© Semiconductor Components Industries, LLC, 2015
March, 2015 − Rev. 7
1 Publication Order Number:
MC74AC646/D
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.
Features
• 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
• These are Pb−Free Devices
REAL TIME TRANSFER
A‐BUS TO B‐BUS
REAL TIME TRANSFER
B‐BUS TO A‐BUS
REG
REG REG REG
REG REG REG REG
B‐BUS B‐BUS
A‐BUS A‐BUS
B‐BUS B‐BUS
A‐BUS A‐BUS
STORAGE
FROM BUS TO REGISTER
TRANSFER
FROM REGISTER TO BUS
Figure 1. Figure 2.
Figure 3. Figure 4.
www.onsemi.com
MARKING DIAGRAMS
A = Assembly Location
WL = Wafer Lot
YY = Year
WW = Work Week
G = Pb−Free Package
SO−24
DW SUFFIX
CASE 751E
ACT646
AWLYYWWG
1
24
AC646
AWLYYWWG
See detailed ordering and shipping information in the package
dimensions section on page 9 of this data sheet.
ORDERING INFORMATION
