74HCT4538

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.

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

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
74HCT4538DB
NRND
Not for design in4.5 - 5.5TTL+/- 430low-40~12514842.0SSOP16
74HCT4538PWProduction4.5 - 5.5TTL± 430low-40~1251091.037TSSOP16

Package

Type numberPackageOutline versionReflow-/Wave solderingPackingStatusMarkingOrderable part number, (Ordering code (12NC))
74HCT4538D
SO16
(SOT109-1)
SOT109-1SO-SOJ-REFLOW
SO-SOJ-WAVE
Reel 13" Q1/T1Active74HCT4538D74HCT4538D,118
( 9337 153 90118 )
Bulk PackActive74HCT4538D74HCT4538D,112
( 9337 153 90112 )
74HCT4538DB
NRND

SSOP16
(SOT338-1)
SOT338-1SSOP-TSSOP-VSO-REFLOW
SSOP-TSSOP-VSO-WAVE
Reel 13" Q1/T1ActiveHT453874HCT4538DB,118
( 9351 887 80118 )
74HCT4538PW
TSSOP16
(SOT403-1)
SOT403-1SSOP-TSSOP-VSO-WAVE
Reel 13" Q1/T1ActiveHCT453874HCT4538PW,118
( 9351 891 40118 )
Bulk PackActiveHCT453874HCT4538PW,112
( 9351 891 40112 )

Discontinuation information

Type numberOrderable part number, (Ordering code (12NC))Last time buy dateLast time delivery dateReplacement productStatusComments
74HCT4538DB9351887801122018-12-312019-06-3074HCT4538DB

    Quality, reliability & chemical content

    Type numberOrderable part numberChemical contentRoHS / RHFLeadfree conversion dateEFRIFRMTBF (hour)MSLMSL leadfree
    74HCT4538D74HCT4538D,11874HCT4538Dweek 6, 200484.96.621.51E811
    74HCT4538D74HCT4538D,11274HCT4538Dweek 6, 200484.96.621.51E811
    74HCT4538DB
    NRND
    74HCT4538DB,11874HCT4538DBweek 12, 200511
    74HCT4538PW74HCT4538PW,11874HCT4538PWweek 10, 200584.96.621.51E811
    74HCT4538PW74HCT4538PW,11274HCT4538PWweek 10, 200584.96.621.51E811
    Quality and reliability disclaimer

    Documentation (16)

    File nameTitleTypeDate
    74HCT4538Dual retriggerable precision monostable multivibratorData sheet2017-03-23
    SOT109-1_431SO16; Reel sulfur barrier pack, SMD, 13" Q1/T1 standard product orientation Orderable part number ending ,431 or Z Ordering code (12NC) ending 431Packing2016-08-25
    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
    SO-SOJ-REFLOWFootprint for reflow solderingReflow soldering2009-10-08
    SO-SOJ-WAVEFootprint for wave solderingWave soldering2009-10-08
    SOT403-1_623TSSOP16; Reel pack; SMD, 13"; Q1 Standard product orientation; Orderable part number ending, 623 or HL; Ordering code (12NC) ending 623Packing2013-05-15
    SOT403-1_118TSSOP16; Reel pack; SMD, 13" Q1/T1 Standard product orientation Orderable part number ending ,118 or J Ordering code (12NC) ending 118Packing2013-04-08
    SOT403-1_128TSSOP16; Reel pack; SMD, 13", Turned Q4/T2 180 deg product orientation Orderable part number ending ,128 or HP Ordering code (12NC) ending 128Packing2014-10-14
    SOT403-1_653TSSOP16; Reel pack; SMD, 13"; Q1 Standard product orientation; Orderable part number ending, 653 or HL; Ordering code (12NC) ending 653Packing2013-05-15
    SOT403-1plastic, thin shrink small outline package; 16 leads; 5 mm x 4.4 mm x 1.1 mm bodyOutline drawing2018-11-14
    SSOP-TSSOP-VSO-WAVEFootprint for wave solderingWave soldering2009-10-08
    SOT338-1_431SSOP16; Reel pack, SMD, 13" Q1/T1 standard product orientation Orderable part number ending ,431 or Z Ordering code (12NC) ending 431Packing2016-10-05
    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
    SSOP-TSSOP-VSO-REFLOWFootprint for reflow solderingReflow soldering2009-10-08
    SSOP-TSSOP-VSO-WAVEFootprint for wave solderingWave soldering2009-10-08

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