SN54221,SN54LS221,SN74221,SN74

The '221 and 'LS221 devices are monolithic dual mulTIvibrators with performance characterisTIcs virtually idenTIcal to those of the '121 devices. Each mulTIvibrator features a negative-transition- triggered input and a positive-transition-triggered input, either of which can be used as an inhibit input.

Pulse triggering occurs at a particular voltage level and is not directly related to the transition time of the input pulse. Schmitt-trigger input circuitry (TTL hysteresis) for B input allows jitter-free triggering from inputs with transition rates as slow as 1 V/s, providing the circuit with excellent noise immunity, typically of 1.2 V. A high immunity to V_CC noise, typically of 1.5 V, is also provided by internal latching circuitry.