LP2951 Voltage Regulator: Pinout, Equivalent and Datasheet

Symbol

Footprint

3D Model

The LP2951 is micropower voltage regulator with very low quiescent current (75μA typ.) and very low dropout voltage (typ. 40mV at light loads and 380mV at 100mA). It is ideally suited for use in battery-powered systems. Furthermore, the quiescent current of the LP2950/LP2951 increases only slightly in dropout, prolonging battery life. The 8-lead LP2951 is available in plastic, ceramic dual-in-line, LLP, or metal can packages and offers additional system functions. The LP2951 is micropower voltage regulator that are specifically designed to maintain proper regulation with an extremely low input−to−output voltage differential. The device features a very low quiescent bias current of 75 A and are capable of supplying output currents in excess of 100 mA. Internal current and thermal limiting protection is provided. 

This device can provide low dropout regulation in a wide range of output voltage ranging from 1.235V to 30V. Therefore, it has become a popular choice for microcircuits that require micropower regulators that can provide up to 100 mA load current. And this article will provide you with a basic overview of the LP2951 voltage regulator, including its pin descriptions, functions and specifications, etc., so that to help you quickly understand what LP2951 is.

• 5V, 3V, and 3.3V versions available

• High accuracy output voltage

• Guaranteed 100mA output current

• Extremely low quiescent current

• Low dropout voltage

• Extremely tight load and line regulation

• Very low temperature coefficient

• Use as Regulator or Reference

• Needs minimum capacitance for stability

• Current and Thermal Limiting

• Stable with low-ESR output capacitors (10mΩ to 6Ω)

• Error flag warns of output dropout

• Logic-controlled electronic shutdown

• Output programmable from 1.24 to 29V

The LP2951 device is bipolar, low-dropout voltage regulator that can accommodate a wide input supply-voltage range of up to 30 V. The 8-pin LP2951 device is able to output either a fixed or adjustable output from the same device. The 8-pin LP2951 device also offers additional functionality that makes it particularly suitable for battery-powered applications. For example, a logic-compatible shutdown feature allows the regulator to be put in standby mode for power savings. The LP2951 device is designed to minimize all error contributions to the output voltage. With a tight output tolerance (0.5% at 25°C), a very low output voltage temperature coefficient (20 ppm typical), extremely good line and load regulation (0.3% and 0.4% typical), and remote sensing capability, the parts can be used as either low-power voltage references or 100-mA regulators.

Compared with LP2950, The LP2951 has three additional features. The first is the Error Output that can be used to signal external circuitry of an out of regulation condition, or as a microprocessor power−on reset. The second feature allows the output voltage to be preset to 5.0 V, 3.3 V or 3.0 V output (depending on the version) or programmed from 1.25 V to 29 V. It consists of a pinned out resistor divider along with direct access to the Error Amplifier feedback input. The third feature is a Shutdown input that allows a logic level signal to turn−off or turn−on the regulator output.

The LP2950/LP2951 regulators are designed with internal current limiting and thermal shutdown making them user−friendly. These regulators are not internally compensated and thus require a 1.0 F (or greater) capacitance between the LP2950/LP2951 output terminal and ground for stability. Most types of aluminum, tantalum or multilayer ceramic will perform adequately. Solid tantalums or appropriate multilayer ceramic capacitors are recommended for operation below 25°C. At lower values of output current, less output capacitance is required for output stability. The capacitor can be reduced to 0.33 F for currents less than 10 mA, or 0.1 F for currents below 1.0 mA. Using the 8 pin versions at voltages less than 5.0 V operates the error amplifier at lower values of gain, so that more output capacitance is needed for stability. For the worst case operating condition of a 100 mA load at 1.23 V output (output Pin 1 connected to the feedback Pin 7) a minimum capacitance of 3.3 F is recommended. A bypass capacitor is recommended across the LP2950/LP2951 input to ground if more than 4 inches of wire connects the input to either a battery or power supply filter capacitor.

Block Diagram

LP2951 Functional Block Diagram

Schematic Diagram

Both LP2950 and LP2951 feature low quiescent current and low dropout voltage (typical 50mV at light load and 380mV at 100mA). These devices are an excellent choice for use in battery powered application such as cordless telephones, radio control systems and portable computers.

• Applications with High-Voltage Input

• Power Supplies

SOIC−8 NB package

SOIC−8 NB package

Texas Instruments (TI) emerges as a globally recognized semiconductor manufacturer expanded into 35 countries. It has seen a rapid growth. In 1958, TIer firstly introduced the working integrated circuit. And today more than 30,000 TIers worldwide are committed to designing, manufacturing, and selling analog and embedded processing chips. They aspire to solve challenges as well as change the world through their technologies.

Texas Instruments (TI) is an American technology company that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globally. Its headquarters are in Dallas, Texas, United States. TI is one of the top ten semiconductor companies worldwide, based on sales volume.Texas Instruments's focus is on developing analog chips and embedded processors, which accounts for more than 80% of their revenue. TI also produces TI digital light processing (DLP) technology and education technology products including calculators, microcontrollers and multi-core processors. To date, TI has more than 43,000 patents worldwide.

Download datasheets and manufacturer documentation for Texas Instruments LP2951CM.