ZHCSHX8D September   2017  – October 2019 TPS50601A-SP

PRODUCTION DATA.  

  1. 1 特性
    1.     VIN = PVIN = 5V 条件下的效率
  2. 2 应用
  3. 3 说明
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  VIN and Power VIN Pins (VIN and PVIN)
      2. 7.3.2  Voltage Reference
      3. 7.3.3  Adjusting the Output Voltage
      4. 7.3.4  Safe Start-Up Into Prebiased Outputs
      5. 7.3.5  Error Amplifier
      6. 7.3.6  Slope Compensation
      7. 7.3.7  Enable and Adjust UVLO
      8. 7.3.8  Adjustable Switching Frequency and Synchronization (SYNC)
      9. 7.3.9  Slow Start (SS/TR)
      10. 7.3.10 Power Good (PWRGD)
      11. 7.3.11 Sequencing (SS/TR)
      12. 7.3.12 Output Overvoltage Protection (OVP)
      13. 7.3.13 Overcurrent Protection
        1. 7.3.13.1 High-Side MOSFET Overcurrent Protection
        2. 7.3.13.2 Low-Side MOSFET Overcurrent Protection
      14. 7.3.14 Thermal Shutdown
      15. 7.3.15 Turn-On Behavior
      16. 7.3.16 Small Signal Model for Frequency Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Fixed-Frequency PWM Control
      2. 7.4.2 Continuous Current Mode (CCM) Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Operating Frequency
        2. 8.2.2.2 Output Inductor Selection
        3. 8.2.2.3 Output Capacitor Selection
        4. 8.2.2.4 Slow Start Capacitor Selection
        5. 8.2.2.5 Undervoltage Lockout (UVLO) Set Point
        6. 8.2.2.6 Output Voltage Feedback Resistor Selection
        7. 8.2.2.7 Compensation Component Selection
      3. 8.2.3 Parallel Operation
      4. 8.2.4 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 文档支持
      1. 11.1.1 相关文档
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 Glossary
  12. 12机械、封装和可订购信息

7.3.7 Enable and Adjust UVLO

The EN pin provides electrical on and off control of the device. When the EN pin voltage exceeds the threshold voltage, the device starts operation. If the EN pin voltage is pulled below the threshold voltage, the regulator stops switching and enters low Iq state. The EN pin has an internal pullup current source, allowing the user to float the EN pin for enabling the device. If an application requires controlling the EN pin, use open-drain or open-collector output logic to interface with the pin.

The device implements internal UVLO circuitry on the VIN pin. The device is disabled when the VIN pin voltage falls below the internal VIN UVLO threshold. The internal VIN UVLO threshold has a hysteresis of 150-mV typical.

If an application requires either a higher UVLO threshold on the VIN pin or a secondary UVLO on the PVIN in split-rail applications, then the EN pin can be configured as shown in Figure 15, Figure 16, and Figure 17. A ceramic capacitor in parallel with the bottom resistor R2 is recommended to reduce noise on the EN pin as used in the TPS50601A-SP Evaluation Module, SLVUB65.

The EN pin has a small pullup current, Ip, which sets the default state of the pin to enable when no external components are connected. The pullup current is also used to control the voltage hysteresis for the UVLO function because it increases by Ih after the EN pin crosses the enable threshold. Calculate the UVLO thresholds with Equation 2 and Equation 3.

TPS50601A-SP adj_vin_slvsdf5.gifFigure 15. Adjustable VIN UVLO
TPS50601A-SP adj_pvin_slvsdf5.gifFigure 16. Adjustable PVIN UVLO
TPS50601A-SP adj_combo_slvsdf5.gifFigure 17. Adjustable VIN and PVIN UVLO
Equation 2. TPS50601A-SP eq_uvlo1.gif
Equation 3. TPS50601A-SP eq_uvlo2.gif

where

  • Ih = 3 μA
  • Ip = 6.1 μA
  • VENRISING = 1.14 V
  • VENFALLING = 1.11 V