© 2001 Fairchild Semiconductor Corporation DS006244 www.fairchildsemi.com
April 1984
Revised July 2001
DM74ALS874B Dual 4-Bit D-Type Edge-Triggered Flip-Flop with 3-STATE Outputs
DM74ALS874B
Dual 4-Bit D-Type Edge-Triggered Flip-Flop
with 3-STATE Outputs
General Description
This dual 4-bit register features totem-pole 3-STATE out-
puts designed specifically for driving highly-capacitive or
relatively low-impedance loads. The high-impedance state
and increased high-logic-level drive provide this register
with the capability of being connected directly to and driv-
ing the bus lines in a bus-organized system without need
for interface or pull-up components. It is particularly attrac-
tive for implementing buffer registers, I/O ports, bidirec-
tional bus drivers, and working registers.
The eight flip-flops of the DM74ALS874B are edge-trig-
gered D-type flip-flops. On the positive transition of the
clock, the Q outputs will be set to the logic states that were
set up at the D inputs.
A buffered output control input can be used to place the
eight outputs in either a normal logic state (HIGH or LOW
logic levels) or a high-impedance state. In the high-imped-
ance state the outputs neither load nor drive the bus lines
significantly.
The output control does not affect the internal operation of
the flip-flops. That is, the old data can be retained or new
data can be entered even while the outputs are OFF.
Features
■ Switching specifications at 50 pF
■ Switching specifications guaranteed over full tempera-
ture and V
CC
range
■ Advanced oxide-isolated, ion-implanted Schottky TTL
process
■ 3-STATE buffer-type outputs drive bus lines directly
■ Space saving 300 mil wide package
■ Asynchronous clear
Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Order Number Package Number Package Description
DM74ALS874BWM M24B 24-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
DM74ALS874BNT N24C 24-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
