Redundant output terminals should be suspended, and should not be directly connected to VDD or VSS, otherwise excessive short-circuit current will be generated and the device will be damaged. The output terminals of CM0S circuits with different logic functions cannot be directly connected together, otherwise the turned-on P-channel MOS FET and the turned-on N-channel MOS FET form a low-resistance path, resulting in short circuit of power supply and device damage.
Extended data
TTL level signal:
Signals with 1 and TTL levels are often used because data representation usually adopts binary rules, +5V is equivalent to logic "1" and 0V is equivalent to logic "0", which is called TTL (transistor-transistor logic level) signal system, and it is a standard technology for communication between various parts of equipment controlled by computer processors.
2. The data transmission in the equipment controlled by the computer processor has low requirements for power supply and low heat loss. In addition, the TTL level signal is directly connected to the integrated circuit, without expensive line drivers and receiver circuits.
The data transmission inside the equipment controlled by the computer processor is carried out at high speed, and the operation of TTL interface can just meet this requirement.
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