Q. What must be done to interface TTL to CMOS? (Solved)
1. a dropping resistor must be used on the cmos of 12 v supply to reduce it to 5 v for the ttl
2. as long as the cmos supply voltage is 5 v they can be interfaced (however, the fan- out of the ttl is limited to five cmos gates)
3. a 5 v zener diode must be placed across the inputs of the ttl gates in order to protect them from the higher output voltages of the cmos gates
4. a pull-up resistor must be used between the ttl output-cmos input node and vcc; the value of rp will depend on the number of cmos gates connected to the node
- d. a pull-up resistor must be used between the ttl output-cmos input node and vcc; the value of rp will depend on the number of cmos gates connected to the node