September 1983
Revised February 1999
MM74HC165 Parallel-in/Serial-out 8-Bit Shift Register
© 1999 Fairchild Semiconductor Corporation DS005316.prf www.fairchildsemi.com
MM74HC165
Parallel-in/Serial-out 8-Bit Shift Register
General Description
The MM74HC165 h i gh sp ee d PARALLEL-IN/S E RIA L-O UT
SHIFT REGISTER utilizes advanced silicon-gate CMOS
technology. It has the low power consumption and high
noise immunity of standard CMOS integrated circuits,
along with the ability to drive 10 LS-TTL loads.
This 8-bit serial shift register shifts data from Q
A
to Q
H
when clocked. Parallel inputs to each stage are enabled by
a low level at the SHI FT/LOAD input. Also included is a
gated CLOCK in put and a comple mentary output fr om the
eighth bit.
Clocking is accomplished throu gh a 2-inp ut NOR ga te permitting one input to be used as a CLOCK INHIBIT function.
Holding either of the CL OCK inputs high in hibits clocking,
and holding either CLOCK input low with the SHIFT/LOAD
input high enables the othe r CLOCK input. Data transfer
occurs on the positive going edge of the clock. Parallel
loading is inhibited as long as the SHIFT/LOAD input is
HIGH. When taken LOW, data at the parallel inputs is
loaded directly into the re gister ind epend ent of the stat e of
the clock.
The 74HC logic family is functionally as well as pin-out
compatible with the standard 74LS logic family. All inputs
are protected from damage due to static discharge by internal diode clamps to V
CC
and ground.
Features
■ Typical propagation delay: 20 ns (clock to Q)
■ Wide operating supply voltage range: 2–6V
■ Low input current: 1 µA maximum
■ Low quiescent suppl y current: 80 µA maximum (74HC
Series)
■ Fanout of 10 LS-TTL loads
Ordering Code:
Devices also availab le in Tape and Reel. Specify by appending th e s uffix let t er “X” to the ordering cod e.
Connection Diagram
Pin Assignments f or DIP, SOIC, SOP and TSSOP
Top View
Function Table
H = HIGH Level (steady state), L = LOW Level (steady state)
X = Irrelevant (any input, inc luding transitions)
↑ = Transition from LOW-to-HIGH level
Q
A0
, QB0, QH0 = The lev el of QA, QB, or QH, respectively, before the indi-
cated steady-stat e input conditions were es t ablished.
Q
AN
, QGN = The level of QA or QG before the most recent ↑ transition of the
clock; indicates a one-bit shift.
Order Number Package Number Package Description
MM74HC165M M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow
MM74HC165SJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
MM74HC165MTC MTC16 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
MM74HC165 N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
Inputs Internal Output
Shift/ Clock
Clock Serial
Parallel
Outputs
Q
H
Load Inhibit
A. . .H Q
AQB
LXXXa...habh
HL LX XQ
A0QB0QH0
HL ↑ HXHQANQ
GN
HL ↑ LXLQANQ
GN
HHXX XQA0QB0Q
H0