SLVS441D December  2002  – December  2014 TPS61042


  1. Features
  2. Applications
  3. Description
  4. Typical Application
  5. Revision History
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1Absolute Maximum Ratings
    2. 7.2ESD Ratings
    3. 7.3Recommended Operating Conditions
    4. 7.4Thermal Information
    5. 7.5Electrical Characteristics
    6. 7.6Typical Characteristics
  8. Detailed Description
    1. 8.1Overview
    2. 8.2Functional Block Diagram
    3. 8.3Feature Description
      1. 8.3.1Boost Converter
      2. 8.3.2Peak Current Control (Boost Converter)
      3. 8.3.3Softstart
      4. 8.3.4Control (CTRL)
      5. 8.3.5Applying a PWM Signal to the CTRL Pin with an On-Time tp≤2.5µs
    4. 8.4Device Functional Modes
      1. 8.4.1Overvoltage Protection (OVP)
      2. 8.4.2Undervoltage Lockout
      3. 8.4.3Thermal Shutdown
  9. Application and Implementation
    1. 9.1Application Information
      1. 9.1.1Efficiency
      2. 9.1.2Setting The LED Current
      3. 9.1.3PWM Control With Separate Enable
      4. 9.1.4Example Schematics
    2. 9.2Typical Application
      1. 9.2.1Design Requirements
      2. 9.2.2Detailed Design Procedure
        1. Selection, Maximum Load Current, and Switching Frequency
        2. Capacitor Selection and Line Regulation
        3. Capacitor Selection
        4. Selection
      3. 9.2.3Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1Layout Guidelines
    2. 11.2Layout Example
      1. 11.2.1Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1Device Support
      1. 12.1.1Third-Party Products Disclaimer
    2. 12.2Documentation Support
      1. 12.2.1Related Documentation
    3. 12.3Trademarks
    4. 12.4Electrostatic Discharge Caution
    5. 12.5Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DRB|8
Orderable Information

1 Features

  • Current Source With Overvoltage Protection
  • Input Voltage Range: 1.8 V to 6 V
  • Internal 30 V Switch
  • Up to 85% Efficiency
  • Precise Brightness Control Using PWM Signal or Analog Signal
  • Switching Frequency: Up to 1 MHz
  • Internal Power MOSFET Switch: 500 mA
  • Operates With Small Output Capacitors Down to 100 nF
  • Disconnects LEDs During Shutdown
  • No Load Quiescent Current: 38 µA Typ
  • Shutdown Current: 0.1 µA Typ
  • Available in a Small 3 mm × 3 mm QFN Package

2 Applications

  • White LED Supply for Backlight/Sidelight Displays
    • PDA, Pocket PC, Smart Phones
    • Handheld Devices
    • Cellular Phones

3 Description

The TPS61042 is a high frequency boost converter with constant current output that drives white LEDs or similar. The LED current is set with the external sense resistor (RS) and is directly regulated by the feedback pin (FB) that regulates the voltage across the sense resistor RS to 252 mV (typ). To control LED brightness, the LED current can be pulsed by applying a PWM (pulse width modulated) signal with a frequency range of 100 Hz to 50 kHz to the control pin (CTRL). To allow higher flexibility, the device can be configured where the brightness can be controlled by an analog signal as well, as described in the application information section. To avoid possible leakage currents through the LEDs during shutdown, the control pin (CTRL) disables the device and disconnects the LEDs from ground. For maximum safety during operation, the output has integrated overvoltage protection that prevents damage to the device in case of a high impedance output (e.g. faulty LED).

Device Information(1)

TPS61042SON (8)3.00 mm × 3.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

4 Typical Application

Larger output capacitor values of 1 µF and larger, reduce the LED ripple current and improve line regulation.