Tuesday, March 27, 2007

PCB update

posting after a while now.




PCB is almost finished. A few loose ends to tie up.




RF2420 has been replaced by AT-4521 from honeywell; as RFMD discontinued the production. The only attenuator that i can get from digikey would be AT4521 with a serial interface; as opposed to the parellel rf2420. no probs thr; since i'll just have to live with a few more z8 ios freed up.




LPF has to be redesigned for 0.01R input impdeance and 50R output impedance. may be a matching network?




finally decided no output buffer; since the current from adc output driver ths3201 is above the magical 100ma mark. I had to replace AD8003 by ths3201 (from TI); as you can only get AD8003 in multiples of 250. heh. Long live TI and their fed-exed samples. I will definitely use TI for industrial projects;cos i have more experience with them.




have to check with darrell regarding the 2.5V step up.




and loads of other changes. I'll add them here whn i remember them.




a quick glance at the PCB. I shaved off about 30 sq inches. this one here is 24 sqinches.












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