The TC74AC393 is an advanced high speed CMOS 4-BIT BINARY COUNTER fabricated with silicon gate and double-layer metal wiring C2MOS technology. It achieves the high speed operation similar to equivalent Bipolar Schottky TTL while maintaining the CMOS low power dissipation. It contains two independent counter circuits in one package, so that counting or frequency division of eight binary bits can be achieved with one IC. This device changes state on the negative going transition of the CLOCK pulse. The counter can be reset to “0” (QA to QD = “L”) by a high at the CLEAR input regardless of other inputs. All inputs are equipped with protection circuits against static discharge or transient excess voltage.

Features
• High speed: fmax = 180 MHz (typ.) at VCC = 5 V
• Low power dissipation: ICC = 8 μA (max) at Ta = 25°C
• High noise immunity: VNIH = VNIL = 28% VCC (min)
• Symmetrical output impedance: |IOH| = IOL = 24 mA (min)
                                Capability of driving 50 Ω
                                transmission lines.
• Balanced propagation delays: tpLH ∼ − tpHL
• Wide operating voltage range: VCC (opr) = 2 to 5.5 V
• Pin and function compatible with 74F393