ADS1292R: trouble of double ads1292R working

user1915296

Part Number: ADS1292R
Other Parts Discussed in Thread: ADS1292

I have two ads1292RS.They use the same SPI bus and different CLK,CS and DRDY. Both of them use the internal clock. We set both chips at 250SPS continous sample but found one chip will pause(no DRDY signal) about 50ms a t every 2s, at the same time ,the oher chip alwways stopabout 50ms after 4-5 samples. Following the manual,when using the same spi BUS, the Clock PIN should be connect,if we don't connect

these two pin, can the chip work correctly?

over 3 years ago

0 Alexander Smith over 3 years ago

TI__Mastermind 47625 points

Hi,

You would want to route the internal clock from one ADS1292 to the other ADS1292, such that both devices are running off of the same clock. It is possible for these chips to work correctly without doing this, however the data will not be taken at exactly the same time. It is also possible that there is a timing issue. The BIOFAQ can be used to help diagnose if this is the issue: https://e2e.ti.com/support/data-converters/f/73/p/772058/2855202

0 user1915296 over 3 years ago in reply to Alexander Smith

Prodigy 90 points

We want to try the the following way： one chip is set to continuous sample mode，the 2st chip is set to single sample mode and started by the soft command after receiving 1st chip's DRDY. Do you have some suggestions for this way？Thanks!

0 Alexander Smith over 3 years ago in reply to user1915296

TI__Mastermind 47625 points

Hi,

Since both devices are sharing the same SPI bus, the data from one device must be relayed by the other. I don't think this will work if both devices are running off of different clocks since getting the timing to align without truncated samples would be very difficult. If this is what you would like to do, then I would recommend routing separate SPI communication lines to both devices.

Data converters

Data converters forum

ADS1292R: trouble of double ads1292R working