MC74AC646, MC74ACT646
Octal Transceiver/Register
with 3-State Outputs
(Non-inverting)
The MC74AC646/74ACT646 consist of registered bus transceiver
circuits, with outputs, D–type flip–flops and control circuitry
providing multiplexed transmission of data directly from the input
bus or from the internal storage registers. Data on the A or B bus will
be loaded into the respective registers on the LOW–to–HIGH
transition of the appropriate clock pin (CAB or CBA). The four
fundamental data handling functions available are illustrated Figures
1 to 4.
http://onsemi.com
PDIP–24
N SUFFIX
CASE 724
24
1
SO–24
DW SUFFIX
CASE 751E
• Independent Registers for A and B Buses
• Multiplexed Real–Time and Stored Data Transfers
• Choice of True and Inverting Data Paths
• 3–State Outputs
24
1
MARKING DIAGRAMS
PDIP–24
• 300 mil Slim Dual In–Line Package
• Outputs Source/Sink 24 mA
• ′ACT646 Has TTL Compatible Inputs
MC74AC646N
AWLYYWW
REAL TIME TRANSFER
AĆBUS TO BĆBUS
REAL TIME TRANSFER
BĆBUS TO AĆBUS
MC74ACT646N
AWLYYWW
AĆBUS
AĆBUS
REG
REG
REG
REG
SO–24
BĆBUS
BĆBUS
AC646
AWLYYWW
Figure 1.
Figure 2.
ACT646
AWLYYWW
STORAGE
TRANSFER
FROM BUS TO REGISTER
FROM REGISTER TO BUS
AĆBUS
AĆBUS
A
= Assembly Location
L, WL = Wafer Lot
Y, YY = Year
W, WW = Work Week
REG
REG
REG
REG
BĆBUS
BĆBUS
ORDERING INFORMATION
Figure 3.
Figure 4.
Device
Package
PDIP–24
PDIP–24
SOIC–24
Shipping
MC74AC646N
15 Units/Rail
15 Units/Rail
30 Units/Rail
MC74ACT646N
MC74AC646DW
MC74AC646DWR2
SOIC–24 1000 Tape & Reel
SOIC–24 30 Units/Rail
MC74ACT646DW
MC74ACT646DWR2 SOIC–24 1000 Tape & Reel
Semiconductor Components Industries, LLC, 2001
1
Publication Order Number:
May, 2001 – Rev. 5
MC74AC646/D
ONSEMI [ ONSEMI ]
