ADS131M04-Q1: ADS131M04-Q1

Hi Ankush,

As you can see the details in the section of 8.3.5 Clocking and Power Modes in ADS131M04-Q1 datasheet, an LVCMOS clock must be provided at the CLKIN pin continuously when the ADS131M04-Q1 is running in normal operation, so you can use either an external oscillator or a clock from your microcontroller. Depending on the power mode, you can select and use a clock of 8.192MHz, 4.096MHz or 2.048MHz frequency. For any other frequency clock, you may not be able to get an output data rate specified in the table 8-2 in ADS131M04-Q1 datasheet. The output data rate is determined by CLOCK/(2*OSR).

If you have any question about RM48L540, please post your query on TI Arm-based microcontroller forum.

BR,

Dale

Thanks for the information .

Hi Dale,

I’m using a packaged quartz oscillator as a patch on my PCB:

WE-SPXO Simple Packaged Quartz Oscillator
Würth Electronics part no: 831021890

When the oscillator is fitted and running, I see noise appearing on the SPI lines. The noise disappears as soon as I remove the oscillator (or stop it), so I suspect the oscillator or its supply/layout is coupling into the SPI signals.

Could you please help with the oscillator circuit / layout recommendations? Below are the details and steps I’ve tried so far:

Symptoms

• Noise appears on MOSI / MISO / SCLK (SPI) when oscillator is present.

• Noise stops when oscillator is removed.

• The oscillator is used as a local clock source (patch-mounted on PCB).

What I’ve tried

• Removed the oscillator — noise disappears.

• Verified power rail is stable (basic probing).

• Kept SPI frequency unchanged while testing.

Quick questions (if you have time)

1. Do you have the oscillator output type for PN 831021890 handy (CMOS, TTL, LVCMOS, drive strength)?

2. Do you know recommended VCC decoupling and ferrite recommendations for this part?

3. Do you have a reference oscillator schematic / recommended PCB layout footprint or keep-out area?

If you can share a recommended oscillator circuit (VCC decoupling + ferrite + series resistor values) and any layout do’s/don’ts, that would be extremely helpful. If useful, I can attach the PCB snapshot (area around oscillator and SPI routing) and screenshots of the scope traces.

Thanks a lot for your help — I’m keen to get this resolved quickly.

Hi Dale,

I’m using a packaged quartz oscillator as a patch on my PCB:

WE-SPXO Simple Packaged Quartz Oscillator
Würth Electronics part no: 831021890

When the oscillator is fitted and running, I see noise appearing on the SPI lines. The noise disappears as soon as I remove the oscillator (or stop it), so I suspect the oscillator or its supply/layout is coupling into the SPI signals.

Could you please help with the oscillator circuit / layout recommendations? Below are the details and steps I’ve tried so far:

Symptoms

• Noise appears on MOSI / MISO / SCLK (SPI) when oscillator is present.

• Noise stops when oscillator is removed.

• The oscillator is used as a local clock source (patch-mounted on PCB).

What I’ve tried

• Removed the oscillator — noise disappears.

• Verified power rail is stable (basic probing).

• Kept SPI frequency unchanged while testing.

Quick questions (if you have time)

1. Do you have the oscillator output type for PN 831021890 handy (CMOS, TTL, LVCMOS, drive strength)?

2. Do you know recommended VCC decoupling and ferrite recommendations for this part?

3. Do you have a reference oscillator schematic / recommended PCB layout footprint or keep-out area?

If you can share a recommended oscillator circuit (VCC decoupling + ferrite + series resistor values) and any layout do’s/don’ts, that would be extremely helpful. If useful, I can attach the PCB snapshot (area around oscillator and SPI routing) and screenshots of the scope traces.

Thanks a lot for your help — I’m keen to get this resolved quickly.

Hi Ankush,

First, I'm not an expert for oscillator. Second, we can not support and answer your questions for a device which is not TI's product. I would suggest you to contact Würth Electronics or check TI's clock product by posting your query on TI Clcok&timing forum.

Thanks for your understanding.

BR,

Dale

Hi Dale ,

I know you are not expert on oscillator but you can guide me on ADS131M04-Q1 behavior after connecting oscillator this is designing issue ??