SLVSGF4B june   2022  – may 2023 TPS1641

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  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 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Enable and Shutdown Input (EN/SHDN)
      2. 8.3.2  Overvoltage Protection (OVP)
      3. 8.3.3  Output Slew Rate and Inrush Current Control (dVdt)
      4. 8.3.4  Active Current Limiting (ILIM) With the TPS16412, TPS16413, TPS16416, and TPS16417
      5. 8.3.5  Active Power Limiting (PLIM) With the TPS16410, TPS16411, TPS16414, and TPS16415
        1. 8.3.5.1 Internal Current Limit for the TPS16410 and TPS16411
      6. 8.3.6  Overcurrent Protection (IOCP) and Blanking Time (IDLY or PDLY) for Transient Loads
      7. 8.3.7  Fast-Trip and Short-Circuit Protection
      8. 8.3.8  Analog Load Current Monitor (IMON) on the IOCP Pin
      9. 8.3.9  IN to OUT Short Detection (TPS16410, TPS16411, TPS16412, and TPS16413)
      10. 8.3.10 Thermal Shutdown and Overtemperature Protection
      11. 8.3.11 Fault Response and Indication (FLT)
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application: 15-W Power Limiting for Low Power Circuits (LPCs)
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Setting Overvoltage Setpoints
        2. 9.2.2.2 Setting the Output Overcurrent Setpoint (IOCP)
        3. 9.2.2.3 Setting the Output Power Limit
        4. 9.2.2.4 Monitoring the Output Current
        5. 9.2.2.5 Limiting the Inrush Current and Setting the Output Slew Rate
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 Accurate Power or Current Limiting at the Output of DC/DC or Flyback Converter
    4. 9.4 Best Design Practices
    5. 9.5 Power Supply Recommendations
      1. 9.5.1 Transient Protection
    6. 9.6 Layout
      1. 9.6.1 Layout Guidelines
      2. 9.6.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.3 Output Slew Rate and Inrush Current Control (dVdt)

During hot plug events or while trying to charge a large output capacitance, there can be a large inrush current. If the inrush current is not managed properly, it can damage the input connectors and cause the system power supply to droop leading to unexpected restarts elsewhere in the system. The inrush current during turn-on is directly proportional to the load capacitance and rising slew rate. Equation 1 can be used to find the output slew rate (SR) required to limit the inrush current (IINRUSH) for a given output capacitance (COUT).

Equation 1. SR = IINRUSHCOUT

A capacitance can be added to the dVdt pin to control the rising slew rate and lower the inrush current during turn-on. The required CdVdt capacitance to produce a given slew rate can be calculated using Equation 2.

Equation 2. CdVdt = IdVdt × GdVdt SR

The fastest output slew rate is achieved by leaving the dVdt pin open. If dVdt pin is connected to GND, the device will not power up the output. Figure 8-8 illustrates the output slew rate control in the TPS1641x devices. Figure 8-9 shows the output slew rate control response of the device.

GUID-20211220-SS0I-BDRJ-90FD-QR9MSZCK5LXC-low.svg Figure 8-8 Output Slew Rate Control in the TPS1641x
GUID-20220603-SS0I-97KC-HPGQ-MQBLXT4925TT-low.png Figure 8-9 Output Slew Rate Control with VIN = 12 V, CdVdt = 150 nF, and COUT = 470 μF