Datasheet

308
XMEGA D4 [DATASHEET]
8135P–AVR–01/2014
Problem fix/Workaround
Keep the amplified voltage output from the ADC gain stage below 2.4V in order to get a correct result, or keep
ADC voltage reference below 2.4V.
6. ADC Event on compare match non-functional
ADC signalling event will be given at every conversion complete even if Interrupt mode (INTMODE) is set to
BELOW or ABOVE.
Problem fix/Workaround
Enable and use interrupt on compare match when using the compare function.
7. ADC propagation delay is not correct when 8x -64x gain is used
The propagation delay will increase by only one ADC clock cycle for 8x and 16x gain setting, and 32x and 64x gain
settings.
Problem fix/Workaround
None.
8. Bandgap measurement with the ADC is non-functional when VCC is below 2.7V
The ADC can not be used to do bandgap measurements when VCC is below 2.7V.
Problem fix/Workaround
None.
9. Accuracy lost on first three samples after switching input to ADC gain stage
Due to memory effect in the ADC gain stage, the first three samples after changing input channel must be disre-
garded to achieve 12-bit accuracy.
Problem fix/Workaround
Run three ADC conversions and discard these results after changing input channels to ADC gain stage.
10. Configuration of PGM and CWCM not as described in XMEGA A Manual
Enabling Common Waveform Channel Mode will enable Pattern generation mode (PGM), but not Common Wave-
form Channel Mode.
Enabling Pattern Generation Mode (PGM) and not Common Waveform Channel Mode (CWCM) will enable both
Pattern Generation Mode and Common Waveform Channel Mode.
1x gain: 2.4V
2x gain: 1.2V
4x gain: 0.6v
8x gain: 300mV
16x gain: 150mV
32x gain: 75mV
64x gain: 38mV