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
1
•
•
•
•
•
•
•
Independent Registers for A and B Buses
Multiplexed Real–Time and Stored Data Transfers
Choice of True and Inverting Data Paths
3–State Outputs
300 mil Slim Dual In–Line Package
Outputs Source/Sink 24 mA
′ACT646
Has TTL Compatible Inputs
REAL TIME TRANSFER
A BUS TO B BUS
A BUS
REG
B BUS
REG
REG
B BUS
REAL TIME TRANSFER
B BUS TO A BUS
A BUS
REG
24
MARKING DIAGRAMS
PDIP–24
MC74AC646N
AWLYYWW
MC74ACT646N
AWLYYWW
SO–24
AC646
AWLYYWW
Figure 1.
Figure 2.
STORAGE
FROM BUS TO REGISTER
A BUS
REG
B BUS
REG
TRANSFER
FROM REGISTER TO BUS
A BUS
REG
B BUS
REG
ACT646
AWLYYWW
A
= Assembly Location
L, WL = Wafer Lot
Y, YY = Year
W, WW = Work Week
ORDERING INFORMATION
Device
MC74AC646N
MC74ACT646N
MC74AC646DW
MC74AC646DWR2
MC74ACT646DW
MC74ACT646DWR2
Package
PDIP–24
PDIP–24
SOIC–24
SOIC–24
SOIC–24
SOIC–24
Shipping
15 Units/Rail
15 Units/Rail
30 Units/Rail
1000 Tape & Reel
30 Units/Rail
1000 Tape & Reel
Figure 3.
Figure 4.
©
Semiconductor Components Industries, LLC, 2001
1
May, 2001 – Rev. 5
Publication Order Number:
MC74AC646/D
ONSEMI [ ON SEMICONDUCTOR ]
