# How to lower voltage of frequency signal

Discussion in 'General Electronics Discussion' started by chinna723, Jun 15, 2020.

1. ### chinna723

3
0
Mar 17, 2020
Hi,

I have a speed sensor which gives a frequency output signal with voltage 12V. But my controller frequency input pin configuration has 0-5V range. To connect the speed sensor to my controller input, I have to lower the speed sensor frequency signal from 0-12V to 0-5V . How can I do that ? If I use the voltage divider, does it distort the signal ?

2. ### Harald KappModeratorModerator

11,810
2,751
Nov 17, 2011
Not if well constructed. A resistive divider is the perfect choice.

3. ### Wollowstone

18
4
Mar 26, 2018
A static voltage divider is nice, but the involved resistances have to be small, so that the "equivalent resistance" of whatever you add in parallel to one of the resistor appears "big" (1000 times, or higher), but that may draw a lot of current, if not too much, from the original source (sensor, whatever). As example, if your divider is two resistors of 1k, then if you add a circuit worth of 100 ohm in parallel to the second resistor, you end up with 1000 + ( 1000 // 100 ) == 1000 + 90 not dividing the initial voltage by two anymore.

You can check the paper scea062a.pdf, at ti.com, for a short comparison with some dynamic solutions alternatives, including one of their specialized IC.

2,148
807
Nov 8, 2019

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