AVR16EB32 datasheet(25/46 Pages) MICROCHIP

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AVR16EB32 Curiosity Nano

Hardware Implementation

User Guide

DS50003605B - 25

output voltage, and the ambient temperature. The figure below shows the safe operating area for

the regulator, with an input voltage of 5.1V and an ambient temperature of 23°C.

Figure 4-7. Target Regulator Safe Operation Area

The voltage output of the target regulator is continuously monitored (measured) by the on-board

debugger. An error condition will be flagged - and the target voltage regulator will be switched off,

detecting and handling any short-circuit conditions if it is more than 100 mV over/under the set

device voltage. It will also detect and handle if an external voltage, which causes VCC_TARGET to

move outside the voltage setting monitoring window of ±100 mV, is suddenly applied to the VTG pin

without setting the VOFF pin low.

Info: The on-board debugger has a monitoring window of VCC_TARGET±100 mV,

and the status LED will blink rapidly if the external voltage is under this limit.

The on-board debugger status LED will continue to shine if the external voltage

surpasses this limit. When removing the external voltage, the status LED will start

blinking rapidly until the on-board debugger detects the new situation and turns

the target voltage regulator back on.

4.4.3

External Supply

Instead of the on-board target regulator, an external voltage can power the AVR16EB32 Curiosity

Nano. When shorting the Voltage Off (VOFF) pin to the ground (GND) pin, the on-board debugger

firmware disables the target regulator, and it is safe to apply an external voltage to the VTG pin.

It is also safe to apply an external voltage to the VTG pin when no USB cable is plugged into the

DEBUG connector on the board.

The VOFF pin can be tied low/let go at any time, which will be detected by a pin-change interrupt to

the on-board debugger, which controls the target voltage regulator accordingly.

Applying an external voltage to the VTG pin without shorting VOFF to GND may

cause permanent damage to the board.

AVR16EB32 데이터시트(PDF) 25 Page - Microchip Technology