© 2005 Fairchild Semiconductor Corporation DS005366 www.fairchildsemi.com
Februa ry 198 4
Revised May 2005
MM74HCT245 Octal 3-STATE Transceiver
MM74HCT245
Octal 3-STATE Transceiver
General Descript ion
The MM74HCT245 3-STATE bi-directional buffer utilizes
advanced silicon-gate CMOS technology and is intended
for two-way asynchronous communication between data
buses. It has hi gh drive current outp uts which ena ble high
speed operation even when driving large bus capaci-
tances. Thi s circuit pos sesses the l ow power consumpt ion
of CMOS circuitry, yet has speeds comparable to low
power Schottky TTL circuits.
This de vice is TTL i npu t co mpat ib le a nd can dr i ve up to 15
LS-TTL loads, and all inputs are protected from damage
due to static discharge by diodes to VCC and ground.
The MM74HCT245 has one active low enable input (G),
and a di r ectio n co ntr ol ( D IR) . W he n the DIR input i s HIGH ,
data flows from the A inputs to the B out puts. When DI R is
LOW, data flows from B to A.
MM74HCT devices ar e intended to interfa ce betwe en TTL
and NMOS components and standard CMOS devices.
These parts are also plug-in replacements for LS-TTL
devices and can be used to red uce power consump tion in
existing designs.
Features
■TTL input compatible
■3-STATE outputs for connection to system busses
■High output drive current: 6 mA (min)
■High speed: 16 ns typi cal pro pagat i on dela y
■Low power: 80
P
A (74HCT Series)
Ordering Code:
Devices also available in Tape and R eel. Specify by appending the suffix let t er “X” to the or dering code.
Connection Diagram
Pin Assignments for DIP, SOIC, SOP and TSSOP
Top View
Truth Table
H
HIGH Level
L
LOW Le vel
X
Irrelevant
Order Number Package Number Package Description
MM74HCT245WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
MM74HCT245SJ M20D 20-Lead Small Outline Package (SOP) , EIAJ TYPE II, 5.3mm Wide
MM7 4HC T 24 5M TC MTC2 0 20-Le ad T hin S hr in k Sm al l Ou t li n e Pac ka ge ( TS S OP ), J E DE C MO - 15 3 , 4.4 mm W id e
MM74HCT245N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Control Operation
Inputs
GDIR 245
L L B data to A bus
L H A data to B bus
H X isolation