afz23
Full Member level 3
Hi guys
I have a PLL at 1.8GHz,the dc-dc converter which provides
15 volts supply to PLL board have ripples of 50mVpp at its switching frequency 125kHz.
I am observing spurious at 125kHz and its multiples at locked VCO output.The spectrum thus appears to be a mudulated signal at 125kHz.
Since such a spectrum is undesirable as the level of these spurious components is as high as -30dBc.
I need your expert opinion to sort out this problem,what kind of filtering do you suggest at 15 volt line.
I have a PLL at 1.8GHz,the dc-dc converter which provides
15 volts supply to PLL board have ripples of 50mVpp at its switching frequency 125kHz.
I am observing spurious at 125kHz and its multiples at locked VCO output.The spectrum thus appears to be a mudulated signal at 125kHz.
Since such a spectrum is undesirable as the level of these spurious components is as high as -30dBc.
I need your expert opinion to sort out this problem,what kind of filtering do you suggest at 15 volt line.