M54HC693

The HC690/691/692/693 are high speed CMOS COUNTER/REGISTER fabricated in silicon gate C²MOS technology.

HC690/691/692/693 have the same high speed performance of LSTTL combined with true CMOS low power consumption.

The internal circuit HC690/691/692/693 is composed of 3 stages including buffer output, which offers high noise immunity and stable output. These devices incorporate a synchronous counter, four-bit D-type register, and quadruple two-line to one-line multiplexers with three-state outputs in a single 20-pin package. The counter can be programmed from the data inputs and have enable P and enable Tinputs and a ripplecarry output for easy expansion. The register/ counter select input, R/C, selects the counter when low or the register when high for the threestate outputs, QA, QB, QC, and QD.

If the HC690/691/692/693 LOADinput (LOAD)is held "L" DATA input (AD) are loaded in to the internal counter at positive edge of counter clock input (CCK). In the counter mode, internal counter counts up at the positive of the counter clock. If the counter clear input (CCLR) is held "L", the internal counter is cleared ( synchronously to the counter clock for HC692/HC693, and asynchronously for HC690/HC691). The internal counter's outputs are stored in the output register at the positive edge of the register clock (RCK). If the register clear input (RCLR) is held "L" the register is cleared (synchronously to register clock for HC692/HC693 and asynchronously for HC690/HC691). All inputs are equipped with protection circuits against static discharge and transient excess voltage.