Need good phase-splitter

There are several ways you can design such a thing. My favorite is to use a differential with a current source under the cathodes/sources/emitters. Put the signal in on one side of the differential and ground the other, unused input. Take your outputs from both sides of the differential and you're in business.

phase splitter

I suggest a single FET with equal values of resistance in the source and drain leads. Then bias it so that you have about 1/3rd of the supply voltage across each resistor. Make sure the resistor values are large enough so that you don't cook the FET. A heat sink might be useful.


2001-06-01 4:53 pm
TI (Burr-Brown) also have differential drivers, the DRV134 and DRV135. I haven't compared the specs but for me the TI parts are way easier to get (i.e. via Digi-key) than the Analog Devices ones.

Oh. No negative feedback. I vote for Grey's suggestion then. See the Pass articles for more info.
Hey, this link from another thread here may have what you're looking for - a differential pair using JFETs:
For the simpler one that FEThead suggests, just search for phase splitter on the net and you should find a bunch.
Just a note - the IC versions have higher performance. You pay for it in higher (internal) circuit complexity, which may be audible to some, but they're sure easy to use. I use the IC versions for distributing audio through my house.
Nelson did a lovely writeup on DIY Opamps that includes both differentials and current sources. Even better still, there are schematics. I would recommend that you read that.
The only thing that you will need to change is that both sides of the differential will need load resistors. Use the same value on both sides.