AT90PWM81 Atmel Corporation, AT90PWM81 Datasheet - Page 192

• Manufacturer Part Number: AT90PWM81
• Manufacturer: Atmel Corporation

Specifications of AT90PWM81

• Flash (kbytes): 8 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 20
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 3
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 125
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 1
• Output Compare Channels: 8
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

Figure 15-2.
15.4
Figure 15-3.
192
1.0
1.5
BG Ref erence
0.5
Temperature Measurement
AT90PWM81
-40
VPTAT
Illustration of Vbg as a function of temperature.
Temperature sensor Circuitry
-20
BGCRR is used to move the top of the Vbg curve to the
center of the temperature range of interest
The temperature measurement is based on an on-chip temperature sensor that is coupled to a single ended
ADC12 channel, as shown on
Selecting the ADC12 channel by writing the MUX3..0 bits in ADMUX register to “1100” enables the
temperature sensor (see
ADC voltage reference source is the internal 2.56V voltage reference for temperature sensor measure-
ment. When the temperature sensor is enabled, the ADC converter can be used in single conversion mode
to measure the voltage over the temperature sensor. The amplifier allows to charge the ADC sample
capacitor at full CKadc clock speed. The measured voltage has a linear relationship to temperature as
-0
Enable when
ADEN=1
Current-voltage
Convertor
Temperature range of interest
20
40
See “ADC Multiplexer Register – ADMUX” on page
Enable when
ADC Mux=1100
Temperature (°C)
Figure
60
+
-
15-3.
80
ADC Mux=1100
100
Vtemp
216.). The recommended
7734P–AVR–08/10