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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
  • Fully static operation
  • 5 V, 10 V, and 15 V parametric ratings
  • Standardized symmetrical output characteristics
  • Specified from -40 °C to +85 °C and -40 °C to +125 °C
  • Complies with JEDEC standard JESD 13-B

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
HEF4538BTProduction4.5 - 15.5CMOS± 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
Reel 13" Q1/T1 CECCActiveHEF4538BTHEF4538BT,653
( 9335 079 70653 )

The variants in the table below are discontinued. See the table Discontinuation information for more information.

Type numberPackagePackage informationReflow-/Wave solderingPackingStatusMarkingOrderable part number, (Ordering code (12NC))
HEF4538BT
SO16
(SOT109-1)
SOT109-1SO-SOJ-REFLOW
SO-SOJ-WAVE
Bulk Pack, CECCDiscontinued / End-of-lifeHEF4538BTHEF4538BT,652
( 9335 079 70652 )

Discontinuation information

Type numberOrderable part number, (Ordering code (12NC))Last time buy dateLast time delivery dateReplacement productStatusComments
HEF4538BT933507970652

Quality, reliability & chemical content

Type numberOrderable part numberChemical contentRoHS / RHFLeadfree conversion dateEFRIFRMTBF (hour)MSLMSL leadfree
HEF4538BTHEF4538BT,653HEF4538BTweek 12, 200565.01.28.33E811

The variants in the table below are discontinued. See the table Discontinuation information for more information.

Type numberOrderable part numberChemical contentRoHS / RHFLeadfree conversion dateEFRIFRMTBF (hour)MSLMSL leadfree
HEF4538BTHEF4538BT,652HEF4538BTweek 12, 200565.01.28.33E811
Quality and reliability disclaimer

Documentation (8)

File nameTitleTypeDate
HEF4538BDual precision monostable multivibratorData sheet2018-10-19
AN11051Pin FMEA HEF4000 familyApplication note2019-01-09
Nexperia_Selection_guide_2020Nexperia Selection Guide 2020Selection guide2020-01-31
Nexperia_Selection_guide_2021Nexperia Selection Guide 2021Selection guide2021-01-08
SO-SOJ-WAVEFootprint for wave solderingWave soldering2009-10-08
SO-SOJ-REFLOWFootprint for reflow solderingReflow soldering2009-10-08
SOT109-1plastic, small outline package; 16 leads; 1.27 mm pitch; 9.9 mm x 3.9 mm x 1.75 mm bodyPackage information2021-01-06
WAVE_BG-BD-1Wave soldering profileWave soldering2021-09-08

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