I am using a TLV62568 (https://www.ti.com/lit/gpn/tlv62568) synchronous buck converter. TLV62568's output can be adjusted using two resistors. I have configured the TLV as per the datasheet with the resistors adjusted such that my output voltage is 2.8v. I then attach a resistor of 400 ohm as load. Then I vary the input voltage from 5v to 2.8v using a dc supply. My current draw from the supply should be greater than 7mA i.e. 2.8v/400ohm. But I see some strange behavior, where my current is 4.5mA when input voltage is 5v and then gradually increases and goes upto 7mA as I decrease the input voltage to 2.8v while my output voltage is 2.8v at all times of varying input voltage. If someone could explain what is happening here.