quantizer for LT Spice
in [Design]
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From: John Larkin on 18 Apr 2010 01:10 Here's a quantizer in LT Spice: ftp://jjlarkin.lmi.net/Quantizer.jpg It wasn't hard, but the HELP is really obscure about syntax, and there is no example of a schematic with a b-source that I could find. There is a sample-and-hold schematic symbol, so one can simulate the effects of a clocked ADC or a DAC on a control loop. John Version 4 SHEET 1 880 680 WIRE 48 48 0 48 WIRE 112 48 48 48 WIRE 384 48 320 48 WIRE 432 48 384 48 WIRE 0 96 0 48 WIRE 112 112 112 48 WIRE 320 112 320 48 WIRE 432 128 432 48 WIRE 0 224 0 176 WIRE 112 224 112 192 WIRE 320 240 320 192 WIRE 432 240 432 208 FLAG 0 224 0 FLAG 320 240 0 FLAG 112 224 0 FLAG 432 240 0 FLAG 48 48 X FLAG 384 48 OUT SYMBOL bv 320 96 R0 WINDOW 3 36 198 Left 0 SYMATTR InstName B1 SYMATTR Value V=int(5.1*V(X))*0.2 SYMBOL voltage 0 80 R0 WINDOW 3 16 199 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value SINE(0 1 1k 0 0 0 3) SYMBOL res 96 96 R0 SYMATTR InstName R1 SYMATTR Value 1k SYMBOL res 416 112 R0 SYMATTR InstName R2 SYMATTR Value 1k TEXT 144 40 Left 0 !.tran 0 .005 0 1u
From: Grant on 18 Apr 2010 02:03 On Sat, 17 Apr 2010 22:10:09 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >Here's a quantizer in LT Spice: > >ftp://jjlarkin.lmi.net/Quantizer.jpg > >It wasn't hard, but the HELP is really obscure about syntax, and there >is no example of a schematic with a b-source that I could find. > >There is a sample-and-hold schematic symbol, so one can simulate the >effects of a clocked ADC or a DAC on a control loop. > >John > > > >Version 4 >SHEET 1 880 680 >WIRE 48 48 0 48 >WIRE 112 48 48 48 >WIRE 384 48 320 48 >WIRE 432 48 384 48 >WIRE 0 96 0 48 >WIRE 112 112 112 48 >WIRE 320 112 320 48 >WIRE 432 128 432 48 >WIRE 0 224 0 176 >WIRE 112 224 112 192 >WIRE 320 240 320 192 >WIRE 432 240 432 208 >FLAG 0 224 0 >FLAG 320 240 0 >FLAG 112 224 0 >FLAG 432 240 0 >FLAG 48 48 X >FLAG 384 48 OUT >SYMBOL bv 320 96 R0 >WINDOW 3 36 198 Left 0 >SYMATTR InstName B1 >SYMATTR Value V=int(5.1*V(X))*0.2 >SYMBOL voltage 0 80 R0 >WINDOW 3 16 199 Left 0 >WINDOW 123 0 0 Left 0 >WINDOW 39 0 0 Left 0 >SYMATTR InstName V1 >SYMATTR Value SINE(0 1 1k 0 0 0 3) >SYMBOL res 96 96 R0 >SYMATTR InstName R1 >SYMATTR Value 1k >SYMBOL res 416 112 R0 >SYMATTR InstName R2 >SYMATTR Value 1k >TEXT 144 40 Left 0 !.tran 0 .005 0 1u > > Shouldn't those steps spend equal time inside and outside the sine wave? Grant. -- http://bugs.id.au/
From: Andrew Holme on 18 Apr 2010 05:02 "Grant" <omg(a)grrr.id.au> wrote in message news:q38ls59vs9ja60rp7gmv17hra9u4oluva5(a)4ax.com... > On Sat, 17 Apr 2010 22:10:09 -0700, John Larkin > <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >> >>Here's a quantizer in LT Spice: >> >>ftp://jjlarkin.lmi.net/Quantizer.jpg >> >>It wasn't hard, but the HELP is really obscure about syntax, and there >>is no example of a schematic with a b-source that I could find. >> >>There is a sample-and-hold schematic symbol, so one can simulate the >>effects of a clocked ADC or a DAC on a control loop. >> >>John >> >> >> >>Version 4 >>SHEET 1 880 680 >>WIRE 48 48 0 48 >>WIRE 112 48 48 48 >>WIRE 384 48 320 48 >>WIRE 432 48 384 48 >>WIRE 0 96 0 48 >>WIRE 112 112 112 48 >>WIRE 320 112 320 48 >>WIRE 432 128 432 48 >>WIRE 0 224 0 176 >>WIRE 112 224 112 192 >>WIRE 320 240 320 192 >>WIRE 432 240 432 208 >>FLAG 0 224 0 >>FLAG 320 240 0 >>FLAG 112 224 0 >>FLAG 432 240 0 >>FLAG 48 48 X >>FLAG 384 48 OUT >>SYMBOL bv 320 96 R0 >>WINDOW 3 36 198 Left 0 >>SYMATTR InstName B1 >>SYMATTR Value V=int(5.1*V(X))*0.2 >>SYMBOL voltage 0 80 R0 >>WINDOW 3 16 199 Left 0 >>WINDOW 123 0 0 Left 0 >>WINDOW 39 0 0 Left 0 >>SYMATTR InstName V1 >>SYMATTR Value SINE(0 1 1k 0 0 0 3) >>SYMBOL res 96 96 R0 >>SYMATTR InstName R1 >>SYMATTR Value 1k >>SYMBOL res 416 112 R0 >>SYMATTR InstName R2 >>SYMATTR Value 1k >>TEXT 144 40 Left 0 !.tran 0 .005 0 1u >> >> > Shouldn't those steps spend equal time inside and outside the sine wave? Use round() instead of int(): SYMATTR Value V=round(5*V(X))/5
From: Helmut Sennewald on 18 Apr 2010 06:09 "John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> schrieb im Newsbeitrag news:gg4ls5pv8lc786qhcg1en9ag63cq54huuv(a)4ax.com... > > Here's a quantizer in LT Spice: > > ftp://jjlarkin.lmi.net/Quantizer.jpg > > It wasn't hard, but the HELP is really obscure about syntax, and there > is no example of a schematic with a b-source that I could find. > > There is a sample-and-hold schematic symbol, so one can simulate the > effects of a clocked ADC or a DAC on a control loop. > > John Hello John, Here is an example with the "Sample"-device. Best regards, Helmut Version 4 SHEET 1 920 680 WIRE -112 -16 -160 -16 WIRE 176 0 144 0 WIRE -160 32 -160 -16 WIRE 448 48 352 48 WIRE 592 48 544 48 WIRE 176 64 144 64 WIRE 544 80 544 48 WIRE -160 144 -160 112 WIRE -112 208 -160 208 WIRE 544 208 544 160 WIRE -160 256 -160 208 WIRE -160 368 -160 336 FLAG 544 208 0 FLAG 592 48 sq IOPIN 592 48 Out FLAG -160 144 0 FLAG -112 -16 s0 FLAG 144 0 s0 FLAG -160 368 0 FLAG -112 208 fs FLAG 144 64 fs FLAG 448 48 vs0 SYMBOL bv 544 64 R0 SYMATTR InstName B1 SYMATTR Value V=int(V(vs0)) SYMBOL voltage -160 16 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value SINE(0 7.5 {f0}) SYMBOL SpecialFunctions\\sample 256 32 R0 WINDOW 3 0 0 Invisible 0 SYMATTR InstName A1 SYMATTR Value2 vhigh=1e6 vlow=-1e6 SYMATTR Value vt=0.5 SYMBOL voltage -160 240 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value PULSE(0 1 0 1n 1n 10u {1/fs}) TEXT -176 -160 Left 0 !.tran 0 3m 0 1u TEXT -176 -128 Left 0 !.options plotwinsize=0 TEXT -176 -96 Left 0 !.param f0=1k fs=20k
From: Jim Thompson on 18 Apr 2010 10:33
On Sat, 17 Apr 2010 22:10:09 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >Here's a quantizer in LT Spice: > >ftp://jjlarkin.lmi.net/Quantizer.jpg > >It wasn't hard, but the HELP is really obscure about syntax, and there >is no example of a schematic with a b-source that I could find. > >There is a sample-and-hold schematic symbol, so one can simulate the >effects of a clocked ADC or a DAC on a control loop. > >John > > [snip] Where's the 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 | The only thing bipartisan in this country is hypocrisy |