HD74HCT688
8-bit Magnitude Comparator
Description
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. A single active low enable is provided to facilitate cascading of several packages and enable comparison of words greater than 8 bits. This device is useful in memory block decoding applications, where memory block enable signals must be generated from computer address information.
Features
* * * * * * 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 A max Low Quiescent Supply Current: ICC (static) = 4 A max (Ta = 25C)
Function Table
Inputs Data P, Q P=Q P>Q PHD74HCT688
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 = 25C Item Input voltage Symbol VIH VIL Output voltage VOH Ta = -40 to +85C Max -- 0.8 -- -- 0.1 0.33 1.0 40 A A V Unit V V V Test Conditions VCC (V) 4.5 to 5.5 4.5 to 5.5 4.5 4.5 4.5 4.5 5.5 5.5 Vin = VIH or VIL I OH = -20 A I OH = -4 mA Vin = VIH or VIL I OL = 20 A I OL = 4 mA Vin = VCC or GND Vin = VCC or GND, Iout = 0 A
Min Typ Max Min 2.0 -- 4.4 -- -- -- -- 2.0
0.8 -- -- -- 4.4 4.13
4.18 -- VOL -- -- Input current Iin -- -- -- -- -- --
0.1 -- 0.26 -- 0.1 -- 4.0 --
Quiescent current I CC
AC Characteristics (CL = 50 pF, Input tr = tf = 6 ns)
Ta = 25C Item Symbol Ta = -40 to +85C Max 53 53 30 30 19 10 ns pF ns Unit ns Test Conditions VCC (V) 4.5 4.5 4.5 4.5 4.5 -- Enable to output Por Q to output
Min Typ Max Min -- -- -- -- -- -- 17 19 9 12 5 5 42 42 24 24 15 10 -- -- -- -- -- --
Propagation delay t PLH time t PHL t PLH t PHL Output rise/fall time Input capacitance t TLH t THL Cin
4
Unit: mm
24.50 25.40 Max 20 11 7.00 Max 6.30 1 0.89
1.27 Max
10 1.30 2.54 Min 5.08 Max 7.62
0.51 Min
2.54 0.25
0.48 0.10
0.25 - 0.05 0 - 15
+ 0.11
Hitachi Code JEDEC EIAJ Weight (reference value)
DP-20N -- Conforms 1.26 g
Unit: mm
12.6 13 Max
20
11
1
10
5.5
0.80 Max
2.20 Max
*0.22 0.05 0.20 0.04
0.20 7.80 + 0.30 -
1.15
0 - 8
0.70 0.20
1.27 *0.42 0.08 0.40 0.06
0.12 M
*Dimension including the plating thickness Base material dimension
0.10 0.10
0.15
Hitachi Code JEDEC EIAJ Weight (reference value)
FP-20DA -- Conforms 0.31 g
Unit: mm
12.8 13.2 Max 20 11 7.50 1 0.935 Max 10
2.65 Max
*0.27 0.05 0.25 0.04
0.25 10.40 + 0.40 -
1.45
0.20 0.10
0 - 8
0.57 0.70 + 0.30 -
1.27
*0.42 0.08 0.40 0.06
0.15 0.12 M
Hitachi Code JEDEC EIAJ Weight (reference value) FP-20DB Conforms -- 0.52 g
*Dimension including the plating thickness Base material dimension
Cautions
1. Hitachi neither warrants nor grants licenses of any rights of Hitachi's or any third party's patent, copyright, trademark, or other intellectual property rights for information contained in this document. Hitachi bears no responsibility for problems that may arise with third party's rights, including intellectual property rights, in connection with use of the information contained in this document. 2. Products and product specifications may be subject to change without notice. Confirm that you have received the latest product standards or specifications before final design, purchase or use. 3. Hitachi makes every attempt to ensure that its products are of high quality and reliability. However, contact Hitachi's sales office before using the product in an application that demands especially high quality and reliability or where its failure or malfunction may directly threaten human life or cause risk of bodily injury, such as aerospace, aeronautics, nuclear power, combustion control, transportation, traffic, safety equipment or medical equipment for life support. 4. Design your application so that the product is used within the ranges guaranteed by Hitachi particularly for maximum rating, operating supply voltage range, heat radiation characteristics, installation conditions and other characteristics. Hitachi bears no responsibility for failure or damage when used beyond the guaranteed ranges. Even within the guaranteed ranges, consider normally foreseeable failure rates or failure modes in semiconductor devices and employ systemic measures such as failsafes, so that the equipment incorporating Hitachi product does not cause bodily injury, fire or other consequential damage due to operation of the Hitachi product. 5. This product is not designed to be radiation resistant. 6. No one is permitted to reproduce or duplicate, in any form, the whole or part of this document without written approval from Hitachi. 7. Contact Hitachi's sales office for any questions regarding this document or Hitachi semiconductor products.
Hitachi, Ltd.
Semiconductor & Integrated Circuits. Nippon Bldg., 2-6-2, Ohte-machi, Chiyoda-ku, Tokyo 100-0004, Japan Tel: Tokyo (03) 3270-2111 Fax: (03) 3270-5109
URL
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Hitachi Semiconductor (America) Inc. 179 East Tasman Drive, San Jose,CA 95134 Tel: <1> (408) 433-1990 Fax: <1>(408) 433-0223 Hitachi Europe GmbH Electronic components Group Dornacher Strae 3 D-85622 Feldkirchen, Munich Germany Tel: <49> (89) 9 9180-0 Fax: <49> (89) 9 29 30 00 Hitachi Europe Ltd. Electronic Components Group. Whitebrook Park Lower Cookham Road Maidenhead Berkshire SL6 8YA, United Kingdom Tel: <44> (1628) 585000 Fax: <44> (1628) 778322 Hitachi Asia Pte. Ltd. 16 Collyer Quay #20-00 Hitachi Tower Singapore 049318 Tel: 535-2100 Fax: 535-1533 Hitachi Asia Ltd. Taipei Branch Office 3F, Hung Kuo Building. No.167, Tun-Hwa North Road, Taipei (105) Tel: <886> (2) 2718-3666 Fax: <886> (2) 2718-8180 Hitachi Asia (Hong Kong) Ltd. Group III (Electronic Components) 7/F., North Tower, World Finance Centre, Harbour City, Canton Road, Tsim Sha Tsui, Kowloon, Hong Kong Tel: <852> (2) 735 9218 Fax: <852> (2) 730 0281 Telex: 40815 HITEC HX
Copyright ' Hitachi, Ltd., 1999. All rights reserved. Printed in Japan.
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