
94
1477K–AVR–08/10
ATtiny26(L)
Analog to
Digital
Converter
Features
10-bit Resolution
±2 LSB Absolute Accuracy
0.5 LSB Integral Non-linearity
Optional Offset Cancellation
13 - 260 s Conversion Time
11 Multiplexed Single Ended Input Channels
8 Differential Input Channels
7 Differential Input Channels with Optional Gain of 20x
Optional Left Adjustment for ADC Result Readout
0 - AVCC ADC Input Voltage Range
Selectable ADC Reference Voltage
Free Running or Single Conversion Mode
Interrupt on ADC Conversion Complete
Sleep Mode Noise Canceler
The ATtiny26(L) features a 10-bit successive approximation ADC. The ADC is connected to an
11-channel Analog Multiplexer which allows eight differential voltage input combinations or 11
single-ended voltage inputs constructed from seven pins from Port A and four pins from Port B.
Seven of the differential inputs are equipped with a programmable gain stage, providing amplifi-
cation steps of 0 dB (1x) and 26 dB (20x) on the differential input voltage before the A/D
conversion. There are four groups of three differential analog input channel selections. All input
channels in each group share a common negative terminal, while another ADC input can be
selected as the positive input terminal. The single-ended voltage inputs refer to 0V (GND).
The ADC contains a Sample and Hold Amplifier 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 51.
The ADC has an analog supply voltage pin, AVCC. The voltage on AVCC must not differ more
how to connect these pins.
An internal reference voltage of nominally 2.56V is provided On-chip, and this reference may be
externally decoupled at the AREF pin by a capacitor.