ATxmega192A3U Atmel Corporation, ATxmega192A3U Datasheet - Page 364

• Manufacturer Part Number: ATxmega192A3U
• Manufacturer: Atmel Corporation

Specifications of ATxmega192A3U

• Flash (kbytes): 192 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 50
• Ext Interrupts: 50
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 10
• Twi (i2c): 2
• Uart: 7
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 16
• Adc Resolution (bits): 12
• Adc Speed (ksps): 2000
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 2
• Dac Resolution (bits): 12
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• Sram (kbytes): 16
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.6 to 3.6
• Operating Voltage (vcc): 1.6 to 3.6
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 7
• Output Compare Channels: 22
• Input Capture Channels: 22
• Pwm Channels: 22
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

28.10 ADC Input Model
8331A–AVR–07/11
The voltage input must charge the sample and hold (S/H) capacitor in the ADC in order to
achieve maximum accuracy. Seen externally the ADC input consists of an input channel (R
nel
28-20 on page 364
Figure 28-19. ADC input for single ended measurements
Figure 28-20. ADC input for differential measurements and differential measurements with gain
In order to achieve n bit of accuracy, the source output resistance, R
ADC input resistance on a pin:
where the ADC sample time, T
For details on R
teristic in the device data sheet.
R
T
) and switch (R
source
s
Negative
≤
Positive
Positive
input
input
input
-------------------
2 f ⋅
≤
1
ADC
---------------------------------------------- - R
C
sample
channel
⋅
T
switch
ln
s
shows the ADC input channels.
(
2
, R
) resistance, and the S/H capacitor.
n
+
1
switch
)
–
and C
channel
S
is one half ADC clock cycle given by:
R
R
R
channel
channel
sample
channel
–
R
switch
refer to the ADC and ADC gain stage electrical charac-
Atmel AVR XMEGA AU
R
R
R
switch
switch
switch
Figure 28-19 on page 364
source
, must be less than the
C
C
C
Sample
Sample
Sample
and
VCC/2
VCC/2
Figure
chan-
364