ROB304 is a negative voltage regulator from ICCE/Romania, manufactured during cold war, and compatible with
LM304 from National Semiconductor. Both ROB304 and LM304 have the same schematic, same capsule (10 pins metal can) and identical datasheets (except at least two schematic mistakes in the Romanian translated datasheet - i.e. 22k instead of 22\$\Omega\$, and a pin 5 left unconnected
).
Both ICCE and NS datasheets only show a single packaging type, round metal can 10 pins.
However, the few NOS of ROB304 I have are in a DIL-14 plastic case, which is not shown in the Ro datasheet.
The schematic happens to have 2 resistors (30k and 1k) exposed between pins 9-8-7 of the metal can version. Turned out those resistors were corresponding to pins 13-12-11 in the DIL packaging, so I've assumed they've just left unused pins 6-7-8-9 from the DIL package.
Well, it didn't work. The chips were made during the 70's, and they were from grey market (which were often defective or out of specs parts), so it was puzzling why it didn't work. Though, living the most right-hand 4 pins from the DIL package out of the pins numbering was unusual, so I kept measuring voltages and resistance between pins, and they didn't make any sense by comparing with the internal schematic of the IC.
Eventually, with the DMM on diode, managed to identify the NC pins, and turned out that pins 1,4,7,8 from DIL were skipped while counting!!!
-pinout-mapping-metal-can-10-pins-to-plastic-dil-14-pins/?action=dlattach;attach=2001145;image)
Took me a couple of hours to figure out they skipped some pins while mapping to DIL.
Good news is now I have the DIL14 pinout of ROB304, and all the NOS chips are working.
I wonder if this mapping between TO-100 and DIL-14 is normal, or if other manufacturers packaged LM304 in a DIL-14?
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