What is a one quadrant multiplier ?

[pol_sky]

hi ,
I want to design a PFC chips, I need a one quadrant multiplier, But I don't have experences about the multiplier, who can give me help? thanks!

 

[Vamsi Mocherla]

Re: need help Multiplier

A simple single quadrant multiplier could be a CMOS switch.

 

[FvM]

Re: need help Multiplier

A simple single quadrant multiplier could be a CMOS switch.

How? In a classical PFC design, the controller output (current demand) is multiplied with the rectified input voltage used as a sine waveform reference to generate a variable sine waveform current setpoint. I don't see, how a CMOS switch should perform this task.

 

[jiripolivka]

Re: need help Multiplier

Please see Analog Devices; they have analog multiplier ICs and there may be a White Paper on how to use them.

 

[pol_sky]

Re: need help Multiplier

Thanks to replying,
I see some book about the one quadrant multiplier,but I can't clear, who have referring to paper,and send to me, Thank you very much!!!! My mail :0917zxg@163.com

 

[FvM]

Re: need help Multiplier

I think, multiplier building blocks are among the basic analog IC "ingredients" that are discussed in profound text books. I wouldn't expect specialized books about each of it. In case of a PFC, the multiplier requirements won't be particularly critical. It's more a question of minimizing the effort. So a differential pair operated as basic "gm" (transconductance) multiplier should do the job.

 

[jiripolivka]

Re: need help Multiplier

I have used only simple multipliers as synchronous detectors. I have here an old
"IC-OPAMP Cook Book " by W.G. JUng, SAMS 1994: there are two four-quadrant multipliers described, one with Motorola 1495, another with AD534.

I think those are now obsolete; please look at "www.analog.com", they have updated components and also White Papers on how to best use them.

 

[pol_sky]

Re: need help Multiplier

Ok, thanks FvM and jiripolivka for great propose.