Sample and Hold Functions¶
This function enables sample and hold of the CTDAC output.
Cy_CTB_DACSampleAndHold(CTBM_Type *base, cy_en_ctb_sample_hold_mode_t mode)
Perform sampling and holding of the CTDAC output.
To perform a sample or a hold, a preparation step must first be executed to open the required switches. Because of this, each sample or hold requires three function calls:
Call this function to prepare for a sample or hold
Enable or disable the CTDAC output
Call this function again to perform a sample or hold
It takes 10 us to perform a sample of the CTDAC output to provide time for the capacitor to settle to the new value.
/* Scenario: Opamp0 has been configured as a buffer for the CTDAC output * with the sample and hold (S/H) capacitor connected. * This code samples the CTDAC output once. */ /* Prepare for sample. */ Cy_CTB_DACSampleAndHold(CTBM0, CY_CTB_SH_PREPARE_SAMPLE); /* Turn on DAC output. */ Cy_CTDAC_SetOutputMode(CTDAC0, CY_CTDAC_OUTPUT_VALUE); /* Sample DAC output. */ Cy_CTB_DACSampleAndHold(CTBM0, CY_CTB_SH_SAMPLE); /* Allow time for voltage to settle across the hold capacitor. */ Cy_SysLib_DelayUs(10);
/* Scenario: Turn off the CTDAC output to save power and * hold the output voltage across the S/H capcitor. * The DAC output needs to be turned on and sampled periodically. * See the device datasheet for the hold duration. */ /* Prepare for hold. */ Cy_CTB_DACSampleAndHold(CTBM0, CY_CTB_SH_PREPARE_HOLD); /* Turn off DAC output. */ Cy_CTDAC_SetOutputMode(CTDAC0, CY_CTDAC_OUTPUT_HIGHZ); /* Hold voltage. */ Cy_CTB_DACSampleAndHold(CTBM0, CY_CTB_SH_HOLD);
- Function Usage
- Function Usage
base – Pointer to structure describing registers
mode – Mode to prepare or perform a sample or hold, or disable the ability