74HCT221D: Dual non-retriggerable monostable multivibrator with reset

The 74HC/74HCT221 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A.

The 74HC/HCT221 are dual non-retriggerable monostable multivibrators. Each multivibrator features an active LOW-going edge input (nA) and an active HIGH-going edge input (nB), either of which can be used as an enable 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 for the nB inputs allow jitter-free triggering from inputs with slow transition rates, providing the circuit with excellent noise immunity.

Once triggered, the outputs (nQ, nQ) are independent of further transitions of nA and nB inputs and are a function of the timing components. The output pulses can be terminated by the overriding active LOW reset inputs (nR D ). Input pulses may be of any duration relative to the output pulse.

Pulse width stability is achieved through internal compensation and is virtually independent of VCC and temperature. In most applications pulse stability will only be limited by the accuracy of the external timing components.

The output pulse width is defined by the following relationship:

tW=CEXT REXT In2

tW= 0.7CEXT REXT

Pin assignments for the '221' are identical to those of the '123' so that the '221' can be substituted for those products in systems not using the retrigger by merely changing the value of REXT and/or CEXT.

sot109-1_3d
Data Sheets (1)
Name/DescriptionModified Date
Dual non-retriggerable monostable multivibrator with reset (REV 3.0) PDF (199.0 kB) 74HCT221 [English]26 Oct 2016
Application Notes (2)
Name/DescriptionModified Date
Live Insertion Aspects of Philips Logic Families (REV 1.0) PDF (73.0 kB) AN252 [English]13 Mar 2013
Pin FMEA 74HC/74HCT family (REV 1.0) PDF (51.0 kB) AN11044 [English]16 Mar 2011
Users Guides (1)
Name/DescriptionModified Date
HC/T User Guide (REV 1.0) PDF (508.0 kB) HCT_USER_GUIDE [English]01 Nov 1997
Package Information (1)
Name/DescriptionModified Date
plastic small outline package; 16 leads; body width 3.9 mm (REV 1.0) PDF (192.0 kB) SOT109-1 [English]08 Feb 2016
Packing (1)
Name/DescriptionModified Date
SO16; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or J Ordering... (REV 4.0) PDF (210.0 kB) SOT109-1_118 [English]24 Apr 2013
Supporting Information (2)
Name/DescriptionModified Date
Footprint for reflow soldering (REV 1.0) PDF (9.0 kB) SO-SOJ-REFLOW [English]08 Oct 2009
Footprint for wave soldering (REV 1.0) PDF (8.0 kB) SO-SOJ-WAVE [English]08 Oct 2009
Ordering Information
ProductStatusFamilyFunctionVCC (V)Logic switching levelsDescriptionOutput drive capability (mA)Package versiontpd (ns)Power dissipation considerationsTamb (Cel)Rth(j-a) (K/W)Ψth(j-top) (K/W)Rth(j-c) (K/W)Package nameNo of pins
74HCT221DActiveHC(T)Multivibrators4.5 - 5.5TTLTTL enabled+/- 4SOT109-132low-40~125621.019SO1616
Package Information
Product IDPackage DescriptionOutline VersionReflow/Wave SolderingPackingProduct StatusPart NumberOrdering code(12NC)MarkingChemical ContentRoHS / Pb Free / RHFLeadFree Conversion DateEFRIFR(FIT)MTBF(hour)MSLMSL LF
74HCT221DSOT109-1SO-SOJ-REFLOW SO-SOJ-WAVE
SO-SOJ-REFLOW SO-SOJ-WAVE
Reel 13" Q1/T1Active74HCT221D,118 (9337 151 10118)74HCT221D74HCT221Dweek 4, 200484.96.621.51E811
Bulk PackActive74HCT221D,112 (9337 151 10112)74HCT221D74HCT221Dweek 4, 200484.96.621.51E811
Dual non-retriggerable monostable multivibrator with reset 74HCT221D
Live Insertion Aspects of Philips Logic Families 74HC_T_245_Q100
Pin FMEA 74HC/74HCT family 74HC_T_597_Q100
HC/T User Guide 74HCU04PW
plastic small outline package; 16 leads; body width 3.9 mm NPIC6C596A_Q100
Footprint for reflow soldering NPIC6C596A_Q100
Footprint for wave soldering NPIC6C596A_Q100
SO16; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or J Ordering... NPIC6C596A_Q100
SA614A