TLC5955 Datasheet, PDF (39/53 Pages) Texas Instruments – TLC5955 48-Channel, 16-Bit, PWM LED Driver with DC, BC, LED Open-Short Detection, and Internal Current Setting

www.ti.com
TLC5955
SBVS237 – MARCH 2014
9.2.1.2 Detailed Design Procedure
9.2.1.2.1 Step-by-Step Design Procedure
To begin the design process, a few parameters must be decided upon. The designer needs to know the
following:
• Maximum output constant-current value for each color LED ramp.
• Maximum LED forward voltage (V_F).
• Current ratio of red, green, and blue LED lamps for the best white balance.
• Are the auto display repeat function, display timing reset function, or auto data refresh function used?
• Which PWM control method is used: ES-PWM or conventional PWM?
• Is the LED short detect (LSD) function used? If so, which detection level (70% VCC or 90% VCC) is used?
9.2.1.2.2 Maximum Current (MC) Data
There are a total of nine bits of MC data for the red, green, and blue LED ramp. Select the MC data to be greater
than each LED ramp current and write the data with other control data.
9.2.1.2.3 Global Brightness Control (BC) Data
There are a total of three sets of 7-bit BC data for the red, green, and blue LED ramp. Select the BC data for the
best white balance of the red, green, and blue LED ramp and write the data with other control data.
9.2.1.2.4 Dot Correction (DC) Data
There are a total of 48 sets of 7-bit DC data for each current adjustment. Select the DC data for the best
uniformity of each color LED ramp and write the data with other control data.
9.2.1.2.5 Grayscale (GS) Data
There are a total of 48 sets of 16-bit GS data for the PWM control of each output. Select the GS data of the LED
ramp intensity and color control and write the data with other GS data.
9.2.1.2.6 Other Control Data
There are five bits control data to set the function mode for the auto display repeat, display timing reset, auto
data refresh, ES-PWM, and LSD functions explained in the Device Functional Modes section. Write the 5-bit
control data for the appropriate operation of the display system with MC, BC, and DC data as the control data.
Copyright © 2014, Texas Instruments Incorporated
Product Folder Links: TLC5955
Submit Documentation Feedback
39