what device can i use other than zener diode as an constant voltage source

Thread Starter

premkumar

Joined Jul 2, 2007
2
Hi guys,
I have been working on an over voltage protection circuit (OVPC), I used a zener diode for giving an constant voltage to the gate of an P-MOSFET (enh) as an reference voltage of the input . Now what i want to know is ... Is there any other alternative to that ZENER diode , that can be used as an constant voltage source for my OVPC. Please give me an solution . Thanks a lot in advance.

Bye.

PREM
 

Papabravo

Joined Feb 24, 2006
14,393
Hi guys,
I have been working on an over voltage protection circuit (OVPC), I used a zener diode for giving an constant voltage to the gate of an P-MOSFET (enh) as an reference voltage of the input . Now what i want to know is ... Is there any other alternative to that ZENER diode , that can be used as an constant voltage source for my OVPC. Please give me an solution . Thanks a lot in advance.

Bye.

PREM
There is the band gap reference, and the plain old voltage regulator.
 

Gadget

Joined Jan 10, 2006
614
Lots and lots of voltage reg chips out there. The 78 series +ve fixed regs, 79 series -ve regs.... the LM317 variable +ve reg..... 337 variable -ve reg then there are other devices with a reasonably constant forward (as opposed to the zeners constant reverse) voltage.... red LED's (around 1.7 volts), green LEDs (around 2.2 volts) white LEDs (around 3.5 volts)... and even the standard silicon diode ( 0.6 volts)
 

recca02

Joined Apr 2, 2007
1,214
i was thinking about something like a series pass regulator,
i may be wrong here since i m no good at electronics but for a gate of mosfet isnt using chips or a complete circuit going overboard.
 

Papabravo

Joined Feb 24, 2006
14,393
i was thinking about something like a series pass regulator,
i may be wrong here since i m no good at electronics but for a gate of mosfet isnt using chips or a complete circuit going overboard.
We said nothing about the original request, and I must agree it seems strange to speak of a reference for a device with only one input. It would make more sense if he was talking about a comparator.
 

recca02

Joined Apr 2, 2007
1,214
oh!
the question was intended for the op actually.

maybe a thermistor to or rtd having its characterstics properly calculated but even that wud be hard.
 

Thread Starter

premkumar

Joined Jul 2, 2007
2
Hi guys,
Thanks for the various solutions.Sorry for the delayed reply. I need to replace it with FET ( Is it possible?)Actually i was talking about a comparators reference input only. But here i am using a p-channel MOSFET as a comparator and gave the ref. voltage through the zener 1N751 (Vz=5.1V). I need to replace this zener only.

-Premkumar
 
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