at90pwm81-16se ATMEL Corporation, at90pwm81-16se Datasheet - Page 190

• Manufacturer Part Number: at90pwm81-16se
• Description: 8-bit Avr Microcontroller With 8k Bytes In- System Programmable Flash
• Manufacturer: ATMEL Corporation

Figure 16-1.
16.3
16.3.1
190
BG Calibr ation
Reg isters
BGCC R, BGCRR
BG Calibr ation
Fus es
Aref
AVc c
VPTAT
BG Ref erence
Register Description
AT90PWM81
BGCCR – Bandgap Calibration Current Register
Reference Circuitry
AT90PWM81 has an On-chip temperature sensor for monitoring the die temperature. A voltage Propor-
tional-To-Absolute-Temperature, VPTAT, is generated in the voltage reference circuit and after
buffering, is connected to the ADC multiplexer. This temperature sensor can be used for runtime compen-
sation of temperature drift in both the voltage reference and the On-chip Oscillator. To get the absolute
temperature in degrees Kelvin, the measured Vtemp voltage must be scaled with the Vtemp factory cali-
bration value stored in the signature row. See Section “Temperature Measurement”, page 192 for details.
Vbg and Vtemp can be measured with the integrated ADC by selecting the proper ADC channel with
ADMUX (see
Bit
SW0
Vbg
SW1
SW2
See “ADC Multiplexer Register – ADMUX” on page
7
6
ADC
Comp
5
SW3
REFS0,REFS1
are used to
control
SW0..3
Voltage Ref e rence
/1.60
/2.13
/3.20
/6.40
4
Vref
3
2
216.)
1
0
7734M–AVR–03/10