Produktdetails

Function Counter Bits (#) 8 Technology family ALS Supply voltage (min) (V) 4.5 Supply voltage (max) (V) 5.5 Input type Bipolar Output type Push-Pull Features High speed (tpd 10-50ns) Operating temperature range (°C) 0 to 70 Rating Catalog
Function Counter Bits (#) 8 Technology family ALS Supply voltage (min) (V) 4.5 Supply voltage (max) (V) 5.5 Input type Bipolar Output type Push-Pull Features High speed (tpd 10-50ns) Operating temperature range (°C) 0 to 70 Rating Catalog
SOIC (DW) 24 159.65 mm² 15.5 x 10.3
  • Fully Programmable With Synchronous Counting and Loading
  • SN74ALS867A and ´AS867 Have Asynchronous Clear; SN74ALS869 and ´AS869 Have Synchronous Clear
  • Fully Independent Clock Circuit Simplifies Use
  • Ripple-Carry Output for n-Bit Cascading
  • Package Options Include Plastic Small-Outline (DW) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (NT) and Ceramic (JT) 300-mil DIPs

 

  • Fully Programmable With Synchronous Counting and Loading
  • SN74ALS867A and ´AS867 Have Asynchronous Clear; SN74ALS869 and ´AS869 Have Synchronous Clear
  • Fully Independent Clock Circuit Simplifies Use
  • Ripple-Carry Output for n-Bit Cascading
  • Package Options Include Plastic Small-Outline (DW) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (NT) and Ceramic (JT) 300-mil DIPs

 

These synchronous, presettable, 8-bit up/down counters feature internal-carry look-ahead circuitry for cascading in high-speed counting applications. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincidentally with each other when so instructed by the count-enable (,) inputs and internal gating. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple-clock) counters. A buffered clock (CLK) input triggers the eight flip-flops on the rising (positive-going) edge of the clock waveform.

These counters are fully programmable; they may be preset to any number between 0 and 255. The load-input circuitry allows parallel loading of the cascaded counters. Because loading is synchronous, selecting the load mode disables the counter and causes the outputs to agree with the data inputs after the next clock pulse.

The carry look-ahead circuitry provides for cascading counters for n-bit synchronous applications without additional gating. Two count-enable (and ) inputs and a ripple-carry () output are instrumental in accomplishing this function. Both and must be low to count. The direction of the count is determined by the levels of the select (S0, S1) inputs as shown in the function table. is fed forward to enable . thus enabled produces a low-level pulse while the count is zero (all outputs low) counting down or 255 counting up (all outputs high). This low-level overflow-carry pulse can be used to enable successive cascaded stages. Transitions at and are allowed regardless of the level of CLK. All inputs are diode clamped to minimize transmission-line effects, thereby simplifying system design.

These counters feature a fully independent clock circuit. With the exception of the asynchronous clear on the SN74ALS867A and ´AS867, changes at S0 and S1 that modify the operating mode have no effect on the Q outputs until clocking occurs. For the ´AS867 and ´AS869, any time ENP\ and/or ENT\ is taken high, either goes or remains high. For the SN74ALS867A and SN74ALS869, any time is taken high, either goes or remains high. The function of the counter (whether enabled, disabled, loading, or counting) is dictated solely by the conditions meeting the stable setup and hold times.

 

The SN54AS867 and SN54AS869 are characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS867A, SN74ALS869, SN74AS867, and SN74AS869 are characterized for operation from 0°C to 70°C.

 

 

These synchronous, presettable, 8-bit up/down counters feature internal-carry look-ahead circuitry for cascading in high-speed counting applications. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincidentally with each other when so instructed by the count-enable (,) inputs and internal gating. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple-clock) counters. A buffered clock (CLK) input triggers the eight flip-flops on the rising (positive-going) edge of the clock waveform.

These counters are fully programmable; they may be preset to any number between 0 and 255. The load-input circuitry allows parallel loading of the cascaded counters. Because loading is synchronous, selecting the load mode disables the counter and causes the outputs to agree with the data inputs after the next clock pulse.

The carry look-ahead circuitry provides for cascading counters for n-bit synchronous applications without additional gating. Two count-enable (and ) inputs and a ripple-carry () output are instrumental in accomplishing this function. Both and must be low to count. The direction of the count is determined by the levels of the select (S0, S1) inputs as shown in the function table. is fed forward to enable . thus enabled produces a low-level pulse while the count is zero (all outputs low) counting down or 255 counting up (all outputs high). This low-level overflow-carry pulse can be used to enable successive cascaded stages. Transitions at and are allowed regardless of the level of CLK. All inputs are diode clamped to minimize transmission-line effects, thereby simplifying system design.

These counters feature a fully independent clock circuit. With the exception of the asynchronous clear on the SN74ALS867A and ´AS867, changes at S0 and S1 that modify the operating mode have no effect on the Q outputs until clocking occurs. For the ´AS867 and ´AS869, any time ENP\ and/or ENT\ is taken high, either goes or remains high. For the SN74ALS867A and SN74ALS869, any time is taken high, either goes or remains high. The function of the counter (whether enabled, disabled, loading, or counting) is dictated solely by the conditions meeting the stable setup and hold times.

 

The SN54AS867 and SN54AS869 are characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS867A, SN74ALS869, SN74AS867, and SN74AS869 are characterized for operation from 0°C to 70°C.

 

 

Herunterladen Video mit Transkript ansehen Video

Ähnliche Produkte, die für Sie interessant sein könnten

Ähnliche Funktionalität wie verglichener Baustein
CD74ACT163 AKTIV Synchrone voreinstellbar binäre Zähler mit synchronem Reset Higher average drive strength (24mA)
SN74LV163A AKTIV Synchroner Binärzähler, 4 Bit Voltage range (2V to 5.5V), average drive strength (12mA), average propagation delay (9ns)

Technische Dokumentation

star =Von TI ausgewählte Top-Empfehlungen für dieses Produkt
Keine Ergebnisse gefunden. Bitte geben Sie einen anderen Begriff ein und versuchen Sie es erneut.
Alle anzeigen 11
Typ Titel Datum
* Data sheet Synchronous 8-Bit Up/Down Counters datasheet (Rev. C) 01 Jan 1995
Selection guide Logic Guide (Rev. AB) 12 Jun 2017
Application note Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) 02 Dez 2015
User guide LOGIC Pocket Data Book (Rev. B) 16 Jan 2007
Application note Semiconductor Packing Material Electrostatic Discharge (ESD) Protection 08 Jul 2004
Application note TI IBIS File Creation, Validation, and Distribution Processes 29 Aug 2002
Application note Bus-Interface Devices With Output-Damping Resistors Or Reduced-Drive Outputs (Rev. A) 01 Aug 1997
Application note Designing With Logic (Rev. C) 01 Jun 1997
Application note Input and Output Characteristics of Digital Integrated Circuits 01 Okt 1996
Application note Live Insertion 01 Okt 1996
Application note Advanced Schottky (ALS and AS) Logic Families 01 Aug 1995

Design und Entwicklung

Weitere Bedingungen oder erforderliche Ressourcen enthält gegebenenfalls die Detailseite, die Sie durch Klicken auf einen der unten stehenden Titel erreichen.

Evaluierungsplatine

14-24-LOGIC-EVM — Generisches Logikprodukt-Evaluierungsmodul für 14-polige bis 24-polige D-, DB-, DGV-, DW-, DYY-, NS-

Das 14-24-LOGIC-EVM-Evaluierungsmodul (EVM) ist für die Unterstützung aller Logikgeräte konzipiert, die sich in einem 14-Pin- bis 24-Pin-D-, DW-, DB-, NS-, PW-, DYY- oder DGV-Gehäuse befinden.

Benutzerhandbuch: PDF | HTML
Gehäuse Pins CAD-Symbole, Footprints und 3D-Modelle
SOIC (DW) 24 Ultra Librarian

Bestellen & Qualität

Beinhaltete Information:
  • RoHS
  • REACH
  • Bausteinkennzeichnung
  • Blei-Finish/Ball-Material
  • MSL-Rating / Spitzenrückfluss
  • MTBF-/FIT-Schätzungen
  • Materialinhalt
  • Qualifikationszusammenfassung
  • Kontinuierliches Zuverlässigkeitsmonitoring
Beinhaltete Information:
  • Werksstandort
  • Montagestandort

Support und Schulungen

TI E2E™-Foren mit technischem Support von TI-Ingenieuren

Inhalte werden ohne Gewähr von TI und der Community bereitgestellt. Sie stellen keine Spezifikationen von TI dar. Siehe Nutzungsbedingungen.

Bei Fragen zu den Themen Qualität, Gehäuse oder Bestellung von TI-Produkten siehe TI-Support. ​​​​​​​​​​​​​​

Videos