Hi Guys
Can someone who knows what their talking about explain the function of this circuit for me. Here is what i think it does:
Intro:
D1 is a 2.5V shunt regulator. The whole purpose of this circuit is to test the diode to see if its doing what its spec says it should. Between 400uA and 10mA the didode should have a rock steady voltage of 2.5V.
Basically the op amp inverting pin is supplied with a voltage so that it turns the fet hard on and appears across r1. A current is produced and flows through D1. This whole circuit is acting like a constant current circuit.
e.g 10 volts supply into the comparator, r1 = 1K, the current flowing will be 10mA through the diode.
What i dont understand is what does the feedback do? I know if the inverting pin is higher than the non inverting pin the output is high.
How does this circuit control itself, threough the feedback but how does it work?
cheers guys
Andy
Can someone who knows what their talking about explain the function of this circuit for me. Here is what i think it does:
Intro:
D1 is a 2.5V shunt regulator. The whole purpose of this circuit is to test the diode to see if its doing what its spec says it should. Between 400uA and 10mA the didode should have a rock steady voltage of 2.5V.
Basically the op amp inverting pin is supplied with a voltage so that it turns the fet hard on and appears across r1. A current is produced and flows through D1. This whole circuit is acting like a constant current circuit.
e.g 10 volts supply into the comparator, r1 = 1K, the current flowing will be 10mA through the diode.
What i dont understand is what does the feedback do? I know if the inverting pin is higher than the non inverting pin the output is high.
How does this circuit control itself, threough the feedback but how does it work?
cheers guys
Andy