ZHCSIS8F September   2018  – March 2024 TPS7H2201-SEP , TPS7H2201-SP

PRODUCTION DATA  

  1.   1
  2. 特性
  3. 应用
  4. 说明
  5. Device Options
  6. Pin Configuration and Functions
  7. 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: All Devices
    6. 6.6  Electrical Characteristics: CFP and KGD Options
    7. 6.7  Electrical Characteristics: HTSSOP Option
    8. 6.8  Switching Characteristics (All Devices)
    9. 6.9  Quality Conformance Inspection
    10. 6.10 Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Enable, Undervoltage, and Overvoltage Protection
      2. 8.3.2 Adjustable Rise Time
      3. 8.3.3 Programmable Current Limiting
      4. 8.3.4 Programmable Fault Timer
      5. 8.3.5 Current Sense
      6. 8.3.6 Parallel Operation
      7. 8.3.7 Reverse Current Protection
      8. 8.3.8 Forward Leakage Current
    4. 8.4 Device Functional Modes
  10. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Redundancy
      2. 9.2.2 Protection
      3. 9.2.3 Design Requirements
      4. 9.2.4 Detailed Design Procedure
        1. 9.2.4.1 Undervoltage Lockout
        2. 9.2.4.2 Overvoltage Protection
        3. 9.2.4.3 Current Limit
        4. 9.2.4.4 Programmable Fault Timers
        5. 9.2.4.5 Soft Start Time
      5. 9.2.5 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 支持资源
    4. 10.4 Trademarks
    5. 10.5 静电放电警告
    6. 10.6 术语表
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Forward Leakage Current

When VIN is powered but the TPS7H2201 is disabled (EN is low), the internal FETs are disabled, creating a high impedance path from VIN to VOUT. However, there are parasitic leakage paths that can cause VOUT to slowly charge. The forward leakage current, IF, indicates how much current flows from VIN to VOUT during this situation. The maximum forward of the TPS7H2201-SP current is specified at 250 μA across voltage, temperature and radiation.

Some applications need to pay particular attention to this behavior. Is particularly relevant when VOUT is a high impedance node (and therefore the leakage current goes entirely to charging VOUT instead of being dissipated). By using the basic capacitor equation shown in Equation 11, the time for the voltage to rise to a given value can be theoretically calculated.

Equation 11. Δt = ΔVOUT × COUT / IF

where

  • Δt = time to charge to final value
  • ΔVOUT = change in output voltage; for a 0 V starting voltage, use VIN

For example, with a 7-V input voltage and a 220-µF output capacitance, VOUT typically charge to 7 V in approximately 6.2 seconds (using IF = 150 μA, ΔVOUT = 7 V, COUT = 220 µF).

If the output voltage must remain below a certain value, a pull-down resistor can be utilized with a value as calculated by using Equation 12.

Equation 12. VOUTLKG_MAX = IF × RPULL_DOWN

where

  • VOUTLKG_MAX = maximum output voltage due to leakage current, IF
  • RPULL_DOWN = external pull-down resistor from VOUT to GND

For example, placing a 2.6-kΩ resistor between VOUT and ground makes sure VOUT does not rise above 0.65-V worse case due to the IF current. The resistor need to be able to handle the worst case power dissipation when the switch is enabled and VOUT ≈ VIN.