74HC251; 74HCT251

8-input multiplexer; 3-state

The 74HC251; 74HCT251 is an 8-bit multiplexer with eight binary inputs (I0 to I7), three select inputs (S0 to S2) and an output enable input (OE). The select inputs select one of the eight binary inputs and route it to the complementary outputs (Y and Y). A HIGH on OE causes the outputs to assume a high-impedance OFF-state. Inputs include clamp diodes that enable the use of current limiting resistors to interface inputs to voltages in excess of VCC.

Features and benefits

  • Wide supply voltage range from 2.0 V to 6.0 V
  • CMOS low power dissipation
  • High noise immunity
  • Latch-up performance exceeds 100 mA per JESD 78 Class II Level B
  • Complies with JEDEC standards:
    • JESD8C (2.7 V to 3.6 V)
    • JESD7A (2.0 V to 6.0 V)
  • Input levels:
    • For 74HC251: CMOS level
    • For 74HCT251: TTL level
  • Non-inverting data path
  • ESD protection:
    • HBM JESD22-A114F exceeds 2000 V
    • MM JESD22-A115-A exceeds 200 V
  • Specified from -40 °C to +85 °C and from -40 °C to +125 °C


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
74HC251DProduction2.0 - 6.0CMOS± 5.218low-40~125804.138SO16
74HC251PWProduction2.0 - 6.0CMOS± 5.218low-40~1251142.041.9TSSOP16
74HCT251DProduction4.5 - 5.5TTL± 422low-40~125804.138SO16
74HCT251PWProduction4.5 - 5.5TTL± 422low-40~1251142.041.9TSSOP16


Type numberPackagePackage informationReflow-/Wave solderingPackingStatusMarkingOrderable part number, (Ordering code (12NC))
Reel 13" Q1/T1 CECCActive74HC251D74HC251D,653
( 9337 135 20653 )
Bulk Pack, CECCActive74HC251D74HC251D,652
( 9337 135 20652 )
Reel 13" Q1/T1ActiveHC25174HC251PW,118
( 9351 883 90118 )
Bulk PackActiveHC25174HC251PW,112
( 9351 883 90112 )
Reel 13" Q1/T1 CECCActive74HCT251D74HCT251D,653
( 9337 135 30653 )
Bulk Pack, CECCActive74HCT251D74HCT251D,652
( 9337 135 30652 )
Reel 13" Q1/T1ActiveHCT25174HCT251PW,118
( 9351 883 80118 )
Bulk PackActiveHCT25174HCT251PW,112
( 9351 883 80112 )

Quality, reliability & chemical content

Type numberOrderable part numberChemical contentRoHS / RHFLeadfree conversion dateEFRIFRMTBF (hour)MSLMSL leadfree
74HC251D74HC251D,65374HC251Dweek 6, 200484.96.621.51E811
74HC251D74HC251D,65274HC251Dweek 6, 200484.96.621.51E811
74HC251PW74HC251PW,11874HC251PWweek 10, 200584.96.621.51E811
74HC251PW74HC251PW,11274HC251PWweek 10, 200584.96.621.51E811
74HCT251D74HCT251D,65374HCT251Dweek 6, 200484.96.621.51E811
74HCT251D74HCT251D,65274HCT251Dweek 6, 200484.96.621.51E811
74HCT251PW74HCT251PW,11874HCT251PWweek 10, 200584.96.621.51E811
74HCT251PW74HCT251PW,11274HCT251PWweek 10, 200584.96.621.51E811
Quality and reliability disclaimer

Documentation (8)

File nameTitleTypeDate
74HC_HCT2518-input multiplexer; 3-stateData sheet2021-02-08
AN11044Pin FMEA 74HC/74HCT familyApplication note2019-01-09
HCT_USER_GUIDEHC/T User GuideUser manual1997-10-31
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
SO-SOJ-WAVEFootprint for wave solderingWave soldering2009-10-08
SO-SOJ-REFLOWFootprint for reflow solderingReflow soldering2009-10-08
SSOP-TSSOP-VSO-WAVEFootprint for wave solderingWave soldering2009-10-08
SOT403-1plastic, thin shrink small outline package; 16 leads; 5 mm x 4.4 mm x 1.1 mm bodyPackage information2020-04-21


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