Can't find the datasheet - IC made by ITT - Page 1
Forum section: electronics / projects

author: masster
author_rank: Regular Contributor
timestamp: March 09, 2014, 02:49:12 am
content: hiI am new to this forum and I need your help.I am working at my 1997 car's tachometer (analogue type) and I need the datasheet of the IC that is driving it. I couldn't find anything on the Internet and it is soooooo frustrating... Any information will be greatly appreciated.Chip name:KEFB-842made byITTin the '90sHere are some photos:The chip itselfThe schematics I reversed engineered from PCBPCB detail showing how pins 3-9 are used

author: SeanB
author_rank: Super Contributor
timestamp: March 09, 2014, 06:53:58 am
content: You have a mask programmed microcontroller there. It will most likely have a faulty crystal on pins 11 and 12, and that is most likely to be not oscillating. Unsolder the crystal, turn it around and solder it back in and see if it then works, or get a new crystal. Otherwise you need a new chip, and as ITT is now a part of Nokia or Phillips and it is likely they no longer have any data on those devices you are SOL.

author: masster
author_rank: Regular Contributor
timestamp: March 09, 2014, 02:03:13 pm
content: Quote from: SeanB on March 09, 2014, 06:53:58 amI don't remember saying the tachometer is faulty and I don't know how to repair it. It is NOT faulty. I only said I need thedatasheetof the IC driving it.Quote from: SeanB on March 09, 2014, 06:53:58 amWrong. ITT is part of Micronas. I contacted them asking for KEFB-842datasheetbut they didn't answer in months now.Somebody having old IC catalogues, please blow the dust on them and check for any reference. Thank you.

author: dannyf
author_rank: Super Contributor
timestamp: March 09, 2014, 02:54:49 pm
content: It looks like a microcontroller.Do you have a sense of what it does? If so, maybe you can replicate its functionality with another microcontroller.

author: masster
author_rank: Regular Contributor
timestamp: March 09, 2014, 03:21:34 pm
content: OK, it is a microcontroller.I don't want to repair it.I don't want to replace it.I know what it should be doing, it is a frequency to voltage controller, like any other tachometer driver.But that is NOT the point!All I need to know is this:- what is the maximum input voltage for the input signal?- what is changing if I pull down pins 3-9 in combination?By looking at PCB it is obvious the IC operation can be altered by shorting those pins to ground. The same PCB would be good for engines with ECU, engines with carburetor (no ECU), and Diesel engines. But on each of these 3 cases, the signal for rev counter is coming fro ECU, ignition coil, and alternator respectively.That is why I am asking for that ****ingdatasheet. I can't guess anything without it.

author: dannyf
author_rank: Super Contributor
timestamp: March 09, 2014, 03:28:10 pm
content: QuoteMore like you are demanding it.I was trying to help you. But now, I think I will do something else.

author: free_electron
author_rank: Super Contributor
timestamp: March 09, 2014, 03:48:04 pm
content: It is NOT a microcontroller. These chips are custom asics made by ITT in Freiburg ( itt was sold to micronas years ago)No chance finding data for those. Only the oem has it (the company that had the chip designed)

author: BillyD
author_rank: Regular Contributor
timestamp: March 09, 2014, 04:07:06 pm
content: First rule of repair: check voltage levels. Have you checked voltage levels?Also check for dry joints and hairline cracks in the tracks around it.

author: Dr. Frank
author_rank: Super Contributor
timestamp: March 09, 2014, 06:23:02 pm
content: It's presumably an f/V converter.Perhaps a former colleague of mine has designed that.What kind of car (manufacturer, model) do you have?Would you mind taking a photo of the instrument cluster?Is 1997 the manufacturing date? I doubt. Maybe 1993.Then I'll check tomorrow.

author: free_electron
author_rank: Super Contributor
timestamp: March 09, 2014, 07:07:55 pm
content: It looks like the pcb straps allow to program a scaling factor. The top strip goes to the pin. Bottom left is ground , bottom right is some supply voltage.Note the two of them are hard connected to ground.

author: dr.diesel
author_rank: Super Contributor
timestamp: March 09, 2014, 07:19:35 pm
content: Quote from: BillyD on March 09, 2014, 04:07:06 pmQuote from: masster on March 09, 2014, 02:03:13 pmQuote from: masster on March 09, 2014, 03:21:34 pmBilly, you must have missed the part where the OP was being an Ass, I copied said action above for your amusement!

author: masster
author_rank: Regular Contributor
timestamp: March 09, 2014, 07:30:58 pm
content: Quote from: Dr. Frank on March 09, 2014, 06:23:02 pmWoweven in my wildest dreams I wouldn't have dreamed I could meet the designer(sMy car is a Skoda Felicia, the first car made by Czechs as VAG members. Felicia was produced during 1994-2001 period and it is still a car very much appreciated. The instrument cluster has several variations, depending of the luxury class (LX had only an analogue clock while GLX had an analogue tachometer and a digital clock) and also depending of the type of engine (Diesel, carburetor, SPi, MPi). For some unknown reason theinstrument cluster schematicsare kept secret(?) even after 14 years the last car was built...Here are the photos you asked for:Instrument cluster Skoda FeliciaGLXInstrument cluster Skoda FeliciaLXPCB - components side (from a car with 1.3 l engine, SPi)PCB - routes side (from a car with 1.3 l engine, SPi)Tachometer area details

author: Fraser
author_rank: Super Contributor
timestamp: March 09, 2014, 07:47:36 pm
content: This thread certainly made intreresting reading........It was not unreasonable of forum members to ASSUME that the OP wanted help with a repair as he was asking for a datasheet, which is normally the first step in such. What amazes me is the ATTITUDE displayed by the OP to a simple mistake by others. Such an attitude does not encourage others to assistThe fact that the device is custom appears pretty much agreed at this time so we can park that.If I had such a WORKING instrument I would first look at the signals and power rails from the host vehicle and get my operational characteristics from there. If no host is available, I would connect the power rails to a variable PSU then wind up the voltage whilst watching the oscillator and the current drawn. If it comes to life at 9V I would assume it was actually a 12V device. If it comes to life at 3 or 4 volts it would likely be a 5V device. All very rough but good enough for checks. I would then connect an Audio frequency signal generator to the Tacho input and watch to see if the needle responds as I increase the voltage. When it starts to respond you know the low voltage threshold and can estimate a nominal level from it. i.e if it operrates at xxxmV it has a front end amplifier so a low signal level is needed, say less tha 1V p-p. It it needs 3 or 4 volts then it could be logic input levels of 0 and 5V. If it needs a monster signal of say 10V than it is running at 0 and 12V input and you should ensure that the tacho is running at 12V as well.Now once you have the thing running on a power supply and signal generator with a reading of say 1000 RPM, start experimenting with the jumpers to see what effect each has. It is possible that the jumpers are set for differing transmissions and road wheel diameters, so the changes may not be that great for tyre diameters but large for transmissions.If all this is too much hassle, and the tacho is not going in the original host, you may wish to consider buying a new unit that comes with instructions.Others may be willing to chip in with comments but after your getting annoyed, do not count on it.

author: masster
author_rank: Regular Contributor
timestamp: March 09, 2014, 07:52:14 pm
content: Quote from: dr.diesel on March 09, 2014, 07:19:35 pmNow really, if you ask SPECIFICALLY for apples and you get melons, what would you expect? A medal? Why people have to imply something that hasn't been said or reply to something that hasn't been asked... beats me. I asked for a datasheet and there were 2 possibilities: I don't have it -> I don't reply OR I have it and I share/sell it. If these set of expectations qualify me as an a$$, then either USA morals had suddenly jumped three classes up towards respecting other non-US citizens, other countries' independence and towards dropping that sick exceptionalism dream OR USA men are puberty girls and we don't have to hurt their feelings with any harsh truth... So please exercise your sarcasm elsewhere. In Iraq or Afghanistan for instance.

author: dr.diesel
author_rank: Super Contributor
timestamp: March 09, 2014, 07:57:39 pm
content: Quote from: Aurora on March 09, 2014, 07:47:36 pmYup, you're slightly more politically correct than I.I bet he lasts about as long as Roland.

author: Rerouter
author_rank: Super Contributor
timestamp: March 09, 2014, 08:02:46 pm
content: Those pads are likely to be the calibration switches for the tachometer (V4, V6, V8) and possibly something else that they figured to break out even iff it would never be used in there vehicle,as for the calibration, if its a hall type sender on the gearbox the signal will be from 7 to 12V swing, if its inductive it can range from +-1V to +-18V for some odd models, but normally greater than +-6V will drive just about any vdo tachometerhope this helps, as i myself cant find any info on the chip,

author: AlfBaz
author_rank: Super Contributor
timestamp: March 09, 2014, 08:04:32 pm
content: If I may offer some advice master... Don't worry about the data sheet just go and buythis

author: true
author_rank: Frequent Contributor
timestamp: March 09, 2014, 08:10:55 pm
content: Quote from: masster on March 09, 2014, 07:52:14 pmIf I got them for free, I certainly wouldn't be a little whiny bitch about it.Quote from: masster on March 09, 2014, 07:52:14 pmKeep it up, you are entertaining.Quote from: AlfBazI recommendthis

author: dr.diesel
author_rank: Super Contributor
timestamp: March 09, 2014, 08:16:17 pm
content: No no,thisis the one he needs.

author: masster
author_rank: Regular Contributor
timestamp: March 09, 2014, 08:32:17 pm
content: Quote from: true on March 09, 2014, 08:10:55 pmThat was not said by me. In fact it was not said by anyone in this topic. Try to quote me right, dr. Freud. In fact I see there are only delusional doctors in here that keep trolling off-topic without anything useful on the subject. At least (for instance) Aurora made some very interesting observations, showing (s?)he has great knowledge on electronics. But you, dr. diesel and co, nothing. Cheap jokes and hot air. Now really, boys, tell us how often you buy Tampax for your wifes

author: dr.diesel
author_rank: Super Contributor
timestamp: March 09, 2014, 08:41:03 pm
content: You've gotten more than you deserve, must be way past your bedtime son, you can try again tomorrow.

author: BillyD
author_rank: Regular Contributor
timestamp: March 09, 2014, 08:54:46 pm
content: Quote from: dr.diesel on March 09, 2014, 07:19:35 pmThanks Dr. Have to confess I did that deliberately. When a couple of people had tried to be helpful only to be met with abuse I was curious to see how he would react to a patently useless response. This thread is certainly turning into quite a study of (lack of) interpersonal skills.

author: Bored@Work
author_rank: Super Contributor
timestamp: March 09, 2014, 08:57:15 pm
content: Quote from: Aurora on March 09, 2014, 07:47:36 pmBut still, there is always someone with a helper complex rewarding someone like the OP.

author: dannyf
author_rank: Super Contributor
timestamp: March 09, 2014, 09:06:28 pm
content: QuoteQuoteSpot on, gents.QuoteExcellent suggestion for a post-doctoral level class for the OP.

author: masster
author_rank: Regular Contributor
timestamp: March 09, 2014, 09:18:00 pm
content: Quote from: BillyD on March 09, 2014, 08:54:46 pmAbuse? Cry me a river... what a bunch of crying girls...You'll see what abuse means when Obama and your 'strategic' ally will drone you if you don't wear kippah and speak yiddish. Or even better, when people around the world will pay you back for all the 'good' you did in each and every war inflicted in Europe & Middle East on false pretexts.

author: free_electron
author_rank: Super Contributor
timestamp: March 09, 2014, 10:10:58 pm
content: what the hell is this ? some political troll rant ? what does the USA have to do with this thing ?That pcb is made in Czechoslovakia using a german made chip following design from VDO ( german company )the chip is a custom device made for VDO by ITT. Schematics are only available from VDO. There is no datasheet, only a design spec and that is property of VDO and ITT.you can't get your hands on it unless you know someone who designed the damn thing.if you want to know the voltage levels : stick it in the car and hook up a scope. it'll tell you all you need.

author: masster
author_rank: Regular Contributor
timestamp: March 09, 2014, 10:32:08 pm
content: Quote from: free_electron on March 09, 2014, 10:10:58 pmI want to know if I can feed 12V input pulses (from ignition coil primary) instead of TTL pulses coming from ECU (as it is now) without damaging the chip. My plan is to use my instrument cluster on another car that has no ECU.

author: krivx
author_rank: Frequent Contributor
timestamp: March 09, 2014, 11:17:57 pm
content: I would not trust anything applied to an ignition coil primary to be limited to +12V.

author: Zepnat
author_rank: Regular Contributor
timestamp: March 09, 2014, 11:38:48 pm
content: I fitted a little Lcd rev counter to a really old vehicle about 10 years ago, so old it was just when they changed from dynamo to alternator. I dug into a winding before the rectifier and fed the ac signal to a F/V converter IC, no idea of the model number (google?) but it was some common device from maplins. once the IC was adjusted correctly it all worked surprisingly well for such a simple set up. You could maybe do something similar the only hard part would be setting up something to drive the RPM meter.

author: echen1024
author_rank: Super Contributor
timestamp: March 09, 2014, 11:50:33 pm
content: Quote from: dr.diesel on March 09, 2014, 07:57:39 pmWhat happened to roland? The one with the pen plotter?

author: c4757p
author_rank: Super Contributor
timestamp: March 10, 2014, 12:11:02 am
content: Quote from: Bored@Work on March 09, 2014, 08:57:15 pmNah, I won't touch this one. He's all yours.Quote from: echen1024 on March 09, 2014, 11:50:33 pmYup. Trolled a bit too much and got the boot.

author: nctnico
author_rank: Super Contributor
timestamp: March 10, 2014, 12:27:22 am
content: Quote from: echen1024 on March 09, 2014, 11:50:33 pmThe ink went dryTo the OP: I wouldn't take any chance and limit the pulses with a zener diode (4.7V) and a resistor. In these situations I usually use a resistor between the chip and the zener and a resistor between the zener and the (input) signal.

author: masster
author_rank: Regular Contributor
timestamp: March 10, 2014, 12:44:17 am
content: Quote from: krivx on March 09, 2014, 11:17:57 pmWhy is that?

author: true
author_rank: Frequent Contributor
timestamp: March 10, 2014, 01:10:36 am
content: Quote from: massterWhat the hell do "USA morals," soverign states, Obama with drones, yiddish, puberty girly men in Iraq or Afghanistan have to do with this topic?Because those are things you brought up.Yeah, I'm feeding you now.Regardless, inquiring minds want to know how those things are on topic.Quote from: massterAnd perhaps you don't understand, so I'll restate what others have said: with that attitude, you deserve nothing.And if you do understand, then your plan is coming together perfectly!But here, I'll be nice and help you.Quote from: massterIt takes 48V.Quote from: BillyDNot enough fun threads like this in my opinion

author: masster
author_rank: Regular Contributor
timestamp: March 10, 2014, 01:37:35 am
content: I have just received through PM the schematic diagrams for the instrument cluster I have. For those interested, it is designed indeed by VDO Germany as somebody mentioned earller. Full tachometer chip specifications coming soon. Yes, it is a custom ITT proprietary chip for auto industry. It was used by many European car makes, not only by VAG.

author: calexanian
author_rank: Super Contributor
timestamp: March 10, 2014, 04:21:19 am
content: "It appears to run on some sort of electricity!"-Captain America

author: SeanB
author_rank: Super Contributor
timestamp: March 10, 2014, 05:02:03 am
content: Use the coil voltage, and run it through the zener clipper as recommended above. Resistor in series with the line, between 1k and around 2k2 0.5W rating, zener diode of 4V7 400mW to ground to limit the voltage to under 5V, a capacitor of around 1n across the zener to reduce noise and another 1k resistor to the input of the chip. The coil connection of a car produces pulses of over 400V when the contacts open, very bad for a direct connection to any IC designed to have TTL input levels.

author: Bored@Work
author_rank: Super Contributor
timestamp: March 10, 2014, 06:03:33 am
content: Quote from: calexanian on March 10, 2014, 04:21:19 amThe Edison or the Tesla kind of electricity?

author: Dr. Frank
author_rank: Super Contributor
timestamp: March 10, 2014, 08:12:08 am
content: Quote from: masster on March 09, 2014, 03:21:34 pm- Pin 16 = VSS/ 0V- Pin 1 = VDD; 7.5 .. 8.5V nom. / 10V max.all other pins may vary between -0.5V .. VDD + 0.7VThis ASIC measures the periodtime of the incoming frequency, then converts this by PWMs to two output voltages and additionally changes output polarity according to the correct octant, as it's intended for the old cross-coil movements. It also contains full bridge output drivers.So this IC is some sort of state machine with an analog block.A block schematic is given, but no circuit details. Pity that.Didn't even find a table for the conversion factor (divider chain, gain) for pins 3-9. You'll have to try.

author: masster
author_rank: Regular Contributor
timestamp: March 10, 2014, 09:18:33 am
content: Quote from: SeanB on March 10, 2014, 05:02:03 amWell, my car has an electronic ignition from the factory, it is not the mechanical contacts type. A coil on the distributor picks 4 pulses/revolution and feeds to the said electronic ignition (schematic below). Do you think there are 400V spikes on the primary of the ignition coil?

author: krivx
author_rank: Frequent Contributor
timestamp: March 10, 2014, 01:33:15 pm
content: Quote from: masster on March 10, 2014, 12:44:17 amjjEven if the battery is good the 12V supply in a car is subject to lots of inductive loads and the voltage regulators can be pretty poor. I would expect lots of noise and high-voltage spikes, going with some kind of clamping circuit as others have suggested is a good idea.

author: calexanian
author_rank: Super Contributor
timestamp: March 10, 2014, 07:31:40 pm
content: Quote from: Bored@Work on March 10, 2014, 06:03:33 amIts been over a month since is aw that movie. I think its time. Wonder if its on netflix or amazon prime. Perhaps Xfinity...

author: mctutano
author_rank: Newbie
timestamp: May 22, 2015, 10:19:21 am
content: ITT was built this CI and offer it to many tachometer manufacturers like VDO or Veglia.At Veglia is labeled as V3003.393 or V3001.519 ( identical IC ) , in the same way there is no datasheet, and Micronas claims nothing to know about it.I don't know where that technical information has been able to go, can go to trash or sleeping in a drawer... who knows.Fiat, Audi , Skoda, VW, Porsche or Piaggio are some brands of automotive where these circuits were used.Maybe can be reproduced by other IC functions, like Hz/V ( Frequency to voltage) converter and others, avaiable in market.