Overview
HD74HC668 is listed in the Logic IC category. Available datasheets include documents from Hitachi Semiconductor, Renesas Technology Corp. DigiCamel provides a local PDF for online reference.
Summary
Synchronous UP/Down Decade,4-bit binary Counter
Description
This synchronous presettable decade counter features an internal carry look-ahead for cascading in highspeed counting applications. 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 inputs and internal gating. This mode of operation helps eliminate the output counting spikes that are normally associated with asynchronous (ripple-clock) counters.
Source title
HD74HC668 Datasheet(PDF) - Hitachi Semiconductor