Need an Op amp which can take a 60V - 140 V input

[illum]

Hi
I really need help on this thing. i need and opamp that will not burn or get spoiled by giving it a high voltage input. like 60 to 140 v input.

plz reply asap my project is stuck on this part.

 

[pinkmouse]

Why does it need to be so high?

 

[bocka]

The OPA445 has a power suplly range from +/- 10V to +/-45 V. Maybe that part fits in your project. Sometimes it's better to use a voltage divider on the input or an difference amplifier like the INA117. Both devices are from TI.

 

[paulb]

This company has them. They're expensive.
http://eportal.apexmicrotech.com/mainsite/index.asp

 

[peranders]

60-140 V in but what about out? The same as a LM3886 can deliver or more?

What about a voltage divider at the input? Is this enough?

Can you please describe more what your goal is? I think it's pretty easy to solve.

One solution is this

 

[illum]

basically i need something that will amplify a signal less then 15V and reduce the voltage of signal with voltage more then 40V

 

[macboy]

Hi
I really need help on this thing. i need and opamp that will not burn or get spoiled by giving it a high voltage input. like 60 to 140 v input.

Everyone seems to be assuming that you mean 60 to 140 V power supply. But you said input. So I will assume that you really meant input.

What you need to do is use a voltage divider before the input of the opamp. A 10:1 divider will reduce the voltage to 6 to 14 V which is within the range of most opamps. Your power supply should be a few more volts than the maximum input voltage. Of course, your output voltage will also be limited by the power supply voltage, but since you didn't mention a specific required voltage, we can only assume that you don't need anything special.

 

[jacco vermeulen]

One solution is this

Dear PerAnders,

Me thinks Mark Alexander's IGBT amplifier is not a pretty easy solution.

 

[peranders]

basically i need something that will amplify a signal less then 15V and reduce the voltage of signal with voltage more then 40V

What kind of input is it and what is the load (output), how much power?

 

[illum]

it basically is a telephone signal. when simple voice is transmitted the voltage is low but when a ring signal is suppose to be passed the voltage is between 40 - 160. so i need to reduce this voltage with out disrupting the normal voice signals.

 

[GregGC]

it basically is a telephone signal. when simple voice is transmitted the voltage is low but when a ring signal is suppose to be passed the voltage is between 40 - 160. so i need to reduce this voltage with out disrupting the normal voice signals.

Can't you just clamp it with zeners or something similar....

 

[peranders]

First of all you must have a signal transformer, then you only need some zener protection. You can't connect the telephone line directly to the amp becuse the signal is floating and balanced. The result will be a huge hum.

 

[K-amps]

it basically is a telephone signal. when simple voice is transmitted the voltage is low but when a ring signal is suppose to be passed the voltage is between 40 - 160. so i need to reduce this voltage with out disrupting the normal voice signals.

Abey Saaley, kiya kar raha hai phone key saath?

Jacco me thinks this guy is doing something "interesting"... especially if he is between the age group of 15-25 Seen a lot of that. Me also hypothesizes he blew whatever he had working when the tel rang.....

 

[jacco vermeulen]

Arif, me thinks he is listening in.
Naughty phonecalls maybe

 

[moamps]

.

 

[K-amps]

Arif, me thinks he is listening in.
Naughty phonecalls maybe