SNVSCD2 September   2024 LM704A0-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Input Voltage Range (VIN)
      2. 6.3.2  High-Voltage Bias Supply Regulator (VCC, BIAS, VDDA)
      3. 6.3.3  Enable (EN)
      4. 6.3.4  Power-Good Monitor (PG)
      5. 6.3.5  Switching Frequency (RT)
      6. 6.3.6  Dual Random Spread Spectrum (DRSS)
      7. 6.3.7  Soft Start
      8. 6.3.8  Output Voltage Setpoint (FB)
      9. 6.3.9  Minimum Controllable On-Time
      10. 6.3.10 Error Amplifier and PWM Comparator (FB, EXTCOMP)
      11. 6.3.11 Slope Compensation
      12. 6.3.12 Shunt Current Sensing
      13. 6.3.13 Hiccup Mode Current Limiting
      14. 6.3.14 Device Configuration (CONFIG)
      15. 6.3.15 Single-Output Dual-Phase Operation
      16. 6.3.16 Pulse Frequency Modulation (PFM) / Synchronization
      17. 6.3.17 Thermal Shutdown (TSD)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Standby Mode
      3. 6.4.3 Active Mode
      4. 6.4.4 Sleep Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Power Train Components
        1. 7.1.1.1 Buck Inductor
        2. 7.1.1.2 Output Capacitors
        3. 7.1.1.3 Input Capacitors
        4. 7.1.1.4 EMI Filter
      2. 7.1.2 Error Amplifier and Compensation
      3. 7.1.3 Maximum Ambient Temperature
        1. 7.1.3.1 Derating Curves
    2. 7.2 Typical Applications
      1. 7.2.1 Design 1 – High Efficiency, Wide Input, 400kHz Synchronous Buck Regulator
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 7.2.1.2.2 Custom Design With Excel Quickstart Tool
          3. 7.2.1.2.3 Buck Inductor
          4. 7.2.1.2.4 Current-Sense Resistance
          5. 7.2.1.2.5 Output Capacitors
          6. 7.2.1.2.6 Input Capacitors
          7. 7.2.1.2.7 Frequency Set Resistor
          8. 7.2.1.2.8 Feedback Resistors
          9. 7.2.1.2.9 Compensation Components
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Design 2 – High Efficiency 24V to 3.3V 400kHz Synchronous Buck Regulator
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Thermal Design and Layout
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
        1. 8.2.1.1 PCB Layout Resources
        2. 8.2.1.2 Thermal Design Resources
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Tape and Reel Information

6.4.1 Shutdown Mode

The EN / UVLO pin provides ON / OFF control for the LM704A0-Q1. When VEN is below 0.55V (typical), the device is in shutdown mode. Both the internal LDO and the switching regulator are off. The quiescent current in shutdown mode drops to 2.3μA (typical). The LM704A0-Q1 also includes undervoltage (UV) protection of the internal bias LDO. If the internal bias supply voltage is below the UV threshold level, the switching regulator remains off.