN–GND–OUT) as the industry-standard 78L05, enabling direct replacement without PCB modification. However, LP2950CN delivers significantly tighter output accuracy (±0.5% vs. ±5%), lower dropout (380 mV vs. ~1.7 V), and ultra-low quiescent current (75 µA vs. ~3.5 mA)-making it a performance upgrade for existing 78L05 designs where battery life, precision, or input headroom are critical constraints.