At 2002-12-03 11:29 -0800, Shazze wrote: >any body here know about such integrated circuit in which more then 8 or 16 opamp >exist, like TL084 in which quad opamp present.
Since the opamps are not interconnected there is no need to put a lot of them on a big chip. It's for several reasons much better to put only upto 4 in one package: - production wise: they can make a small chip and use a cheap standard 14 or 16 pin housing - board space wise: three 14 pin chips take about as much space as one (traditionally shaped) 24 pin chip, yet you have 14*3=42 instead of 24 pins of functionality (minus some pins that are needed on each chip like 0V and 5V and perhaps clock and enable inputs. - stock space wise: manufacturers, distributors and users only have to stock one type of chip - design functionality: you waste less unused opamps An eye-opener in this respect can be this example: I once used an 74154 to decode 4 lines to 16, but later someone explained to me that it's much better to use two 74138's. It was for a bus-system for my old TRS-80 home computer and in fact I have never made more than two additional expansion cards so one 74138 with it's 8 outputs would have been more than enough. Of course for hobby projects like this or for prototypes material savings like these are not relevant but for serial and mass production every $0.10 saved has to be multiplied with 1000, 10000, 100000 or more later in the production phase. Greetings, Jaap -- Author: Jaap van Ganswijk INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
