Register once, drag and drop ECAD models into your CAD tool and speed up your design.

Click here for more information


4-bit x 16-word FIFO register

The 74HC40105 is a first-in/first-out (FIFO) "elastic" storage register that can store 16 4-bit words. It can handle input and output data at different shifting rates. This feature makes it particularly useful as a buffer between asynchronous systems. Each word position in the register is clocked by a control flip-flop, which stores a marker bit. A logic 1 signifies that the data at that position is filled and a logic 0 denotes a vacancy in that position. The control flip-flop detects the state of the preceding flip-flop and communicates its own status to the succeeding flip-flop. When a control flip-flop is in the logic 0 state and sees a logic 1 in the preceding flip-flop, it generates a clock pulse. The clock pulse transfers data from the preceding four data latches into its own four data latches and resets the preceding flip-flop to logic 0. The first and last control flip-flops have buffered outputs. All empty locations "bubble" automatically to the input end, and all valid data ripples through to the output end. As a result, the status of the first control flip-flop (data-inreadyoutput-DIR) indicates if the FIFO is full. The status of the last flip-flop (data-outreadyoutput-DOR) indicates whether the FIFO contains data. As the earliest data is removed from the bottom of the data stack (output end), all data entered later will automatically ripple toward the output. Inputs include clamp diodes that enable the use of current limiting resistors to interface inputs to voltages in excess of VCC.

This product has been discontinued, click here for discontinuation information and replacement parts.

Orderable parts

Type number Orderable part number Ordering code (12NC) Package Buy from distributors

Features and benefits

  • Independent asynchronous inputs and outputs
  • Expandable in either direction
  • Reset capability
  • Status indicators on inputs and outputs
  • 3-state outputs
  • CMOS input levels
  • Complies with JEDEC standard JESD7A
  • 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)fmax (MHz)Power dissipation considerationsTamb (°C)Rth(j-a) (K/W)Ψth(j-top) (K/W)Rth(j-c) (K/W)Package name
74HC40105DEnd of life2.0 - 6.0CMOS± 5.21530low-40~125671.024SO16


All type numbers in the table below are discontinued. See the table Discontinuation information for more information.

Type numberOrderable part number, (Ordering code (12NC))StatusMarkingPackagePackage informationReflow-/Wave solderingPacking
( 9337 147 40653 )
Discontinued / End-of-life74HC40105D
Reel 13" Q1/T1 CECC
( 9337 147 40652 )
Discontinued / End-of-life74HC40105DBulk Pack, CECC

Discontinuation information

Type numberOrderable part numberOrdering codeLast time buy dateLast time delivery dateReplacement productStatusComments
74HC40105D74HC40105D,6539337147406532021-06-302021-12-31No replacementFull withdrawal
74HC40105D74HC40105D,6529337147406522021-06-302021-12-31No replacementFull withdrawal

Quality, reliability & chemical content

All type numbers in the table below are discontinued. See the table Discontinuation information for more information.

Type numberOrderable part numberChemical contentRoHS / RHFMSLMSL leadfree
Quality and reliability disclaimer

Documentation (5)

File nameTitleTypeDate
74HC401054-bit x 16-word FIFO registerData sheet2019-04-19
AN11044Pin FMEA 74HC/74HCT familyApplication note2019-01-09
HCT_USER_GUIDEHC/T User GuideUser manual1997-10-31
SO-SOJ-REFLOWFootprint for reflow solderingReflow soldering2009-10-08
SO-SOJ-WAVEFootprint for wave solderingWave soldering2009-10-08


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.