SLVSAD4B August   2010  – April 2015 TPS22934

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  Switching Characteristics: VIN = 3.6 V
    7. 6.7  Switching Characteristics: VIN = 2.5 V
    8. 6.8  Switching Characteristics: VIN = 1.8 V
    9. 6.9  Switching Characteristics: VIN = 1.5 V
    10. 6.10 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 and OFF Control
      2. 8.3.2 Undervoltage Lockout
      3. 8.3.3 Quick Output Discharge
    4. 8.4 Device Functional Modes
  9. 9 Applications and Implementation
    1. 9.1 Application Information
      1. 9.1.1 VIN to VOUT Voltage Drop
      2. 9.1.2 Input Capacitor
      3. 9.1.3 Output Capacitor
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Input Capacitor
        2. 9.2.2.2 Output Capacitor
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1 Trademarks
    2. 12.2 Electrostatic Discharge Caution
    3. 12.3 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 TPS22934 is a single-channel, 1-A load switch in a small, space-saving DSBGA-4 package. These devices implement a P-channel MOSFET to provide a low ON-resistance for a low voltage drop across the device. A controlled rise time is used in applications to limit the inrush current. The switch is controlled by an ON/OFF input (ON), which has built-in hysteresis (VTH+(typ) = 2.35 V) allowing an easy use of TPS22934 in power-rail sequencing applications.

8.2 Functional Block Diagram

TPS22934 block_dgm_lvsad4.gif

8.3 Feature Description

Table 2. Feature List

rON (TYP)
AT 3.6 V		 SLEW RATE (TYP)
AT 3.6 V		 QUICK OUTPUT DISCHARGE MAXIMUM OUTPUT CURRENT ENABLE
TPS22934 63 mΩ 26 µs Yes 1 A Hysteresis Input
VTH+(typ) = 2.35 V

8.3.1 ON and OFF Control

The ON pin controls the state of the switch. The TPS22934 has built-in hysteresis on its control inputs. The load switch is active when the ON voltage is greater than the positive going voltage threshold (VTH+). If the ON voltage is lower than the negative going voltage threshold (VTH-), then the pass FET is deactivated and the active pulldown from VOUT to GND is activated.

This scenario is ideal for power-rail sequencing applications as shown in Figure 30 where the 2.8-V supply must be valid before the 1.8-V supply turnon.

8.3.2 Undervoltage Lockout

The undervoltage lockout turns off the switch if the input voltage drops below the undervoltage lockout threshold. With the ON pin active, the input voltage rising above the undervoltage lockout threshold causes a controlled turnon of the switch, which limits current overshoots.

8.3.3 Quick Output Discharge

The TPS22934 includes the Quick Output Discharge (QOD) feature. When the switch is disabled, a discharge resistance with a typical value of 35 Ω is connected between the output and ground. This resistance pulls down the output and prevents it from floating when the device is disabled.

8.4 Device Functional Modes

Table 3. Function Table

ON (Control Signal) VIN to VOUT VOUT to GND
VON < VTH- OFF ON
VON > VTH+ ON OFF