Electronic – step down voltage follower

voltagevoltage dividervoltage-regulator

I'm trying to create a circuit that will divide the input voltage in half, but still be able to supply a high current to the load.

My input voltage varies from 10-15v and I want the output voltage to variate in proportion to this. So between 5-7.5V. The load should be able to draw about 1A, so the components needs to be able to handle this.

I'm thinking it's going to be a voltage diveder and a voltage follower, but I'm not completely sure. Whats the best solution to this?

Tnx.

Best Answer

If you needed better efficiency than a linear regulator, you could use a buck SMPS and use a current mirror to adjust the voltage based on the input voltage.

Here's a generalized schematic.

schematic

simulate this circuit – Schematic created using CircuitLab

The current Iadj increases linearly with the input voltage. This pulls current out of the voltage feedback net which causes the output voltage to increase.

You can pick out a buck SMPS IC that meets your needs and then design the current mirror around that.