TTL TO 12 V CMOS Converter

The MC14504B is a hex nonāˆ’inverting level shifter using CMOS technology. The level shifter will shift a TTL signal to CMOS logic levels for any CMOS supply voltage between 5 and 15 volts.

A control input also allows interface from CMOS to CMOS at one logic level to another logic level: Either up or down level translating is accomplished by selection of power supply levels Vdd and Vcc.  The Vcc level sets the input signal levels while Vdd selects the output voltage levels. 

Features of the MC14504B include:
  • Translates from a Low to a High voltage or from a High to a Low voltage
  • Input threshold can Be shifted for TTL compatibility
  • 3 V to 18 V DC operation for VDD and VCC
  • Capable of driving two low-power TTL Loads

Since the peak output signal needs to be 12 V, the MC1450B is used to convert the 5 V TTL signal to 12 V CMOS level. The CMOS level is the standard level of voltage and current that signals are required to be for interfacing to other CMOS type circuits.

The input mode is set to TTL by connecting pin 13 to pin 1 hence the input signal  (at pin 9) will be expected to be a TTL signal with a 5 V peak, in addition Vcc is set at +5 V hence input will be at +5 V. Vdd is set to +12 V because we want the output signal (pin 10)  to be at 12 V peak; hence the peak of the signal will be shifted up to +12 V.

I decided to use this solution for voltage translating partly for safety and simplicity making sure that the signals were to recognised industrial standards for interfacing.

Frequency multiplier using LM311

Tacho pulse multiplier using a Phase Lock Loop (PLL)

12 V Tacho signal to 5 V converter
LM565 Phase Lock loop (PLL) Circuit
Divide by 16 Counter 74LS93
TTL TO 12 V CMOS Converter
-5 V from +5 V Converter Chip
Circuit Diagram & Documentation

Author: Peter J. Vis