SLVSFQ6A November   2020  – June 2021 TPS2640

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Undervoltage Lockout (UVLO)
      2. 9.3.2 Overvoltage Protection (OVP)
      3. 9.3.3 Reverse Input Supply Protection
      4. 9.3.4 Hot Plug-In and In-Rush Current Control
      5. 9.3.5 Overload and Short Circuit Protection
        1. 9.3.5.1 Overload Protection
          1. 9.3.5.1.1 Active Current Limiting
          2. 9.3.5.1.2 Electronic Circuit Breaker with Overload Timeout, MODE = OPEN
        2. 9.3.5.2 Short Circuit Protection
          1. 9.3.5.2.1 Start-Up With Short-Circuit On Output
        3. 9.3.5.3 FAULT Response
          1. 9.3.5.3.1 Look Ahead Overload Current Fault Indicator
        4. 9.3.5.4 Current Monitoring
        5. 9.3.5.5 IN, OUT, RTN, and GND Pins
        6. 9.3.5.6 Thermal Shutdown
        7. 9.3.5.7 Low Current Shutdown Control (SHDN)
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Step by Step Design Procedure
        2. 10.2.2.2 Undervoltage Lockout and Overvoltage Set Point
        3. 10.2.2.3 Programming Current Monitoring Resistor—RIMON
        4. 10.2.2.4 Setting Output Voltage Ramp Time—(tdVdT)
          1. 10.2.2.4.1 Case 1: Start-Up Without Load—Only Output Capacitance C(OUT) Draws Current During Start-Up
          2. 10.2.2.4.2 Case 2: Start-Up With Load—Output Capacitance C(OUT) and Load Draws Current During Start-Up
          3. 10.2.2.4.3 Support Component Selections—RFLTb and C(IN)
      3. 10.2.3 Application Curves
    3. 10.3 System Examples
      1. 10.3.1 Acive ORing Operation
      2. 10.3.2 Field Supply Protection in PLC, DCS I/O Modules
      3. 10.3.3 Simple 24-V Power Supply Path Protection
    4. 10.4 Do's and Dont's
  11. 11Power Supply Recommendations
    1. 11.1 Transient Protection
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

10.3.1 Acive ORing Operation

GUID-20201012-CA0I-GWV5-XGDN-S3C8XK9FS3BL-low.gif Figure 10-15 Active ORing Application Schematic

Figure 10-15 shows a typical redundant power supply configuration of the system. Schottky ORing diodes have been popular for connecting parallel power supplies, such as parallel operation of wall adapter with a battery or a hold-up storage capacitor. The disadvantage of using ORing diodes is high voltage drop and associated power loss. The TPS26400 with integrated, N-channel back to back FETs provide a simple and efficient solution.

A fast reverse comparator controls the internal FET and it is turned ON or OFF with hysteresis as shown in Figure 10-16. The internal FET is turned off within 1.5 μs (typical) as soon as V(IN) – V(OUT) falls below –110 mV. It turns on within 40 μs (typical) once the differential forward voltage V(IN) – V(OUT) exceeds 100 mV. Figure 10-17 and Figure 10-18 show typical switch-over waveforms of Active ORing implementation using the TPS26400.

GUID-20200603-SS0I-V0GH-GPLV-KJ9HRTQ0XVVS-low.gif Figure 10-16 Active ORing Thresholds
GUID-20200603-SS0I-PDHC-PFHR-N5GQVPRCTFSX-low.png

VIN1 = 22 V

Cout = 47 μF

VIN2: Plugged In

at 24 V

Rload = 24 Ω

C(dVdT) = 22 nF

Figure 10-17 Active ORing Between Two Supplies VOUT Change Over to VIN2
GUID-20200603-SS0I-KMNG-6VCR-F4W5M9Z099V7-low.png

VIN1 = 22 V

Cout = 47 μF

VIN2: Plugged In

at 24 V

Rload = 24 Ω

C(dVdT) = 22 nF

Figure 10-18 Active ORing Between Two Supplies VOUT Change Over to VIN1
Note:

All control pins of the un-powered TPS26400 device in the Active ORing configuration will measure approximately 0.7 V drop with respect to GND. The system micro-controller should ignore IMON and FLT pin voltage measurements of this device when these signals are being monitored.