ADC test

incomplete Σ Δ ADC -- since i don't quite grasp it's operation yet -- just to see where it goes . . .

the CLK not verified as opt. for this v. but for it's predecessor that was tracking the analog input with the analog summer - the D-Flop output was basically the same only it was without the U/D counter ...

the following shows the effect of resetting the U/D count to 0 after specific time interval (number of clocks)
--  the effect with pure*sine wave here is the "reset" (actually a periodic substraction of some constant) integrates the derivative of it* back to it* -- it's a lot of tedious testing to determine what to actually implement in circuit . . . but the following is showing the prev. test being on the right track

what is surprising here is that the lesser number of clocks gives better results ???

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DAC test

CD4069 outputs are referenced to supply median

checking if such produces a linear ramp . . .
all fun of resolving a simple 3 - supply voltage divider (finding the formula for U_X)

. . . checking if such produces a linear ramp in excel . . .
-- the value 1/2 used in LT Spice seems to be incorrect . . .

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Absolute Voltage 2

the followup of the prev. post -- tested the experimental reference + came up with a new 1

the near zero error gives us the "absolute" voltage ref. -- tough -- there's no information about it's response to varying temperature !!!

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some experimental 1.2V supply designs + rnd. osc. variant

Originally designed for 3-5V operation , also studied for 1.2V
as with the 555 --  the basic operating mode's to generate low duty pulses -- economizing the battery

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 Hi precision supply -- preserving near ® precision and with added current limit

Simple not limited 1.2V linear voltage regulator

the Op Amp variant of the above " Hi precision supply" without current limiting
-- the design has a "new" type of adjustable voltage reference that has not especially been optimized nor tested for varying operating conditions !!! (i just needed one and simple here !fast (as in common))

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+ some more : update 2017-02-13 (1-st time to break the ±1µV error !?)

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Op Amp "Internal ground"

the experiment

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LM308 macro model substitute

my component level models perform basically the same while .cir model doesnot quite get "there" (what's expected)

googling for substitutes didn't revealed any credible results so - going to error~trial ...

the following figure sows a TOP - dn list of most possible substitutes for the LM308

although the LTC1047 looks a better match by gain curve - then after reading the datasheets of the bad boy (LM308) itself and it's other 3 top substitute candidates the LT1366 seems to be preferred coz LTC1047 needs extra feedback capacitors and LT1880 is referred to as super ß Op Amp (the input sensitivity of such may be a likely source to some instability . . . maybe . . . . . . . . . the LM308 is supposedly not so calm as it's macro-model lets it show ???) - so the LM1366 may be too calm coz it's internal capacitors maybe not - anyway it performs near excellent at the following quick check !

semi theoretical - mathematical application test ...
-- just a quick pileup from scratch -- to get some idea of it's behavior / performance (if it's a right chip for the task and/or substituting . . .)

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