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I have a 1.2-4.5vdc output from a hall sensor throttle control and I need 0-5vdc signal for the input of a bldc motor controller. I'm not sure of the input signal current needs of the controller. I do not have this data available to me. My best estimate is 20mA would be the highest possible value.

I just learned these words, but gain and offset with op-amp and voltage divider sound good, but which op amp, and how to set it up?

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As already mentioned by @Velvet, you need to subtract 1.2V and then you need to add some gain.

Something like below can do the job. enter image description here

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What supply voltage do you have available? If just 5V you need to use a rail-to-rail op-amp. If higher like 12V you can use a common op-amp.

Btw, you need to decrease the signal -0.35V first, then amplify it x1.2 around middle (2.5V).

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    \$\begingroup\$ Your solution will convert 1.2V ... 4.5V to 1V ... 5V (see i.sstatic.net/KnFAusbG.png). Instead, you want to subtract 1.2V and then amplify by 5/3.3 (see i.sstatic.net/9hWVZJKN.png). \$\endgroup\$
    – Velvet
    Commented Nov 12 at 8:11
  • \$\begingroup\$ @Velvet I thought about amplification around 2.5V. But your solution is also possible. \$\endgroup\$
    – Michal Podmanický
    Commented Nov 12 at 8:38

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