I am restoring an old ROTEL turntable and have come across a "NEC MPC1003C" chip, acting (I think) as voltage regulator. I can not find any information on the internet. Does anybody know any info on this chip? Thanks!
Electronic – NEC “MPC 1003C” chip
component-selectioncomponentsidentification
Related Solutions
The first chip is most likely a 74L93. It is the 74L family (low-power) version of the 7493 4-bit counter.
The second pair of chips may be 7442 BCD to decimal converters.
It is an Atmel AT24C08C I2C-Compatible, (2-wire) Serial EEPROM, 8-Kbit (1024 x 8). The type is actually given by the second line via its
Truncation Code ###: 08C
The first line is not really the type, but indicates the manufacturer (Atmel) and date of manufacture: the 42nd week of 2013.
Also, @ = Country of Assembly and AAA...A = Atmel Wafer Lot Number.
Much is owed to https://reverseengineering.stackexchange.com/questions/4526/identifying-an-unknown-chip-on-a-pcb which identified a similar chip.
Best Answer
There doesn't seem to be much information available anyway, but you need to use the correct part number for the best chance of finding anything.
Although written on your schematic as "MPC 1003C", the correct NEC part number of this IC from the 1970s is:
it is sometimes also written as:
μPC1003C
(no space between letters and numbers)
uPC1003C
(NEC used the small Greek letter "Mu", but that is frequently replaced by the similar-looking small letter "u")
(I have read that the original IC was the uPC1003, and that the uPC1003C and uPC1003C2 were later versions)
UPC1003
(all capital letters)
and similar variations.
I can only guess that organisations who wrote "MPC 1003" on their schematics, as in the one you supplied, actually capitalised the Greek letter "Mu" (a capital Greek "Mu" looks like a capital letter "M").
Actually that IC is some kind of servo motor driver - notice the feedback signal from the motor to pin 1 on the IC. It was used in some 1970s (and 1980s?) tape recorders and turntables, to maintain speed control of the motors. You will sometimes find it mentioned on vintage audio forums.
You can try using the part numbers I have given above (perhaps starting with uPC1003) to search for what little information seems to be available. A few of the ICs still appear to be for sale (as "new old stock" / NOS), although production seems to have stopped a long time ago. I didn't find a datasheet, but by using the correct part number in your future searches, you have a chance for more success.