Thursday, December 28, 2017

www voltage multiplier test

src ::
(i donno why they have to post circuits in the web that add up to the climate warming ...)

mod/fix ::
(the circuit'd do better with true complement wave drive -- e.g. -- a RS digital flop driving two powerful buffers -- in our case -- 555-s)


Tuesday, December 26, 2017

the Actual/Built LED verifier

as i was not about to build a PCB for this the sot-jFets were not used . . .

Spice design ::

Real build ::


Friday, December 22, 2017

Comparing Constant Current Circuits (to sort/verify the LED-s with)

▼Fast/Simple/Robust/Trivial Op-Amp + BJT Setup▼
→ apx. 16mA ±30µA(0.2%)
▼Complex/Trivial Op-Amp + BJT Setup▼
 → apx. 18mA ±24µA(0.1%)
▼Simple/Experimental BJT Setup ( !? the Best ?! )▼
→ apx. 18mA ±60nA(0.0003%) 
▼Full/Trivial BJT + N-jFet Setup ( also better than any op-amp variant ??? )▼
→ apx. 18mA ±300nA(0.002%) 
▼Complex/Experimental Op-Amp + MOS-Fet Setup▼
(likely worse than it's BJT alternate -- the 2-nd ↑↑ fig. )
→ apx. 18mA ±120µA(0.7%) 
▼Trying to get it right here▼
-- it seems that the op-amps should be fed from the separate supplies or otherwise the PSRR won't recover the precision reached at reference voltages
→ apx. 18mA ±48µA(0.3%) 

((the work is in progress ...))

If you are stupid then knowing the right Op-Amp-s could save your day
(the node "SE" had the greatest error although the node "a0" has the least ??? -- about LT1012A)
→ apx. 18mA ±10µA(0.06%)

-------- Update 2017.12.24 ::

▼a conditional opposite to "If you are stupid then knowing the right Op-Amp-s could save your day"▼

→ apx. 18mA ±7µA(0.04%)
a "Russian LM308" **
** it's nearest LT's substitute (so far)


Wednesday, December 20, 2017

Saturday, December 16, 2017

Random Op-Amp TEST - 2

Heuristic Test /// note that no matter these results may seem poor , they are poor in conjunction to the (perhaps a poor) test setup and relative to each other - - - i never test poor amplifiers (e.g. something that i know will fail my application) or do not test such without especially denoting it . . . as in fact the TLV314 was the best performer of a previous tests of it's kind (Low-power , Low-Voltage CMOS Op Amps) - - - here we have a high slew rate and/or high slew rate to bandwidth ratio Op Amps tested (where the TLV314 is just for comparison)

Fuzzily about how it works


Monday, December 11, 2017

Random Op-Amp Test

it fails the internal ground test ← which is somewhat expected for the "Smart" OP-Amp

Test #2 , as it turned out with erroneous formula guess
+ i must read the specs again about common . . . differential mode range

(the next "Error" will reject it as not LTSpice compatible . . .)

Test #2 again , this time with correct formula but with a different OpAmp to compare to

Test #3 -- about the biasing specifics

Comparative Test #4

PS! the integrity of this test setup has not yet been fully verified !!!

[in progress]


Saturday, December 9, 2017

500kHz DAC

the 2.5V ref. is provided for possible more exact v. of this -- for example -- forward normalizing the output as Uout=Uin*Vref/(Vsup/2)

Comparative ref. test

Experimental /// Alternative (the best) /// Datasheet (the 2-nd best)

it seems that the inverter/comparator type ADC ↓↓ is the fastest here
now with CMOS-Comparators ((i tiled it up intuitively -- a top-down design -- surprisingly or not it came out the same as at the linked one ↑above↑))

(the chosen resistor values may be not the optimal or not the realistic 1-s)


Monday, December 4, 2017

yet another DAC

it seems the Spice Models do "Count" -- although this may seem a far shot -- then there is actually a real life analogy or at least a strong potential -- that the certain components or a combination of produces far better results than some others !!

perhaps continued ...

optimistic with "continuous"/slow slope signal