ATtiny167 datasheet(191/282 Pages) ATMEL

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191

7728D–AVR–07/09

ATtiny87/ATtiny167

17. ADC – Analog to Digital Converter

17.1

Features

• 10-bit Resolution

• 1.0 LSB Integral Non-linearity

• ± 2 LSB Absolute Accuracy

• 13 - 260 µs Conversion Time (Low - High Resolution)

• Up to 15 kSPS at Maximum Resolution

• 11 Multiplexed Single Ended Input Channels

• 8 Differential input pairs with selectable gain

• Temperature sensor input channel

• Voltage from Internal Current Source Driving (ISRC)

• Optional Left Adjustment for ADC Result Readout

• 0 - AVcc ADC Input Voltage Range

• Selectable 1.1V / 2.56V ADC Voltage Reference

• 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

17.2

Overview

The ATtiny87/167 features a 10-bit successive approximation ADC. The ADC is connected to

a 11-channel Analog Multiplexer which allows 16 differential voltage input combinations and

11 single-ended voltage inputs constructed from the pins PA7..PA0 or PB7..PB4. The differen-

tial input is equipped with a programmable gain stage, providing amplification steps of 8x or

20x on the differential input voltage before the A/D conversion. The single-ended voltage

inputs refer to 0V (AGND).

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

17-1.

Internal reference voltages of nominally 1.1V or 2.56V are provided On-chip. Alternatively,

AVcc can be used as reference voltage for single ended channels. There are also options to

output the internal 1.1V or 2.56V reference voltages or to input an external voltage reference

and turn-off the internal voltage reference. These options are selected using the REFS[1:0]

bits of the ADMUX control register and using AREFEN and XREFEN bits of the AMISCR con-

trol register.

ATtiny167 Datasheet(PDF) 191 Page - ATMEL Corporation