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8-bit synchronous binary down counter

The 74HC40103 is an 8-bit synchronous down counter. It has control inputs for enabling or disabling the clock (CP), for clearing the counter to its maximum count and for presetting the counter either synchronously or asynchronously. In normal operation, the counter is decremented by one count on each positive-going transition of the clock (CP). Counting is inhibited when the terminal enable input (TE) is HIGH. The terminal count output (TC) goes LOW when the count reaches zero if TE is LOW, and remains LOW for one full clock period. When the synchronous preset enable input (PE) is LOW, data at the jam input (P0 to P7) is clocked into the counter on the next positive-going clock transition regardless of the state of TE. When the asynchronous preset enable input (PL) is LOW, data at the jam input (P0 to P7) is asynchronously forced into the counter regardless of the state of PE, TE, or CP. The jam inputs (P0 to P7) represent a single 8-bit binary word. When the master reset input (MR) is LOW, the counter is asynchronously cleared to its maximum count (decimal 255) regardless of the state of any other input. If all control inputs except TE are HIGH at the time of zero count, the counters will jump to the maximum count, giving a counting sequence of 256 clock pulses long. Device may be cascaded using the TE input and the TC output, in either a synchronous or ripple mode. 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
74HC40103D 74HC40103D,653 933714730653 SOT109-1 Order product
74HC40103D 74HC40103D,652 933714730652 SOT109-1 Order product

Features and benefits

  • Cascadable
  • Synchronous or asynchronous preset
  • Low-power dissipation
  • Complies with JEDEC standard no. 7A
  • CMOS input levels
  • ESD protection:
    • HBM JESD22-A114F exceeds 2000 V
    • MM JESD22-A115-A exceeds 200 V
  • Multiple package options
  • Specified from -40 °C to +80 °C and from -40 °C to +125 °C


  • Divide-by-n counters
  • Programmable timers
  • Interrupt timers
  • Cycle/program counters.


Type numberProduct statusVCC (V)Output drive capability (mA)Logic switching levelstpd (ns)Power dissipation considerationsTamb (°C)Rth(j-a) (K/W)Ψth(j-top) (K/W)Rth(j-c) (K/W)Package name
74HC40103DProduction2.0 - 6.0± 5.2CMOS15low-40~125561.012SO16


Type numberOrderable part number, (Ordering code (12NC))StatusMarkingPackagePackage informationReflow-/Wave solderingPacking
( 9337 147 30653 )
Reel 13" Q1/T1 CECC
( 9337 147 30652 )
Active74HC40103DBulk Pack, CECC

Quality, reliability & chemical content

Type numberOrderable part numberChemical contentRoHS / RHFEFRIFRMTBF (hour)MSLMSL leadfree
Quality and reliability disclaimer

Documentation (5)

File nameTitleTypeDate
74HC401038-bit synchronous binary down counterData sheet2017-03-17
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


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Ordering, pricing & availability

Type numberOrderable part numberOrdering code (12NC)PackingBuy online
74HC40103D74HC40103D,653933714730653Reel 13" Q1/T1 CECCOrder product
74HC40103D74HC40103D,652933714730652Bulk Pack, CECCOrder product


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