1. General description

The 74LV123 is a dual retriggerable monostable multivibrator with reset. The basic output pulse

width is programmed by selection of external components (REXT and CEXT). 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 (nQ = HIGH, nQ = 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. Control inputs include clamp diodes. This enables the use of current limiting resistors

to interface inputs to voltages in excess VCC. Schmitt-trigger action at nA and nB inputs makes the

circuit tolerant of slower input rise and fall times.

2. Features and benefits

• Wide supply voltage range from 1.0 V to 5.5 V

• CMOS low power dissipation

• Latch-up performance exceeds 100 mA per JESD 78 Class II Level B

• Optimized for low-voltage applications: 1.0 V to 3.6 V

• Accepts TTL input levels between VCC = 2.7 V and VCC = 3.6 V

• Typical output ground bounce: < 0.8 V at VCC = 3.3 V and Tamb = 25 °C

• Typical HIGH-level output voltage (VOH) undershoot: > 2 V at VCC = 3.3 V and Tamb = 25 °C

• DC triggered from active HIGH or active LOW inputs

• Retriggerable for very long pulses up to 100 duty factor

• Direct reset terminates output pulses

• Schmitt-trigger action on all inputs except for the reset input

• Complies with JEDEC standards:

• JESD8-7 (1.65 V to 1.95 V)

• JESD8-5 (2.3 V to 2.7 V)

• JESD8C (2.7 V to 3.6 V)

• JESD36 (4.5 V to 5.5 V)

• ESD protection:

• HBM JESD22-A114F exceeds 2000 V

• MM JESD22-A115-A exceeds 200 V

• Multiple package options

• Specified from -40 °C to +85 °C and from -40 °C to +125 °C