Hitachi HD3233 and Toshiba TM4312/TM4352/TM4356
Integrated Circuits

These ICs are commonly found as inverters and drivers in LSI calculators with vacuum fluorescent displays.
Period: Used from (approx.) 1972 to 1976.
Source of Data: Data for these devices was derived from reverse engineering of a Ricomac 1216, Miida MC840, Olympia CD401A, Sharp ELSI 804, etc.
Technology: Probably just a PNP bipolar transistor for each inverter with all the emitters tied to GND.
Supply Voltage: No direct connection of the supply voltage to the IC is required. However they were used in environments where the logic supply was -15V.
Logic: Logic levels are GND and -15V.
Outputs are open-collector. The TM4312 may have internal pull-down resistors on the bases while the others do not, although this has not been confirmed.
Packaging: Standard 16-pin DIP.
  • Although several of these devices have the same pinout there are differences between them. The HD3233 and TM4312 were used for logic-level inverters. The TM4352 tended to be used for drivers for vacuum fluorescent displays. Presumably the TM4352 has higher breakdown voltages to handle the approx. -50V display supply. Consequently, the HD3233 or TM4312 should not be used to replace the TM4352.
  • IC packages as viewed from above.

  Vacuum Flourescent Drivers
Calculators | Integrated Circuits | Displays | Simulations
2000 Aug