Showing posts with label LTC1047. Show all posts
Showing posts with label LTC1047. Show all posts

Thursday, November 16, 2017

Testing couple of rectifier circuits from datasheets

The following schematics are from LT1122 and LTC1047 d/s-s
while the first performs more than good -- then on a contrary i had to modify the 2-nd

↓Src::LT1122 datasheet -- not tested at various frequencies nor input amplitudes/wave-forms
 

↓Src::LTC1047 datasheet -- the 10kHz seems to be the limit for the outp integrity here


//// recently i noticed something while using a variant of the ideal diode circuit as shown in the "Low Voltage Op-Amps -- in-simulation TEST" -- so i am about to test through all "Absolute circuits" for their particular peculiarities . . .

↓Src::NE5535 datasheet


↓Src::http://nptel.ac.in/courses/117107094/17


↓Src::https://www.planetanalog.com/author.asp?section_id=3065&doc_id=562650 -- the circuit can do just at about 200kHz !? //// note :: i forgot to change the counter-weight 1N4148-s to 1N34-s below (their effect is not studied here , purpose = pending -- what seems obvious is not always that -- it must be verified whether there should be counter-balance for rectifying diodes or not . . .)


↓Src::https://forum.allaboutcircuits.com/threads/a-full-wave-precision-rectifier-query.9821/ --


↓Src::http://sound.whsites.net/appnotes/an001.htm -- it can go up to the limits defined by the frequency & slew of the Op Amp in use ((!? amazing circuit ?!))


↓Src::http://www.learningelectronics.net/worksheets/opamp8.html --the ® had a "bug" so i made random guesses . . . came out as good as previous ((at least what it seems so far ?)) /// edit : the R9 should be Rcp (although there seems no significant current to/from GND from/to U2.non-inverting_input) /// the input signal amplitude range is ±1.8V @ ±5V supply and ±10V @ ±15V supply -- simplified to a line equation y = ax + b where a = 1.219512195 , b = 2.804878049 , y = VsupTOT/2 , x= abs(±VmaxINP) referenced to the GND ( = Vsup "median" )



updates 'll follow ...



[Eop]

Sunday, February 5, 2017

Thursday, February 2, 2017

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 . . .)



[Eop]