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Product details

Parameters

Technology Family HC VCC (Min) (V) 2 VCC (Max) (V) 6 Bits (#) 4 Voltage (Nom) (V) 3.3, 5 F @ nom voltage (Max) (MHz) 28 ICC @ nom voltage (Max) (mA) 0.08 tpd @ nom Voltage (Max) (ns) 41 IOL (Max) (mA) 5.2 IOH (Max) (mA) -5.2 Function Counter Product type Binary Rating Catalog Operating temperature range (C) -40 to 85 open-in-new Find other Counter, arithmetic & parity function ICs

Package | Pins | Size

PDIP (N) 16 181 mm² 19.3 x 9.4 SOIC (D) 16 59 mm² 9.9 x 6 SOP (NS) 16 80 mm² 10.2 x 7.8 open-in-new Find other Counter, arithmetic & parity function ICs

Features

  • Wide Operating Voltage Range of 2 V to 6 V
  • Outputs Can Drive Up To 10 LSTTL Loads
  • Low Power Consumption, 80-µA Max ICC
  • Typical tpd = 13 ns
  • ±4-mA Output Drive at 5 V
  • Low Input Current of 1 µA Max
  • Single Down/Up Count-Control Line
  • Look-Ahead Circuitry Enhances Speed of Cascaded Counters
  • Fully Synchronous in Count Modes
  • Asynchronously Presettable With Load Control

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Description

The ’HC191 devices are 4-bit synchronous, reversible, up/down binary counters. Synchronous counting operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when instructed by the steering logic. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple-clock) counters.

The outputs of the four flip-flops are triggered on a low- to high-level transition of the clock (CLK) input if the count-enable (CTEN)\ input is low. A high at CTEN\ inhibits counting. The direction of the count is determined by the level of the down/up (D/U\) input. When D/U\ is low, the counter counts up, and when D/U\ is high, it counts down.

These counters feature a fully independent clock circuit. Change at the control (CTEN\ and D/U\) inputs that modifies the operating mode have no effect on the contents of the counter until clocking occurs. The function of the counter is dictated solely by the condition meeting the stable setup and hold times.

These counters are fully programmable; that is, each of the outputs can be preset to either level by placing a low on the load (LOAD)\ input and entering the desired data at the data inputs. The output changes to agree with the data inputs independently of the level of CLK. This feature allows the counters to be used as modulo-N dividers simply by modifying the count length with the preset inputs.

Two outputs are available to perform the cascading function: ripple clock (RCO)\ and maximum/minimum (MAX/MIN) count. MAX/MIN produces a high-level output pulse with a duration approximately equal to one complete cycle of the clock while the count is zero (all outputs low) counting down, or maximum (9 or 15) counting up. RCO\ produces a low-level output pulse under those same conditions, but only while CLK is low. The counters can be cascaded easily by feeding RCO\ to CTEN\ of the succeeding counter if parallel clocking is used, or to CLK if parallel enabling is used. MAX/MIN can be used to accomplish look ahead for high-speed operation.

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Technical documentation

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Type Title Date
* Datasheet SN54HC191, SN74HC191 datasheet (Rev. D) Oct. 02, 2003
Selection guides Logic Guide (Rev. AB) Jun. 12, 2017
Application notes Implications of Slow or Floating CMOS Inputs (Rev. D) Jun. 23, 2016
Application notes Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) Dec. 02, 2015
User guides LOGIC Pocket Data Book (Rev. B) Jan. 16, 2007
Application notes Semiconductor Packing Material Electrostatic Discharge (ESD) Protection Jul. 08, 2004
User guides Signal Switch Data Book (Rev. A) Nov. 14, 2003
More literature Logic Cross-Reference (Rev. A) Oct. 07, 2003
Application notes HCMOS Design Considerations (Rev. A) Sep. 09, 2002
Application notes TI IBIS File Creation, Validation, and Distribution Processes Aug. 29, 2002
Application notes CMOS Power Consumption and CPD Calculation (Rev. B) Jun. 01, 1997
Application notes Designing With Logic (Rev. C) Jun. 01, 1997
Application notes Input and Output Characteristics of Digital Integrated Circuits Oct. 01, 1996
Application notes Live Insertion Oct. 01, 1996
Application notes SN54/74HCT CMOS Logic Family Applications and Restrictions May 01, 1996
Application notes Using High Speed CMOS and Advanced CMOS in Systems With Multiple Vcc Apr. 01, 1996

Design & development

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Hardware development

EVALUATION BOARDS Download
document-generic User guide
$10.00
Description
This EVM is designed to support any logic device that has a D, DW, DB, NS, PW, P, N, or DGV package in a 14 to 24 pin count.
Features
  • Board design allows for versatility in evaluation
  • Supports a wide-range of logic devices

CAD/CAE symbols

Package Pins Download
PDIP (N) 16 View options
SO (NS) 16 View options
SOIC (D) 16 View options

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