SNVS159H October   2001  – July 2015 LP3981

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 On/Off Input Operation
      2. 8.3.2 Fast On-Time
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation with VOUT(TARGET) + 0.3 V ≤ VIN ≤ 6 V
      2. 8.4.2 Operation With EN Control
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Power Dissipation and Device Operation
        2. 9.2.2.2 External Capacitors
        3. 9.2.2.3 Input Capacitor
        4. 9.2.2.4 Output Capacitor
        5. 9.2.2.5 No-Load Stability
        6. 9.2.2.6 Noise Bypass Capacitor
        7. 9.2.2.7 Capacitor Characteristics
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Community Resources
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • 2.5-V to 6-V Input Range
  • 300-mA Output Current
  • 60-dB PSRR at 1 kHz
  • ≤ 1-μA Quiescent Current When Shut Down
  • Fast Turnon Time: 120 μs (typical) with CBYPASS = 0.01 µF
  • 132-mV Typical Dropout with 300-mA Load
  • 35-μVrms Output Noise Over 10 Hz to 100 kHz
  • Logic Controlled Enable
  • Stable With Ceramic and High-Quality Tantalum Capacitors
  • Thermal Shutdown and Short-Circuit Current Limit
  • Low Thermal Resistance in WSON-6 Package Gives Excellent Power Capability

2 Applications

  • CDMA Cellular Handsets
  • Wideband CDMA Cellular Handsets
  • GSM Cellular Handsets
  • Portable Information Appliances

3 Description

Performance of the LP3981 device is optimized for battery-powered systems to deliver ultra-low-noise, extremely low dropout voltage, and low quiescent current. Regulator ground current increases only slightly in dropout, further prolonging the battery life.

Power supply rejection is better than 60 dB at low frequencies. This high power supply rejection is maintained down to lower input voltage levels common to battery-operated circuits.

The device is ideal for mobile phone and similar battery-powered wireless applications. It provides up to 300 mA, from a 2.5-V to 6-V input, consuming less than 1 µA in disable mode.

The LP3981 is available in 8-pin VSSOP-8 and 6-pin WSON packages. Performance is specified for −40°C to +125°C temperature range. The device available in the following output voltages: 2.5 V, 2.7 V, 2.8 V, 2.83 V, 3 V, 3.03 V and 3.3 V as standard. Other output options can be made available; contact your local TI sales office for more information.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LP3981 WSON (6) 4.00 mm x 3.00 mm
VSSOP (8) 3.00 mm x 3.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application Circuit

LP3981 20020302.gif
Note: Pin numbers in parenthesis indicate WSON package.