Revisions Affected

Description

ADC can have errors at the rate as high as 1 in 330 million ADC conversions. When a conversion error occurs, the error results in a jump in the digital output of the ADC without a corresponding change in the ADC input voltage, otherwise known as a ‘sparkle code’. The magnitude of the jump is 64 LSBs higher or lower than the expected ADC output when ADC is used in 12-bit resolution setting. The magnitude of the jump decreases to +/-16 LSBs for 10-bit resolution and +/-4 LSBs when set to 8-bit resolution.

Workaround

The error rate can be reduced to 1 error in 80 billion ADC conversions by setting ADC.DEBUG1:CTRL[10:9] bits high.

Other software workarounds like a best-out-of-three, where out of three consecutive samples, the one with the highest standard deviation is discarded and the other two averaged to generate the ADC output can also be considered.

Software averaging of 16 consecutive ADC outputs decreases the deviation of the ADC output to +/- 4 LSBs when set to 12-bit resolution.

These workarounds will be incorporated into a future release of the SimpleLink™ Low Power F3 software development kit (SDK) for the CC23xx devices.