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74HC161DB

Presettable synchronous 4-bit binary counter; asynchronous reset

The 74HC161 is a synchronous presettable binary counter with an internal look-head carry. Synchronous operation is provided by having all flip-flops clocked simultaneously on the positive-going edge of the clock (CP). The outputs (Q0 to Q3) of the counters may be preset HIGH or LOW. A LOW at the parallel enable input (PE) disables the counting action and causes the data at the data inputs (D0 to D3) to be loaded into the counter on the positive-going edge of the clock. Preset takes place regardless of the levels at count enable inputs (CEP and CET). A LOW at the master reset input (MR) sets Q0 to Q3 LOW regardless of the levels at input pins CP, PE, CET and CEP (thus providing an asynchronous clear function). The look-ahead carry simplifies serial cascading of the counters. Both CEP and CET must be HIGH to count. The CET input is fed forward to enable the terminal count output (TC). The TC output thus enabled will produce a HIGH output pulse of a duration approximately equal to a HIGH output of Q0. This pulse can be used to enable the next cascaded stage. The maximum clock frequency for the cascaded counters is determined by the CP to TC propagation delay and CEP to CP set-up time, according to the following formula:

fmax= 1 / ( tP(max)(CPtoTC) + tSU(CEPtoCP) ).

Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.

Not recommended for new designs (NRND).
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

  • Complies with JEDEC standard no. 7A
  • Input levels:
    • For 74HC161: CMOS level
  • Synchronous counting and loading
  • 2 count enable inputs for n-bit cascading
  • Asynchronous reset
  • Positive-edge triggered clock
  • ESD protection: category:
    • HBM JESD22-A114F exceeds 2000 V
    • MM JESD22-A115-A exceeds 200 V
  • Multiple package options
  • Specified from -40 °C to +85 °C and -40 °C to +125 °C

Applications

Parametrics

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)Package name
74HC161DB
NRND
End of life2.0 - 6.0+/- 5.2CMOS19low-40~12514842.0SSOP16

Package

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
74HC161DB
NRND
74HC161DB,118
( 9351 745 10118 )
Discontinued / End-of-lifeHC161
SSOP16
(SOT338-1)
SOT338-1SSOP-TSSOP-VSO-REFLOW
SSOP-TSSOP-VSO-WAVE
Reel 13" Q1/T1
74HC161DB,112
( 9351 745 10112 )
Discontinued / End-of-lifeHC161Bulk Pack

Discontinuation information

Type numberOrderable part numberOrdering codeLast time buy dateLast time delivery dateReplacement productStatusComments
74HC161DB
NRND
74HC161DB,1189351745101182020-06-302020-12-3074HC161PWFull withdrawal
74HC161DB
NRND
74HC161DB,1129351745101122020-06-302020-12-3074HC161PWFull 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
74HC161DB
NRND
74HC161DB,11874HC161DB11
74HC161DB
NRND
74HC161DB,11274HC161DB11
Quality and reliability disclaimer

Documentation (6)

File nameTitleTypeDate
74HC161Presettable synchronous 4-bit binary counter; asynchronous resetData sheet2018-10-04
AN11044Pin FMEA 74HC/74HCT familyApplication note2019-01-09
hchc Spice modelSPICE model2013-05-06
HCT_USER_GUIDEHC/T User GuideUser manual1997-10-31
SSOP-TSSOP-VSO-WAVEFootprint for wave solderingWave soldering2009-10-08
SSOP-TSSOP-VSO-REFLOWFootprint for reflow solderingReflow soldering2009-10-08

Support

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Models

File nameTitleTypeDate
hchc Spice modelSPICE model2013-05-06