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HEF4538B

Dual precision monostable multivibrator

The HEF4538B is a dual retriggerable-resettable monostable multivibrator. Each multivibrator has an active LOW trigger/retrigger input (nA), an active HIGH trigger/retrigger input (nB), an overriding active LOW direct reset input (nCD), an output (nQ) and its complement (nQ), and two pins (nREXT/CEXT, and nCEXT, always connected to ground) for connecting the external timing components CEXT and REXT. Typical pulse width variation over the specified temperature range is ±0.2 %.

The multivibrator may be triggered by either the positive or the negative edges of the input pulse and will produce an accurate output pulse with a pulse width range of 10 μs to infinity. 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 REXT × CEXT. The linear design techniques in LOCMOS (Local Oxide CMOS) guarantee precise control of the output pulse width. A LOW level at nCD terminates the output pulse immediately. The trigger inputs’ Schmitt trigger action makes the circuit highly tolerant of slower rise and fall times.

It operates over a recommended VDD power supply range of 3 V to 15 V referenced to VSS (usually ground). Unused inputs must be connected to VDD, VSS, or another input.

Features and benefits

  • Tolerant of slow trigger rise and fall times

  • Wide supply voltage range from 3.0 V to 15.0 V

  • CMOS low power dissipation

  • High noise immunity

  • Fully static operation

  • 5 V, 10 V, and 15 V parametric ratings

  • Standardized symmetrical output characteristics

  • Complies with JEDEC standard JESD 13-B

  • ESD protection:
    • HBM JESD22-A114F exceeds 2 kV

    • MM JESD22-A115-B exceeds 200 V

  • Specified from -40 °C to +85 °C and -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
HEF4538BTProduction3.0 - 15CMOS± 2.460medium-40~85783.537SO16

Package

Type numberPackagePackage informationReflow-/Wave solderingPackingStatusMarkingOrderable part number, (Ordering code (12NC))
HEF4538BT
SO16
(SOT109-1)
SOT109-1SO-SOJ-REFLOW
SO-SOJ-WAVE
SOT109-1_653ActiveHEF4538BTHEF4538BT,653
( 9335 079 70653 )

Discontinuation information

Type numberOrderable part number, (Ordering code (12NC))Last time buy dateLast time delivery dateReplacement productStatusComments
HEF4538BT9335079706522021-12-312022-06-30HEF4538BT

    Environmental information

    Type numberOrderable part numberChemical contentRoHSRHF-indicatorLeadfree conversion date
    HEF4538BTHEF4538BT,653HEF4538BTweek 12, 2005
    Quality and reliability disclaimer

    Documentation (7)

    File nameTitleTypeDate
    HEF4538BDual precision monostable multivibratorData sheet2022-03-04
    AN11051Pin FMEA HEF4000 familyApplication note2019-01-09
    Nexperia_Selection_guide_2023Nexperia Selection Guide 2023Selection guide2023-05-10
    SO-SOJ-WAVEFootprint for wave solderingWave soldering2009-10-08
    SO-SOJ-REFLOWFootprint for reflow solderingReflow soldering2009-10-08
    WAVE_BG-BD-1Wave soldering profileWave soldering2021-09-08
    SOT109-1plastic, small outline package; 16 leads; 1.27 mm pitch; 9.9 mm x 3.9 mm x 1.75 mm bodyPackage information2023-11-07

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