SLVS875C January   2009  – November 2014 TPS54332

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Efficiency
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics: Characterization Curves
    8. 6.8 Typical Characteristics: Supplemental Application Curves
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fixed Frequency PWM Control
      2. 7.3.2  Voltage Reference (Vref)
      3. 7.3.3  Bootstrap Voltage (BOOT)
      4. 7.3.4  Enable and Adjustable Input Undervoltage Lockout (VIN UVLO)
      5. 7.3.5  Programmable Slow-Start Using SS Pin
      6. 7.3.6  Error Amplifier
      7. 7.3.7  Slope Compensation
      8. 7.3.8  Current Mode Compensation Design
      9. 7.3.9  Overcurrent Protection and Frequency Shift
      10. 7.3.10 Overvoltage Transient Protection
      11. 7.3.11 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation With VIN < 3.5 V
      2. 7.4.2 Operation With EN Control
      3. 7.4.3 Eco-Mode
  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  Switching Frequency
        2. 8.2.2.2  Output Voltage Set Point
        3. 8.2.2.3  Input Capacitors
        4. 8.2.2.4  Output Filter Components
        5. 8.2.2.5  Inductor Selection
        6. 8.2.2.6  Capacitor Selection
        7. 8.2.2.7  Compensation Components
        8. 8.2.2.8  Bootstrap Capacitor
        9. 8.2.2.9  Catch Diode
        10. 8.2.2.10 Output Voltage Limitations
        11. 8.2.2.11 Power Dissipation Estimate
      3. 8.2.3 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Estimated Circuit Area
    4. 10.4 Electromagnetic Interference (EMI) Considerations
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

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机械数据 (封装 | 引脚)
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订购信息

Enable and Adjustable Input Undervoltage Lockout (VIN UVLO)

The EN pin has an internal pullup current source that provides the default condition of the TPS54332 operating when the EN pin floats.

The TPS54332 is disabled when the VIN pin voltage falls below internal VIN UVLO threshold. TI recommends using an external VIN UVLO to add Hysteresis unless VIN is greater than (VOUT + 2 V). To adjust the VIN UVLO with Hysteresis, use the external circuitry connected to the EN pin as shown in Figure 11. Once the EN pin voltage exceeds 1.25 V, an additional 3 μA of hysteresis is added. Use Equation 1 and Equation 2 to calculate the resistor values needed for the desired VIN UVLO threshold voltages. The VSTART is the input start threshold voltage, the VSTOP is the input stop threshold voltage and the VEN is the enable threshold voltage of 1.25 V. The VSTOP should always be greater than 3.5 V.

TPS54332 lock_out_lvs875.gifFigure 11. Adjustable Input Undervoltage Lockout
Equation 1. TPS54332 q1_lvs839.gif
Equation 2. TPS54332 q2_lvs839.gif