LP2985 Low-Dropout Regulator

19 June 2020 - 0 Comments

LP2985 Low-Dropout Regulator

LP2985 Regulator Pinout

The LP2985 is a fixed output, low drop-out (LDO) regulator with output current capability of 150 mA, very low dropout voltage (280 mV), and better than 1.5 % Voltage Regulation Accuracy. LP2985 has an Enable pin to provide Zero-current shutdown mode. This voltage regulator comes with features, such as overcurrent and over-temperature protection.

LP2985 LDO Pinout Configuration

Pin No.	Pin Name	Description
1	V_IN	Supply Input
2	GND	Ground
3	ON/OFF	Active-low shutdown pin. Logic-high = enable, logic-low or open = shutdown
4	BYP	Reference Bypass: Connect external 470 pF capacitor to GND to reduce output noise. May be left open.
5	OUT	Regulator Output

Features

Input Supply Voltage: 2.2V to 16V
Output Voltage: 3.3 V
Output Current: 150mA
Drop-out Voltage: 280 mV
Voltage Regulation Accuracy: 1.5 %
Operating Supply Current: 850 uA
Line Regulation: 0.014 % / V
Shutdown Current: 0.01 μA
Overcurrent and Thermal Protection
High Peak-Current Capability
Available in SOT-23-5 Package

Note: The Complete Technical Details can be found in the LP2985 datasheet given at the end of this page.

LP2985 Equivalents

MIC5205, TPS73633, TLV713

Alternative LDO Regulators

AP2112K, AMS1117, MIC5225

LP2985 Introduction

LP2985 is specially designed for Portable Devices, Digital Cameras, and MP3 players by Texas Instruments. The input voltage of the Regulator can be between 2.2V to 16V, the LP2985 includes a CMOS or TTL compatible enable/shutdown control input. When shutting down, power consumption drops nearly to zero. Output noise in LP2985 is further reduced by bypass pin. The functional block diagram of LP2985 is shown below. Main components of this regulator are the Reference voltage, Error amplifier, and Pass element (transistor).

LP2985 Functional Block Diagram

How to use the LP2985 LDO

LP2985 low dropout regulator comes in a 5-pin package. In LP2985 regulator, an extra bypass pin is introduced for further output noise reduction. This pin is connected to the ground through an optional 10nf capacitor. Vin pin is connected to the input power supply and a 1µf ceramic capacitor is used for input noise cancellation. The regulated voltage is obtained from the Vout pin. Enable pin can be used to turn on or off the regulator, this helps the designers to turn off the regulator and prevent battery usage when not in use. The application diagram for the LP2985 voltage regulator is shown below.

LP2985 Application Circuit