SLVSCM8D May   2015  – August 2021 TPS61088

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 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 Enable and Start-up
      2. 7.3.2 Undervoltage Lockout (UVLO)
      3. 7.3.3 Adjustable Switching Frequency
      4. 7.3.4 Adjustable Peak Current Limit
      5. 7.3.5 Overvoltage Protection
      6. 7.3.6 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation
        1. 7.4.1.1 PWM Mode
        2. 7.4.1.2 PFM 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 Custom Design with WEBENCH Tools
        2. 8.2.2.2 Setting Switching Frequency
        3. 8.2.2.3 Setting Peak Current Limit
        4. 8.2.2.4 Setting Output Voltage
        5. 8.2.2.5 Inductor Selection
        6. 8.2.2.6 Input Capacitor Selection
        7. 8.2.2.7 Output Capacitor Selection
        8. 8.2.2.8 Loop Stability
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design with WEBENCH Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.1 Operation

The synchronous boost converter TPS61088 operates at a quasi-constant frequency pulse width modulation (PWM) in moderate-to-heavy load condition. Based on the VIN to VOUT ratio, a circuit predicts the required off-time of the switching cycle. At the beginning of each switching cycle, the low-side N-MOSFET switch, as shown in Section 7.2, is turned on, and the inductor current ramps up to a peak current that is determined by the output of the internal error amplifier. After the peak current is reached, the current comparator trips. It turns off the low-side N-MOSFET switch and the inductor current goes through the body diode of the high-side N-MOSFET in a dead-time duration. After the dead-time duration, the high-side N-MOSFET switch is turned on. Since the output voltage is higher than the input voltage, the inductor current decreases. The high-side switch is not turned off until the fixed off-time is reached. After a short dead-time duration, the low-side switch turns on again and the switching cycle is repeated.

In light load condition, the TPS61088 implements two operation modes, PFM mode and forced PWM mode, to meet different application requirements. The operation mode is set by the status of the MODE pin. When the MODE pin is connected to ground, the device works in forced PWM mode. When the MODE pin is left floating, the device works in PFM mode.