Input Impedance of AnalogX and Voltage Divider

Q&A for AnalogX Analog to CAN interface. <a href="https://wiki.autosportlabs.com/AnalogX">Installation and Operation Guide</a>
Guzel Sans
Posts: 1
Joined: Sat Sep 23, 2017 9:18 pm

Input Impedance of AnalogX and Voltage Divider

The specification page of AnalogX displays the input impedance of the device to be 10 Megaohms (Link page: https://wiki.autosportlabs.com/AnalogX. Whereas AnalogX takes an input of 5 V.

Let's say I am designing a voltage divider with two resistors of 40 kiloohms and 20 kiloohms.
Now for the loading condition of 10 Mohm, I am still getting the output voltage 16.644. I am using this loading calculator http://www.voltagedividercalculator.com ... r-dc-load/ putting 10 M ohm as the loaded resistors. I do know that raising the resistance values can impact in better output, but this will also reduce current to zero.

In the present scenario, I am getting 0.0000016 A, for higher value resistors I am hoping it to further scale down? So what will be the optimal solution for my case?

brentp
Posts: 6233
Joined: Wed Jan 24, 2007 6:36 am
Hi,

Because of the buffered inputs and that the input impedance is so high, you can effectively ignore any loading on the circuit. You should be able to use a simple voltage divider calculator.

Hope this helps!
Brent Picasso
CEO and Founder, Autosport Labs