Datasheet
206
ATmega169A/PA/329A/PA/649A/P/3290A/PA/6490A/P [DATASHEET]
8284E–AVR–02/2013
When this bit is written logic one, the digital input buffer on the AIN1/0 pin is disabled. The corresponding PIN Register bit will always read as zero w hen this bit i s set. When an analog si gnal is appli ed to the AIN1 /0 pin and the digital inpu t from this pin is not needed, this bit s hould be wr itten logic one to reduce power consumpti on in the di gital input bu ffer.
23. Analog to Digital Converter
23.1 Features
• 10-bit resolution
• 0.5LSB integral non-linearity
• ±2LSB absolute accuracy
• 13µs - 260µs conversion time (50kHz to 1MHz ADC clock)
• Up to 15kSPS at maximum resolution (200kHz ADC clock)
• Eight multiplexed single ended input channels
• Optional left adjustment for ADC result readout
• 0 - V
CC
ADC input voltage range
• Selectable 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 Mmode noise canceler
23.2 Overview
The Atmel ATmega169A/169PA/329A/329PA/3290A/3290PA/649A/649P/6490A/6490P features a 10-bit succes-
sive 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 F. 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 in Figure 23-1 on page 207.
The ADC has a separate analog supply voltage pin, AVCC. AV
CC
must not differ more than ±0.3V from V
CC
. See
the paragraph ”ADC Noise Canceler” on page 212 on how to connect this pin.
Internal reference voltages of nominally 1.1V or AVCC are provided On-chip. The voltage reference may be exter-
nally decoupled at the AREF pin by a capacitor for better noise performance.
The PRADC, in ”PRR – Power Reduction Register” on page 45 must be written to zero to enable the ADC module.