INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
• The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications • The IC06 74HC/HCT/HCU/HCMOS Logic Package Information • The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
74HC/HCT688 8-bit magnitude comparator
Product specification File under Integrated Circuits, IC06 December 1990
Philips Semiconductors
Product specification
8-bit magnitude comparator
FEATURES • Compare two 8-bit words • Output capability: standard • ICC category: MSI GENERAL DESCRIPTION
74HC/HCT688
The 74HC/HCT688 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC/HCT688 are 8-bit magnitude comparators. They perform comparison of two 8-bit binary or BCD words. The output provides P = Q.
QUICK REFERENCE DATA GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns TYPICAL SYMBOL tPHL/ tPLH PARAMETER propagation delay Pn, Qn to P = Q E to P = Q CI CPD Notes 1. CPD is used to determine the dynamic power dissipation (PD in µW): PD = CPD × VCC2 × fi + ∑ (CL × VCC2 × fo) fi = input frequency in MHz fo = output frequency in MHz ∑ (CL × VCC2 × fo) = sum of outputs CL = output load capacitance in pF VCC = supply voltage in V 2. For HC the condition is VI = GND to VCC For HCT the condition is VI = GND to VCC − 1.5 V ORDERING INFORMATION See “74HC/HCT/HCU/HCMOS Logic Package Information”. where: input capacitance power dissipation capacitance per package notes 1 and 2 CONDITIONS HC CL = 15 pF; VCC = 5 V 17 8 3.5 30 17 12 3.5 30 ns ns pF pF HCT UNIT
December 1990
2
Philips Semiconductors
Product specification
8-bit magnitude comparator
PIN DESCRIPTION PIN NO. 1 2, 4, 6, 8, 11, 13, 15, 17 3, 5, 7, 9, 12, 14, 16, 18 10 19 20 SYMBOL E P0 to P7 Q0 to Q7 GND P=Q VCC NAME AND FUNCTION enable input (active LOW) word inputs word inputs ground (0 V) equal to output positive supply voltage
74HC/HCT688
Fig.1 Pin configuration.
Fig.2 Logic symbol.
Fig.3 IEC logic symbol.
December 1990
3
Philips Semiconductors
Product specification
8-bit magnitude comparator
74HC/HCT688
Fig.4 Functional diagram.
Fig.5 Logic diagram.
FUNCTION TABLE INPUTS DATA Pn, Qn P=Q X P>Q P
