8-bit magnitude comparator

The 74HC688 is an 8-bit magnitude comparator. It performs comparisons of two 8-bit binary or BCD words. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.

Orderable parts

Type number Orderable part number Ordering code (12NC) Package Buy from distributors
74HC688D 74HC688D,653 933713900653 SOT163-1 Order product
74HC688D 74HC688D,652 933713900652 SOT163-1 Order product


  • Compare two 8-bit words
  • Wide supply voltage range from 2.0 to 6.0 V
  • CMOS input levels
  • Complies with JEDEC standard: no. 7A
  • ESD protection:
    • HBM JESD22-A114-F 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

Target applications


Type numberProduct statusVCC (V)Logic switching levelsOutput drive capability (mA)tpd (ns)No of bitsPower dissipation considerationsTamb (Cel)Rth(j-a) (K/W)Ψth(j-top) (K/W)Rth(j-c) (K/W)Package name
74HC688DProduction2.0 - 6.0CMOS+/- 5.2178low-40~1258224.358SO20


Type numberOrderable part number, (Ordering code (12NC))StatusMarkingPackageOutline versionReflow-/Wave solderingPacking
( 9337 139 00653 )
SOT163-1Reel 13" Q1/T1 CECC
( 9337 139 00652 )
Active74HC688DBulk Pack, CECC

Quality, reliability & chemical content

Type numberOrderable part numberChemical contentRoHS / RHFLeadfree conversion dateEFRIFRMTBF (hour)MSLMSL leadfree
74HC688D74HC688D,65374HC688Dweek 30, 200484.96.621.51E811
74HC688D74HC688D,65274HC688Dweek 30, 200484.96.621.51E811
Quality and reliability disclaimer

Documentation (5)

File nameTitleTypeDate
74HC6888-bit magnitude comparatorData sheet2018-07-04
AN11044Pin FMEA 74HC/74HCT familyApplication note2019-01-09
D12_PC_sch_ver2_0-Design support1998-04-22
HCT_USER_GUIDEHC/T User GuideUser manual1997-10-31
SOT163-1plastic, small outline package; 20 leads; 1.27 mm pitch; 12.8 mm x 7.5 mm x 2.65 mm bodyOutline drawing2018-10-18


If you are in need of design/technical support, let us know and fill in the answer form, we'll get back to you shortly.


File nameTitleTypeDate
D12_PC_sch_ver2_0-Design support1998-04-22

Ordering, pricing & availability

Type numberOrderable part numberOrdering code (12NC)PackingBuy online
74HC688D74HC688D,653933713900653Reel 13" Q1/T1 CECCOrder product
74HC688D74HC688D,652933713900652Bulk Pack, CECCOrder product


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