Correct Method to Set the IDAC Current - KBA213666

Version: **

 

Question:

The resolution of the IDAC is 1 µA/bit and the code is as follows. The output current is 120 µA instead of the expected current of 200 µA. What is the reason for this?

 

"void main()
{ IDAC_1_SetValue(200);
IDAC_1_Start(); ..... }. "

 

Answer:

IDAC's configuration should be done only after starting the IDAC_1 User module. If not done this way, you won't get 200 µA of current. In the customizer, by default, the initial value for resolution of 1 µA/bit will be set to 120, resulting in only 120 µA output current.

 

If you want the initial current to be 200 µA, change the initial value to 200 in the customizer as shown in the following figure. The other way to move the SetValue() API next to Start() API but there might be some delay

 

PSoC 4 IDAC Configuration

PSoC_4_IDAC_Configuration.png

 

PSoC 3/5 IDAC Configuration

PSoC_3-5_IDAC_Configuration.png