© 2005 Fairchild Semiconductor Corporation DS009893 www.fairchildsemi.com
July 1988
Revised March 2005
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74AC299 74ACT299
8-Input Universal Shift/Storage Register
with Common Parallel I/O Pins
General Description
The AC/ACT299 is an 8-bit universal shift/storage register
with 3-STATE outputs. Four modes of operation are possi-
ble: hold (store), shift left, shift right and load data. The par-
allel load inputs and flip-flop outputs are multiplexed to
reduce the total number of package pins. Additional out-
puts are provided for flip-flops Q
0
, Q
7
to allow easy serial
cascading. A separate active LOW Master Reset is used to
reset the register.
Features
a73 I
CC
and I
OZ
reduced by 50%
a73 Common parallel I/O for reduced pin count
a73 Additional serial inputs and outputs for expansion
a73 Four operating modes: shift left, shift right, load
and store
a73 3-STATE outputs for bus-oriented applications
a73 Outputs source/sink 24 mA
a73 ACT299 has TTL-compatible inputs

Ordering Code:
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.
Pb-Free package per JEDEC J-STD-020B.
Note 1: “_NL” indicates Pb-Free package (per JEDEC J-STD-020B). Device available in Tape and Reel only.
Connection Diagram Pin Descriptions
FACTc165 is a trademark of Fairchild Semiconductor Corporation.
Order Number Package Number Package Description
74AC299SC M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
74AC299SCX_NL
(Note 1)
M20B Pb-Free 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300"
Wide
74AC299SJ M20D Pb-Free 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74AC299MTC MTC20 20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74AC299PC N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
74ACT299SC M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
74ACT299MTC MTC20 20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74ACT299PC N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Pin Names Description
CP Clock Pulse Input
DS
0
Serial Data Input for Right Shift
DS
7
Serial Data Input for Left Shift
S
0
, S
1
Mode Select Inputs
MR Asynchronous Master Reset
OE
1
, OE
2
3-STATE Output Enable Inputs
I/O
0
–I/O
7
Parallel Data Inputs or
3-STATE Parallel Outputs
Q
0
, Q
7
Serial Outputs