Reasonable and effective use of components is an important guarantee for circuit board performance and quality stability.
So, what problems should be paid attention to when using CMOS components?
1. Limit the output current, avoid CMOS circuits create a lock-in effect:
The lock-in effect means that there are parasitic PNP transistors and NPN transistors on the internal structure of the CMOS circuit, and a parasitic PNPN thyristor structure is formed between them.
A common solution is to separate each output from its cable with a resistor, and to clamp the cable to VDD (Voltage Drain Drain) and VSS (Voltage Source-to-Source) with two high-speed switching diodes.

2. Use a filter network:
Sometimes long input cables are required between the CMOS circuitry and the mechanical contacts, which increases the possibility of electromagnetic interference and should consider using a filter network.
3. Form the RC network:
For sensitive inputs of bipolar devices, the effects of electrostatic discharge can be reduced by using an RC network of high value resistors and capacitors of at least 100pF.
4. Avoid suspended the input pins of CMOS devices:
This is because once the input pin is suspended, the input potential will be in an unstable state, which will not only destroy the normal logic relationship of the circuit, but also easily cause electrostatic breakdown and external noise interference. For the redundant input terminals should be dealt with separately according to the function of the circuit.
The above are a few problems that should be paid attention to when using CMOS components, we hope it will be helpful to our customers and friends.