Hi Aaron,

Not sure what the real advantages are since I´m not an expert, but concerning the resistors I guess the will be necessary (with the corresponding reference voltage in the mid-point) in order to guarantee the output CM of the circuit: since its output is differential you need to force the output common-mode.

Regards
Tosei

I actually tried using that structure a few years ago, except the MOS version.

It never made it into the final design, but I seem to remember it was a bit quieter than the differential pair (everything else being the same) but had nothing of significance to offer that I can remember.

Differential pairs that are driven with one side AC grounded dont give a perfectly complementary amplitude signal out, and If I recall that also offered better amplitude balance.

Patented? Why would that indicate that it has value or merit? (Sort of kidding!) Seriously, don't allow any presence of a patent ***ever*** fool you into thinking that an idea has merit or is unique. A lot of patents are pretty worthless. (and yes, I have patents that I consider worthless, but the company I was working for wanted the concept patented!)

Jerry