bigal_scorpio
Active Member
Hi to all,
I have been trying to understand how the MAX4172 works and must be missing something.
I have the IC set up as per the diagram and it is indeed working. I think!
I get the low output on PG that lights my led and also get the expected change in Volts out (across Rout and Gnd) with a change in load across RS.
Edit: With no load I get an Rout reading of .15v ?
With a load of 5.35mA I get an Rout reading of .335v
With a load of 19.9mA I get an Rout reading of .865v
With a load of 910mA I get an Rout reading of 3.5v N.B. my 5vPSU is only rated at 1Amp so this would almost be as much as I ever need to measure current wise.
My R sense Resistor is 1ohm which is the smallest I have in a reasonable wattage.
My Rout Resistor is 3k48 as suggested in the text, which for some reason seems to remain the same through the entire table of suggested values! Puzzling!
My actual problem is that no matter how many times I refer to the datasheet, I cannot work out the formula for converting the Rout reading to true Volts.
Can anyone explain this in simple terms please? I am really struggling and maths is not my forte.
Thanks, Al
I have been trying to understand how the MAX4172 works and must be missing something.
I have the IC set up as per the diagram and it is indeed working. I think!
I get the low output on PG that lights my led and also get the expected change in Volts out (across Rout and Gnd) with a change in load across RS.
Edit: With no load I get an Rout reading of .15v ?
With a load of 5.35mA I get an Rout reading of .335v
With a load of 19.9mA I get an Rout reading of .865v
With a load of 910mA I get an Rout reading of 3.5v N.B. my 5vPSU is only rated at 1Amp so this would almost be as much as I ever need to measure current wise.
My R sense Resistor is 1ohm which is the smallest I have in a reasonable wattage.
My Rout Resistor is 3k48 as suggested in the text, which for some reason seems to remain the same through the entire table of suggested values! Puzzling!
My actual problem is that no matter how many times I refer to the datasheet, I cannot work out the formula for converting the Rout reading to true Volts.
Can anyone explain this in simple terms please? I am really struggling and maths is not my forte.
Thanks, Al
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