ATXMEGA256A3B_09 ATMEL [ATMEL Corporation], ATXMEGA256A3B_09 Datasheet - Page 93

• Manufacturer Part Number: ATXMEGA256A3B_09
• Description: 8/16-bit XMEGA A3B Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

36. Errata
36.1
36.1.1
8116F–AVR–09/09
ATxmega256A3B
rev. C
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1. Bandgap voltage input for the ACs cannot be changed when used for both ACs
2. ADC gain stage output range is limited to 2.4 V
3. Sampled BOD in Active mode will cause noise when bandgap is used as reference
Bandgap voltage input for the ACs cannot be changed when used for both ACs simultaneously
ADC gain stage output range is limited to 2.4V
Sampled BOD in Active mode will cause noise when bandgap is used as reference
Bandgap measurement with the ADC is non-functional when V
BOD will be enabled after any reset
ADC has increased INL error for some operating conditions
DAC has increased INL or noise for some operating conditions
VCC voltage scaler for AC is non-linear
Maximum operating frequency below 1.76V is 8 MHz
simultaneously
If the bandgap voltage is selected as input for one Analog Comparator (AC) and then
selected/deselected as input for the another AC, the first comparator will be affected for up
to 1 us 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.
The amplified output of the ADC gain stage will never go above 2.4 V, hence the differential
input will only give correct output when below 2.4 V/gain. For the available gain settings, this
gives a differential input range of:
Problem fix/Workaround
Keep the amplified voltage output from the ADC gain stage below 2.4 V in order to get a cor-
rect result, or keep ADC voltage reference below 2.4 V.
Using the BOD in sampled mode when the device is running in Active or Idle mode will add
noise on the bandgap reference for ADC, DAC and Analog Comparator.
–
–
–
–
–
–
–
16x
32x
64x
1x
2x
4x
8x
gain:
gain:
gain:
gain:
gain:
gain:
gain:
300
150
2.4
1.2
0.6
75
38
V
V
V
mV
mV
mV
mV
CC
is below 2.7V
XMEGA A3B
93