Introduction

The LP2985 series of fixed output, low-dropout regulators provide excellent, cost-effective performance for portable and non-portable applications. This post can help you learn its pinout and configuration as well as CAD model, specification, applications, and features.

Catalog

ⅠLP2985 Description

ⅡLP2985 Pinout

ⅢLP2985 LDO Pinout Configuration

ⅣLP2985 Features

ⅤLP2985-33DBVR CAD Model

Ⅵ LP2985 Parameters

Ⅶ LP2985 Equivalents

Ⅷ LP2985 Functional Block Diagram

Ⅸ LP2985 Layout Example

Ⅹ How to use the LP2985 LDO

Ⅺ Applications

Ⅻ LP2985 Package

XIII Dropout Voltage vs Temperature for New Chip

XIV LP2985 Datasheet PDF

XV LP2985 Frequently Asked Questions

ⅠLP2985 Description

The LP2985 is a fixed-output, wide-input, low-noise, low-dropout voltage regulator supporting an input voltage range from 2.5 V to 16 V and up to 150 mA of load current. The LP2985 supports an output range of 1.2 V to 5.0 V (for a new chip). LP2985 has an Enable pin to provide Zero-current shutdown mode. This voltage regulator comes with features, such as overcurrent and over-temperature protection.

Ⅱ LP2985 Pinout

Figure1-LP2985 Pinout

Ⅲ LP2985 LDO Pinout Configuration

Ⅳ LP2985 Features

• VINrange (new chip): 2.5 V to 16 V
• VOUTrange (new chip): 1.2 V to 5.0 V (fixed, 100-mV steps)
• VOUTaccuracy:
  • ±1% for A-grade legacy chip
  • ±1.5% for standard-grade legacy chip
  • ±0.5% for new chip only
• ±1% output accuracy over load, and temperature for new chip
• Output current: Up to 150 mA
• Low IQ(new chip): 71 µA at ILOAD = 0 mA
• Low IQ(new chip): 750 µA at ILOAD = 150 mA
• Shutdown current:
  • 01 µA (typ) for legacy chip
  • 12 µA (typ) for new chip
• Low noise: 30 µVRMSwith 10-nF bypass capacitor
• Output current limiting and thermal protection
• Stable with 2.2-µF ceramic capacitors
• High PSRR: 70 dB at 1 kHz, 40 dB at 1 MHz
• Operating junction temperature: –40°C to +125°C
• Package: 5-pin SOT-23 (DBV)

Ⅴ LP2985-33DBVR CAD Model

LP2985-33DBVR Symbol

Figure2-LP2985-33DBVR Symbol

LP2985-33DBVR Footprint

Figure3-LP2985-33DBVR footprint

LP2985-33DBVR 3D Model

Figure4-LP2985-33DBVR 3d model

Ⅵ LP2985 Parameters

Ⅶ LP2985 Equivalents

MIC5205, TPS73633, TLV713

Ⅷ LP2985 Functional Block Diagram

Figure5-LP2985 Functional Block Diagram

Ⅸ LP2985 Layout Example

Figure6-LP2985 layout example

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 the bypass pin. The functional block diagram of LP2985 is shown below. The main components of this regulator are the Reference voltage, Error amplifier, and Pass element (transistor).

Ⅹ How to use the LP2985 LDO

LP2985 low dropout regulator comes in a 5-pin package. In the 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. A 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.

Figure7-how to use LP2985 LDO

Ⅺ Applications

• Portable Devices
• Digital Cameras and Camcorders
• CD Players
• MP3 Players

Typical Application Circuit

Figure8-Typical Application Circuit

 Ⅻ LP2985 Package

Dimensions for the LP2985 Voltage Regulator are given below.

 Figure9-LP2985 Package

XIII Dropout Voltage vs Temperature for New Chip

 Figure10-Dropout Voltage vs Temperature for New Chip

XIV LP2985 Datasheet PDF

LP2985 Datasheet