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How to design a voltage divider to optimize the measurement error?

Intuitively I would take the same ratio $$\frac{load}{divider} = \frac{divider}{measurement}$$ As follow: the voltage is roughly divided by 5. The divider induces 1% error on the load, and the measurement 1% error on the divider.

Is it a good practice?

schematic

simulate this circuit – Schematic created using CircuitLab

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  • \$\begingroup\$ You can use a voltage follower. Adding a voltage follower to the voltage divider circuit isolates the load impedance (Rmeasurement) so that VOUT is dependent upon R1 and R2, not Rmeasurement. \$\endgroup\$ – Remco Vink Oct 16 '18 at 8:31
  • \$\begingroup\$ yeah sure, but I want to make it simple, I have 32 inputs in parallel and do not want to implement 32 voltage followers :) so I want to optimize my voltage divider \$\endgroup\$ – Rémi Baudoux Oct 16 '18 at 8:36
  • \$\begingroup\$ What makes you say that the "divider introduces 1% error on the load"? The voltage across the load and across the divider must be identical (for an ideal voltage source). \$\endgroup\$ – Elliot Alderson Oct 16 '18 at 13:27
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This is about what I was looking for:

http://www.ti.com/lit/an/slva450a/slva450a.pdf

enter image description here

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