
WARNING
The absolute maximum external voltage range for the AVR128DB48 is 1.8–5.5V. Applying a higher voltage
may cause permanent damage to the board.
By default AVR128DB48 Curiosity Nano board is configured for single-supply mode. To use Dual-Supply mode some
hardware modifications are required.
WARNING
Before any hardware modifications are done, make sure the board is disconnected from USB or external
power.
• Disconnect resistor R204 connecting VDDIO2 to VCC_TARGET
• Connect a new power supply to VDDIO2 and ground at
• J212 does not have reverse polarity protection. Make sure to match polarity between the power supply and
J212. Positive-polarity to J212-pin 1 and negative-polarity to J212-pin 2
The resistor R204, VDDIO2 and J212 can be seen in
.
Figure 5-4. MVIO and VDDIO2 Connections
J212
R204
WARNING
Applying an external voltage to VDDIO2 pin without removing resistor R204 may cause permanent
damage to the board.
WARNING
J212 does not have reverse polarity protection. Applying voltage to the wrong pin may cause permanent
damage to the board.
5.1.4
Operational Amplifiers
AVR128DB48 features three internal operational amplifiers with a flexible connection scheme using analog
multiplexers and resistor ladders. This allows a large number of analog signal conditioning configurations, many
requiring no external components.
Table 5-1. OPAMP Pin Connections
OPAMP
Poisitive Input (INP)
Negative Input (INN)
Output (OUT)
OP0
PD1
PD3
PD2
OP1
PD4
PD7
PD5
AVR128DB48 Curiosity Nano
Hardware User Guide
©
2020 Microchip Technology Inc.
User Guide
DS50003037A-page 28