SLVS821E May   2008  – May 2019 TPS61087

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Soft-Start
      2. 7.3.2 Frequency Select Pin (FREQ)
      3. 7.3.3 Undervoltage Lockout (UVLO)
      4. 7.3.4 Thermal Shutdown
      5. 7.3.5 Overvoltage Prevention
    4. 7.4 Device Functional Modes
  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 Inductor Selection
        2. 8.2.2.2 Rectifier Diode Selection
        3. 8.2.2.3 Setting the Output Voltage
        4. 8.2.2.4 Compensation (COMP)
        5. 8.2.2.5 Input Capacitor Selection
        6. 8.2.2.6 Output Capacitor Selection
      3. 8.2.3 Application Curves
    3. 8.3 System Examples
      1. 8.3.1 General Boost Application Circuits
      2. 8.3.2 TFT LCD Application
      3. 8.3.3 White LED Applications
  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 Third-Party Products Disclaimer
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 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 boost converter is designed for output voltages of up to 18.5 V with a switch peak current limit of 3.2 A minimum. The device, which operates in a current mode scheme with quasi-constant frequency, is externally compensated for maximum flexibility and stability. The switching frequency is selectable between 650 kHz and 1.2 MHz, and the minimum input voltage is 2.5 V. To limit the inrush current at start-up, a soft-start pin is available.

The novel topology of the TPS60187 boost converter uses adaptive off-time to provide superior load and line transient responses. This topology also operates over a wider range of applications than conventional converters.

The selectable switching frequency offers the possibility to optimize the design either for the use of small-sized components (1.2 MHz) or for higher system efficiency (650 kHz). However, the frequency changes slightly because the voltage drop across the rDS(on) has some influence on the current and voltage measurement and thus on the on-time (the off-time remains constant).

The converter operates in continuous conduction mode (CCM) as soon as the input current increases above half the ripple current in the inductor, for lower load currents it switches into discontinuous conduction mode (DCM). If the load is further reduced, the part starts to skip pulses to maintain the output voltage.