ADG3308 Output oscillating when low

Hi Frankziegler,

I'm looking into this, in the meantime here are some comments:

• Have you checked if your ground lines are stable?
• What is the load of the ADG3308? How much sink/source does it need from the level translator during low level translation?
• How fast is the level translation frequency?
• Can you share the scope shot showing the oscillation?

Regards,

May

Hi Frankziegler,

I'm looking into this, in the meantime here are some comments:

• Have you checked if your ground lines are stable?
• What is the load of the ADG3308? How much sink/source does it need from the level translator during low level translation?
• How fast is the level translation frequency?
• Can you share the scope shot showing the oscillation?

Regards,

May

I have one 93M ref driving a 3.3V FS7145 PLL which may be too high a frequency, now I think about it.

Two outputs are static, the other three are SPI driving a cmos DAC 1/4" away, these are the ones osclillating.

I tried a third card with no issues, even has the En tied to the 1.8V A side.

Could just be that one part.

Hi Frankziegler,

Please take note that the maximum data rate of the ADG3308 is up to 50Mbps only which is also equivalent to 25MHz. 

I'm not sure if the problem was caused by using over the maximum data rates but I'm glad your system works fine now.

Thanks,

May