THS4521: Resistorless Single Ended to Differential output

Part Number: THS4521

Hi,

       I'm trying the THS4521 as a drop in replacement for a configuration without resistors. The amplifier is powered from 0 to 5 V, with the VOCM set to 1V  and single ended input from 0.5-1.5V.

The circuit is a simply, the single ended input goes to the + ve input of the amplifier with the +ve output fed back into the -ve input. There is no feedback from the -ve output  and no resistance in the feedback

from the +ve output.  (There is 100ohm differential load).

This does work but is a bit noisy (~1mV, on each signal ) but most of this cancels differentially. Is this approach for single ended -> differential with G=2 fundamentally wrong and would I get far better noise performance using resistors in a feedback loops? 

    

1 Reply

  • Hi Carl,

    I would not recommend using the THS4521 without any feedback/ gain setting resistors as it is fundamentally wrong for a device that primarily operates through feedback for setting the gain. I think it would be far better performance wise (both stability and noise) using resistors in feedback loops.

    Best Regards,
    Rohit