
September 1983
Revised February 1999
MM74HC165 Parallel-in/Serial-out 8-Bit Shift Register
© 1999 Fairchild Semicond uctor Corpor ation DS005316.prf www.fairchildsemi.com
MM74HC165
Parallel-in/Serial-out 8-Bit Shift Register
General Descript ion
The MM 74HC165 h igh speed PARALLE L-I N /SE RIA L-O U T
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 QA to QH
when clocked. Parallel inputs to each stage are enabled by
a low level at the SHIFT/LOAD input. Also included is a
gated CLOCK in put and a compl ementa ry output from t he
eighth bit.
Clocking is accomplishe d throu gh a 2-inp ut NOR ga te per-
mitting one input to be used as a CLOCK INHIBIT function.
Holding either of the CLOCK in puts high inhibits clocking,
and holding either CLOCK input low with the SHIFT/LOAD
input high enables the other 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 inter-
nal diode clamps to VCC and ground.
Features
■Typical propagation delay: 20 ns (clock to Q)
■Wide operating supply voltage range: 2–6V
■Low input curre nt: 1 µA maximum
■Low quiescent supply current: 80 µA maximum (74HC
Series)
■Fanout of 10 LS-TTL loads
Ordering Code:
Devices also ava ilable in Ta pe and Reel. Spe ci fy by append ing the suffix let t er “X” to the o rdering code.
Connection Diagram
Pin Assignments for DIP, SOIC, SOP and TSSOP
Top View
Function Table
H = HIGH Level (steady state), L = LOW Level (steady sta t e)
X = Irrelevant (an y input, including trans it ions)
↑ = Transition from LOW-to-HIGH level
QA0, QB0, QH0 = The level of QA, QB, or Q H, respectively, before the indi-
cated s te ady-stat e input con dit ions were establ is hed.
QAN, QGN = The level of QA or QG before the most recent ↑ transition of the
clock; indicates a one-bit s hif t .
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 QH
Load Inhibit A. . .H QAQB
LXXXa...habh
HL LX XQ
A0 QB0 QH0
HL ↑HXHQ
AN QGN
HL ↑LXLQ
AN QGN
HHXX XQ
A0 QB0 QH0