Barebones PFD and charge pump chip?
时间:04-06
整理:3721RD
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I wanted to start designing some polar feedback systems using a PLL for phase correction, but I really want to avoid using a digitally programmable PLL. I'm able to use microcontrollers and such, but I really don't want to put one on a PCB for the soul purpose of programming a PLL once on power up. So I was hoping to basically find a chip with a good PFD, and hopefully a charge pump, built in. A built in VCO is fine, but not necessary. No R or N dividers, since I want a 1:1 ratio. My intended frequency ranges from 50-150MHz.
So basically I'm looking for a higher frequency version of the old CD4046. Any ideas?
So basically I'm looking for a higher frequency version of the old CD4046. Any ideas?
http://www.hittite.com/products/view...ew/HMC439QS16G
Any XOR gate will work too.
You can use an I/Q mixer for an analog output
Yes, that looks good, though very expensive and not available at distributors... but the HMC1031 looks suitable as well, and is more available, thanks.
I need to be able to track frequency and phase without error, even with large transient steps, so I'm pretty sure an XOR wouldn't work as a PFD.
Could you explain using an I/Q mixer for PFD a bit more? I know that mixing can give a phase/frequency error measurement, but how could the I/Q error signals be used with a VCO in order to lock frequency and phase (without a DSP to do the math)?
