ATxmega128B1 Atmel Corporation, ATxmega128B1 Datasheet - Page 333

• Manufacturer Part Number: ATxmega128B1
• Manufacturer: Atmel Corporation

Specifications of ATxmega128B1

• Flash (kbytes): 128 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 32 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 53
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Segment Lcd: 160
• 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
• Temp. Sensor: Yes
• Crypto Engine: AES/DES
• 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: 3
• Output Compare Channels: 10
• Input Capture Channels: 10
• Pwm Channels: 10
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Figure 25-17. ADC timing for one single conversion with 64x gain.
25.10 ADC Input Model
8291A–AVR–10/11
GAINSTAGE SAMPLE
CONVERTING BIT
CONVERTING BIT
ADC SAMPLE
ADC SAMPLE
AMPLIFY
AMPLIFY
START
clk
ADC
IF
IF
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
Figure 25-19 on page 333
Figure 25-18. ADC input for single-ended measurements.
Figure 25-19. ADC input for differential measurements and differential measurements with gain.
channel
1
Negative
Positive
Positive
input
input
input
) and switch (R
2
msb
10
3
9
switch
show the ADC input channel.
msb
8
) resistance and the S/H capacitor.
4
10
7
R
R
R
channel
channel
channel
9
6
5
8
5
7
4
6
6
3
R
R
R
Atmel AVR XMEGA B
switch
switch
switch
5
2
7
4
1
Figure 25-18 on page 333
lsb
3
8
2
1
C
C
C
Sample
Sample
9
Sample
lsb
10
VCC/2
VCC/2
and
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