Antilog

KRAL wrote Regarding compression-decompression: In this context, we're referring to a situation in which we are processing an input signal that has a large dynamic range, and a large Signal/Noise ratio is desired for low level inputs. You can not simply amplify the input, because the output would saturate in the p

Hi all, I have some questions related to log and antiloge amplifiers. 1- how does the log and antilog amplifier circuits look like? 2- what does the two circuits do? 3- how does the circuits work? 4- the applications of both log and antilog amplifiers? 5- examples of where we can find these circuits? I hope to hear from you soon

can anyone say me how to realize log and antilog in same fpga hardware using lookup table(LUT),interpolation steps.please send me the codes and other detail to execute my final yr project.

hi, how abt taking a log of the number and then its antilog? i have studied the implementation (not board level) of thse circuits using Opamp in my course.. any badsic book has them too... hope this helps.. incase u are interested i ll try to get those materials posted here.. good luck.. :) /Am

Hi I'm trying to implement a power function,x to the power of y , in hardware. y is a real number, not an integer. Both x and y are variables i thought of implementing x power y using log function ie y log(x), but it requires LUT's to store the log and antilog info. CORDIC algorithms can also be used, but i'm interested in imple

hai .... i have some problem .... hope u guys can help ... if i have a set of numbers ... (10002,10568,14587, .....) is it posibble to scale the numbers into specific range ... i need to scale the number into (0 to 255). i only know how to scale the number into (0 to 1) thanx Take logarithm, process the data, a

Yes,it might be better if you use transistors. Secondly the o/p of both loggers must be connected to negative terminal of summer. Thirdly,you need antilog, this can be accomplished by using another op-amp which has diode or preferably transistor connected to negative terminal and resistance in feedback You can also eliminate the summing amplif

Hi Abo_Ayat, I assume you need "true" multiplication, i.e., not for modulation/demodulation or similar applications. One method is using logarithmic amplifiers for both signals, then summing and finally an antilog amplifier. This method uses Op Amps and external transistors. Regards Z

hi! i know of no paper but op amps with diodes produce nonlinear outputs. try searching for log and antilog amps in google. Ü - al

You must be referring to the standard normal (gaussian) distributions' tail probability (Q function) table. Log normal is a distrbution where, if you consider the logarithm of the random variable, it is gausian distrbuted. Shadowing (slow fading) in wireless channel is taken as lognormal. So you could look up tail proability using thg the s

Whats the difference between slopes VS curves? example: zero to +10 volts range If i say the slope rises from zero to +10 volts it looks like a rise time But i say the curve rises from zero to +10 volts it looks like what? Where can i find different terms or names for curves please? Some curves build or rise differential and other

Reviewing this classical document, I was aware that Vahab actually didnt't mention if the application is kHz or MHz domain. For low frequency (e. g. audio) range, a log/antilog circuit, either as an IC or built from individual parts, is offering superior dynamic, for high frequency, only gilbert-cell multiplier circuits or thermal detectors are usa

you have to build log and anti log amplifier. It so difficult. log-antilog analog mutipliers are of no use in frequency mixing. Balanced mixers (diode quartetts or analog 4-quadrant multipliers) give the best performance and a considerable suppression of input signals, which is an important advantage, if the output frequency is n

an arithmetic divider that operates ideally at any frequency Keep on dreaming. From the existing analog multiplier/divider variants, only "gilbert cell" (gm multiplier) is wideband. Log/antilog offers higher dynamic range but is restricted to MHz bandwidth at best, hall sensor multipliers (rather unusual) possibly achieve a sim

In logarithmic or antilogarithmic Amplifier using OPAMP (IC 741) sometimes we use a diode and sometimes we use a transistor.. Which one is mostly used?? Please explain..

A multiplier is basically a nonlinear circuit, needing non-linear elements other than OPs. Depending on the intended operation (1/2/4-quadrant), dynamic and frequency range, different multiplier circuits or ICs are available. Some of them are log/antilog mutiplier (1-Q, high dynamic, limited bandwidth) basic gm-multiplier, also OTA-IC (2-Q, fa

Hai all, I am looking for Quad matched pair transistor for analog divition. Need minimum 3 matched pair, two for log and one for antilog. I found MAT14, Do you have any other part, Thanks Grittin

I'm trying to set up a Linear to Exponential/antilog current source to drive a transistor differential amp (that has a linear response). Using a Linear current mirror with an input voltage of 0 to 2.5V, converted to approx. 0 to

The log/antilog circuit doesn't work as shown and the transfer characteristic isn't calculated correctly. It would work for sqrt(x*y). But to calculate x*y, the adder must have a gain factor of 1 for both inputs. So the output has an unwanted offset of 1*Vbe. For a temperature indepent log/antilog multiplier, you need a third log stage with a const

You need to reconstruct a bipolar signal to get correct fundamental frequency display. The non-linear waveform distortion vy log operation creates harmonics that aren't in the original signal. antilog transformation (if possible according to the magnitude resolution) could improve the spectral display.

There are basically two types of analog dividers: - based on four quadrant multipliers (e.g. AD734) - based on log/antilog circuits The log/antilog designs are slower and restricted to single quadrant operation but offer a higher dynamic range. AD538 is an example of an integrated version, but this circuits can be also build from OPs and trans

The fast way is to... take the logarithm of your number. (Any base) Subtract from zero (the log of 1). Or change the sign. Take the antilog. This gives you the reciprocal of your original number. It's easier if your pic has a logarithm table.

In Pspice, a square root circuit can be easily "designed" by using ABM (analog behaviour modelling). For a real hardware circuit, you can refer to analog multipliers, see an example in the AD633 datasheet Or use a suitable combination of log/antilog circuits. The basic conce

geneiusxie, A/B = antilog (logA -logB), A^B = anti log (B * log A). I think you should brush up on your maths. jeffrey samuel, sorry, I last worked on analogue computers in 1969 and I can't remember much at all other then the fantastic multi turn pots they used (50mm in diameter!). Frank

Hi! I have to design a circuit whose output should be the product of the two input voltages. The voltages can vary from -3 to +3 V and max. frequency is 10kHz. I am not supposed to use any analog multiplier IC. I thought of the log-antilog technique but it won't work as I have negative inputs. There was a circuit using MOSFETs in wikibooks but that

they simply represents reflection back... e.g. if S11=-10db or 10Log(a/b)=-10db (where a is port 1 and b is port 2 of any circuit..( Twoport network) ) log(a/b)=-1 taking antilog.... a/b=0.1 or a=b/10 means if you insert a signal in port a.... 1/10th part will refelect back andremaing 9/10 part will be transferred forw

Hi all, is there any way we can work the 555 VCO such that its frequency increases when input voltage decreases ? Didn't you have a similar start a new thread when that thread is only 15 days old ????