Comments on: Summing Amplifier Calculator

By: Adrian S. Nastase

Adrian S. Nastase — Sun, 31 May 2020 17:23:10 +0000

In reply to C. Bruce Preston. I am glad it helped. No, you cannot buy it. You can come back here and use it anytime you need. Just let the very few ads to be displayed to support this website.

By: C. Bruce Preston

C. Bruce Preston — Thu, 05 Mar 2020 19:02:55 +0000

An excellent Calculator! It has saved me a lot of design time.
2 comments: The comments and procedure seem to be “print locked”. I am very old school and have a difficult time following a procedure that is not printed material.
This calculator is also very valuable for my work; Can I buy this app so that I can install it on my PC?

By: Adrian S. Nastase

Adrian S. Nastase — Sat, 15 Feb 2020 21:50:59 +0000

In reply to Marceli Firlej. I'm glad you liked it.

By: Marceli Firlej

Marceli Firlej — Wed, 29 Jan 2020 02:31:40 +0000

Very efficient calculator while using LT1635 chip and LTspiceXVII to simulate it as well.

By: Adrian S. Nastase

Adrian S. Nastase — Sun, 28 Apr 2019 02:26:29 +0000

In reply to Ralph Vetter. Glad to hear that.

By: Ralph Vetter

Ralph Vetter — Wed, 03 Apr 2019 20:32:18 +0000

Thank you very much, great tool, nice explanation. Your site saved me a ot of time!

By: Adrian S. Nastase

Adrian S. Nastase — Thu, 24 May 2018 23:19:48 +0000

In reply to John. If the input range is -1V to 4V, you need to have a bipolar power supply for your op amp. If your op amp is rail-to-rail both input and output, you need at least a -2V supply to allow its output to go to 0V and its input to take a -1V signal. Also a +6V positive supply so that the output can go to +5V. If it is not rail-to-rail, a negative voltage -5V and positive of +10V will do.

By: John

John — Thu, 24 May 2018 05:20:10 +0000

Hello,
I tried the circuit for an input range of -1V to 4V with an output of 0V to 5V
and a ref voltage is 2.5V.

It half works. With an input of zero the output is 1V which is correct but the output is not linear and does not correspond to the input Voltage +1V. As the input goes up the output goes up but by less and less with increased input voltage.

My goal to have 0 to 5V to feed a ADC from a -1 to 4V input (Both 5V range)

Any ideas?

Thank you.

By: Adrian S. Nastase

Adrian S. Nastase — Wed, 13 Dec 2017 22:41:14 +0000

In reply to George. Use the calculator in this article. Vin1 = 5V, Vin2 = -5V, Vout1 = 0V, Vout2 = -5V. Choose a reference voltage V2 = -2.5V to shift the output below 0V.

By: George

George — Wed, 22 Nov 2017 19:26:34 +0000

How to shift the following voltages:
+5V to -5V -> 0V to -5V
I can apply any reference voltage.