ADS 1291 clock problem

Luis Torres

Other Parts Discussed in Thread: MSP430F4617, ADS1291

Good Day,

I'm using an ADS1291 AFE along with a MSP430F4617.

After making all the connections according to the datasheet, I am able to connect to the device using SPI and configure the registers, but I am not able to start capturing data, and setting the clock output bit in the CONFIG register would not output the clock in the CLK pin, even when the CLK_SEL pin is set high.

I also tried supplying an external 512Khz clock with CLK_SEL low and it would still not allow me to capture.

is there any setting or connection I could test out before calling it DOA?

I'm sure I'm missing out something as I currently have 2 1291 chips misbehaving the same way

Thanks

over 12 years ago

0 Tom Hendrick over 12 years ago

TI__Guru**** 175131 points

Hi Luis,

Welcome to the Precision Data Converter Forum! Could you possibly post us a schematic of your board? Perhaps there is a connection missing somewhere that we can help you spot.

0 Luis Torres over 12 years ago in reply to Tom Hendrick

Prodigy 20 points

This is the schematic of the AFE part of the board, with the pins that are being connected to the MSP430

also to clarify a little, I believe there is an issue with the clock because the DRDY pin does not change value once the start command is sent or the START pin is set after everything is configured.
Neither when the CLK_SEL and START pins are set during device power up, which according to the datasheet should make the DRDY pin toggle at a certain frequency.

0 Tom Hendrick over 12 years ago in reply to Luis Torres

TI__Guru**** 175131 points

Hi Luis,

One thing I noticed in your schematic is that the VREFN pin appears to be floating. This should tie to the same GND that you have the AVSS pin connected to. Can you also verify the RESET/PWDN pin is pulled high?

0 Tom Hendrick over 12 years ago in reply to Tom Hendrick

TI__Guru**** 175131 points

Hi Luis,

Have you made any progress on this issue?

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ADS 1291 clock problem