The ’ACT161 devices are 4-bit binary counters. These synchronous, presettable counters feature an internal carry look-ahead for application in high-speed counting designs. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when so instructed by the count-enable (ENP, ENT) inputs and internal gating. This mode of operation eliminates the output counting spikes that normally are associated with synchronous (ripple-clock) counters. A buffered clock (CLK) input triggers the four flip-flops on the rising (positive-going) edge of the clock waveform.
These devices are fully programmable; that is, they can be preset to any number between 0 and 9 or 15. Presetting is synchronous; therefore, setting up a low level at the load input disables the counter and causes the outputs to agree with the setup data after the next clock pulse, regardless of the levels of the enable inputs.
The clear function is asynchronous. A low level at the clear (CLR)\ input sets all four of the flip-flop outputs low, regardless of the levels of the CLK, load (LOAD)\, or enable inputs.
The carry look-ahead circuitry provides for cascading counters for n-bit synchronous applications without additional gating. Instrumental in accomplishing this function are ENP, ENT, and a ripple-carry output (RCO). Both ENP and ENT must be high to count, and ENT is fed forward to enable RCO. Enabling RCO produces a high-level pulse while the count is maximum (9 or 15 with QA high). This high-level overflow ripple-carry pulse can be used to enable successive cascaded stages. Transitions at ENP or ENT are allowed, regardless of the level of CLK.
The counters feature a fully independent clock circuit. Changes at control inputs (ENP, ENT, or LOAD\) that modify the operating mode have no effect on the contents of the counter until clocking occurs. The function of the counter (whether enabled, disabled, loading, or counting) is dictated solely by the conditions meeting the stable setup and hold times.
| Typ | Titel | Datum | ||
|---|---|---|---|---|
| * | Data sheet | CD54ACT161, CD74ACT161 datasheet (Rev. B) | 24 Mär 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 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 | Selecting the Right Level Translation Solution (Rev. A) | 22 Jun 2004 | ||
| 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 | Using High Speed CMOS and Advanced CMOS in Systems With Multiple Vcc | 01 Apr 1996 |
Weitere Bedingungen oder erforderliche Ressourcen enthält gegebenenfalls die Detailseite, die Sie durch Klicken auf einen der unten stehenden Titel erreichen.
| Gehäuse | Pins | Herunterladen |
|---|---|---|
| CDIP (J) | 16 | Optionen anzeigen |
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.