SLVSB34A October   2011  – June 2015 TPS22933

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  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 Typical Characteristics
  7. Parametric Measurement Information
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 ON and OFF Control
      2. 8.3.2 Power Changeover
    4. 8.4 Device Functional Modes
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 LDO Capacitor (for CAP Pin)
      2. 9.1.2 Using the CAP Pin as a Power Output
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  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

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ
発注情報

8 Detailed Description

8.1 Overview

The TPS22933 is a triple-input power multiplexer with auto-input selection and a low dropout linear regulator. The device contains three P-channel MOSFETs that can operate over an input voltage range of 2.5 V to 12 V. The TPS22933 automatically selects the highest voltage level (from BAT, USB, and DC_IN) and enables that input to source the LDO. LOUT is an always-on output from the LDO, but VOUT can be switched on and off using the EN pin.

8.2 Functional Block Diagram

TPS22933 bd_lvsb34.gif

8.3 Feature Description

8.3.1 ON and OFF Control

The EN pin controls the state of the VOUT switch and VOUT pulldown switch. EN has no control over LOUT. Asserting EN enables the VOUT switch and disables the Quick Output Discharge (QOD) switch. Deasserting EN disables the VOUT switch and enables the QOD switch. EN is active high and has a low threshold, making it capable of interfacing with low voltage signals. The EN pin is compatible with standard GPIO Logic threshold and can be used with any microcontroller with 1.2-V, 1.8-V, 2.5-V or 3.3-V GPIOs.

8.3.2 Power Changeover

The TPS22933 LDO is powered by the highest level input. When input voltages change, the TPS22933 may change which input powers the LDO. During initial power up, the input that reaches the highest value first will power the LDO. Once that decision is made, changing between input sources is based on VCO. When an input source becomes VCO over the input currently supplying power to the LDO, changeover will occur and the new, higher input will power the LDO.

8.4 Device Functional Modes

Table 2 and Table 3 show the behavior of the device with various voltage conditions for the inputs and enable pin.

Table 2. Function Table

EN LDO TO LOUT LDO TO VOUT VOUT TO GND
L ON OFF ON
H ON ON OFF

Table 3. Input Selection Table (V1 > V2 > V3)

BAT USB DC_IN LDO SUPPLY
V1 V2 or V3 V2 or V3 BAT
V2 or V3 V1 V2 or V3 USB
V2 or V3 V2 or V3 V1 DC_IN
V1 V1 V1 See (1)
(1) Whichever source achieves the highest level the fastest will supply the LDO.