Dac – digital to analog converter, 1 features, 2 overview – Rainbow Electronics ATmega64M1 User Manual
Page 265
265
8209A–AVR–08/09
ATmega16M1/32M1/64M1
25. DAC – Digital to Analog Converter
25.1
Features
•
10 bits resolution
•
8 bits linearity
•
+/- 0.5 LSB accuracy between 100mV and AVcc-100mV
•
Vout = DAC*Vref/1023
•
The DAC could be connected to the negative inputs of the analog comparators and/or to a
dedicated output driver.
•
The output impedance of the driver is around 100 Ohms. So the driver is able to load a 1nF
capacitance in parallel with a resistor higher than 33K with a time constant around 1us.
25.2
Overview
The ATmega16M1/32M1/64M1 features a 10-bit Digital to Analog Converter. This DAC can be
used for the analog comparators and/or can be output on the D2A pin of the microcontroller via
a dedicated driver.
The DAC has a separate analog supply voltage pin, AV
CC
. AV
CC
must not differ more than ±
0.3V from V
CC
. See the paragraph
“ADC Noise Canceler” on page 232
on how to connect this
pin.
The reference voltage is the same as the one used for the ADC,
. These nominally 2.56V Vref or AV
CC
are provided On-chip. The
voltage reference may be externally decoupled at the AREF pin by a capacitor for better noise
performance.