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ADL5801 - IFoutput biasing

Question asked by veera on Sep 19, 2012
Latest reply on Dec 19, 2012 by bkamak

In most of the mixers, including ADL5801, the IF output port is biased either using choke ar feeding the positive supply to the center tap of the output Transformer.

Is this bias required only to pull-up the open collector output or is it also required to be reflected at the output as DC offset value?

We are planning to have a passive Band pass filter at output of the transformer which will remove this DC component at the output. If the IF output signal requires DC offset, we cannot use these filters. So my doubt is do we require DC offset value at single ended IF output from the transformer?

 

Also we are planning to use balanced Bandpass filter module immediately at the IF output and the output of the filter to Transformer for single ended conversion. In this case, please explain the appropriate output bias technique. Can we still give the Vpos to the centre tap?

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