MC34063 with small inductors
in [Design]
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From: Winfield Hill on 7 Apr 2010 20:44 Joerg wrote... > >Winfield Hill wrote: >> Jim Thompson wrote... >>> Is the model in text format or is it encrypted? >> >> The Intusoft version is in plain text. I think this >> is it, along with an X1 call. It's not exactly what >> I expected to see. E.g., who's Kehinde Omolayo? Hmm, >> Magnetico, Inc. Hmm, 2003, "Standex International Corp. >> has purchased substantially all of the assets..."; the >> trail grows cold. >> >> X1 7 4 5 0 8 6 7 7 MC34063AX2 { } >> .SUBCKT MC34063AX2 1 2 3 4 5 6 7 8 [ snip ] > There's actually three more models around but they essentially > behave similar. Thing is, the chip is not supposed to turn off > the switch during the positive ramp because the comparator does > not tie into the reset input of the register, only the set input. > > <scratching_ head> What, you analyzed it in two minutes? I have to make a schematic drawing from the spice net list, and analyze that. <scratching_ head> -- Thanks, - Win
From: dagmargoodboat on 7 Apr 2010 21:38 On Apr 7, 7:06 pm, Joerg <inva...(a)invalid.invalid> wrote: > Winfield Hill wrote: > > Jim Thompson wrote... > >> Is the model in text format or is it encrypted? > > > The Intusoft version is in plain text. I think this > > is it, along with an X1 call. It's not exactly what > > I expected to see. E.g., who's Kehinde Omolayo? Hmm, > > Magnetico, Inc. Hmm, 2003, "Standex International Corp. > > has purchased substantially all of the assets..."; the > > trail grows cold. > > > X1 7 4 5 0 8 6 7 7 MC34063AX2 { } > > .SUBCKT MC34063AX2 1 2 3 4 5 6 7 8 > > *exempt 20030227 20395 -30736294 > > *BY KEHINDE OMOLAYO 2-20-03 > > *TERMINAL ID > > *SWITCH COLLECTOR=1 SWITCH EMITTER=2 TIMING CAPACITOR=3 GND=4 > > *COMPARATOR INVERTING INPUT=5 VCC=6 IPK SENSE=7 DRIVER COLLECTOR=8 > > .MODEL DMC34063 D (CJO=2P N=0.05) > > .MODEL QSWITCH NPN BF=75 CJC=2P IS=3E-9 RB=1 RC=0.45 RE=0 > > + VJC=.75 VJE=.75 VJS=.75 > > E1 10 0 5 4 1 > > R1 4 5 10MEG > > V1 20 0 PULSE 0 2 > > E2 11 0 3 4 1 > > B1 13 0 V=1M/(ABS((27.475-195M*V(12))+(36.002+244M*V(12))*V(9)- > > +(302.302+651M*V(12))*V(9)^2)+1F) > > E3 12 0 6 4 1 > > E4 9 0 6 7 1 > > R2 6 7 10MEG > > B2 14 0 V=1M*((-10.765-151M*V(12))+(45.344+864M*V(12))*V(9)- > > +(35.99+1.378*V(12))*V(9)^2+(8.341+839M*V(12))*V(9)^3) > > B4 15 0 V=V(9)>0.32 ? V(14) : V(13) > > C1 19 0 10P > > B5 16 0 V= V(20)<1 ? 2 : V(24)>1 ? 2 : V(19)>1 ? 0 : 2 > > R3 16 17 150 > > C2 17 0 10P > > B6 18 0 V=V(20)<1 ? 0 : V(24)>1 ? 0 : V(11)<(1.083-1.239*V(29)) ? 2 : > > + V(17)>1 ? 0 : 2 > > R4 18 19 150 > > D1 4 3 DMC34063 > > D2 3 6 DMC34063 > > C3 11 31 1N > > B7 4 36 I=V(17)>1 ? -(224.4U+2.359U*V(12))*0.77 : V(15)*0.77 > > C5 23 0 10P > > B9 21 0 V= V(20)<1 ? 2 : V(17)>1 ? 2 : V(26)>1 ? 0 : 2 > > R5 27 26 150 > > C6 26 0 10P > > B10 27 0 V=V(20)<1 ? 0 : V(17)>1 ? 0 : V(10)<1.25 ? 2 : V(23)>1 ? 0 : 2 > > R6 21 23 150 > > B12 33 0 V=V(11)>(1.148+184.6M*V(29)) ? 2 : 0 > > R13 33 24 10K > > C8 24 0 10P > > Q1 8 30 25 QSWITCH > > Q2 1 25 2 QSWITCH > > R15 25 2 100 > > D5 2 30 DMC34063 > > G1 2 30 26 23 5M > > R16 2 4 10MEG > > R23 31 28 1M > > V6 28 0 > > V7 36 3 > > B13 29 0 V=I(V6)/(I(V7)+866.8M*I(V6)) > > .ENDS > > There's actually three more models around but they essentially behave > similar. Thing is, the chip is not supposed to turn off the switch > during the positive ramp because the comparator does not tie into the > reset input of the register, only the set input. > > <scratching_ head> Yeah. I read TI's app note. So it can start an ON cycle any time during ramp up, but can't ever stop until ramp-down. Crude. Burp, sputter, and cough, in this application. -- Cheers, James Arthur
From: Joerg on 7 Apr 2010 22:45 Winfield Hill wrote: > Joerg wrote... >> Winfield Hill wrote: >>> Jim Thompson wrote... >>>> Is the model in text format or is it encrypted? >>> The Intusoft version is in plain text. I think this >>> is it, along with an X1 call. It's not exactly what >>> I expected to see. E.g., who's Kehinde Omolayo? Hmm, >>> Magnetico, Inc. Hmm, 2003, "Standex International Corp. >>> has purchased substantially all of the assets..."; the >>> trail grows cold. >>> >>> X1 7 4 5 0 8 6 7 7 MC34063AX2 { } >>> .SUBCKT MC34063AX2 1 2 3 4 5 6 7 8 > > [ snip ] > >> There's actually three more models around but they essentially >> behave similar. Thing is, the chip is not supposed to turn off >> the switch during the positive ramp because the comparator does >> not tie into the reset input of the register, only the set input. >> >> <scratching_ head> > > What, you analyzed it in two minutes? I have to > make a schematic drawing from the spice net list, > and analyze that. <scratching_ head> > No, I am scratching my head about this a bit longer than two minutes, tried various models, etc. :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 7 Apr 2010 22:48 dagmargoodboat(a)yahoo.com wrote: > On Apr 7, 7:06 pm, Joerg <inva...(a)invalid.invalid> wrote: >> Winfield Hill wrote: >>> Jim Thompson wrote... >>>> Is the model in text format or is it encrypted? >>> The Intusoft version is in plain text. I think this >>> is it, along with an X1 call. It's not exactly what >>> I expected to see. E.g., who's Kehinde Omolayo? Hmm, >>> Magnetico, Inc. Hmm, 2003, "Standex International Corp. >>> has purchased substantially all of the assets..."; the >>> trail grows cold. >>> X1 7 4 5 0 8 6 7 7 MC34063AX2 { } >>> .SUBCKT MC34063AX2 1 2 3 4 5 6 7 8 >>> *exempt 20030227 20395 -30736294 >>> *BY KEHINDE OMOLAYO 2-20-03 >>> *TERMINAL ID >>> *SWITCH COLLECTOR=1 SWITCH EMITTER=2 TIMING CAPACITOR=3 GND=4 >>> *COMPARATOR INVERTING INPUT=5 VCC=6 IPK SENSE=7 DRIVER COLLECTOR=8 >>> .MODEL DMC34063 D (CJO=2P N=0.05) >>> .MODEL QSWITCH NPN BF=75 CJC=2P IS=3E-9 RB=1 RC=0.45 RE=0 >>> + VJC=.75 VJE=.75 VJS=.75 >>> E1 10 0 5 4 1 >>> R1 4 5 10MEG >>> V1 20 0 PULSE 0 2 >>> E2 11 0 3 4 1 >>> B1 13 0 V=1M/(ABS((27.475-195M*V(12))+(36.002+244M*V(12))*V(9)- >>> +(302.302+651M*V(12))*V(9)^2)+1F) >>> E3 12 0 6 4 1 >>> E4 9 0 6 7 1 >>> R2 6 7 10MEG >>> B2 14 0 V=1M*((-10.765-151M*V(12))+(45.344+864M*V(12))*V(9)- >>> +(35.99+1.378*V(12))*V(9)^2+(8.341+839M*V(12))*V(9)^3) >>> B4 15 0 V=V(9)>0.32 ? V(14) : V(13) >>> C1 19 0 10P >>> B5 16 0 V= V(20)<1 ? 2 : V(24)>1 ? 2 : V(19)>1 ? 0 : 2 >>> R3 16 17 150 >>> C2 17 0 10P >>> B6 18 0 V=V(20)<1 ? 0 : V(24)>1 ? 0 : V(11)<(1.083-1.239*V(29)) ? 2 : >>> + V(17)>1 ? 0 : 2 >>> R4 18 19 150 >>> D1 4 3 DMC34063 >>> D2 3 6 DMC34063 >>> C3 11 31 1N >>> B7 4 36 I=V(17)>1 ? -(224.4U+2.359U*V(12))*0.77 : V(15)*0.77 >>> C5 23 0 10P >>> B9 21 0 V= V(20)<1 ? 2 : V(17)>1 ? 2 : V(26)>1 ? 0 : 2 >>> R5 27 26 150 >>> C6 26 0 10P >>> B10 27 0 V=V(20)<1 ? 0 : V(17)>1 ? 0 : V(10)<1.25 ? 2 : V(23)>1 ? 0 : 2 >>> R6 21 23 150 >>> B12 33 0 V=V(11)>(1.148+184.6M*V(29)) ? 2 : 0 >>> R13 33 24 10K >>> C8 24 0 10P >>> Q1 8 30 25 QSWITCH >>> Q2 1 25 2 QSWITCH >>> R15 25 2 100 >>> D5 2 30 DMC34063 >>> G1 2 30 26 23 5M >>> R16 2 4 10MEG >>> R23 31 28 1M >>> V6 28 0 >>> V7 36 3 >>> B13 29 0 V=I(V6)/(I(V7)+866.8M*I(V6)) >>> .ENDS >> There's actually three more models around but they essentially behave >> similar. Thing is, the chip is not supposed to turn off the switch >> during the positive ramp because the comparator does not tie into the >> reset input of the register, only the set input. >> >> <scratching_ head> > > Yeah. I read TI's app note. So it can start an ON cycle any time > during ramp up, but can't ever stop until ramp-down. Crude. Burp, > sputter, and cough, in this application. > Well, if it did that I'd be happy. But it does cut during ramp-down and according to the internal wire-up it's not supposed to. Helmut Sennewald, one of the LTSpice gurus, could not reproduce the error I saw. Sent him my file, so we'll see. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: John Larkin on 8 Apr 2010 00:07
On Wed, 07 Apr 2010 09:14:29 -0700, Joerg <invalid(a)invalid.invalid> wrote: >Jim Thompson wrote: >> On Tue, 06 Apr 2010 18:00:41 -0700, Joerg <invalid(a)invalid.invalid> >> wrote: >> >>> Hello Folks, >>> >>> Have to correct a design with a 34063 in there. Buck, VIN 16-30V, VOUT >>> slightly under 12V, 400mA max output. And no, I don't like it much :-) >>> >>> One of the issues is a saturating inductor. Can't change the layout and >>> to be able to cram one in there I probably have to drop down to 47uH, >>> maybe 68uH if lucky. >>> >>> SPICE says it's ok but none of the datasheets or app notes recommends >>> going that low. Any reason why not? >> >> Just stick a CD4060 in there. That oughta fix it ;-) >> > >Hold your coffee, but I did one with a CD40106. Still in mass >production, 15 years and counting. That was probably the lowest cost >switcher I ever did. Pretty darn efficient as well, nothing gets hot. > >Oh, and this was one of the many cases where the client already had a >design but had a Maxim chip in there. Which, predictably, turned into >unobtanium. That called for the big knife. My first switcher was a hysteretic 24 to 5 buck, for a military control system, the engine room controls for the LHA helicopter assault ships. I used an uncompensated uA709 as the comparator, driving a 2N2905 PNP, driving a 2N3055 emitter follower. The 3055 didn't saturate so was pretty fast. I ran it at 22 KHz because I could hear 20K in those days. I used a schottky catch diode, which was pretty radical in those days. A few years later, the Navy ripped the system out and replaced it with pneumatic controls, because they couldn't find people who could maintain it. John |