74HCT4538D

Dual retriggerable precision monostable multivibrator

The 74HCT4538 is a dual retriggerable-resettable monostable multivibrator. Each multivibrator has two trigger/retrigger inputs (nA and nB), a direct reset input (nCD), two complementary outputs (nQ and nQ), and two pins (nREXT/CEXT and nCEXT) for connecting the external timing components CEXT and REXT. Typical pulse width variation over temperature range is ± 0.2 %. The device may be triggered by either the positive or the negative edges of the input pulse. The duration and accuracy of the output pulse are determined by the external timing components CEXT and REXT. The output pulse width (TW) is equal to 0.7 × REXT × CEXT. The linear design techniques guarantee precise control of the output pulse width. A LOW level at nCD terminates the output pulse immediately. Schmitt-trigger action in the trigger inputs makes the circuit highly tolerant to slower rise and fall times. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.

Orderable parts

Type number Orderable part number Ordering code (12NC) Package Buy from distributors
74HCT4538D 74HCT4538D,118 933715390118 SOT109-1 Order product
74HCT4538D 74HCT4538D,112 933715390112 SOT109-1 Order product

Features

  • Tolerant of slow trigger rise and fall times
  • Separate reset inputs
  • Triggering from falling or rising edge
  • Complies with JEDEC standard no. 7A
  • TTL input levels
  • 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

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)Rth(j-c) (K/W)Package name
74HCT4538DProduction4.5 - 5.5TTL± 430low-40~125741.732.8SO16

Package

Type numberOrderable part number, (Ordering code (12NC))StatusMarkingPackageOutline versionReflow-/Wave solderingPacking
74HCT4538D74HCT4538D,118
( 9337 153 90118 )
Active74HCT4538D
SO16
(SOT109-1)
SOT109-1SO-SOJ-REFLOW
SO-SOJ-WAVE
Reel 13" Q1/T1
74HCT4538D,112
( 9337 153 90112 )
Active74HCT4538DBulk Pack

Quality, reliability & chemical content

Type numberOrderable part numberChemical contentRoHS / RHFEFRIFRMTBF (hour)MSLMSL leadfree
74HCT4538D74HCT4538D,11874HCT4538D84.96.621.51E811
74HCT4538D74HCT4538D,11274HCT4538D84.96.621.51E811
Quality and reliability disclaimer

Documentation (8)

File nameTitleTypeDate
74HCT4538Dual retriggerable precision monostable multivibratorData sheet2017-03-23
AN11044Pin FMEA 74HC/74HCT familyApplication note2019-01-09
hchc Spice modelSPICE model2013-05-06
HCT_USER_GUIDEHC/T User GuideUser manual1997-10-31
SO-SOJ-REFLOWFootprint for reflow solderingReflow soldering2009-10-08
SO-SOJ-WAVEFootprint for wave solderingWave soldering2009-10-08
SOT109-1_118SO16; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or J Ordering code (12NC) ending 118Packing2013-04-24
SOT109-1plastic, small outline package; 16 leads; 1.27 mm pitch; 9.9 mm x 3.9 mm x 1.35 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
74HCT4538D74HCT4538D,118933715390118Reel 13" Q1/T1Order product
74HCT4538D74HCT4538D,112933715390112Bulk PackOrder product

Sample

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Sample orders normally take 2-4 days for delivery.

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