CMOS Op Amp - simplified models

 arctan()/(π/2) versus tanh() ::

PS! :: this model was created for the fast retrieving of the effect and the response of the particular P-MOS input stage ... the output starts behaving weird near the rails !!!

which means the model cannot be used for conventional simulation purposes !!!

---

! Update ::

---

 the (simplified-inexact MCP601) model for conventional use (compared against the Ti-s LMV831) ::

? interestingly the Ti's model has a suspicious behaviour on the input exceeding the supply rails ???

? the P-Spice model of the LMV831 accounts the common mode range ending some 1V below the upper rail so it likely suits better the simulation that needs to take into account that limitation . . . my simplified MCP601 model is brought below ::

Listing of the : MCP601SM.cir ::

* Universal Op Amp * IN NI OUT Vss Vdd .SUBCKT MCP601SM 1 2 3 4 5 PARAMS: Rt=18 gms=1 nms=1 pms=.5 * USE C=30 PF IN MAIN CIRCUIT (CA TO CB). * INPUT R1 5 51 R=Rd R2 5 52 R=Rd M1 55 55 51 51 PcMfT m=pm M2 50 55 52 52 PcMfT m=pm C1 50 55 .2p M3 43 1 50 50 PcMfT m=pm M4 44 2 50 50 PcMfT m=pm M5 43 44 41 41 NcMfT m=nm M6 44 44 42 42 NcMfT m=nm R3 41 4 R=Rs R4 42 4 R=Rs I1 55 4 35u load * DIFFERENTIAL R6 8 17 100k B1 7 17 V=V(43,44) R7 7 17 10k C2 7 17 {srf} * MEDIAN / CLIPPER / Vcp B5 10 0 V=V(5,4)/2-vfz R5 10 0 10k * CP B3 8 0 V=(V(4)+V(5))/2 R8 8 0 10k * MED B11 8 13 V=V(10) B12 12 8 V=V(10) D1 6 12 SjD D2 13 6 SjD R11 11 6 1 * GAIN / SLEW L1 10 8 300n * V.med modified ! B4 10 11 I=(V(5,4)/2+vfz)*tanh(2**bm*V(7,17))/10k R10 11 8 10k C3 11 8 {srf} * OUTP B2 9 8 V=V(11,8) R9 9 8 R=10k C4 9 8 {srf} R12 9 3 R=30 .param gm={gms} .param nm={nms*gm} .param pm={pms*gm} .param Rd={Rt*2/6} .param Rs={Rt-Rd} * .param bm=13.25 .param bm=6.223 .param vfz=0.45 .param srf={0.23n/2} .MODEL NcMfT NMOS(L=2u W=42u KP=35u LEVEL=1) .MODEL PcMfT PMOS(L=2u W=84u KP=7u LEVEL=1) .MODEL SjD D(Is=2.52n Rs=.568 N=1.752 Cjo=4p M=.4 tt=20n Iave=200m Vpk=75 mfg=OnSemi type=silicon) .ENDS

---

[EoP]

DC-DC LED-s Spice Experiment

No over-voltage protection ... no under-voltage lock-down ... no reverse polarity protection ... not built/tested in real life ... ::

555´s alternate ...

---

[Eop]

Wide frequency range - narrow bandwidth LM324 oscillator

Reviewed an old concept - came out wit a new one . . .

in the follofing the timescale shows the actual time . . .

---

[Eop]

Comparing TTL JK Triggers' Logic Designs

There was recently needed a realistic JK Simulation for which i had to set up one coz the Spice has no built in version . . . so i compared the equivalent circuits at d/s-s and made few additional 1-s.

It turned out that at high speed some perform more accurate than the others

From d/s - the only good one was 74LS73 , from custom 1-s - 2 became out credible : a mod of '7474 into JK --and-- a "self-confirming" JK -- that was made to have a least error JK to compare others against . . .


In the moderate/high speeds all perform correct

The variations occur near the speed limit

+ The last two compared ...

---

[Eop]

High Immunity Logic - web circuit mod.

src. ::

Simulated with the zener  and it's substiute

The substitute

Update for wider supply range -- with "doable" alternate for the questionable (6.2V) zener -- questionable as ? does it actually behave as it simulates . . .

---

[Eop]

Progressive current limiting

Figures ::

Legend :: opamp.Q1 mirrors the current at R5 , opamp.Q2 limits the current progressively ... and incase of the SC it cuts the output the more off the lower is the output voltage -- so there's double level progressive limiting (the fig.2 shows the 1-st and the fig.-s 3 to 5 show the 2-nd - a short circuit - limiting levels) . . . the resistor values for R24 to R26 and R21 , R22 , also for the R14 may need to be adjusted to get the real build of the circuit stable (maybe it takes more adjustments -- but these are known to be more likely critical at this stage of dev.)

---

[Eop]

LM710 from d/s

the previous attempt to make it work (just by principal schematic) failed ... from d/s the magical h_FE seems to be 11 . . . ??? (as it's the same timer as 54x00 74x00 series -- the gained information may be practical in getting these models to work with the d/s specified resistances . . .)

my input sensitivity is a bit poorer than the К554СА2 documentation specifies , but basically it will do

---

note :: even if it takes dual supply and more power than new comparators - then it usually is up to 10 times cheaper for experimental circuits - and someone still may have a storefull of them . . .

---

the h_FE is not matching the 74x00 series

the pages 7,8 have a scope diagram for comparator compared to TTL inverter ::
https://www.analog.com/media/en/technical-documentation/data-sheets/lt1016.pdf

Reproduced experiment ??? ::

---

[Eop]

SMPS -- (bad) design attempts

1. -- Testing out a random circuit from www

2. -- Testing loosely pre-calculated design (not fully conceptually correct)

---

[Eop]

Comparing Different 6LF22 to +5V supplies

Circuits ::

---

Cross Ref. ::

Param.	100	110	120	122	124	128
Description	Pos. collector-load linear-reg.	Pos. collector-load linear-reg. with fold-back	Pos. experimental Op-Amp regulated collector-load linear-reg.	Neg. j-Fet - emitter-load linear-reg. with fold-back	Pos. emitter-load linear-reg. with current lim.	Pos. VF-PWM buck conv.
Average Efficiency	51%	53%	57%	38%	28%	83%
Short-Circuit Current	120 mA	1.7 mA	NOT Ltd.	2.6 mA	* 57 mA	NOT Ltd.
Voltage Regulation	± 600 µV	± 250 µV	± 300 µV	± 15 µV	(± 550µV)	± 54 mV
Output Current : Nominal (Max.)	80 (85) mA	80 (145) mA	80 (150) mA	50 (105) mA	* 50 (54) mA	200 (>400) mA

---

Source Circuits ::

↑↑ src :: ISBN 5-440-00345-2

↑↑ src :: GE Transistor Manual 1964 ↑↑

↑↑ found from :: LED Torch Circuits ↑↑

---

[Eop]

9V-to-5V Step-down concep design

the thing

switching wave-forms at max.-min. load

---

[Eop]

revised the yy78Lxx 5V variants

tests so far ::
PS! -- although the following setups perform well the real tings may not coz the Spice models use highly accurate fixed current sources - - - while there's no indication the real 78Lxx-s had any implemented //// the last time i tested my real 78Lxx-s showed an ulta poor performance where the voltage started to drop already at !!!above 30-/40 mA drain and significantly differed from the nominal at 50mA (while i didn't notice them getting hot -- so that a possible thermal prot. feature could have had engaged ???)

partial apx. match to d/s ::

---

[Eop]

Improving LM339 + "tunable" osc variant

► the tunable osc. as by selecting the RC net-wk

► the tests that lead to (as by what i've tested so far) "improved" v. of LMx93

► 2MHz - TEST (driven from realistic src. 74HC04 -- 1 gate has just about the power required!?)

---

[Eop]