Texas Instruments SN54221
the SN54221, 2 kΩ to 40 kΩ for the SN74221, 2 kΩ to 70 kΩ for the SN54LS221, and 2 kΩ to 100 kΩ for the SN74LS221).D Dual Versions of Highly Stable SN54121 and SN74121 One Shots D SN54221 and SN74221 Demonstrate Electrical and Switching Characteristics That Are Virtually Identical to the SN54121 and SN74121 One Shots D Pinout Is Identical to the SN54123, SN74123, SN54LS123, and SN74LS123 D Overriding Clear Terminates Output Pulse TYPE SN54221 SN74221 SN54LS221 SN74LS221 MAXIMUM OUTPUT PULSE LENGTH(S) 21 28 49 70 description/ordering information The ’221 and ’LS221 devices are dual multivibrators with performance characteristics virtually identical to those of the ’121 devices. Each multivibrator features a negative-transitiontriggered input and a positive-transition-triggered input, either of which can be used as an inhibit input. SN54221, SN54LS221, SN74221, SN74LS221 DUAL MONOSTABLE MULTIVIBRATORS WITH SCHMITTĆTRIGGER INPUTS SDLS213B − DECEMBER 1983 − REVISED NOVEMBER 2004 SN54221, SN54LS221 . . . J PACKAGE SN74221 . . . N PACKAGE SN74LS221 . . . D, DB, N, OR NS PACKAGE (TOP VIEW) 1A 1B 1CLR 1Q 2Q 2Cext 2Rext/Cext GND 1 2 3 4 5 6 7 8 16 VCC 15 1Rext/Cext 14 1Cext 13 1Q 12 2Q 11 2CLR 10 2B 9 2A SN54LS221 . . .