High side current sensing at 56V / 3A not working

[Xtal011]

Hello everyone, newbie here.
After a few months thinking about it I started to design my own power supply and after a few itherations finally got something promising, it all works fairly well until tried to implement a self made High side current sensing amplifier that could measure the current through a shunt resistor user for short circuit protection.

After some research I whipped up a somewhat functional circuit based on an opamp, two voltage dividers and a few resistors  nonetheless this circuit is not working as intended as the output voltage is offseted by at least 1.465V, is there any way to bring down the output level to 0V at 0V input?.

Schematics and simulation results attached

Edit: Added the application note from which I based this design, te base design is in figure 2 (pages 2 and 3)

[eblc1388]

...circuit is not working as intended as the output voltage is offseted by at least 1.465V, is there any way to bring down the output level to 0V at 0V input?

Sure. Just provide a negative power supply of 5V or more to the LF351 pin#4.

The output of the LF351 opamp cannot reach V- by a margin of two to three volts. If you connect V- to ground, then the output will not goes below 2V in general. You are lucky to get only 1.465V.
 

[Xtal011]

Sorry for the late response.
Tried the tip you gave me and it worked like a charm, although extra steps were needed, once I added the negative power rail to the opamp the offset decreased to arround 10 mV but that was fixable with a trim pot between the offset null pins with the winding tap connected to the negative power rail. Once I did that it worked perfectly.

@eblc1388 : thanks for the tip