© 2000 Fairchild Semiconductor Corporation DS006431 www.fairchildsemi.com
April 1986
Revised March 2000
DM74LS373

•
D
M
74LS37
4 3-
ST
A
T
E
Octal
D-
T
ype T
r
anspar
ent
Lat
ches a
nd Edge-
T
r
i
ggere
d
Fl
ip-
F
l
ops
DM74LS373 • DM74LS374
3-STATE Octal D-Type Transparent Latches
and Edge-Triggered Flip-Flops
General Description
These 8-bit registers feature totem-pole 3-STATE outputs
designed specifically for driving highly-capacitive or rela-
tively low-impedance loads. The high-impedance state and
increased high-logic level drive provide these registers with
the capability of being connected directly to and driving the
bus lines in a bus-organized system without need for inter-
face or pull-up components. They are particularly attractive
for implementing buffer registers, I/O ports, bidirectional
bus drivers, and working registers.
The eight latches of the DM74LS373 are transparent D-
type latches meaning that while the enable (G) is HIGH the
Q outputs will follow the data (D) inputs. When the enable
is taken LOW the output will be latched at the level of the
data that was set up.
The eight flip-flops of the DM74LS374 are edge-triggered
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 latches or flip-flops. That is, the old data can be
retained or new data can be entered even while the outputs
are OFF.
Features
a73 Choice of 8 latches or 8 D-type flip-flops in a single
package
a73 3-STATE bus-driving outputs
a73 Full parallel-access for loading
a73 Buffered control inputs
a73 P-N-P inputs reduce D-C loading on data lines

Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Order Number Package Number Package Description
DM74LS373WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74LS373SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74LS373N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
DM74LS374WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74LS374SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
IDM29901NC N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide