Electronics Handbook/Circuits/Voltage Divider

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Voltage Divider[edit]

If two circuit elements are in series, there is a voltage drop across each element, but the current through both must be the same. The voltage at any point in the chain divides according to the resistances. A simple circuit with two (or more) resistors in series with a source is called a voltage divider.

PotentialDivider.png

Figure A: Voltage Divider circuit.

Transfer Function of Voltage Divider[edit]

Consider the circuit in Figure A. According to KVL the voltage is dropped across resistors and . If a current i flows through the two series resistors then by Ohm's Law.

.

So

Therefore