TMS570LC4357: KELVIN-GND connection for crystals with 4 pins

phitastic

Part Number: TMS570LC4357
Other Parts Discussed in Thread: LAUNCHXL2-570LC43

Tool/software:

Hi experts,

In the reference designs (launchXL2-570LC43 and HDK) crystals with 2 pins are chosen. The board design guidelines (link) and other forum links (1, 2) clearly state that "Kelvin_GND should not be connected to any other GND", and that's what's done in both reference designs.

Many automotive crystals have 4 pins, however. For example, ABM8AIG has the following pinout:

Could you share how crystals with 4 pins shall be connected to Kelvin-GND, and how the other GND pins should be wired up?

Thanks!

over 1 year ago

0 jagadish gundavarapu over 1 year ago

TI__Guru 69871 points

Hi Phitastic,

I found one of the reference connectivity in our TI boards and it should be as below:

With our TMS570LC43x we can connect as below:

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Thanks & regards,
Jagadish.

0 phitastic over 1 year ago in reply to jagadish gundavarapu

Prodigy 95 points

Thanks, jagadish gundavarapu. Just to confirm: the upper schematic was for AM263 where GND is connected to crystal's G, but for the TMS570 we do not connect any pad to GND (all go to KELVIN-GND). Thanks

+1 jagadish gundavarapu over 1 year ago in reply to phitastic

TI__Guru 69871 points

Hi Phitastic,

Yes, in our case we should give all the pins to KELVIN_GND only.

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Thanks & regards,
Jagadish.

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TMS570LC4357: KELVIN-GND connection for crystals with 4 pins