# Boost converter output still active when boost IC is turned off

Am using the tps61175 boost converter ic in a project. per the datasheet here

i noticed when i pull the EN(enable) PIN LOW and the boost converter ic turns OFF , i still read voltage at the output Vout and the voltage corresponds to my input voltage Vin.

To further elaborate, say i connect a 3v battery to Vin and pull the EN(enable) PIN HIGH for the boost converter ic to start working with a Vout of 5.1v. When i pull the EN(enable) pin low, the Vout is becomes 3v.

The first picture shows what i did to turn the circuit off completely. That approach also lead to loss of about 400mA and the output voltage broke down to 4V instead of the desired 5V.

I need help about how to make the output Vout 0v when the boost ic is OFF, thus turn the circuit of completely.

• i figured i should add the MOSFET or BJT to the Vin side instead since adding them to Vout was done after the boost IC feedback circuit and as such voltage and current losses cannot be compensated for by the feedback circuit. what is your thought on this approach @The Photon – Banini Prince Nov 4 '19 at 12:24