HD74AC Datasheet, PDF (2/52 Pages) Hitachi Semiconductor – HD74AC Series Common Information

FACT Descriptions and Family Characteristics
FACT Descriptions and Family Characteristics
1. Advanced CMOS FACT Logic
FACT logic offers a unique combination of high speed, low power dissipation, high noise immunity, wide
fanout capability, extended power supply range and high reliability.
This data book describes the product line with device specifications as well as material discussing design
considerations and comparing the FACT family to predecessor technologies.
For direct replacement of LS, ALS and other TTL devices, HD74ACT circuits with TTL-type input
thresholds are included in the FACT family. These include the more popular bus drivers/transceivers as
well as many other HD74ACTXXX devices.
1.1 Characteristics
• Full logic product line
• Industry standard functions and pinouts for SSI and MSI
• Meets or exceeds JEDEC standards for HD74ACXX family
• TTL inputs on selected circuits
• High performance outputs
 Common output structure for standard and buffer drivers
 Output Sink/Source Current of 24 mA
 Transmission line driving 50 Ω guaranteed
• Operation from 2 to 6 volts guaranteed
• Temperature range –40°C to +85°C
• Improved ESD protection network
• High current latch-up immunity
1.2 Interfacing
FACT devices have a wide operating voltage range (V_CC = 2 to 6 VDC) and sufficient current drive to
interface with most other logic families available today.
Device designators are as follows:
• HD74AC is a high-speed CMOS device with CMOS input switching levels and buffered CMOS outputs
that can drive ±24 mA of I_OH and I_OL current. Industry standard HD74AC nomenclature and pinouts are
used.
• HD74ACT is a high-speed CMOS device with a TTL-to-CMOS input buffer stage. These device inputs
are designed to interface with TTL outputs operating with a V_CC = 5 V ±0.5 V with V_OH = 2.4 V and V_OL
= 0.4 V, but are functional over the entire FACT operating voltage range of 2.0 to 5.5 VDC. These
devices have buffered outputs that will drive CMOS or TTL devices with no additional interface
circuitry. HD74ACT devices have the same output structures as HD74AC devices.
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