LP2950 Datasheet | Next Electromics

LP2950/LP2951 Micropower Voltage Regulator Technical Summary

Overview

The LP2950 and LP2951 are high-efficiency, low-dropout (LDO) voltage regulators designed for battery-powered and power-sensitive applications. These micropower regulators feature an exceptionally low quiescent current of 75 µA (typical) and a minimal dropout voltage, making them ideal for extending battery life in portable electronics. The LP2950 is a fixed-output regulator, while the LP2951 offers adjustable output voltage capability. Both variants maintain stable operation with very low power dissipation across a wide range of load conditions.

Key Features

Ultra-Low Quiescent Current: 75 µA typical (significantly lower than standard regulators)
Low Dropout Voltage:
- 40 mV typical at light loads
- 380 mV at 100 mA load current
Multiple Fixed Output Voltages: 5V, 3V, and 3.3V versions available (LP2950)
Adjustable Output: LP2951 version supports 1.23V to 30V output range
Battery Life Optimization: Quiescent current only slightly increases in dropout condition
Error Flag Output: LP2951 includes warning signal for low output voltage (power fail indicator)
Thermal Protection: Built-in shutdown for overtemperature conditions
Current Limiting: Protection against short circuits and overloads

Applications

The LP2950/LP2951 regulators are particularly suited for applications where power efficiency and extended battery life are critical:

Battery-powered portable electronics
Medical and healthcare devices
Wireless sensors and IoT devices
Handheld instrumentation
Power management for microcontrollers
Backup power supply regulation
Automotive electronics
Consumer electronics (cameras, audio devices)

Electrical Characteristics

The following table summarizes key electrical parameters (typical values at 25°C unless otherwise noted):

Absolute Maximum Ratings

Input Voltage: 30V
Power Dissipation: Internally limited
Operating Junction Temperature: -40°C to +125°C
Storage Temperature: -65°C to +150°C

Operating Characteristics (5V version example)

Output Voltage Accuracy: ±2% over line, load, and temperature
Line Regulation: 0.03%/V (typical)
Load Regulation: 0.3% (10mA to 100mA)
Dropout Voltage:
- 40 mV at 1mA load
- 380 mV at 100mA load
Quiescent Current:
- 75 µA typical (normal operation)
- 120 µA maximum
Output Noise Voltage: 80 µV RMS (10Hz to 100kHz)
Ripple Rejection: 75 dB at 120Hz

Package Information

The LP2950/LP2951 are available in multiple package options to suit various application requirements:

Standard Packages

TO-92:
- 3-pin through-hole package
- Compact size for space-constrained applications
- Thermal resistance: 160°C/W
SOT-223:
- Surface-mount package with thermal pad
- Improved thermal performance
- Thermal resistance: 62°C/W
8-Pin SOIC (LP2951 only):
- Includes additional features (error flag, shutdown)
- Thermal resistance: 100°C/W

Ordering Information

LP2950-5.0: Fixed 5V output
LP2950-3.3: Fixed 3.3V output
LP2950-3.0: Fixed 3V output
LP2951: Adjustable output version
Suffixes indicate package type (e.g., -TO92, -SOT223)

Design Considerations

When implementing the LP2950/LP2951 in your design, consider the following:

Input/Output Capacitors

Input capacitor (1 µF or greater) recommended for stability
Output capacitor (1 µF minimum) required for stability
Low-ESR capacitors improve transient response
Tantalum or aluminum electrolytic capacitors suitable

Thermal Management

Power dissipation calculated as (V_IN - V_OUT) × I_LOAD
For high current applications, use SOT-223 package or provide adequate heatsinking
Thermal shutdown activates at approximately 160°C