SBVS222C February   2013  – October 2016 TLC59731

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 Parameter Measurement Information
    1. 7.1 Pin-Equivalent Input and Output Schematic Diagrams
    2. 7.2 Test Circuits
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Sink Current Value Setting
      2. 8.3.2 Resistor and Capacitor Value Setting for Shunt Regulator
      3. 8.3.3 Grayscale (GS) Control
      4. 8.3.4 EasySet and Shunt Regulator
      5. 8.3.5 No Limit Cascading
      6. 8.3.6 Connector Design
    4. 8.4 Device Functional Modes
      1. 8.4.1 Grayscale (GS) Function (PWM Control)
        1. 8.4.1.1 PWM Control
    5. 8.5 Programming
      1. 8.5.1 One-Wire Interface (EasySet) Data Writing Method
        1. 8.5.1.1 Data Transfer Rate (TCYCLE) Measurement Sequence
        2. 8.5.1.2 Data 0 and Data 1 Write Sequence (Data Write Sequence)
        3. 8.5.1.3 One Communication Cycle End of Sequence (EOS)
        4. 8.5.1.4 GS Data Latch (GSLAT) Sequence
        5. 8.5.1.5 How to Control Devices Connected in Series
    6. 8.6 Register Maps
      1. 8.6.1 Register and Data Latch Configuration
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Define Basic Parameters
        2. 9.2.2.2 Grayscale (GS) Data
      3. 9.2.3 Application Curve
    3. 9.3 System Examples
    4. 9.4 Do's and Don'ts
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

9.1 Application Information

The device is a 3-channel, constant sink current, LED driver. This device can be connected in series to drive many LED lamps with only a few controller ports. Output current control data and PWM control data can be written from the SIN input terminal. The PWM timing reference clock can be supplied from the internal oscillation.

9.2 Typical Application

TLC59731 typ_app2_bvs222.gif Figure 21. Typical Application Circuit Example (No Internal Shunt Regulator Mode)

9.2.1 Design Requirements

For this design example, use Table 4 as the input parameters.

Table 4. Design Parameters

DESIGN PARAMETER EXAMPLE VALUE
VCC Input Voltage Range 3 V to 5.5 V
LED Lamp (VLED) Input Voltage Range 21 V Maximum
SDI Voltage Range Low Level = GND, High Level = VCC

9.2.2 Detailed Design Procedure

9.2.2.1 Define Basic Parameters

To begin the design process, a few parameters must be decided:

  • Maximum output constant-current value for each color LED lamp
  • Maximum LED forward voltage (Vf) and Maximum VLED
  • Total LEDs and Cascaded IC Number

9.2.2.2 Grayscale (GS) Data

32-bit GS data packets are sent through single-wire interface for the PWM control of three output channels. Select the GS data of each LED lamp and write the GS data to the register following the signal timing.

9.2.3 Application Curve

TLC59731 TLC59731-curve.gif Figure 22. Output Waveform Without GS Data Latch Input

9.3 System Examples

TLC59731 typ_app1_bvs222.gif Figure 23. Typical Application Circuit Example (No Internal Shunt Regulator Mode)
TLC59731 typ_app3_bvs222.gif Figure 24. Typical Application Circuit Example (Internal Shunt Regulator Mode)

9.4 Do's and Don'ts

When the connector pin of the device application printed-circuit-board (PCB) is connected or disconnected to other PCBs, the power must be turned off to avoid device malfunction or failure. Furthermore, designing the connector GND pin to be longer than other pins (as shown in Figure 25) is preferable. This arrangement allows the GND line to either be connected first or disconnected last, which is imperative for proper device function.

TLC59731 ai_connex_pin_design_bvs222.gif Figure 25. Connector Pin Design Application