ATXMEGA64A1 datasheet(43/99 Pages) ATMEL

43 / 99 page

8067I–AVR–04/09

XMEGA A1

25. DAC - 12-bit Digital to Analog Converter

25.1

Features

• Two DACs with 12-bit resolution

• Up to 1 Msps conversion rate for each DAC

• Flexible conversion range

• Multiple trigger sources

• 1 continuous output or 2 Sample and Hold (S/H) outputs for each DAC

• Built-in offset and gain calibration

• High drive capabilities

• Low Power Mode

25.2

Overview

The XMEGA A1 devices features two 12-bit, 1 Msps DACs with built-in offset and gain calibra-

tion, see Figure 25-1 on page 43.

A DAC converts a digital value into an analog signal. The DAC may use an internal 1.1 voltage

as the upper limit for conversion, but it is also possible to use the supply voltage or any applied

voltage in-between. The external reference input is shared with the ADC reference input.

Figure 25-1. DAC overview

Each DAC has one continuous output with high drive capabilities for both resistive and capaci-

tive loads. It is also possible to split the continuous time channel into two Sample and Hold (S/H)

channels, each with separate data conversion registers.

A DAC conversion may be started from the application software by writing the data conversion

registers. The DAC can also be configured to do conversions triggered by the Event System to

have regular timing, independent of the application software. DMA may be used for transferring

data from memory locations to DAC data registers.

The DAC has a built-in calibration system to reduce offset and gain error when loading with a

calibration value from software.

PORTA and PORTB each has one DAC. Notation of these peripherals are DACA and DACB.

respectively.

DAC

Channel A

Channel B

Event

Trigger

Configuration

Reference selection

Channel A

Channel B

ATXMEGA64A1 Datasheet(PDF) 43 Page - ATMEL Corporation