SLVS515D December 2004 – November 2015 TLC5940
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.
The device is a 16-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, dot correction data and PWM control data can be written from the SIN input terminal.
For this design example, use the input parameters shown in Table 4.
|VCC input voltage range||3.0 V to 5.5 V|
|LED lamp (VLED) input voltage range||>Maximum LED forward voltage (VF) + IC knee voltage|
|SIN, SCLK, XLAT, GSCLK, and BLANK voltage range||Low level = GND, High level = VCC|
Figure 22 shows a cascading connection of n TLC5940 devices connected to a controller, building a basic module of an LED display system. The maximum number of cascading TLC5940 devices depends on the application system and is in the range of 40 devices. Equation 9 calculates the minimum frequency needed:
There are a total of 16 sets of 12-bit GS data for the PWM control of each output. Select the GS data of each LED lamp and write the GS data to the register following the signal timing.