4.1
Power Sources
The ATmega328P Xplained Mini kit can be powered by a USB or an external voltage input VIN. The default power
source is 5.0V from a USB. The USB port is protected with a 500 mA PTC resettable fuse.
The ATmega328P is powered from the 5.0V USB voltage by default.
The figure below shows the possible kit power supply connections.
Figure 4-2. Power Supply Block Diagram
Power source
Power switch
Power converter
Power consumer
External input
5V
mEDBG USB
Regulator 3.3V
Input select
jumper
0R
VCC_P5V0
Target select
jumper
0R
mEDBG
&
Target
VCC_P5V0
VCC_P3V3
The input voltage select jumper (J300, 3-pin header footprint) can be soldered in to select between power from the
USB port or the VIN pin on the Arduino power header footprint. By default, the selector is bypassed with a 0Ω resistor
(R300) to connect the USB voltage to the on-board 3.3V/150 mA regulator and target voltage select header.
The target voltage select jumper (J301, 3-pin header footprint) can be soldered in to select between the on-board
3.3V regulator or the voltage from the input voltage select jumper (J300). The selector is bypassed with a 0Ω resistor
(R301) to connect the kit input voltage to the ATmega328P and mEDBG.
Important:
If the target voltage and input voltage select headers are soldered in and used with a jumper,
the bypass 0Ω resistors have to be removed to avoid contention.
4.2
Board Assembly
The Xplained Mini board can easily be assembled into a product prototype for software development and hardware
verification. All signals of the ATmega328P are available in the Xplained Mini board connector grid, enabling easy
connection of external sensors and output devices to prototype the customer-specific application.
4.2.1
Connecting an Arduino Shield
Arduino
®
shields can be mounted in the marked positions (J200, J201, J202, J203, and J204).
WARNING
The ATmega328P Xplained Mini connects VCC_TARGET to the Arduino SPI connector, while all Arduino
boards connect VCC_P5V0 to the same pin. The VCC_TARGET may be either 3.3V or 5.0V, depending
on the configuration of the kit if the kit is configured for 3.3V operation. Connecting an Arduino shield may
damage the board permanently. It is not recommended to solder the SPI connector when using Arduino
shields if not strictly necessary. If the connector is required, it is recommended to remove pin two from the
SPI connector.
ATmega328P Xplained Mini
Hardware User Guide
©
2020 Microchip Technology Inc.
User Guide
DS50002659B-page 15
