SLVS791E November   2007  – July 2016 TPS61160 , TPS61161

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 Timing Requirements
    7. 6.7 Typical Characteristics
      1. 6.7.1 Table Of Graphs
  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-Up
      2. 7.3.2 Open LED Protection
      3. 7.3.3 Current Program
      4. 7.3.4 LED Brightness Dimming Mode Selection
      5. 7.3.5 Undervoltage Lockout
      6. 7.3.6 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
      2. 7.4.2 PWM Brightness Dimming
      3. 7.4.3 Digital One-Wire Brightness Dimming
      4. 7.4.4 External PWM Dimming
    5. 7.5 Programming
      1. 7.5.1 EasyScale: One-Wire Digital Dimming
  8. 8 Application and Implementation Information
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Application of TPS61161
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Maximum Output Current
          2. 8.2.1.2.2 Inductor Selection
          3. 8.2.1.2.3 Schottky Diode Selection
          4. 8.2.1.2.4 Compensation Capacitor Selection
          5. 8.2.1.2.5 Input and Output Capacitor Selection
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Li-Ion Driver for 6 White LEDs with External PWM Dimming Network
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Choosing Component Values
        3. 8.2.2.3 Application Curves
      3. 8.2.3 Li-Ion Driver for 6 White LEDs
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
        3. 8.2.3.3 Application Curves
      4. 8.2.4 Li-Ion Driver for 8 White LEDs
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
        3. 8.2.4.3 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. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
      1. 11.3.1 Related Links
    4. 11.4 Receiving Notification of Documentation Updates
    5. 11.5 Community Resources
    6. 11.6 Trademarks
    7. 11.7 Electrostatic Discharge Caution
    8. 11.8 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

10 Layout

10.1 Layout Guidelines

As for all switching power supplies, especially those high frequency and high current ones, layout is an important design step. If layout is not carefully done, the regulator could suffer from instability as well as noise problems. To reduce switching losses, the SW pin rise and fall times are made as short as possible. To prevent radiation of high frequency resonance problems, proper layout of the high frequency switching path is essential. Minimize the length and area of all traces connected to the SW pin and always use a ground plane under the switching regulator to minimize inter-plane coupling. The loop including the PWM switch, Schottky diode, and output capacitor, contains high current rising and falling in nanosecond and must be kept as short as possible. The input capacitor must not only be close to the VIN pin, but also to the GND pin in order to reduce the device supply ripple. Figure 30 shows a sample layout.

10.2 Layout Example

TPS61160 TPS61161 thrm_cons_lvs791.gif Figure 30. TPS6116x Sample Layout

10.3 Thermal Considerations

The maximum device junction temperature should be restricted to 125°C under normal operating conditions. This restriction limits the power dissipation of the TPS61160 or TPS61161. Calculate the maximum allowable dissipation, PD(max), and keep the actual dissipation less than or equal to PD(max). The maximum-power-dissipation limit is determined using values in Equation 16:

Equation 16. TPS61160 TPS61161 q8_pdm_lvs791.gif

where

  • TA is the maximum ambient temperature for the application
  • RθJA is the thermal resistance junction-to-ambient given in Thermal Information.

The TPS61160 and TSP61161 come in a thermally enhanced WSON package. This package includes a thermal pad that improves the thermal capabilities of the package. The RθJA of the WSON package greatly depends on the PCB layout and thermal pad connection. The thermal pad must be soldered to the analog ground on the PCB. Using thermal vias underneath the thermal pad as illustrated in the layout example. Also see the QFN/SON PCB Attachment application report (SLUA271).