ATxmega128B1 Atmel Corporation, ATxmega128B1 Datasheet - Page 326

• 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

25.3.4
8291A–AVR–10/11
Internal Inputs
Figure 25-4. Single-ended measurement in signed mode.
In unsigned mode, the negative input is connected to half of the voltage reference (VREF) volt-
age minus a fixed offset. The nominal value for the offset is:
Since the ADC is differential, the input range is VREF to zero for the positive single-ended input.
The offset enables the ADC to measure zero crossing in unsigned mode, and allows for calibra-
tion of any positive offset when the internal ground in the device is higher than the external
ground. See
Figure 25-5. Single-ended measurement in unsigned mode.
These internal signals can be measured or used by the ADC.
The temperature sensor gives an output voltage that increases linearly with the internal temper-
ature of the device. One or more calibration points are needed to compute the temperature from
a measurement of the temperature sensor. The temperature sensor is calibrated at one point in
production test, and the result is stored to TEMPESENSE0 and TEMPSENSE1 in the production
signature row. For more calibration condition details, refer to the device datasheet.
The bandgap voltage is an accurate internal voltage reference.
V
V
enables easy measurement of the V
The internal signals need to be enabled before they can be measured. Refer to their manual
sections for Bandgap for details of how to enable these. The sample rate for the internal signals
CC
CC
• Temperature sensor
• Bandgap voltage
• V
• Pad and Internal Ground
can be measured directly by scaling it down by a factor of 10 before the ADC input. Thus, a
CC
of 1.8V will be measured as 0.18V, and V
scaled
Figure 25-11 on page 329
ADC15
ADC0
ADC15
•
•
•
•
•
•
ADC0
•
•
•
CC
voltage.
ΔV
for details.
VREF
=
2
VREF 0.05
−
Δ
CC
V
×
-
-
of 3.6V will be measured as 0.36V. This
Atmel AVR XMEGA B
+
-
326