problem with lm723 (simulation)

[sambkn2bhu]

hi.. m attaching my circuit ... output is supposed to be V=Vref(1+R2/R3)... but m not getting this value... infact i cant increase my output beyond 13.45V...

hav a luk at it n pls trace out the error or watever it is !!...


thanx

 

[FvM]

Who told you to connect Vz to GND?

 

[sambkn2bhu]

i can not just leave the pin open.. it wont simulate... so i ground it... tell me if this is the real problem... n wat to do wid pin Vz !!

thanx

 

[IanP]

The V[z] pin if not used should be left unconnected, but if your simulator doesn't want to accept it that way try to shorten this pin with V[out] .. see attached picture ..

Rgds,
IanP
:|

 

[sambkn2bhu]

yuppp its working !!!

thanx IanP... you rockkkkkkk !!

Added after 4 minutes:

hey IanP.. can u also xplain y is it happening so .. !!

regards
Sameer

 

[FvM]

Connecting Vz to ground makes the zener diode limit the output voltage. I thought, it would be obvious.
In a real design, you possibly damage the chip with your circuit.