Philips 74HCT640
The 74HC/HCT640 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. The 74HC/HCT640 are octal transceivers featuring inverting 3-state bus compatible outputs in both send and receive directions.FEATURES
● Octal bidirectional bus interface● Inverting 3-state outputs
● Output capability: bus driver
● ICC category: MSI
GENERAL DESCRIPTION
74HC/HCT640 7A. The “640” features an output enable (OE) input for easy cascading and a send/receive (DIR) for direction control. OE controls the outputs so that the buses are effectively isolated. The “640” is similar to the “245” but has inverting outputs. QUICK REFERENCE DATA GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns TYPICAL SYMBOL tPHL/ tPLH PARAMETER propagation delay An to Bn; Bn to An input capacitance input/output capacitance power dissipation capacitance per transceiver notes 1 and 2 CONDITIONS HC CL = 15 pF; VCC = 5 V 9 HCT 9 ns UNIT CI CI/O CPD Notes 3.5 10 35 3.5 10 35 pF pF pF 1. CPD is used to determine the dynamic power dissipation (PD in µW): PD = CPD × VCC2 × fi + ∑ (CL × VCC2 × fo) where: 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.