Target Voltage is Different From Setting
This can be caused by an externally applied voltage to the VTG pin, without setting the VOFF pin low. If the target
voltage differ more than 100 mV over/under the voltage setting, it will be detected by the on-board debugger, and the
internal voltage regulator will be shut down. To fix this issue, remove the applied voltage from the VTG pin, and the
on-board debugger will enable the on-board voltage regulator when the new condition is detected. Note that the PS
LED will be blinking rapidly if the target voltage is below 100 mV of the setting, but will be lit normally when it is higher
than 100 mV above the setting.
No, Or Very Low Target Voltage, and PS LED is Blinking Rapidly
This can be caused by a full or partial short-circuit and is really a special case of the issue mentioned above. Remove
the short-circuit, and the on-board debugger will re-enable the on-board target voltage regulator.
No Target Voltage and PS LED is Lit 1
This occurs if the target voltage is set to 0.0V. To fix this, set the target voltage to a value within the specified voltage
range for the target device.
No Target Voltage and PS LED is Lit 2
This can be the issue if power jumper J100 and/or J101 is cut, and the target voltage regulator is set to a value within
the specified voltage range for the target device. To fix this, solder a wire/bridge between the pads for J100/J101, or
add a jumper on J101 if a pin header is mounted.
VBUS Output Voltage is Low or Not Present
This is most lightly caused by a high-current drain on VBUS, and the protection fuse (PTC) will reduce the current or
cut off completely. Reduce the current consumption on the VBUS pin to fix this issue.
3.4
Low Power Measurement
Power to the AVR128DA48 is connected from the on-board power supply and
VTG
pin through a 100 mil pin header
marked with “POWER” in silkscreen (J101). To measure the power consumption of the AVR128DA48 and other
peripherals connected to the board, cut the
Target Power strap
and connect an ammeter over the strap.
To measure the lowest possible power consumption follow these steps:
1.
Cut the POWER strap with a sharp tool.
2.
Solder a 1x2 100 mil pin header in the footprint.
3.
Connect an ammeter to the pin header.
4.
Write firmware that.
4.1.
Tri-states any I/O connected to the on-board debugger.
4.2.
Sets the microcontroller in its lowest power Sleep state.
5.
Program the firmware into the AVR128DA48.
AVR128DA48 Curiosity Nano
Curiosity Nano
©
2020 Microchip Technology Inc.
User Guide
DS50002971A-page 17
