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HEF4538BT ECAD models PCB Symbol, Footprint & ECAD Model

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.

Orderable parts

Type number Orderable part number Ordering code (12NC) Package Buy from distributors
HEF4538BT HEF4538BT,653 933507970653 SOT109-1 Order product
HEF4538BT HEF4538BT,652 933507970652 SOT109-1 Order product
HEF4538BT/S242 HEF4538BT/S242,118 935014980118 SOT109-1 Order product

Features

  • 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

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
HEF4538BTProduction4.5 - 15.5CMOS± 2.460medium-40~85783.537SO16

Package

Type numberOrderable part number, (Ordering code (12NC))StatusMarkingPackageOutline versionReflow-/Wave solderingPacking
HEF4538BTHEF4538BT,653
( 9335 079 70653 )
ActiveHEF4538BT
SO16
(SOT109-1)
SOT109-1SO-SOJ-REFLOW
SO-SOJ-WAVE
Reel 13" Q1/T1 CECC
HEF4538BT,652
( 9335 079 70652 )
ActiveHEF4538BTBulk Pack, CECC

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

Type numberOrderable part number, (Ordering code (12NC))StatusMarkingPackageOutline versionReflow-/Wave solderingPacking
HEF4538BT/S242HEF4538BT/S242,118
( 9350 149 80118 )
Withdrawn / End-of-lifeStandard Marking
SO16
(SOT109-1)
SOT109-1SO-SOJ-REFLOW
SO-SOJ-WAVE
Reel 13" Q1/T1

Discontinuation information

Type numberOrderable part numberlabel.orderingCodeLast time buy dateLast time delivery dateReplacement productStatusComments
HEF4538BT/S242HEF4538BT/S242,118935014980118

Quality, reliability & chemical content

Type numberOrderable part numberChemical contentRoHS / RHFEFRIFRMTBF (hour)MSLMSL leadfree
HEF4538BTHEF4538BT,653HEF4538BT75.32.993.34E811
HEF4538BTHEF4538BT,652HEF4538BT75.32.993.34E811

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

Type numberOrderable part numberChemical contentRoHS / RHFEFRIFRMTBF (hour)MSLMSL leadfree
HEF4538BT/S242HEF4538BT/S242,118Not available75.32.993.34E811
Quality and reliability disclaimer

Documentation (6)

File nameTitleTypeDate
HEF4538BDual precision monostable multivibratorData sheet2018-10-19
AN11051Pin FMEA HEF4000 familyApplication note2019-01-09
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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Ordering, pricing & availability

Type numberOrderable part numberOrdering code (12NC)PackingBuy online
HEF4538BTHEF4538BT,653933507970653Reel 13" Q1/T1 CECCOrder product
HEF4538BTHEF4538BT,652933507970652Bulk Pack, CECCOrder product
HEF4538BT/S242HEF4538BT/S242,118935014980118Reel 13" Q1/T1Order product

Sample

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Sample orders normally take 2-4 days for delivery.

If you do not have a direct account with Nexperia our network of global and regional distributors is available and equipped to support you with Nexperia samples.