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8183F–AVR–06/12
ATtiny24A/44A/84A
16. Analog to Digital Converter
16.1
Features
10-bit Resolution
1 LSB Integral Non-linearity
±2 LSB Absolute Accuracy
13 s Conversion Time
15 kSPS at Maximum Resolution
Eight Multiplexed Single Ended Input Channels
Twelve Differential Input Channels with Selectable Gain (1x, 20x)
Temperature Sensor Input Channel
Optional Left Adjustment for ADC Result Readout
0 - V
CC ADC Input Voltage Range
1.1V ADC Reference Voltage
Free Running or Single Conversion Mode
ADC Start Conversion by Auto Triggering on Interrupt Sources
Interrupt on ADC Conversion Complete
Sleep Mode Noise Canceler
Unipolar / Bipolar Input Mode
Input Polarity Reversal Mode
16.2
Overview
ATtiny24A/44A/84A features a 10-bit, successive approximation Analog-to-Digital Converter
(ADC). The ADC is wired to a nine-channel analog multiplexer, which allows the ADC to mea-
sure the voltage at eight single-ended input pins, or between twelve differential pairs of input
pins, or from one internal, single-ended voltage channel coming from the internal temperature
sensor. Single-ended voltage inputs are referred to 0V (GND), while differential-ended input
pairs are subject to a gain stage with programmable amplification steps of 0 dB (1x) and 26 dB
(20x).
The ADC contains a Sample and Hold circuit which ensures that the input voltage to the ADC is
held at a constant level during conversion. A block diagram of the ADC is shown in
Figure 16-1Internal reference voltage of nominally 1.1V is provided on-chip. Alternatively, V
CC can be used
as reference voltage for single ended channels. There is also an option to use an external volt-
age reference and turn-off the internal voltage reference.