SNVSAH6C June   2018  – May 2021 LM2775-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Switching Characteristics
    7. 6.7 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 Pre-Regulation
      2. 7.3.2 Input Current Limit
      3. 7.3.3 PFM Mode
      4. 7.3.4 Output Discharge
      5. 7.3.5 Thermal Shutdown
      6. 7.3.6 Undervoltage Lockout
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
      2. 7.4.2 Boost Mode
  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 Output Current Capability
        2. 8.2.2.2 Efficiency
        3. 8.2.2.3 Power Dissipation
        4. 8.2.2.4 Recommended Capacitor Types
        5. 8.2.2.5 Output Capacitor and Output Voltage Ripple
        6. 8.2.2.6 Input Capacitor and Input Voltage Ripple
        7. 8.2.2.7 Flying Capacitor
      3. 8.2.3 Application Curve
      4. 8.2.4 USB OTG / Mobile HDMI Power Supply
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
        3. 8.2.4.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.1 Overview

The LM2775-Q1 is a regulated switched capacitor doubler that, by combining the principles of switched-capacitor voltage boost and linear regulation, generates a regulated output from an extended Li-Ion input voltage range. A two-phase non-overlapping clock generated internally controls the operation of the doubler. During the charge phase (φ1), the flying capacitor (C1) is connected between the input and ground through internal pass transistor switches and is charged to the input voltage. In the pump phase that follows (φ2), the flying capacitor is connected between the input and output through similar switches. Stacked atop the input, the charge of the flying capacitor boosts the output voltage and supplies the load current.

A traditional switched capacitor doubler operating in this manner uses switches with very low on-resistance to generate an output voltage that is 2× the input voltage. Regulation is achieved by modulating the current of the two switches connected to the VIN pin (one switch in each phase).