DESCRIPTION
The M74HC691 is an high speed CMOS DECADE/COUNTER REGISTER (3 STATE) fabricated with silicon gate C2MOS technology.
The internal circuit is composed of 3 stages including buffer output, which offers high noise immunity and stable output. This device incorporates 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.

■ HIGH SPEED: fMAX = 53 MHz (TYP.) at VCC = 6V
■ LOW POWER DISSIPATION: ICC = 4µA(MAX.) at TA=25°C
■ HIGH NOISE IMMUNITY: VNIH = VNIL = 28 % VCC (MIN.)
■ SYMMETRICAL OUTPUT IMPEDANCE:
    |IOH| = IOL = 6mA (MIN) for QA to QD OUTPUT
    |IOH| = IOL = 4mA (MIN) for RCO OUTPUT
■ BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL
■ WIDE OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 6V
■ PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 691