Error prevention in TTL circuits.

摘要

A TTL circuit, controllable by an input signal so that when the circuit is in a normal steady-state operating condition it delivers an output signal which will undergo a predetermined change in response to a predetermined change in the input signal, includes error prevention circuitry (DS1-DSn) for preventing such response to said change in the input signal if a power supply voltage (Vcc) applied to the circuit is at a subnormal value, below a threshold value imposed by the error prevention circuitry, for example during start-up of the device.