ADM7151 oscillation

Hi,

I'm using the ADM7151 to supply a PLL/VCO.  It is to be supplied w/ 5V input and give 3.3V output.  See my schematic below.  However the output is actually going to ~4V @ Vin=4.5V, and 4.3V @ Vin=5V.  It's also oscillating badly.  I noticed that my schematic omitted CREF which is in the datasheet as 1uF.  Do you expect this would cause the oscillation and the voltage error?

Thanks

Parents Reply Children
No Data