Table 7-2. ADC single-ended external voltage reference, 3.3V power supply mode.
Signal name Recommended pin connection Description
ADCREF0
ADCREF1
1.0V to 2.6V
1.0V to 2.6V
Single-ended external voltage reference
Single-ended external voltage reference
Figure 7-2. Single-ended external reference, 5V power supply mode.
DC/DC
converter
ADCREF0
1.0 to 3.5 V
DC/DC
converter
ADCREF1
1.0 to 3.5 V
Table 7-3. ADC single-ended external voltage reference, 5V power supply mode.
Signal name Recommended pin connection Description
ADCREF0
ADCREF1
1.0V to 3.5V
1.0V to 3.5V
Single-ended external voltage reference
Single-ended external voltage reference
7.2.2 ADC differential external reference pins (ADCVREFP/ADCVREFN)
In order to use the internal 1V bandgap reference, the ADCVREFP and ADCVREFN
pins must be used with decoupling capacitors (see Figure 7-3 and Table 7-5 for
typical values).
If the internal voltage reference is unused, ADCVREFP and ADCVREFN can be used
as differential external voltage reference (see Figure 7-4 and Table 7-5).
Figure 7-3. ADCVREFP/ADCVREFN external decoupling for use of internal bandgap
reference.
Table 7-4. ADC differential external voltage reference, internal reference used.
Signal name Recommended pin connection Description
ADCVREFP
ADCVREFN
Positive differential voltage
Negative differential voltage
Differential external voltage reference
Differential external voltage reference
10
AVR32768
32157A-AVR-12/10
ATMEL [ ATMEL ]
