54688 Datasheet | National Semiconductor

Description This equality detector utilizes advanced silicon-gate CMOS technology to pare bit for bit two 8-bit words and indicate whether or not they are equal The Pe Q output indicates equality when it is low A single active low enable is provided to facilitate cascading of several packages and enable parison of words greater than 8 bits This device is useful in memory block decoding applications where memory block enable signals must be generated from puter address information The parator bines the low power consumption of CMOS but inputs are patible with TTL logic levels and the output can drive 10 low power Schottky equivalent loads MM54HCT MM74HCT devices are intended to interface between TTL and NMOS ponents and standard CMOS devices These parts are also plug in replacements for LSTTL devices and can be used to reduce power consumption in existing designs All inputs are protected from damage due to static discharge by diodes to VCC and ground Features Y TTL input patible Y Typical propagation delay 20 ns Y Low quiescent current 80 m A maximum (74HCT Series) Y Large output current 4 m A Y Same as HCT521 Logic Diagrams C1995 National Semiconductor Corporation TL F 5371 TL F 5371 - 2 RRD-B30M105 Printed in U S A Absolute Maximum Ratings (Notes 1 2) If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage (VCC) DC Input Voltage (VIN) DC Output Voltage (VOUT) Clamp Diode Current (IIK IOK) DC Output Current per pin (IOUT) DC VCC or GND Current per pin (ICC) Storage Temperature Range (TSTG) Power Dissipation (PD) (Note 3) S O Package only b0 5 to a7 0V b1 5 to VCCa1 5V b0 5 to VCCa0 5V g20 m A g25 m A g50 m A b65 C to a150 C 600 m W 500 m W Lead Temperature (TL) (Soldering 10 seconds) 260 C Operating Conditions Supply Voltage (VCC) DC Input or Output Voltage (VIN VOUT) Operating Temp Range (TA) MM74HCT688 MM54HCT688 Min 45 0 b40 b55 Input Rise or...