High Voltage Voltage Follower

[gravi]

Hi,

I am looking for a cost-effective Opamp to use in high-voltage, voltage follower circuits. Source voltage could be 65V dc, can anyone suggest with op-amps which could operate from 0Volts - 75Volts. I have tested voltage follower up to 30 Volts with LM324 which works well but looking for an opamp that could operate up to 75 Volts.

Warm regards,
Ravi

 

[KlausST]

Hi,

I'd go to the Opamp manufacturer sites and use their selection guide to find devices with suitable supply voltage range.

What exactly do you mean by "source voltage"
You say "operate 0V - 75V". What is this exactly? Supply voltage? Input voltage range? Output voltage range?

Klaus

 

[gravi]

Hi Klaus,

I have gone through several parts OPA454/5, LTC6090, LTC6091, ADHV4702... which are very expensive. I wanted to check if someone could help me to identify an op-amp with operating voltage between 5 Volts to 75 Volts, best suited as a voltage follower.

Thank you,
Ravi.

 

[KlausST]

Hi,

please give clear answers and use common OPAMP terminology.

With "operating voltage" I guess you mean "supply voltage".
But why "5V to 75V"? Do you have a variable power supply? Why down to 5V?

What about input voltage range, output voltage range, output current, frequency, noise, distortion...?

Out of curiosity I tried the Analog devices OPAMP selection: https://www.analog.com/en/parametricsearch/11070#/
Simply input your requirements ..and immediatley get suitable devices with datasheets and price. I guess other manufacturers do it similarely.
Did you try it? What was the result?

Klaus

 

[frankrose]

You can use low voltage opamp too with some extension, quite cheap, check these:

https://www.ti.com/lit/an/sboa510/sboa510.pdf?ts=1641861023340

https://www.analog.com/media/en/technical-documentation/application-notes/an-1593.pdf

 

[dick_freebird]

HA-2640 is an 80V op amp with a decent input common
mode range (says +/-35V for split rails). Dielectric isolation
may make it a bit more spendy than other types. Not real
fast but maybe an option.

 

[Easy peasy]

A true voltage follower adds only current gain - what is the max desired freq and power out ?

is voltage gain required too ?