Understand Diode Connected MOSFET Circuit

[shaikss]

Hi,

Can you please let me know how does the attached circuit work?
Vh and Vl are inputs ; Vbn and Vbp are outputs.

Thanks in advance.

 

[Kholdstare]

Drains of all four MOSFETs are attached to Gates. Thus for all of them Vds=Vgs (> Vgs - Vth). So all of them are in either saturation or cutoff.
However, if Vh and Vl are inputs VBN and VBP will give same output for sure.