PLZ help! Question about PLL.

[foxgan]

I use the TI TRF-3761,and get wrong output. the pll doesn't lock.I don't know which wrong.
the attachment is the output.
plz help me to solve the problem and tell me the reason.

 

[kspalla]

Have you laded the registers correctly?
How do you confirm that you followed the guide line?
Question yourself and make sure that you did no wrong as the part is very genuine.

 

[foxgan]

Thanks
I've just shot the trouble, but i don't know the reason.
at power on, do VCO calibration, the IC work well.
if we don't, it goes wrong.
but i don't know why i need a calibration. and what works when doing VCO calibration.
Thanks!

 

[freedomxn]

The inductance in the circuit may have some error, induce the PLL out of lock, so the calibration is a nessasity. There are some capacitance which is controled by digital switch to compensate the error form the inductance.