Hi all, I have a 200 MHz clock signal to send across the barrier of 5 KV I'm thinking of some RF transformer - perhaps "air core" ... but can't find any good candidate
RF galvanic isolator ...
Started by ●November 8, 2011
Reply by ●November 8, 20112011-11-08
On a sunny day (Tue, 8 Nov 2011 06:41:54 -0800 (PST)) it happened halong <ccon67@netscape.net> wrote in <166ca4de-5668-41b6-8189-8cce9aa41551@s9g2000yqi.googlegroups.com>:>Hi all, > >I have a 200 MHz clock signal to send across the barrier of 5 KV >I'm thinking of some RF transformer - perhaps "air core" ... but can't >find any good candidateJust up the power, and use a folded dipole as antenna ;-)
Reply by ●November 8, 20112011-11-08
On Tue, 8 Nov 2011 06:41:54 -0800 (PST), halong <ccon67@netscape.net> wrote:>Hi all, > >I have a 200 MHz clock signal to send across the barrier of 5 KV >I'm thinking of some RF transformer - perhaps "air core" ... but can't >find any good candidate > > >Fiber optics! Or capacitively couple into a tuned circuit. This is RF! John
Reply by ●November 8, 20112011-11-08
On Nov 8, 9:09=A0am, John Larkin <jjlar...@highNOTlandTHIStechnologyPART.com> wrote:> On Tue, 8 Nov 2011 06:41:54 -0800 (PST), halong <cco...@netscape.net> > wrote: > > >Hi all, > > >I have a 200 MHz clock signal to send across the barrier of 5 KV > >I'm thinking of some RF transformer - perhaps "air core" ... but can't > >find any good candidate > > Fiber optics! > > Or capacitively couple into a tuned circuit. This is RF! > > JohnHi Jan, it's medical environment where any extra EM is regulated.., few winding coils may work better than the dipoles John: capacitive coupling... will it add more crying in hospital ? Optics sounds feasible...but cost more than the air core transformer for sure...
Reply by ●November 8, 20112011-11-08
On Tue, 8 Nov 2011 07:29:40 -0800 (PST), halong <ccon67@netscape.net> wrote:>On Nov 8, 9:09�am, John Larkin ><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: >> On Tue, 8 Nov 2011 06:41:54 -0800 (PST), halong <cco...@netscape.net> >> wrote: >> >> >Hi all, >> >> >I have a 200 MHz clock signal to send across the barrier of 5 KV >> >I'm thinking of some RF transformer - perhaps "air core" ... but can't >> >find any good candidate >> >> Fiber optics! >> >> Or capacitively couple into a tuned circuit. This is RF! >> >> John > >Hi Jan, it's medical environment where any extra EM is regulated.., >few winding coils may work better than the dipoles > >John: capacitive coupling... will it add more crying in hospital ? > >Optics sounds feasible...but cost more than the air core transformer >for sure... > >What's the distance and geometry? Does phase shift matter? John
Reply by ●November 8, 20112011-11-08
On Tue, 08 Nov 2011 06:41:54 -0800, halong wrote:> Hi all, > > I have a 200 MHz clock signal to send across the barrier of 5 KV I'm > thinking of some RF transformer - perhaps "air core" ... but can't find > any good candidateHave you tried widening your search to just specify a 200MHz signal frequency and galvanic isolation? I think the 200MHz part isn't a big deal, but the galvanic isolation may be. If EMI is a concern then an air core transformer may not be a good choice: it's going to leak RF like a sieve, and the spacing you'll need for 5k isolation won't help. If your production volumes are low, anything that works right off the bat is way less expensive than you think -- engineering time costs money, after all. So you may want to at least price out your fiber optics solution. -- www.wescottdesign.com
Reply by ●November 8, 20112011-11-08
On Tue, 08 Nov 2011 10:18:14 -0600, Tim Wescott <tim@seemywebsite.com> wrote:>On Tue, 08 Nov 2011 06:41:54 -0800, halong wrote: > >> Hi all, >> >> I have a 200 MHz clock signal to send across the barrier of 5 KV I'm >> thinking of some RF transformer - perhaps "air core" ... but can't find >> any good candidate > >Have you tried widening your search to just specify a 200MHz signal >frequency and galvanic isolation? I think the 200MHz part isn't a big >deal, but the galvanic isolation may be. > >If EMI is a concern then an air core transformer may not be a good >choice: it's going to leak RF like a sieve, and the spacing you'll need >for 5k isolation won't help. > >If your production volumes are low, anything that works right off the bat >is way less expensive than you think -- engineering time costs money, >after all. So you may want to at least price out your fiber optics >solution.Fiber optics? Definitely best for a clock! ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●November 8, 20112011-11-08
On Nov 8, 10:04=A0am, John Larkin <jjlar...@highNOTlandTHIStechnologyPART.com> wrote:> On Tue, 8 Nov 2011 07:29:40 -0800 (PST), halong <cco...@netscape.net> > wrote: > > > > >On Nov 8, 9:09=A0am, John Larkin > ><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: > >> On Tue, 8 Nov 2011 06:41:54 -0800 (PST), halong <cco...@netscape.net> > >> wrote: > > >> >Hi all, > > >> >I have a 200 MHz clock signal to send across the barrier of 5 KV > >> >I'm thinking of some RF transformer - perhaps "air core" ... but can'=t> >> >find any good candidate > > >> Fiber optics! > > >> Or capacitively couple into a tuned circuit. This is RF! > > >> John > > >Hi Jan, it's medical environment where any extra EM is regulated.., > >few winding coils may work better than the dipoles > > >John: capacitive coupling... will it add more crying in hospital ? > > >Optics sounds feasible...but cost more than the air core transformer > >for sure... > > What's the distance and geometry? > > Does phase shift matter? > > JohnPhase shift is no problem. The clock needs to cross the two "islands" on same PCB...5KV is the different voltage... btw, I think this would be good candidate http://www.analog.com/en/interface/digital-isolators/adum2400/products/prod= uct.html but what I worry about is the pulse with distortion, the datasheet rates max distortion =3D 2ns... Does that means either reference clock- edge (rise/fall) will be 2 ns jitter ?...
Reply by ●November 8, 20112011-11-08
On Nov 8, 10:18=A0am, Tim Wescott <t...@seemywebsite.com> wrote:> On Tue, 08 Nov 2011 06:41:54 -0800, halong wrote: > > Hi all, > > > I have a 200 MHz clock signal to send across the barrier of 5 KV I'm > > thinking of some RF transformer - perhaps "air core" ... but can't find > > any good candidate > > Have you tried widening your search to just specify a 200MHz signal > frequency and galvanic isolation? =A0I think the 200MHz part isn't a big > deal, but the galvanic isolation may be. > > If EMI is a concern then an air core transformer may not be a good > choice: it's going to leak RF like a sieve, and the spacing you'll need > for 5k isolation won't help. > > If your production volumes are low, anything that works right off the bat > is way less expensive than you think -- engineering time costs money, > after all. =A0So you may want to at least price out your fiber optics > solution. > > --www.wescottdesign.comYup, optics, that would be my last plan
Reply by ●November 8, 20112011-11-08
On Tue, 08 Nov 2011 10:08:48 -0700, Jim Thompson wrote:> On Tue, 08 Nov 2011 10:18:14 -0600, Tim Wescott <tim@seemywebsite.com> > wrote: > >>On Tue, 08 Nov 2011 06:41:54 -0800, halong wrote: >> >>> Hi all, >>> >>> I have a 200 MHz clock signal to send across the barrier of 5 KV I'm >>> thinking of some RF transformer - perhaps "air core" ... but can't >>> find any good candidate >> >>Have you tried widening your search to just specify a 200MHz signal >>frequency and galvanic isolation? I think the 200MHz part isn't a big >>deal, but the galvanic isolation may be. >> >>If EMI is a concern then an air core transformer may not be a good >>choice: it's going to leak RF like a sieve, and the spacing you'll need >>for 5k isolation won't help. >> >>If your production volumes are low, anything that works right off the >>bat is way less expensive than you think -- engineering time costs >>money, after all. So you may want to at least price out your fiber >>optics solution. > > Fiber optics? Definitely best for a clock!I hadn't mentioned anything, but presumably he wants to get data back from wherever his clock is going -- fiber would be good for that, too. -- www.wescottdesign.com
