Datasheet

27. ADC - Analog to Digital Converter

27.1 Features

• 10-bit Resolution

• 0.5LSB Integral Non-Linearity

• ±2LSB Absolute Accuracy

• 13 - 260μs Conversion Time

• Up to 15kSPS at Maximum Resolution

• Six Multiplexed Single Ended Input Channels

• Two Additional Multiplexed Single Ended Input Channels (TQFP and QFN/MLF Package only)

• Optional Left Adjustment for ADC Result Readout

• 0 - V

ADC Input Voltage Range

• Selectable 2.56V ADC Reference Voltage

• Free Running or Single Conversion Mode

• Interrupt on ADC Conversion Complete

• Sleep Mode Noise Canceler

27.2 Overview

The ATmega8A features a 10-bit successive approximation ADC. The ADC is connected to an 8-channel

Analog Multiplexer which allows eight single-ended voltage inputs constructed from the pins of Port C.

The single-ended voltage inputs refer to 0V (GND).

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 below.

The ADC has a separate analog supply voltage pin, AV

. AV

must not differ more than ±0.3V from

. See section ADC Noise Canceler on how to connect this pin.

Internal reference voltages of nominally 2.56V or AV

are provided On-chip. The voltage reference may

be externally decoupled at the AREF pin by a capacitor for better noise performance.

AVR 8-Bit Microcontroller

ADC - Analog to Digital Converter

Datasheet Complete

40001974A-page 253