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30 year old piece of equipment operating pretty much flawlessly for
that entire period. VCC and VEE on the 1448 is +/- 15 volts and the chip is overheating..... even with inputs and outputs disconnected the chip still overheats(130 F). I noticed that the manufacturer's sets the MAX power supply voltages at +/- 15 and understand this was probably designed on the hairy edge of failure but like I said its been working for 30 years and replacement chips work no better, what gives. Power supply can not be adjusted and there are other chips on the board that require the +- 15. d BTW cooling the chip makes it work. operating the chip from an external +- 12V power supply makes it work but modifying the circuit may not be an option. I saw where there are some CMOS versions of the 1488, I was wondering if they would handle the +- 15 volts better. TIA Jimmie |
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