ATmega64M1 Atmel Corporation, ATmega64M1 Datasheet - Page 237

• Manufacturer Part Number: ATmega64M1
• Manufacturer: Atmel Corporation

Specifications of ATmega64M1

• Flash (kbytes): 64 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 27
• Ext Interrupts: 27
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 1
• Can: 1
• Lin: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 4
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 14
• Input Capture Channels: 1
• Pwm Channels: 10
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

21.8.1
21.8.2
21.9
8209D–AVR–11/10
Amplifier
User Calibration
Manufacturing Calibration
The measured voltage has a linear relationship to the temperature as described in
The voltage sensitivity is approximately 1mV/
Table 21-3.
The values described in
temperature sensor output voltage varies from one chip to another. To be capable of achieving
more accurate results, the temperature measurement can be calibrated in the application
software.
The software calibration requires that a calibration value is measured and stored in a register or
EEPROM for each chip. The software calibration can be done utilizing the formula:
where ADCH & ADCL are the ADC data registers, k is a fixed coefficient and T
ature sensor offset value determined and stored into EEPROM.
One can also use the calibration values available in the signature row
ture Row from Software” on page 279.
The calibration values are determined from values measured during test at hot temperature
which is approximatively +85°C.
The temperature in Celsius degrees can be calculated utilizing the formula:
Where:
The ATmega16M1/32M1/64M1 features three differential amplified channels with programmable
5, 10, 20, and 40 gain stage.
Because the amplifiers are switching capacitor amplifiers, they need to be clocked by a synchro-
nization signal called in this document the amplifier synchronization clock. To ensure an
accurate result, the amplifier input needs to have a quite stable input value during at least 4
Amplifier synchronization clock periods.
To ensure an accurate result, the amplifier input needs to have a quite stable input value at the
sampling point during at least 4 amplifier synchronization clock periods.
Amplified conversions can be synchronized to PSC events (see
Description in One Ramp Mode” on page 148
Temperature/°C
a. ADCH & ADCL are the ADC data registers
b. TSGAIN is the temperature sensor gain (constant 1, or unsigned fixed point num-
c. TSOFFSET is the temperature sensor offset correction term (2. complement
Voltage/mV
ber, 0x80 = decimal 1.0)
signed byte)
Temperature vs. Sensor Output Voltage (Typical Case)
T = {[(ADCH << 8) | ADCL] × TSGAIN} + TSOFFSET - 273
Table 21-3
T = {[(ADCH << 8) | ADCL] - T
600mV
-40°C
are typical values. However, due to the process variation the
°
C.
and
ATmega16M1/32M1/64M1
“Synchronization Source Description in Cen-
762mv
+25°C
OS
}/k
“Synchronization Source
See “Reading the Signa-
OS
TBD mV
+85°C
is the temper-
Table
21-3.
237