I need to design a simple circuit with an op amp, such that the gain is 1/2 of input voltage. How?

Question

So, how do you design a circuit with an op-amp such that the output voltage is half of the input voltage?

I know it's impossible with an non-inverting amp,

what about other options???

Answer 1

use a resistive attenuator followed by a voltage follower.

Use, for example, two 10k resistors in series, top is input, mid point goes to opamp, bottom to ground.

If that input impedance is too low, up the resistor values, or use another voltage follower.

or a voltage follower followed by a resistor attenuator.

Or, use two opamp inverters, one with gain 1/2, other with gain 1.

.

Answer 2

Simply use a 2x attenuator, followed by a voltage follower circuit. (Output connected to inverting input, input connected to non inverting input).

Answer 3

What you need is a "negative gain" amplifier.

You connect the input voltage to "-" of the Op Amp, and the feedback resistor also to "-" of the Op Amp. The "+" input goes to Ground (0V).

See  http://devices.sapp.org/circuit/negamp/