I have this circuit:
I am giving an input voltage from 0V to 40V shown at the input of the circuit.
When I give 1V at the input, I get the voltage values as such shown below (measured with multimeter and oscilloscope):
0.18V is dropped across D0002 and 0.8V is dropped across the 36V zener diode and the remaining 20mV is dropped across the remaining 2 resistors.
I tried the above circuit in simulator tool as well. I am getting similar results. The current through the components is only the reverse leakage current of the zener diode which is in the range of 10s of microamps.
My Questions :
- My understanding was that when I apply 1V at the input of the circuit, 0.7V would be dropped across D0002 and the remaining 0.3V will be dropped across the other components because diode requires a minimum of 0.7V to conduct. So, when voltage of above 0.7V is applied at the input, the diode conducts and 0.7V will be dropped across the D0002 diode right?
But in my above scenario, why is the voltage across the diode D00002 only 0.18V and D00003 is 0.8V?
- This also brings the question - What does it mean when one says, the diode is forward biased? Once forward biased, the diode should have 0.6V-0.7V voltage drop across it, right? Or what is it that I am misunderstanding?
Please help with the above questions.