Finally zeroing in on modeling the 74HC4046 after finding a unpublished AppNote that gave more details on the innards. This is what a fixed frequency looks like, simulation-wise... http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf Comments? Scalings? (This is based on AppNote and Datasheets claiming trip at VDD/2). First release will be VCO only and will be in LTspice format. Once you approve that, the PFD is virtually all logic. ...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.
Pinging 74HC4046 Users
Started by ●October 15, 2012
Reply by ●October 15, 20122012-10-15
Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>Finally zeroing in on modeling the 74HC4046 after finding a >unpublished AppNote that gave more details on the innards. This is >what a fixed frequency looks like, simulation-wise... > >http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf > >Comments? Scalings? (This is based on AppNote and Datasheets >claiming trip at VDD/2). > >First release will be VCO only and will be in LTspice format. Once >you approve that, the PFD is virtually all logic.Funny. I put a HC7046 into a design recently. Unfortunately there are no design tools for calculating the loop filter components. So how about modeling the HC7046? It is much more interesting because of the lock detect output which can be used as a reset. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
Reply by ●October 15, 20122012-10-15
On 10/15/2012 9:16 PM, Nico Coesel wrote:> Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> > wrote: > >> Finally zeroing in on modeling the 74HC4046 after finding a >> unpublished AppNote that gave more details on the innards. This is >> what a fixed frequency looks like, simulation-wise... >> >> http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf >> >> Comments? Scalings? (This is based on AppNote and Datasheets >> claiming trip at VDD/2). >> >> First release will be VCO only and will be in LTspice format. Once >> you approve that, the PFD is virtually all logic. > > Funny. I put a HC7046 into a design recently. Unfortunately there are > no design tools for calculating the loop filter components. So how > about modeling the HC7046? It is much more interesting because of the > lock detect output which can be used as a reset. >I investigated all the HC versions (HC4046 from several vendors, HC7046, HC9046) about a year back, iirc, and their oscillators are all junk compared with the ancient metal-gate 4046. They're horribly nonlinear, all in different ways, which makes it really hard to build a good PLL. What's worse, their oscillators quit when their control voltages are within a volt or so of ground (the actual threshold for misbehaviour varies from device to device). The 7046 is enough more expensive that I'd be much happier spending the dough on a better oscillator, and using the back end of a normal HC4046 from a good vendor. Cheers Phil Hobs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
Reply by ●October 15, 20122012-10-15
On Tue, 16 Oct 2012 01:16:34 GMT, nico@puntnl.niks (Nico Coesel) wrote:>Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> >wrote: > >>Finally zeroing in on modeling the 74HC4046 after finding a >>unpublished AppNote that gave more details on the innards. This is >>what a fixed frequency looks like, simulation-wise... >> >>http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf >> >>Comments? Scalings? (This is based on AppNote and Datasheets >>claiming trip at VDD/2). >> >>First release will be VCO only and will be in LTspice format. Once >>you approve that, the PFD is virtually all logic. > >Funny. I put a HC7046 into a design recently. Unfortunately there are >no design tools for calculating the loop filter components. So how >about modeling the HC7046? It is much more interesting because of the >lock detect output which can be used as a reset.Funny. I have a HC7046 schematic right here in front of me. Personally I think lock detectors are a farce. But I can certainly add it in. As for "design tools for calculating the loop filter components", come on Nico, that's math, you don't need a "tool" :-) See... http://www.analog-innovations.com/SED/PhaseLockedLoopAnalysis.pdf for a primer. Adjust analysis for edge-detecting PFD "gain". ...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 ●October 15, 20122012-10-15
On Mon, 15 Oct 2012 21:22:04 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>On 10/15/2012 9:16 PM, Nico Coesel wrote: >> Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> >> wrote: >> >>> Finally zeroing in on modeling the 74HC4046 after finding a >>> unpublished AppNote that gave more details on the innards. This is >>> what a fixed frequency looks like, simulation-wise... >>> >>> http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf >>> >>> Comments? Scalings? (This is based on AppNote and Datasheets >>> claiming trip at VDD/2). >>> >>> First release will be VCO only and will be in LTspice format. Once >>> you approve that, the PFD is virtually all logic. >> >> Funny. I put a HC7046 into a design recently. Unfortunately there are >> no design tools for calculating the loop filter components. So how >> about modeling the HC7046? It is much more interesting because of the >> lock detect output which can be used as a reset. >> >I investigated all the HC versions (HC4046 from several vendors, HC7046, >HC9046) about a year back, iirc, and their oscillators are all junk >compared with the ancient metal-gate 4046. They're horribly nonlinear, >all in different ways, which makes it really hard to build a good PLL. >What's worse, their oscillators quit when their control voltages are >within a volt or so of ground (the actual threshold for misbehaviour >varies from device to device). > >The 7046 is enough more expensive that I'd be much happier spending the >dough on a better oscillator, and using the back end of a normal HC4046 >from a good vendor. > > >Cheers > >Phil HobsPhil, What sort of non-linearity are you seeing? All I can think of is perhaps using non-cascoded current mirrors, or just using a gross un-boosted follower. Is it just a bow in the control curve, or are you seeing bow in the capacitor charging voltage? ...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 ●October 15, 20122012-10-15
On Mon, 15 Oct 2012 21:22:04 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>On 10/15/2012 9:16 PM, Nico Coesel wrote: >> Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> >> wrote: >> >>> Finally zeroing in on modeling the 74HC4046 after finding a >>> unpublished AppNote that gave more details on the innards. This is >>> what a fixed frequency looks like, simulation-wise... >>> >>> http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf >>> >>> Comments? Scalings? (This is based on AppNote and Datasheets >>> claiming trip at VDD/2). >>> >>> First release will be VCO only and will be in LTspice format. Once >>> you approve that, the PFD is virtually all logic. >> >> Funny. I put a HC7046 into a design recently. Unfortunately there are >> no design tools for calculating the loop filter components. So how >> about modeling the HC7046? It is much more interesting because of the >> lock detect output which can be used as a reset. >> >I investigated all the HC versions (HC4046 from several vendors, HC7046, >HC9046) about a year back, iirc, and their oscillators are all junk >compared with the ancient metal-gate 4046. They're horribly nonlinear, >all in different ways, which makes it really hard to build a good PLL. >What's worse, their oscillators quit when their control voltages are >within a volt or so of ground (the actual threshold for misbehaviour >varies from device to device). > >The 7046 is enough more expensive that I'd be much happier spending the >dough on a better oscillator, and using the back end of a normal HC4046 >from a good vendor. > > >Cheers > >Phil HobsIt occurs to me that the variable current input quits at about 1*VTH. So you were trying to get to zero frequency ?:-) Add some offset current and it won't quit oscillating. ...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 ●October 15, 20122012-10-15
On Mon, 15 Oct 2012 18:40:41 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Mon, 15 Oct 2012 21:22:04 -0400, Phil Hobbs ><pcdhSpamMeSenseless@electrooptical.net> wrote: > >>On 10/15/2012 9:16 PM, Nico Coesel wrote: >>> Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> >>> wrote: >>> >>>> Finally zeroing in on modeling the 74HC4046 after finding a >>>> unpublished AppNote that gave more details on the innards. This is >>>> what a fixed frequency looks like, simulation-wise... >>>> >>>> http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf >>>> >>>> Comments? Scalings? (This is based on AppNote and Datasheets >>>> claiming trip at VDD/2). >>>> >>>> First release will be VCO only and will be in LTspice format. Once >>>> you approve that, the PFD is virtually all logic. >>> >>> Funny. I put a HC7046 into a design recently. Unfortunately there are >>> no design tools for calculating the loop filter components. So how >>> about modeling the HC7046? It is much more interesting because of the >>> lock detect output which can be used as a reset. >>> >>I investigated all the HC versions (HC4046 from several vendors, HC7046, >>HC9046) about a year back, iirc, and their oscillators are all junk >>compared with the ancient metal-gate 4046. They're horribly nonlinear, >>all in different ways, which makes it really hard to build a good PLL. >>What's worse, their oscillators quit when their control voltages are >>within a volt or so of ground (the actual threshold for misbehaviour >>varies from device to device). >> >>The 7046 is enough more expensive that I'd be much happier spending the >>dough on a better oscillator, and using the back end of a normal HC4046 >>from a good vendor. >> >> >>Cheers >> >>Phil Hobs > >It occurs to me that the variable current input quits at about 1*VTH. >So you were trying to get to zero frequency ?:-) > >Add some offset current and it won't quit oscillating. > > ...Jim ThompsonFurther recollections... I've used OpAmps to force the control linearity. Been a long time, maybe 30 years since I had a VCM need. You could, of course, resurrect one of my MC4024's from the mid '60's :-) ...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 ●October 16, 20122012-10-16
On Oct 15, 7:59=A0pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My- Web-Site.com> wrote:> Finally zeroing in on modeling the 74HC4046 after finding a > unpublished AppNote that gave more details on the innards. =A0This is > what a fixed frequency looks like, simulation-wise... > > http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf > > Comments? =A0Scalings? =A0(This is based on AppNote and Datasheets > claiming trip at VDD/2). > > First release will be VCO only and will be in LTspice format. =A0Once > you approve that, the PFD is virtually all logic. > > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 ...Jim Thompson> -- > | James E.Thompson, CTO =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0| =A0 =A0mens =A0 =A0 |> | Analog Innovations, Inc. =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 | =A0 =A0 et =A0 =A0 =A0|> | Analog/Mixed-Signal ASIC's and Discrete Systems =A0| =A0 =A0manus =A0 ==A0|> | Phoenix, Arizona =A085048 =A0 =A0Skype: Contacts Only =A0| =A0 =A0 =A0 ==A0 =A0 =A0 |> | Voice:(480)460-2350 =A0Fax: Available upon request | =A0Brass Rat =A0| > | E-mail Icon athttp://www.analog-innovations.com| =A0 =A01962 =A0 =A0 | > > I love to cook with wine. =A0 =A0 Sometimes I even put it in the food.Hi Jim, Phil. Here=92s a plot for a 74HC4046 http://bayimg.com/kAEhEaAec And for different =91charging=92 resistors. http://bayimg.com/kAehmaaEC The lines were just drawn by eye. As Phil says the oscillations stop if the control voltage falls below ~1Volt. (I never used the metal can version so don=92t know what I=92m missing.) George H. (trying onece more then)
Reply by ●October 16, 20122012-10-16
On Oct 15, 7:59=A0pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My- Web-Site.com> wrote:> Finally zeroing in on modeling the 74HC4046 after finding a > unpublished AppNote that gave more details on the innards. =A0This is > what a fixed frequency looks like, simulation-wise... > > http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf > > Comments? =A0Scalings? =A0(This is based on AppNote and Datasheets > claiming trip at VDD/2). > > First release will be VCO only and will be in LTspice format. =A0Once > you approve that, the PFD is virtually all logic. > > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0 ...Jim Thompson> -- > | James E.Thompson, CTO =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 =A0| =A0 =A0mens =A0 =A0 |> | Analog Innovations, Inc. =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 ==A0 | =A0 =A0 et =A0 =A0 =A0|> | Analog/Mixed-Signal ASIC's and Discrete Systems =A0| =A0 =A0manus =A0 ==A0|> | Phoenix, Arizona =A085048 =A0 =A0Skype: Contacts Only =A0| =A0 =A0 =A0 ==A0 =A0 =A0 |> | Voice:(480)460-2350 =A0Fax: Available upon request | =A0Brass Rat =A0| > | E-mail Icon athttp://www.analog-innovations.com| =A0 =A01962 =A0 =A0 | > > I love to cook with wine. =A0 =A0 Sometimes I even put it in the food.test reply, (Google won't let me post??) George
Reply by ●October 16, 20122012-10-16
On Tue, 16 Oct 2012 06:11:46 -0700 (PDT), George Herold <gherold@teachspin.com> wrote:>On Oct 15, 7:59�pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My- >Web-Site.com> wrote: >> Finally zeroing in on modeling the 74HC4046 after finding a >> unpublished AppNote that gave more details on the innards. �This is >> what a fixed frequency looks like, simulation-wise... >> >> http://www.analog-innovations.com/SED/HC4046_VCO_2_SIM.pdf >> >> Comments? �Scalings? �(This is based on AppNote and Datasheets >> claiming trip at VDD/2). >> >> First release will be VCO only and will be in LTspice format. �Once >> you approve that, the PFD is virtually all logic. >> >> � � � � � � � � � � � � � � � � � � � � ...Jim Thompson[snip]> >Hi Jim, Phil. Here�s a plot for a 74HC4046 > >http://bayimg.com/kAEhEaAec > >And for different �charging� resistors. > >http://bayimg.com/kAehmaaEC > >The lines were just drawn by eye.Thanks for the plots. Quite puzzling, I'd expect drooping at the high end of the F vs V plot due to gate delays.> >As Phil says the oscillations stop if the control voltage falls below >~1Volt.I think Phil didn't use an "offset" resistor>(I never used the metal can version so don�t know what I�m missing.) > >George H. > >(trying onece more then)Both attempts posted :-) ...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.
