74HCT123D,653

The 74HC123; 74HCT123 is a dual retriggerable monostable multivibrator with reset. The basic output pulse width is programmed by selection of external components (R_EXT and C_EXT). Once triggered this basic pulse width may be extended by retriggering either of the edge triggered inputs (nA or nB). By repeating this process, the output pulse period (ΔnQ = HIGH, nQ(overline) = LOW) can be made as long as desired. Alternatively, an output delay can be terminated at any time by a LOW - going edge on input nRD. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of V_CC. Schmitt - trigger action in the nA and nB inputs, makes the circuit highly tolerant to slower input rise and fall times.

Key features

• Wide supply voltage range from 2.0 V to 6.0 V
• CMOS low power dissipation
• High noise immunity
• Latch - up performance exceeds 100 mA per JESD 78 Class II Level B
• Complies with JEDEC standards:
• JESD8C (2.7 V to 3.6 V)
• JESD7A (2.0 V to 6.0 V)
• Input levels:
• For 74HC123: CMOS level
• For 74HCT123: TTL level
• DC triggered from active HIGH or active LOW inputs
• Retriggerable for very long pulses up to 100 % duty factor
• Direct reset terminates output pulse
• Schmitt - trigger action on all inputs except for the reset input
• ESD protection:
• HBM: ANSI/ESDA/JEDEC JS - 001 class 2 exceeds 2000 V
• CDM: ANSI/ESDA/JEDEC JS - 002 class C3 exceeds 1000 V
• Multiple package options
• Specified from - 40 ℃ to + 85 ℃ and from - 40 ℃ to + 125 ℃