CD54ACT161

CD54ACT161, CD74ACT161 4-BIT SYNCHRONOUS BINARY COUNTERS D Inputs Are TTL-Voltage Compatible D Internal Look-Ahead for Fast Counting D Carry Output for n-Bit Cascading D Synchronous Counting D Synchronously Programmable D SCR-Latchup-Resistant CMOS Process and Circuit Design D Exceeds 2-kV ESD Protection per MIL-STD-883, Method 3015 description/ordering information SCHS298B – APRIL 2000 – REVISED MARCH 2003 CD54ACT161 . . . F PACKAGE CD74ACT161 . . . E OR M PACKAGE (TOP VIEW) CLR 1 CLK 2 A3 B4 C5 D6 ENP 7 GND 8 16 VCC 15 RCO 14 QA 13 QB 12 QC 11 QD 10 ENT 9 LOAD 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, regardle...