SLVSE57C June   2017  – April 2018 TPS2595

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      TPS25953x Overvoltage Clamp Response Time
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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 Switching Characteristics
    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 Undervoltage Protection (UVP) and Undervoltage Lockout (UVLO)
      2. 8.3.2 Overvoltage Protection
        1. 8.3.2.1 Overvoltage Lockout (OVLO)
        2. 8.3.2.2 Overvoltage Clamp (OVC)
      3. 8.3.3 Inrush Current, Overcurrent and Short Circuit Protection
        1. 8.3.3.1 Slew Rate and Inrush Current Control (dVdt)
        2. 8.3.3.2 Active Current Limiting
        3. 8.3.3.3 Short Circuit Protection
      4. 8.3.4 Overtemperature Protection (OTP)
      5. 8.3.5 Fault Indication (FLT )
      6. 8.3.6 Quick Output Discharge (QOD)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Enable and Fault Pin Functional Mode 1: Single Device, Self-Controlled
      2. 8.4.2 Enable and Fault Pin Functional Mode 2: Single Device, Host-Controlled
      3. 8.4.3 Enable and Fault Pin Functional Mode 2: Multiple Devices, Self-Controlled
  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 Programming the Current-Limit Threshold: RILM Selection
        2. 9.2.2.2 Undervoltage Lockout Set Point
        3. 9.2.2.3 Setting Output Voltage Ramp Time (TdVdT)
          1. 9.2.2.3.1 Case 1: Start-Up Without Load. Only Output Capacitance COUT Draws Current
          2. 9.2.2.3.2 Case 2: Start-Up With Load. Output Capacitance COUT and Load Draw Current
      3. 9.2.3 Support Component Selection: CIN
      4. 9.2.4 Application Curves
      5. 9.2.5 Controlled Power Down (Quick Output Discharge) using TPS2595x5
      6. 9.2.6 Overvoltage Lockout using TPS259573
  10. 10Power Supply Recommendations
    1. 10.1 Transient Protection
    2. 10.2 Output Short-Circuit Measurements
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
      2. 12.1.2 Related Links
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.2 Undervoltage Lockout Set Point

The undervoltage lockout (UVLO) trip point is adjusted using the external voltage divider network of R1 and R2 as connected between IN, EN/UVLO and GND pins of the device. The values required for setting the undervoltage are calculated solving Equation 7.

Equation 7. TPS2595 tps2595xx-equation-7.gif

Where VUVLO(R) is UVLO rising threshold (1.2 V). Because R1 and R2 leak the current from input supply VIN, these resistors must be selected based on the acceptable leakage current from input power supply VIN.

The current drawn by R1 and R2 from the power supply is IR12 = VIN / (R1 + R2).

However, leakage currents due to external active components connected to the resistor string can add error to these calculations. So, the resistor string current, IR12 must be chosen to be 20 times greater than the leakage current expected.

To set the UVLO at VUVR = 4.3 V, select R2 = 387 kΩ, and R1 = 1 MΩ.