Hitachi HD74HCT688
The HD74HCT688 compares bit for bit two 8-bit words and indicate whether or not they are equal. The P=Q output indicates equality when it is low. This device is useful in memory block decoding applications, where memory block enable signals must be generated from computer address information.| Part No. | HD74HCT688 |
|---|---|
| Datasheet | HD74HCT688 Download |
| Manufacturer |  Hitachi |
| Description | 8-bit Magnitude Comparator |
| Buy | Stock & Price |
DESCRIPTION
The P=Q output indicates equality when it is low. A single active low enable is provided to facilitate cascading of several packages and enable comparison of words greater than 8 bits.FEATURES
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● LSTTL Output Logic Level Compatibility as well as CMOS Output Compatibility High Speed Operation: tpd (Data to P=Q) = 18 ns typ (CL = 50 pF) High Output Current: Fanout of 10 LSTTL Loads Wide Operating Voltage: VCC = 4.5 to 5.5 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C) Function Table Inputs Data P, Q P=Q P>Q P<Q X Enable G L L L H P=Q L H H H HD74HCT688 Pin Arrangement G P0 Q0 P1 Q1 P2 Q2 P3 Q3 1 2 3 4 5 6 7 8 9 20 VCC 19 P=Q 18 Q7 17 P7 16 Q6 15 P6 14 Q5 13 P5 12 Q4 11 P4 (Top view) GND 10 2 HD74HCT688 Block Diagram P0 Q0 P1 Q1 P2 Q2 P3 Q3 P4 P=Q Q4 P5 Q5 P6 Q6 P7 Q7 G 3 HD74HCT688 DC Characteristics Ta = 25°C Item Input voltage Symbol VIH VIL Output voltage VOH Ta = –40 to +85°C Max — 0.8 — — 0.1 0.33 ±1.0 40 µA µA V...
