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AD7822 questions

Question asked by AdvRdr on Jul 14, 2011
Latest reply on Jul 15, 2011 by AdvRdr

I am implementing the AD7822 into a circuit. I was wondering if anyone can shed some light on my questions below.

 

A) The data sheet says 2 MSPS. But by looking at the timing diagram on page 17, the only way I can see to get that sample rate is to not change channels. And only if t13 does not apply at all if the channel is not changed from one sample to the next. The AD7822 has only one channel, so am I correct in assuming t13 does not apply and the remaining constraint for RD low to CONVST is t8+t3?

 

B) Can I tie RD permanently low? The datasheet implies no in a round about way. I would prefer to not let the outputs go into tristated hi Z.

 

C) t10 is quite short (5ns). Has anyone had better luck in finding a latch with decent margin to use this device in stand alone mode?

 

Thanks

 

AdvRdr

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