Datasheet

[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET]

8067O–AVR–06/2013

 TWI START condition at bus timeout will cause transaction to be dropped

 TWI Data Interrupt Flag erroneously read as set

 WDR instruction inside closed window will not issue reset

1. Bandgap voltage input for the ACs cannot be changed when used for both ACs simultaneously

If the Bandgap voltage is selected as input for one Analog Comparator (AC) and then selected/deselected as input

for another AC, the first comparator will be affected for up to 1 µs and could potentially give a wrong comparison

result.

Problem fix/Workaround

If the Bandgap is required for both ACs simultaneously, configure the input selection for both ACs before enabling

any of them.

2. VCC voltage scaler for AC is non-linear

The 6-bit VCC voltage scaler in the Analog Comparators is non-linear.

Figure 36-1. Analog Comparator Voltage Scaler vs. Scalefac

T = 25°C

Problem fix/Workaround

Use external voltage input for the analog comparator if accurate voltage levels are needed

3. The ADC has up to ±2 LSB inaccuracy

The ADC will have up to ±2 LSB inaccuracy, visible as a saw-tooth pattern on the input voltage/ output value trans-

fer function of the ADC. The inaccuracy increases with increasing voltage reference reaching ±2 LSB with 3V

reference.

3.3 V

2.7 V

1.8 V

0.5

1.5

2.5

3.5

0 5 10 15 20 25 30 35 40 45 50 55 60 65

SCALEFAC

SCALE

[V]