Hi Joel!, Thanks and appreciate your speed of answering, as I know asking questions is a bit easy job for that matter. And for a knowledgeable person like you, answering questions is probably more easy job.
Well, to clarify you on what I stated earlier and considering what all is said in my last post, I'm re-phrasing as below:
Look, considering all the earlier said inputs that essentially states:
- the electrical levels (given in AD8302, data sheet),
- dynamic swing strategy (given in AD8302, data sheet)
- the right ratio (given in AD8302, data sheet),
- and the right limits to comply with on individual attenuator selection (given in AD8302, data sheet), I expect you to help making right choice of the attenuator components for both INPA and INPB of AD8302 which can be sourced from manufacturer.
See, when you know:
- limits of AD8302,
- when you know settings required of attenuators for best dynamic range of AD8302,
- when you know all specs of AD9834 (DDS: used to feed reference i/p to AD8302, and load stimulation signal),
- when you know whats that its going to be, i.e. 50ohms preference for RF circuits, you should easily be able to suggest probable specs for reference attenuator selection, atleast, say INPB.
Further inputs may include:
- type of attenuators: should be of "impedance-matching",
- having low insertion loss,
- low resistance,
- and should not affect frequency characteristic of the system (in my case, operating freq range is 100KHz-30MHz).
Now comes INPA attenuator fixing: It's an unknown signal that comes from some type and range of load, I would say, this load can be a rough estimate at the moment. Say, such an attenuator would be the one which can give maximum flexibility for a passive type of loads having permittivity/capcitance variations.
I understand INPA attenuator selection which is handling unknown signal coming from the load, would be a bad task to do unless we have an exact idea about its load level.
But, as far as INPB attenuator selection goes, which receives referencing from AD9834 (DDS), should not be a problem and should be able to select, considering all available electrical levels given in the data sheets of the relevant components (AD8302 and AD9834). .
Hope, you understand what is said above.
Thanks and look forward to your valuable inputs.
Sincere regards,
Dr.Babankumar