phil@calvin.EE.CORNELL.EDU (Phil Erickson) (02/14/89)
I've seen numerous references to the MAX-232 chip for TTL/RS232 conversion;
who makes this IC (i.e. part number so I can find it in a databook) and
what's a reasonable price?
Thanks a bunch,
--------------------------------------------------------------------------
Phil Erickson
Space Plasma Physics Upson Hall Cornell University Ithaca, NY 14850
ARPA: phil@calvin.ee.cornell.eduhenry@utzoo.uucp (Henry Spencer) (02/15/89)
In article <939@calvin.EE.CORNELL.EDU> phil@calvin.EE.CORNELL.EDU (Phil Erickson) writes: >I've seen numerous references to the MAX-232 chip for TTL/RS232 conversion; >who makes this IC (i.e. part number so I can find it in a databook) ... The part number is MAX-232, just like it says. It's made by Maxim; don't expect to find it in databooks from anyone else yet. -- The Earth is our mother; | Henry Spencer at U of Toronto Zoology our nine months are up. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
gil@limbic.UUCP (Gil Kloepfer Jr.) (02/15/89)
In article <939@calvin.EE.CORNELL.EDU> phil@calvin.EE.CORNELL.EDU (Phil Erickson) writes: >I've seen numerous references to the MAX-232 chip for TTL/RS232 conversion; >who makes this IC (i.e. part number so I can find it in a databook) and >what's a reasonable price? >Phil Erickson > Space Plasma Physics Upson Hall Cornell University Ithaca, NY 14850 >ARPA: phil@calvin.ee.cornell.edu I got my MAX232 chip from Jameco Electronics, 1355 Shoreway Rd, Belmont, CA 94002, tel (415) 592-8097. Jameco is an excellent outfit and has been around for a long time, I recommend them highly as a satisfied customer. The chip costs $4.95. Jameco sometimes is a little more expensive than other outfits, but their stock is good and their customer service is outstanding. Jameco will also send you the spec sheet you desire for an extra 50 cents. According to the specs I have, the chip is made by Maxim. It requires two 10uF and two 4.7uF electrolytics to operate. They recommend an extra 10uF electrolytic be used from Vcc to GND as close to the chip as possible to prevent various sundries from making their way up the power supply lines. The chip supports two RS232 transmitters and two receivers. This makes for a nice port which could handle, say, receive/send data, DSR, and RTS. -------- Gil Kloepfer, Jr. U-Net: {decuac,boulder,talcott,sbcs}!icus!limbic!gil ICUS Software Systems Voice: (516) 968-6860 [H] (516) 746-2350 x219 [W] P.O. Box 1 Internet: gil@icus.islp.ny.us Islip Terrace, NY 11752 "Life's a ... well, you know..."
cwiener@crlabs.CRLABS.COM (Chris Wiener) (02/16/89)
In article <1989Feb14.163116.16322@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <939@calvin.EE.CORNELL.EDU> phil@calvin.EE.CORNELL.EDU (Phil Erickson) writes: >>I've seen numerous references to the MAX-232 chip for TTL/RS232 conversion; >>who makes this IC (i.e. part number so I can find it in a databook) ... > >The part number is MAX-232, just like it says. It's made by Maxim; don't >expect to find it in databooks from anyone else yet. WRONGO! Try Intersil ICL-232 or Teledyne Semiconductors TSC232CPE. I was given this info by a MAXIM apps engineer when I inquired about second sources (required for all parts used by my employer). Call up the factories and ask for the data sheet. I can't believe I actually got one on Henry Spencer. Never thought I'd be able to prove him wrong :-) :-) === Christopher Wiener N2CR CR Labs, Cliffside Park, NJ DOMAIN: cwiener@CRLABS.COM UCCP: ..!killer!crlabs!cwiener "Let's not be too tough on our own ignorance. It's the thing that makes America great. If America weren't incomparably ignorant, how could we have tolerated the last eight years?" ---- Frank Zappa, Feb 1, 1989 ----
rodman@mfci.UUCP (Paul Rodman) (02/16/89)
>>I've seen numerous references to the MAX-232 chip for TTL/RS232 conversion; >>who makes this IC (i.e. part number so I can find it in a databook) ... > >The part number is MAX-232, just like it says. It's made by Maxim; don't >expect to find it in databooks from anyone else yet. Dallas semiconductor makes a similar chip that steals power from the rs232 side for itself. The also make a chip that is powered off the +5 volt side that has a charge pump for making the +- volts for rs232 (I think it uses 9 volts). Sorry my catalog is at home so I don't have the numbers... Paul Rodman/ KA1ZA rodman@mfci.uucp
cook@stout.ucar.edu (Forrest Cook) (02/16/89)
In article <464@limbic.UUCP> gil@limbic.UUCP (Gil Kloepfer Jr.) writes: >In article <939@calvin.EE.CORNELL.EDU> phil@calvin.EE.CORNELL.EDU (Phil Erickson) writes: >>I've seen numerous references to the MAX-232 chip for TTL/RS232 conversion; ... >The chip supports two RS232 transmitters and two receivers. This makes >for a nice port which could handle, say, receive/send data, DSR, and RTS. I highly recommend this chip as a cost saver. It eliminates the need for an extra +-10V supply if all you need is RS-232. This may be pushing the specs a bit, but we have used the MAX-232 to provide power to a CMOS analog mux (DG-509) that is used for selecting on of four RS-232 lines. The mux chip does not draw much current and we are only using one of the two transmitter sections from the MAX-232. We have built about 5 of these boxes and they have worked without problems for over a year. ^ Forrest Cook (The preceding comments were my Opinions) ^ /|\ cook@stout.ucar.edu /|\ /|\ {husc6 | rutgers | ames | gatech}!ncar!stout!cook /|\ /|\ {uunet | ucbvax | allegra | cbosgd}!nbires!ncar!stout!cook /|\
markz@ssc.UUCP (Mark Zenier) (02/16/89)
In article <1989Feb14.163116.16322@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > > The part number is MAX-232, just like it says. It's made by Maxim; don't > expect to find it in databooks from anyone else yet. It's in the 1987 GE/intersil book (page 11-36) marked Preliminary. Mark Zenier uunet!nwnexus!pilchuck!ssc!markz markz@ssc.uucp uunet!amc! uw-beaver!tikal!
pekka@mina.liu.se (Pekka Akselin [The Mad Midnight Hacker]) (02/16/89)
In article <1989Feb14.163116.16322@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <939@calvin.EE.CORNELL.EDU> phil@calvin.EE.CORNELL.EDU (Phil Erickson) writes: >>I've seen numerous references to the MAX-232 chip for TTL/RS232 conversion; >>who makes this IC (i.e. part number so I can find it in a databook) ... > ... and Linear Technology ... -- /pekka _______________________________________________________________________________ pak@ida.liu.se [...The Mad Midnight Hacker Strikes Again...] Pekka Akselin, Univ. of Linkoping, Sweden (The Land Of The Midnight Hacker 8-)
dale@ldgo.columbia.edu (dale chayes) (02/17/89)
In article <939@calvin.EE.CORNELL.EDU>, phil@calvin.EE.CORNELL.EDU (Phil Erickson) writes: > .... MAX-232 chip for TTL/RS232 conversion; > who makes this IC..... Its made by: Maxim Integrated Products Inc. 120 San Gabriel Dr. Sunnyvale, CA 94086 (408) 737-7600 They are available from most IC houses. In NYS, you might try Hall-Mark, Summit, or Pioneer. I can't find my most recent PO, sorry. They also make a newer part that has the caps for the swithching supply onboard which makes life neater. In addition, they make switched capacitor filters, A/Ds, D/A, op amps ect. Usual disclaimer, I use their parts, and don't have any connection with the company... -- Dale Chayes Lamont-Doherty Geological Observatory of Columbia University Route 9W, Palisades, N.Y. 10964 dale@lamont.ldgo.columbia.edu voice: (914) 359-2900 extension 434 fax: (914) 359-6817
henry@utzoo.uucp (Henry Spencer) (02/18/89)
In article <1702@ssc.UUCP> markz@ssc.UUCP (Mark Zenier) writes: >> The part number is MAX-232, just like it says. It's made by Maxim; don't >> expect to find it in databooks from anyone else yet. > >It's in the 1987 GE/intersil book (page 11-36) marked Preliminary. Of course, we all know that "Preliminary" means anything from "we've been making this thing for years but we still reserve the right to change the data sheet without warning" to "we're thinking about making this thing, if we get enough interest". :-) More seriously, yup, I was wrong, second sources have started to appear. Wish Intersil would send me a current databook... -- The Earth is our mother; | Henry Spencer at U of Toronto Zoology our nine months are up. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
neals@tekigm2.MEN.TEK.COM (Neal Sedell) (02/24/89)
In article <1419@ncar.ucar.edu> cook@stout.UCAR.EDU (Forrest Cook) writes: >In article <464@limbic.UUCP> gil@limbic.UUCP (Gil Kloepfer Jr.) writes: >>In article <939@calvin.EE.CORNELL.EDU> phil@calvin.EE.CORNELL.EDU (Phil Erickson) writes: >>>I've seen numerous references to the MAX-232 chip for TTL/RS232 conversion; >... >>The chip supports two RS232 transmitters and two receivers. This makes ... >extra +-10V supply if all you need is RS-232. This may be pushing the specs >a bit, but we have used the MAX-232 to provide power to a CMOS analog >mux (DG-509) that is used for selecting on of four RS-232 lines. Since I have a Maxim spec. sheet here I'll looked it up. They specifically allow drawing a "small amout of power" from the V+ and V- supplies. Typical output impedence for the V+ supply is ~230 Ohms, the V- impedence is ~175 Ohms. These are at 5V input and I assume using 4.7uF caps all around since the adjacent graphs for V+ and V- Supply Voltage vs. Load Current call them out. Give or take the V+ supply will be 8V with a 10mA load including transmitter outputcurrent, the V- supply wil be around -7V with a (-)10mA load.... Seems the input is doubled first then inverted, so the actual impedence of the V- output is Rout+ + Rout- => well over 300 Ohms, the graph is no labeled consistently on the Y axis. Happy hacking, -- Neal Sedell