ATtiny461 Automotive Atmel Corporation, ATtiny461 Automotive Datasheet - Page 145

• Manufacturer Part Number: ATtiny461 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATtiny461 Automotive

• Flash (kbytes): 4 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• 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: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

19.3
7753F–AVR–01/11
Operation
Figure 19-1. Analog to Digital Converter Block Schematic
The ADC converts an analog input voltage to a 10-bit digital value through successive approxi-
mation. The minimum value represents GND and the maximum value represents the voltage on
V
The voltage reference for the ADC may be selected by writing to the REFS2..0 bits in ADMUX.
The VCC supply, the AREF pin or an internal 1.1V / 2.56V voltage reference may be selected as
the ADC voltage reference. Optionally the internal 1.1V / 2.56V voltage reference may be decou-
pled by an external capacitor at the AREF pin to improve noise immunity.
The analog input channel and differential gain are selected by writing to the MUX5..0 bits in
ADMUX. Any of the 11 ADC input pins ADC10..0 can be selected as single ended inputs to the
ADC. The positive and negative inputs to the differential gain amplifier are described in
19-5.
If differential channels are selected, the differential gain stage amplifies the voltage difference
between the selected input pair by the selected gain factor, 1x, 8x, 20x or 32x, according to the
setting of the MUX5..0 bits in ADMUX and the GSEL bit in ADCSRB. This amplified value then
becomes the analog input to the ADC. If single ended channels are used, the gain amplifier is
bypassed altogether.
CC
, the voltage on the AREF pin or an internal 1.1V / 2.56V voltage reference.
ADC10
AGND
ADC9
ADC8
ADC7
ADC6
ADC5
ADC4
ADC3
ADC2
ADC1
ADC0
AREF
VCC
8-BIT DATA BUS
INTERNAL 2.56/1.1V
INTERNAL 1.18V
TEMPERATURE
REFERENCE
REFERENCE
SENSOR
REGISTER B (ADCSRB)
ADC CTRL. & STATUS
INPUT
POS.
MUX
ATtiny261/ATtiny461/ATtiny861
INPUT
NEG.
MUX
MUX DECODER
ADC MULTIPLEXER
SELECT (ADMUX)
DIFFERENTIAL SELECTION
SINGLE ENDED /
+
-
GAIN
AMPLIFIER
10-BIT DAC
REGISTER A (ADCSRA)
ADC CTRL. & STATUS
MUX
ADC CONVERSION
COMPLETE IRQ
CONVERSION LOGIC
PRESCALER
SAMPLE & HOLD
COMPARATOR
+
-
15
MULTIPLEXER OUTPUT
ADC DATA REGISTER
(ADCH/ADCL)
ADC
0
Table
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