
165
8008H–AVR–04/11
ATtiny48/88
Figure 17-1. Analog to Digital Converter Block Schematic Operation
17.3
Operation
In order to be able to use the ADC the Power Reduction bit, PRADC, in the Power Reduction
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 reference
voltage. The ADC voltage reference may be selected by writing the REFS0 bit in the ADMUX
register. Alternatives are the V
CC supply pin and the internal 1.1V voltage reference.
ADC CONVERSION
COMPLETE IRQ
8-BIT DATA BUS
15
0
ADC MULTIPLEXER
SELECT (ADMUX)
ADC CTRL. & STATUS
REGISTER (ADCSRA)
ADC DATA REGISTER
(ADCH/ADCL)
MUX2
ADIE
ADFR
ADSC
ADE
N
ADIF
MUX1
MUX0
ADPS0
ADPS1
ADPS2
MUX3
CONVERSION LOGIC
10-BIT DAC
+
-
SAMPLE & HOLD
COMPARATOR
INTERNAL 1.1V
REFERENCE
MUX DECODER
AVCC
ADC7
ADC6
ADC5
ADC4
ADC3
ADC2
ADC1
ADC0
REFS0
ADLAR
CHA
NN
EL
SELECTIO
N
ADC[9:0]
ADC MULTIPLEXER
OUTPUT
BANDGAP
REFERENCE
PRESCALER
GND
INPUT
MUX
TEMPERATURE
SENSOR