Description

The LP2950 and LP2951 are micropower voltage regulators that are designed for use in battery-powered systems. These regulators have a low quiescent current of typ. 75µA and a low dropout voltage of typ. 45mV at light loads and 380mV at 100mA, which helps to prolong battery life. The quiescent current only slightly increases in dropout. These regulators also have positive transient protection up to 60V and can survive unregulated input transient up to 20V below ground. The LP2950/LP2951 have a tight initial tolerance of typ. 0.5%, excellent load and line regulation of typ. 0.05%, and a very low output voltage temperature coefficient, making them useful as a low-power voltage reference. The LP2950 is offered in the 3-pin TO-92 package while the LP2951 is available in 8-pin plastic SOIC and DIP packages. The LP2951 has additional features including an error flag output to warn of a low output voltage and a logic-compatible shutdown input to enable the regulator to be switched on and off. The LP2951 can be pin-strapped for a 5V, 3.3V, or 3V output, or programmed from 1.24V to 29V with an external pair of resistors.

Specifications and features

• 5V, 3.3V, and 3V Versions at 100mA Output Current
• High Accuracy Output Voltage
• Extremely Low Quiescent Current
• Low Dropout Voltage
• Extremely Tight Load and Line Regulation
• Very Low Temperature Coefficient
• Current and Thermal Limiting
• Needs Minimum Capacitance (1µF) for Stability
• Unregulated DC Positive Transients 60V

Application Scenarios

The LP2950 and LP2951 are commonly used in the following applications:

• Battery Powered Systems
• Portable Consumer Equipment
• Cordless Telephones
• Portable (Notebook) Computers
• Portable Instrumentation
• Radio Control Systems
• Automotive Electronics
• Avionics
• Low-Power Voltage Reference

Comparison

- Low quiescent current and dropout voltage help prolong battery life

- Positive transient protection and ability to survive unregulated input transients enhance device durability

- Tight tolerance, excellent load and line regulation, and low output voltage temperature coefficient make it a good voltage reference

- Additional features in LP2951 include error flag output and logic-controlled shutdown for better system control.

- No specific disadvantages identified