SNVSAF7C August   2016  – October 2025 LM27762

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 Undervoltage Lockout
      2. 6.3.2 Input Current Limit
      3. 6.3.3 PFM Operation
      4. 6.3.4 Output Discharge
      5. 6.3.5 Power-Good Output (PGOOD)
      6. 6.3.6 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Mode
      2. 6.4.2 Enable Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Positive Low-Dropout Linear Regulator and OUT+ Voltage Setting
        2. 7.2.2.2 Charge-Pump Voltage Inverter
        3. 7.2.2.3 Negative Low-Dropout Linear Regulator and OUT– Voltage Setting
        4. 7.2.2.4 External Capacitor Selection
          1. 7.2.2.4.1 Charge-Pump Output Capacitor
          2. 7.2.2.4.2 Input Capacitor
          3. 7.2.2.4.3 Flying Capacitor
          4. 7.2.2.4.4 LDO Output Capacitor
        5. 7.2.2.5 Power Dissipation
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.1 Application Information

The LM27762 input voltage range is from 2.7 V to 5.5 V. The positive LDO provides a positive voltage configurable with external gain setting resistors R1, R2. The low-noise charge-pump voltage converter inverts the input voltage V to a negative output voltage. Charge pump is followed by the negative LDO which regulates a negative output voltage configurable with external gain setting resistors R3, R4. Output voltage range is ± 1.5 V to ± 5 V. When selecting input (VIN) and output (OUT+, OUT-) voltages ranges, headroom required by the charge pump and LDOs must to be considered. Charge-pump minimum headroom can be estimated based on the maximum load current and charge pump output resistance.

The device uses five low-cost capacitors to provide up to 250 mA of output current. The LM27762 operates at a 2-MHz oscillator frequency to reduce charge-pump output resistance and voltage ripple under heavy loads. When using the optional open-drain PGOOD feature, connect a 10-kΩ pullup resistor (RPU) to VIN. Connect pin to ground if PGOOD is not used.