ATxmega128D4 Atmel Corporation, ATxmega128D4 Datasheet - Page 233

• Manufacturer Part Number: ATxmega128D4
• Manufacturer: Atmel Corporation

Specifications of ATxmega128D4

• Flash (kbytes): 128 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 34
• Ext Interrupts: 34
• Usb Speed: No
• Usb Interface: No
• Spi: 4
• Twi (i2c): 2
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 12
• Adc Speed (ksps): 200
• Analog Comparators: 2
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 8
• 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: 4
• Output Compare Channels: 14
• Input Capture Channels: 14
• Pwm Channels: 14
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

20.9
8210B–AVR–04/10
ADC Input Model
Figure 20-15. ADC timing for one single conversion with 8x or 16x gain
Figure 20-16. ADC timing for one single conversion with 32x or 64x gain
An analog voltage input must be able to fully charge the sample and hold (S/H) capacitor in the
ADC in order to achieve maximum accuracy. Seen externally the ADC input consists of a input
channel (R
page 233
Figure 20-17. ADC input for single ended measurements
GAINSTAGE AMPLIFY
GAINSTAGE SAMPLE
GAINSTAGE AMPLIFY
Positive
GAINSTAGE SAMPLE
input
CONVERTING BIT
CONVERTING BIT
ADC SAMPLE
ADC SAMPLE
and
CLK
START
CLK
START
channel
ADC
ADC
IF
IF
Figure 20-18 on page 234
) and the switch (R
1
1
2
2
R
3
channel
3
MSB
switch
4
shows the input models for the ADC inputs.
10
) resistance, and the S/H capacitor.
MSB
4
9
10
5
8
9
5
8
7
R
6
switch
7
6
6
6
5
7
5
4
7
4
3
8
3
2
2
8
C
9
1
Sample
XMEGA D
1
Figure 20-17 on
LSB
LSB
9
10
VCC/2
10
11
233