d123
Advanced Member level 5
Hi!
I think this is a simple question for anybody who is familiar with the TC7107, or voltmeter applications.
I'm using the TC7107 ADC as a 0 to 20V voltmeter for a power supply, and the datasheet says in the electrical specifications on page 5:
"Note 1: Input voltages may exceed the supply voltages, provided the input current is limited to ±100 μA."
The datasheet is here:
https://ww1.microchip.com/downloads/en/DeviceDoc/21455d.pdf
How would I calculate/size the series input resistor (usually 1M in the schematics) to limit a possible maximum power supply output current of 0.75A to the stated ±100 μA value? Do I also need to take into account the maximum wattage that will pass though the output that the voltmeter will be measuring?
Thanks.
I think this is a simple question for anybody who is familiar with the TC7107, or voltmeter applications.
I'm using the TC7107 ADC as a 0 to 20V voltmeter for a power supply, and the datasheet says in the electrical specifications on page 5:
"Note 1: Input voltages may exceed the supply voltages, provided the input current is limited to ±100 μA."
The datasheet is here:
https://ww1.microchip.com/downloads/en/DeviceDoc/21455d.pdf
How would I calculate/size the series input resistor (usually 1M in the schematics) to limit a possible maximum power supply output current of 0.75A to the stated ±100 μA value? Do I also need to take into account the maximum wattage that will pass though the output that the voltmeter will be measuring?
Thanks.