The TC74HC85AF is a high-speed CMOS 4-bit magnitude comparator fabricated with silicon gate CMOS technology. It achieves high-speed operation similar to equivalent Bipolar Schottky TTL while maintaining the CMOS low power dissipation. This device compares two 4-bit words (A and B) and determines whether A is greater than B, A is less than B, or A is equal to B. These conditions are indicated by the appropriate outputs.

Applications

• Parity checkers
• Comparators
• Code converters
• Address decoders
• Memory chip selection

Features

• High Speed: tpd = 14 ns (typ.) at VCC = 5V
• Low Power Dissipation: ICC = 4 µA (max.) at Ta = 25°C
• High Noise Immunity: VNIH = VNIL = 28 % VCC (min.)
• Output Drive Capability: 10 LSTTL Loads
• Symmetrical Output Impedance: |IOH| = IOL = 4 mA (min.)
• Balanced Propagation Delays: tPLH ≈ tPHL
• Wide Operating Voltage Range: VCC (opr) = 2 V ~ 6 V
• Pin and Function Compatible with 74LS85

Benefits

• Fast comparison of 4-bit digital words.
• Low power consumption ideal for battery-powered applications.
• High noise immunity ensures reliable operation in noisy environments.
• Easy integration with other TTL and CMOS logic circuits.
• Wide operating voltage makes it versatile for various power supply conditions.

Additional Details

The TC74HC85AF has three cascading inputs that allow several devices to be cascaded for comparing words of longer length. The device comes in a SOP16 package. The operating temperature range is -40°C to +85°C. The inputs are equipped with protection circuits against static discharge or transient excess voltage.