Author: RyanZ_36 Version: **
The actual IDAC current value (in µA) of PSoC® 4 CapSense® can be calculated with the following equation:
IDAC_Current_Value = IDAC_Gain × IDAC
Where IDAC_Gain is the least significant bit of the IDAC current value (in nA or µA), and IDAC is a Modulator IDAC or Compensation IDAC (if compensation IDAC is enabled) value set in firmware.
When IDAC auto-calibration is disabled, you can set appropriate values for these two IDAC parameters in the CapSense Component Configuration GUI. When IDAC auto-calibration is enabled, CapSense will calibrate suitable values for these two IDAC automatically.
IDAC_Gain can be set as 1.2 µA/bit (default) or 2.4 µA/bit for CSDv1; and 2.4 µA/bit, 300 nA/bit, or 37.5 nA/bit for CSDv2.
Here is an example. Assume IDAC_Gain is 2.4 µA/bit, Modulator IDAC is 11, and Compensation IDAC is 9. Ideally, the actual IDAC current values are:
- Actual Modulator IDAC current value = 2.4 µA/bit ×= 26.4 µA;
- Actual CompensationµA/bit × 9 = 21.6 µA.
Note that PSoC 4 IDAC has a ±10% error for full scale. You should consider this error in your actual applications.
Visit Cypress Community or contact Cypress Sales for more details.