RFQ/BOM 0 Sign In / Register

Select Your Location

user image

How to analyze the reference voltage circuit composed of this op amp and voltage regulator tube?

Hardware design
November 03, 2020 by Sloan 1431

This circuit is a circuit designed by a colleague before. "LVCC" is a 32V power supply, MC34072 is an operational amplifier, and BZX84C12LT1G is a 12V Zener tube.

I didn't understand the role of op-in-circuit in the circuit;

Please help analyze it.

Thank you.

All Comments

user image

Katarina Posted on November 3, 2020

Vref = Vz *  (R311 + R339)  / R311 = 12 * (22 + 7.5) / 22 = 16.09 (V)

0
user image

Valentino Posted on November 3, 2020

22K above is 12V, then calculate how many V above 7.5K.

Vref=12V+12*7.5/22=16.09V
Vref=12(22+7.5)/22=16.09V

0
user image

Amos Posted on November 3, 2020

Unstable, the principle phase is different. The first picture shows that the number of correct positive feedback is 0, and the remaining feedback phase is wrong.

0
user image

Blaise Posted on November 3, 2020

Are there any advantages to this circuit? What are the advantages and disadvantages compared with the benchmark made with TL431?

Does the diode current change with the power supply voltage?

Will the power consumption be lower or the reference voltage will be more stable?

0

Write an answer

You need to log in to reply. Sign In | Register