General Description. The AS and AS are junction isolated ultra well- matched monolithic NPN transistor pairs with an order of magnitude improvement in. LM/LM Supermatch Pair. General Description. The LM and LM are junction isolated ultra well- matched monolithic NPN transistor pairs with an. LM datasheet, LM circuit, LM data sheet: NSC – LM/LM Supermatch Pair,alldatasheet, datasheet, Datasheet search site for Electronic.
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I’m not sure to what extent other parameters would matter, though.
As usual, Maxim parts do not exist. This circuit uses the difference of two transistor currents to generate the log of the input over a pretty wide range. That would more-or-less be an interpolation between 3dB values. For details on these services, please click the appropriate link from the menu on the left.
You can find them datasehet But the plant does not sell them directly. Those “transistors” are identical. There are plenty of arrays of ‘ or ‘ available, but there is no mention of matching in the datasheet. Home Questions Tags Users Unanswered. The well-matched transistor pair Q1a and Q1b are halves of the LM “supermatch” transistor pair. I had this idea for a quick and dirty log amp.
I can use LM array, but the specs are far worse. Chris Johnson 7 The transistors might be on separate dies for all I know. The traditional logarithmic amplifier circuit is described in National Appnote Intersil makes a number of transistor arrays some are certainly single die and well matched. I tried adjusting the Hfe of the transistors and unless it was something like it kept a very clean log output. However, I’m not sure how suitable it is for your application.
How can I cheaply make a logarithm? I just get the default circuit. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site the association bonus does not count.
The chip has almost the same name: It seems that this is not recommended for new designs but the replacement is the MAT TI isn’t making the part at all as far as I can tell. Thank you for your interest in this question.
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Welcome to the ECE Store. The ECE Store provides many services to electrical and computer engineering students in order to create a safe environment in which students have access to the equipment and datasjeet they need. Roman has mentioned that component. What is the new standard log amp circuit?
LM Datasheet, PDF – Alldatasheet
So no cheaper than the LOG How about the LS from Linear Systems? MAT12 is still in production, but octopart.
The specs are identical to the original. If you modulated the reference voltage by 3dB, the output would probably average to about the right value.
Especially in this circuit, which lives and dies by transistor matching, the simulator is going to give a very optimistic performance estimate. I don’t know what the definitive chip is but there are many chips that implement the whole circuit.
So Maxim doesn’t have any either. TI still sells some Burr Brown log amps but they are expensive.