ATXMEGA256A3-MU Atmel, ATXMEGA256A3-MU Datasheet - Page 118

• Manufacturer Part Number: ATXMEGA256A3-MU
• Description: 8-bit Microcontrollers - MCU 8/16 bit 1.6V-3.6V 256KB + 8KB
• Manufacturer: Atmel

Specifications of ATXMEGA256A3-MU

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: AVR
• Data Bus Width: 8 bit/16 bit
• Maximum Clock Frequency: 32 MHz
• Program Memory Size: 256 KB
• Data Ram Size: 16 KB
• On-chip Adc: Yes
• Package / Case: QFN EP
• Mounting Style: SMD/SMT
• A/d Bit Size: 12 bit
• A/d Channels Available: 8
• Data Rom Size: 4 KB
• Interface Type: I2C, SPI, USART
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 50
• Number Of Timers: 7
• Processor Series: ATXMega
• Program Memory Type: Flash
• Factory Pack Quantity: 260
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 1.6 V

8068T–AVR–12/10
Figure 36-5. Analog Comparator Voltage Scaler vs. Scalefac
3.
4. ADC gain stage output range is limited to 2.4 V
Problem fix/Workaround
Use external voltage input for the analog comparator if accurate voltage levels are needed
ADC has increased INL error for some operating conditions
Some ADC configurations or operating condition will result in increased INL error.
In signed mode INL is increased to:
– 6LSB for sample rates above 1Msps, and up to 8 LSB for 2Msps sample rate.
– 6LSB for reference voltage below 1.1V when VCC is above 3.0V.
– 20LSB for ambient temperature below 0 degree C and reference voltage below 1.3V.
In unsigned mode, the INL error cannot be guaranteed, and this mode should not be used.
Problem fix/Workaround
None, avoid using the ADC in the above configurations in order to prevent increased INL
error. Use the ADC in signed mode also for single ended measurements.
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:
–
–
–
–
–
–
–
16x
32x
64x
3.5
2.5
1.5
0.5
1x
2x
4x
8x
3
2
1
0
0
T = 25°C
gain:
gain:
gain:
gain:
gain:
gain:
gain:
5
10
300
150
2.4
1.2
0.6
75
38
15
V
V
V
mV
mV
mV
mV
20
25
SCALEFAC
30
35
40
45
50
55
XMEGA A3
60
65
3.3 V
2.7 V
1.8 V
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