SN74ALS166
PARALLEL-LOAD 8-BIT SHIFT REGISTER
SDAS156D – APRIL 1982 – REVISED AUGUST 2000
D
D
D
D
Synchronous Load
Direct Overriding Clear
Parallel-to-Serial Conversion
Package Options Include Plastic
Small-Outline (D) and Shrink Small-Outline
(DB) Packages and Standard Plastic (N) DIP
D, DB, OR N PACKAGE
(TOP VIEW)
SER
A
B
C
D
CLK INH
CLK
GND
description
The SN74ALS166 parallel-load 8-bit shift register
is compatible with most other TTL logic families.
All inputs are buffered to lower the drive
requirements. Input clamping diodes minimize
switching transients and simplify system design.
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
VCC
SH/LD
H
QH
G
F
E
CLR
These parallel-in or serial-in, serial-out registers have a complexity of 77 equivalent gates on the chip. They
feature gated clocks (CLK and CLK INH) inputs and an overriding clear (CLR) input. The parallel-in or serial-in
modes are established by the shift/load (SH/LD) input. When high, SH/LD enables the serial data (SER) input
and couples the eight flip-flops for serial shifting with each clock pulse. When low, the parallel (broadside) data
(A–H) inputs are enabled and synchronous loading occurs on the next clock pulse. During parallel loading, serial
data flow is inhibited. Clocking is accomplished on the low-to-high-level edge of the clock pulse through a
two-input positive-NOR gate, permitting one input to be used as a clock-enable or clock-inhibit function. Holding
either of the clock inputs high inhibits clocking; holding either low enables the other clock input. This allows the
system clock to be free running and the register can be stopped on command with the clock input. CLK INH
should be changed to the high level only when CLK is high. The buffered CLR overrides all other inputs, including
CLK, and sets all flip-flops to zero.
The SN74ALS166 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
INPUTS
PARALLEL
INTERNAL
OUTPUTS
OUTPUT
QH
CLR
SH/LD
CLK INH
CLK
SER
A...H
QA
L
X
X
X
X
X
L
L
L
H
X
L
L
X
X
QA0
QB0
QH0
QB
H
L
L
↑
X
a...h
a
b
h
H
H
L
↑
H
X
H
QAn
QGn
H
H
L
↑
L
X
L
QAn
QGn
H
X
H
↑
X
X
QA0
QB0
QH0
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright 2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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1
SN74ALS166
PARALLEL-LOAD 8-BIT SHIFT REGISTER
SDAS156D – APRIL 1982 – REVISED AUGUST 2000
logic symbol†
CLR
9
R
15
M1 [Shift]
M2 [Load]
SH/LD
CLK INH
CLK
SER
A
B
C
D
E
F
G
H
SRG8
6
≥1
7
1
C3/1
1, 3D
2
2, 3D
3
2, 3D
4
5
10
11
12
14
13
QH
† This symbol is in accordance with ANSI/IEEE Standard 91-1984 and IEC Publication 617-12.
logic diagram (positive logic)
SER
1
SH/LD
CLR
B
2
C
3
D
4
E
5
F
G
H
10
11
12
14
R
1A
C1
1S
R
1A
C1
1S
R
1A
C1
1S
R
1A
C1
1S
15
9
7
CLK
CLK INH 6
2
A
R
1A
C1
1S
R
1A
C1
1S
R
1A
C1
1S
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R
1A
C1
1S
• DALLAS, TEXAS 75265
13
QH
SN74ALS166
PARALLEL-LOAD 8-BIT SHIFT REGISTER
SDAS156D – APRIL 1982 – REVISED AUGUST 2000
typical clear, shift, load, inhibit, and shift sequences
CLK
CLK INH
CLR
SER
SH/LD
Parallel
Inputs
A
H
B
L
C
H
D
L
E
H
F
L
G
H
H
H
QH
Serial Shift
Clear
H
Inhibit
H
L
H
L
L
H
H
Serial Shift
Load
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
Input voltage range, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
Package thermal impedance, θJA (see Note 1): D package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73°C/W
DB package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82°C/W
N package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67°C/W
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: The package thermal impedance is calculated in accordance with JESD 51-7.
recommended operating conditions
VCC
VIH
Supply voltage
VIL
IOH
Low-level input voltage
IOL
TA
Low-level output current
High-level input voltage
MIN
NOM
MAX
4.5
5
5.5
2
High-level output current
Operating free-air temperature
0
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UNIT
V
V
0.8
V
–0.4
mA
8
mA
70
°C
3
SN74ALS166
PARALLEL-LOAD 8-BIT SHIFT REGISTER
SDAS156D – APRIL 1982 – REVISED AUGUST 2000
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
VOH
TEST CONDITIONS
MIN
VCC = 4.5 V,
VCC = 4.5 V to 5.5 V,
II = –18 mA
IOH = –0.4 mA
VOL
VCC = 4
4.5
5V
IOL = 4 mA
IOL = 8 mA
II
IIH
VCC = 5.5 V,
VCC = 5.5 V,
VI = 7 V
VI = 2.7 V
IIL
IO‡
VCC = 5.5 V,
VCC = 5.5 V,
VI = 0.4 V
VO = 2.25 V
TYP†
MAX
UNIT
–1.5
V
VCC–2
V
0.25
0.4
0.35
0.5
0.1
–30
V
mA
20
µA
–0.1
mA
–112
mA
ICC
VCC = 5.5 V,
See Note 2
14
24
mA
† All typical values are at VCC = 5 V, TA = 25°C.
‡ The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
NOTE 2: With 4.5 V applied to SER and all other inputs, except the clock, grounded, ICC is measured after a clock transition from 0 V to 4.5 V.
timing requirements over recommended operating free-air temperature range (unless otherwise
noted)
MIN
fclock
tw
tsu
Clock frequency
Pulse duration
Setup time before CLK↑
↑
CLR low
9
CLK high
10
CLK low
10
SH/LD
16
Data
UNIT
45
MHz
ns
ns
7
CLR inactive
th
MAX
11
Hold time, data after CLK↑
3
ns
switching characteristics over recommended operating conditions (unless otherwise noted)
(see Figure 1)
FROM
(INPUT)
TO
(OUTPUT)
tPHL
CLR
QH
tPLH
tPHL
CLK
QH
PARAMETER
fmax
MAX
4
9
14
2
7
12
2
9
13
45
† All typical values are at VCC = 5 V, TA = 25°C.
4
TYP†
MIN
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UNIT
MHz
ns
ns
SN74ALS166
PARALLEL-LOAD 8-BIT SHIFT REGISTER
SDAS156D – APRIL 1982 – REVISED AUGUST 2000
PARAMETER MEASUREMENT INFORMATION
Test
Point
TEST TABLE FOR SYNCHRONOUS INPUTS
From Output
Under Test
CL = 50 pF
(see Note A)
RL = 500 Ω
DATA INPUT
FOR TEST
SH/LD
OUTPUT TESTED
(see Note B)
H
0V
QH at tn + 1
Serial input
4.5 V
QH at tn + 1
LOAD CIRCUIT FOR OUTPUT UNDER TEST
tw(clear)
3.5 V
CLR
(see Note C)
CLK
(see Note E)
1.3 V
1.3 V
0.3 V
tn
1.3 V
1.3 V
tn + 1 (see Note D)
tn
1.3 V
tn + 1
3.5 V
1.3 V
0.3 V
tw(CLK)
tsu
th
tsu
1.3 V
1.3 V
th
3.5
Data Input
(see Test Table)
1.3 V
1.3 V
0.3 V
tPHL
tPLH
tPHL
VOH
Output QH
VOL
VOLTAGE WAVEFORMS
NOTES: A.
B.
C.
D.
E.
CL includes probe and jig capacitance.
Propagation delay times (tPLH and tPHL) are measured at tn+1. Proper shifting of data is verified at tn+8 with a functional test.
A clear pulse is applied prior to each test.
tn = bit time before clocking transition, tn+1 = bit time after one clocking transition, and tn+8 = bit time after eight clocking transitions.
The clock pulse has the following characteristics: tw(clock) ≤ 20 ns and PRR = 1 MHz. The clear pulse has the following
characteristics: tw(clear) ≤ 20 ns.
F. All pulse generators have the following characteristics: ZO ≈ 50 Ω; tr = tf = 2 ns. Duty cycle = 50% when testing fmax.
Figure 1. Load Circuit and Voltage Waveforms
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5
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
SN74ALS166D
ACTIVE
SOIC
D
16
40
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS166
SN74ALS166DBR
ACTIVE
SSOP
DB
16
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
G166
SN74ALS166DR
ACTIVE
SOIC
D
16
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS166
SN74ALS166N
ACTIVE
PDIP
N
16
25
RoHS & Green
NIPDAU
N / A for Pkg Type
0 to 70
SN74ALS166N
SN74ALS166NSR
ACTIVE
SO
NS
16
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS166
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of