74HCT123DB NRND

Dual retriggerable monostable multivibrator with reset

The 74HC123; 74HCT123 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 74HC123; 74HCT123 are dual retriggerable monostable multivibrators with output pulse width control by three methods:

  1. The basic pulse is programmed by selection of an external resistor (REXT) and capacitor (CEXT).
  2. Once triggered, the basic output pulse width may be extended by retriggering the gated active LOW-going edge input (nA) or the active HIGH-going edge input (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, which also inhibits the triggering.
  3. An internal connection from nRD to the input gates makes it possible to trigger the circuit by a HIGH-going signal at input nRD as shown in the function table.

Schmitt-trigger action in the nA and nB inputs, makes the circuit highly tolerant to slower input rise and fall times.

The 74HC123; 74HCT123 are identical to the 74HC423; 74HCT423 but can be triggered via the reset input.

Not recommended for new designs (NRND), click here for the alternative product.

Orderable parts

Type number Orderable part number Ordering code (12NC) Package Buy from distributors
74HCT123DB 74HCT123DB,118 935186840118 SOT338-1 Order product
74HCT123DB 74HCT123DB,112 935186840112 SOT338-1 Order product

Features

  • 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 JESD22-A114F exceeds 2000 V
    • MM JESD22-A115-A exceeds 200 V
  • Specified from -40 ℃ to +85 ℃ and from -40 ℃ to +125 ℃

Target applications

Parametrics

Type numberProduct statusVCC (V)Logic switching levelsOutput drive capability (mA)tpd (ns)Power dissipation considerationsTamb (°C)Rth(j-a) (K/W)Ψth(j-top) (K/W)Package name
74HCT123DB
NRND
Not for design in4.5 - 5.5TTL+/- 426low-40~12514842.0SSOP16

Package

Type numberOrderable part number, (Ordering code (12NC))StatusMarkingPackageOutline versionReflow-/Wave solderingPacking
74HCT123DB
NRND
74HCT123DB,118
( 9351 868 40118 )
ActiveHCT123
SSOP16
(SOT338-1)
SOT338-1SSOP-TSSOP-VSO-REFLOW
SSOP-TSSOP-VSO-WAVE
Reel 13" Q1/T1
74HCT123DB,112
( 9351 868 40112 )
ActiveHCT123Bulk Pack

Quality, reliability & chemical content

Type numberOrderable part numberChemical contentRoHS / RHFMSLMSL leadfree
74HCT123DB
NRND
74HCT123DB,11874HCT123DB11
74HCT123DB
NRND
74HCT123DB,11274HCT123DB11
Quality and reliability disclaimer

Documentation (7)

File nameTitleTypeDate
74HC_HCT123Dual retriggerable monostable multivibrator with resetData sheet2017-03-30
AN11044Pin FMEA 74HC/74HCT familyApplication note2019-01-09
hchc Spice modelSPICE model2013-05-06
HCT_USER_GUIDEHC/T User GuideUser manual1997-10-31
SSOP-TSSOP-VSO-WAVEFootprint for wave solderingWave soldering2009-10-08
SSOP-TSSOP-VSO-REFLOWFootprint for reflow solderingReflow soldering2009-10-08
SOT338-1plastic, shrink small outline package; 16 leads; 0.65 mm pitch; 6.2 mm x 5.3 mm x 2 mm bodyOutline drawing2018-10-18

Support

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Models

File nameTitleTypeDate
hchc Spice modelSPICE model2013-05-06

Ordering, pricing & availability

Type numberOrderable part numberOrdering code (12NC)PackingBuy online
74HCT123DB74HCT123DB,118935186840118Reel 13" Q1/T1Order product
74HCT123DB74HCT123DB,112935186840112Bulk PackOrder product

Sample

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