SN54AS163

SN54ALS161B, SN54ALS162B, SN54ALS163B, SN54AS161, SN54AS163 SN74ALS161B, SN74ALS163B, SN74AS161, SN74AS163 SYNCHRONOUS 4-BIT DECADE AND BINARY COUNTERS SDAS276A – DECEMBER 1994 – REVISED JULY 2000 D Internal Look-Ahead Circuitry for Fast Counting D Carry Output for n-Bit Cascading D Synchronous Counting D Synchronously Programmable D Package Options Include Plastic Small-Outline (D) and Shrink Small-Outline (DB) Packages, Ceramic Chip Carriers (FK), Standard Plastic (N) and Ceramic (J) DIPs description These synchronous, presettable, 4-bit decade and binary counters feature an internal carry look-ahead circuitry for application in high-speed counting designs. The SN54ALS162B is a 4-bit decade counter. The ’ALS161B, ’ALS163B, ’AS161, and ’AS163 devices are 4-bit binary counters. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincidentally with each other when instructed by the count-enable (ENP, ENT) 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 four flip-flops on the rising (positive-going) edge of the clock input waveform. SN54ALS161B, SN54ALS162B, SN54ALS163B, SN54AS161, SN54AS163 . . . J PACKAGE SN74ALS161B, SN74AS161, SN74AS163 . . . D OR N PACKAGE SN74ALS163B . . . D, DB, OR N PACKAGE (TOP VIEW) CLR 1 CLK 2 A3 B4 C5 D6 ENP 7 GND 8 16 VCC 15 RCO 14 QA 13 QB 12 ...