We have a couple of DA3 modules connected to a pair of Xilinx Spartan 3 FPGAs. We are generating an audio ferquency baseband signal with at 200 ksps. Looking at the buffered output from the module we periodically see a sub-1us 500uV pulse approximately every 100 samples when outputting a small signal sinewave. Offsetting our sinewave by different amounts can make the problem either better or worse.
The datasheet for the AD5541 DAC talks about a 'Digital-to-analog glitch impulse' that seems to explain our unwanted pulse.
We have crudely filtered out this pulse with an 18pF cap from the DAC output to GND. This does not seem to cause any problems at our relatively low baseband frequency. Is there an accepted method of dealing with these unwanted pulses? Would it be possible to add a position on the Pmod board for a filter to be added?
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KevinS
We have a couple of DA3 modules connected to a pair of Xilinx Spartan 3 FPGAs. We are generating an audio ferquency baseband signal with at 200 ksps. Looking at the buffered output from the module we periodically see a sub-1us 500uV pulse approximately every 100 samples when outputting a small signal sinewave. Offsetting our sinewave by different amounts can make the problem either better or worse.
The datasheet for the AD5541 DAC talks about a 'Digital-to-analog glitch impulse' that seems to explain our unwanted pulse.
We have crudely filtered out this pulse with an 18pF cap from the DAC output to GND. This does not seem to cause any problems at our relatively low baseband frequency. Is there an accepted method of dealing with these unwanted pulses? Would it be possible to add a position on the Pmod board for a filter to be added?
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