Rev.3.00, Jul.15.2005, page 1 of 8

HD74LS221

Dual Monostable Multivibrators

REJ03D0458–0300

Rev.3.00

Jul.15.2005

This 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 of

fired, the outputs are independent of further transitions of the A and B inputs and are a function of the timing

components, or the output pulses can be terminated by the overriding clear. Input pulses may be of any duration

relative to the output pulse. Output rise and fall times are TTL compatible and independent of pulse length.

Typical triggering and clearing sequence are illustrated as a part of the switching characteristics waveforms. Pulse

In most applications, pulse stability will only be limited by the accuracy of external timing components. Jitter-free

to 10

µF) and more than one decade of timing resistance (2 kΩ to 100 kΩ).

• Rext • 1n 2.

Features

• Ordering Information

Part Name

Package Type

Package Code

(Previous Code)

Package

Abbreviation

Taping Abbreviation

(Quantity)

HD74LS221P

DILP-16 pin

PRDP0016AE-B

(DP-16FV)

P

—

HD74LS221RPEL

SOP-16 pin (JEDEC)

PRSP0016DG-A

(FP-16DNV)

RP

EL (2,500 pcs/reel)

Note:

Please consult the sales office for the above package availability.