I am Satyabrata sarangi, currently using AD 9265-125 EBZ evaluation board. Could you please tell me about the significance of the on board red LED(CR2) ? If it glows at any time, is there any problem ?
Not sure why light should be glowing under these conditions since OR output of the ADC should only go high once differential input exeeds VREF (Table 13 of datasheet). Note, EVB's are tested before being placed into stock although I am unsure if test includes functionality of OR signal path. Perhaps you can trace back to pin 27 of the AD9265 to ensure that this pin also is high under 500 mVp.p. conditions (see attachment). Also, can you confirm that you using the balun path (unmodified) with each of the differential inputs biased at VCM (approximately 0.9 V) with a 250 mVp.p. input on both te VIN+ and VIN- inputs. Lastly, are you interfacing the AD9265 EVB to the Analog Devices data capture card such that you can exhibit the digitized waveform in both time and frequency domain. If so.....does frequency (or time) domain results match what you would expect.
This LED indicates that the power is being applied to the EVB via the 6 V jack used to connect to the AC/DC wall plug supply supplied with EVB. Regards.
Thanks for your reply. I am not talking about green LED, which shows
power is being applied. I'm asking about the red one. Number of that LED is CR2-OR.
My apologies. This LED indicates that an overrange condition at the ADC input since this LED is controled by a buffered version of the OR digital output from the ADC. Provided that the analog input of the ADC does not exceed the MAX RATINGS specified on the datasheet............no harm to the device should occur. Regards.
The thing is i was feeding an analog input of 500 mV pk-pk(less than 1.8V(AVDD)) sinusoid to the board, still it was glowing. Why so?
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