CD74HCT161

ACTIVE

High Speed CMOS Logic 4-Bit Binary Counter with Asynchronous Reset

Product details

Function Counter Bits (#) 4 Technology family HCT Supply voltage (min) (V) 4.5 Supply voltage (max) (V) 5.5 Input type TTL-Compatible CMOS Output type Push-Pull Features Balanced outputs, High speed (tpd 10-50ns), Positive input clamp diode Operating temperature range (°C) -55 to 125 Rating Catalog
Function Counter Bits (#) 4 Technology family HCT Supply voltage (min) (V) 4.5 Supply voltage (max) (V) 5.5 Input type TTL-Compatible CMOS Output type Push-Pull Features Balanced outputs, High speed (tpd 10-50ns), Positive input clamp diode Operating temperature range (°C) -55 to 125 Rating Catalog
PDIP (N) 16 181.42 mm² 19.3 x 9.4 SOIC (D) 16 59.4 mm² 9.9 x 6
  • ’HC161, ’HCT161 4-Bit Binary Counter, Asynchronous Reset
  • ’HC163, ’HCT163 4-Bit Binary Counter, Synchronous Reset
  • Synchronous Counting and Loading
  • Two Count Enable Inputs for n-Bit Cascading
  • Look-Ahead Carry for High-Speed Counting
  • Fanout (Over Temperature Range)
    • Standard Outputs...10 LSTTL Loads
    • Bus Driver Outputs...15 LSTTL Loads
  • Wide Operating Temperature Range . . . -55°C to 125°C
  • Balanced Propagation Delay and Transition Times
  • Significant Power Reduction Compared to LSTTL Logic ICs
  • HC Types
    • 2V to 6V Operation
    • High Noise Immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5V
  • HCT Types
    • 4.5V to 5.5V Operation
    • Direct LSTTL Input Logic Compatibility, VIL = 0.8V (Max), VIH = 2V (Min)
    • CMOS Input Compatibility, Il 1µA at VOL, VOH

The CD54HCT161 is obsolete and no longer is supplied.
Data sheet acquired from Harris Semiconductor.

  • ’HC161, ’HCT161 4-Bit Binary Counter, Asynchronous Reset
  • ’HC163, ’HCT163 4-Bit Binary Counter, Synchronous Reset
  • Synchronous Counting and Loading
  • Two Count Enable Inputs for n-Bit Cascading
  • Look-Ahead Carry for High-Speed Counting
  • Fanout (Over Temperature Range)
    • Standard Outputs...10 LSTTL Loads
    • Bus Driver Outputs...15 LSTTL Loads
  • Wide Operating Temperature Range . . . -55°C to 125°C
  • Balanced Propagation Delay and Transition Times
  • Significant Power Reduction Compared to LSTTL Logic ICs
  • HC Types
    • 2V to 6V Operation
    • High Noise Immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5V
  • HCT Types
    • 4.5V to 5.5V Operation
    • Direct LSTTL Input Logic Compatibility, VIL = 0.8V (Max), VIH = 2V (Min)
    • CMOS Input Compatibility, Il 1µA at VOL, VOH

The CD54HCT161 is obsolete and no longer is supplied.
Data sheet acquired from Harris Semiconductor.

The ’HC161, ’HCT161, ’HC163, and ’HCT163 are presettable synchronous counters that feature look-ahead carry logic for use in high-speed counting applications. The ’HC161 and ’HCT161 are asynchronous reset decade and binary counters, respectively; the ’HC163 and ’HCT163 devices are decade and binary counters, respectively, that are reset synchronously with the clock. Counting and parallel presetting are both accomplished synchronously with the negative-to-positive transition of the clock.

A low level on the synchronous parallel enable input, SPE, disables counting operation and allows data at the P0 to P3 inputs to be loaded into the counter (provided that the setup and hold requirements for SPE are met).

All counters are reset with a low level on the Master Reset input, MR. In the ’HC163 and ’HCT163 counters (synchronous reset types), the requirements for setup and hold time with respect to the clock must be met.

Two count enables, PE and TE, in each counter are provided for n-bit cascading. In all counters reset action occurs regardless of the level of the SPE\, PE and TE inputs (and the clock input, CP, in the ’HC161 and ’HCT161 types).

If a decade counter is preset to an illegal state or assumes an illegal state when power is applied, it will return to the normal sequence in one count as shown in state diagram.

The look-ahead carry feature simplifies serial cascading of the counters. Both count enable inputs (PE and TE) must be high to count. The TE input is gated with the Q outputs of all four stages so that at the maximum count the terminal count (TC) output goes high for one clock period. This TC pulse is used to enable the next cascaded stage.

The ’HC161, ’HCT161, ’HC163, and ’HCT163 are presettable synchronous counters that feature look-ahead carry logic for use in high-speed counting applications. The ’HC161 and ’HCT161 are asynchronous reset decade and binary counters, respectively; the ’HC163 and ’HCT163 devices are decade and binary counters, respectively, that are reset synchronously with the clock. Counting and parallel presetting are both accomplished synchronously with the negative-to-positive transition of the clock.

A low level on the synchronous parallel enable input, SPE, disables counting operation and allows data at the P0 to P3 inputs to be loaded into the counter (provided that the setup and hold requirements for SPE are met).

All counters are reset with a low level on the Master Reset input, MR. In the ’HC163 and ’HCT163 counters (synchronous reset types), the requirements for setup and hold time with respect to the clock must be met.

Two count enables, PE and TE, in each counter are provided for n-bit cascading. In all counters reset action occurs regardless of the level of the SPE\, PE and TE inputs (and the clock input, CP, in the ’HC161 and ’HCT161 types).

If a decade counter is preset to an illegal state or assumes an illegal state when power is applied, it will return to the normal sequence in one count as shown in state diagram.

The look-ahead carry feature simplifies serial cascading of the counters. Both count enable inputs (PE and TE) must be high to count. The TE input is gated with the Q outputs of all four stages so that at the maximum count the terminal count (TC) output goes high for one clock period. This TC pulse is used to enable the next cascaded stage.

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Technical documentation

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Type Title Date
* Data sheet CD54/74HC161, CD54/74HCT161, CD54/74HC163, CD54/74HCT163 datasheet (Rev. D) 13 Oct 2003
Application note Implications of Slow or Floating CMOS Inputs (Rev. E) 26 Jul 2021
Selection guide Logic Guide (Rev. AB) 12 Jun 2017
Application note Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) 02 Dec 2015
User guide LOGIC Pocket Data Book (Rev. B) 16 Jan 2007
Application note Semiconductor Packing Material Electrostatic Discharge (ESD) Protection 08 Jul 2004
User guide Signal Switch Data Book (Rev. A) 14 Nov 2003
Application note TI IBIS File Creation, Validation, and Distribution Processes 29 Aug 2002
Application note CMOS Power Consumption and CPD Calculation (Rev. B) 01 Jun 1997
Application note Designing With Logic (Rev. C) 01 Jun 1997
Application note SN54/74HCT CMOS Logic Family Applications and Restrictions 01 May 1996
Application note Using High Speed CMOS and Advanced CMOS in Systems With Multiple Vcc 01 Apr 1996

Design & development

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Evaluation board

14-24-LOGIC-EVM — Logic product generic evaluation module for 14-pin to 24-pin D, DB, DGV, DW, DYY, NS and PW packages

The 14-24-LOGIC-EVM evaluation module (EVM) is designed to support any logic device that is in a 14-pin to 24-pin D, DW, DB, NS, PW, DYY or DGV package,

User guide: PDF | HTML
Not available on TI.com
Package Pins CAD symbols, footprints & 3D models
PDIP (N) 16 Ultra Librarian
SOIC (D) 16 Ultra Librarian

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