74AHCT594
8-BIT SHIFT REGISTER WITH 8-BIT OUTPUT REGISTER
Description
The 74AHCT594 is an advanced high speed CMOS device that is
designed to be pin compatable with 74LS low power Schottky types.
An eight bit shift register accepts data from the serial input (DS) on
each positive transition of the shift register clock (SHCP).
When
asserted low the shift register reset function (SHR) sets all shift
register values to zero and is independent of all clocks. Also when
asserted low, the storage register reset function (STR) sets all shift
register values to zero and is independent of all clocks.
Data from the input serial shift register is placed in the output register
with a rising pulse on the storages resister clock (STCP).
The
storage resister includes output Q7S which is used for cascading
information between devices. As the information moves into the
storage register, it is asserted on the push-pull outputs Q0-Q7.
All registers capture data on rising edge and change output on the
falling edge. If both clocks are connected together, the input shift
register is always one clock cycle ahead of the output register.
Pin Assignments
( Top View )
Q1
Q2
Q3
Q4
Q5
Q6
Q7
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
Vcc
Q0
DS
STR
STCP
SHCP
SHR
Q7S
SO-16 / TSSOP-16
Features
Wide Supply Voltage Range from 4.5V to 5.5V
Sinks or sources 8mA at V
CC
= 4.5V
CMOS low power consumption
Schmitt Trigger Action at All Inputs
Inputs accept up to 6.0V
ESD Protection Tested per JESD 22
Exceeds 200-V Machine Model (A115-A)
Exceeds 2000-V Human Body Model (A114-A)
Exceeds 1000-V Charged Device Model (C101C)
Applications
General Purpose Logic
Serial to Parallel Data conversion
Capture and hold data for extended periods of time.
Allow simple serial bit streams from a microcontroller to control as
many peripheral lines as needed.
Wide array of products such as:
Computer Peripherals
Appliances
Industrial control
Latch-Up Exceeds 250mA per JESD 78, Class II
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
Notes:
Click here for ordering information, located at the end of datasheet
74AHCT594
Document number: DS35485 Rev. 2 - 2
1 of 10
www.diodes.com
June 2013
© Diodes Incorporated
74AHCT594
Functional Description and Timing Diagram
Control
SHR
L
X
H
H
H
STR
X
L
X
H
H
SHCP
X
X
X
STCP
X
X
L
Input
DS
X
X
H or L
X
H or L
Q7S
L
NC
Q6S
NC
Q6S
Output
Qn
NC
L
NC
Qs
QnS
Clear Shift Register
Clear Storage Register
Loads DS into shift register stage 0. All Q
S
shifted
Contents of shift register moved to starge register all Q
S
-> Q
N
Shift Register one pulse count ahead of storage register.
Function
H=HIGH voltage state
L=LOW voltage state
=LOW
to HIGH transition
X= don’t care – high or low (not floating)
NC= No change
Absolute Maximum Ratings
(Note 4) (@T
A
= +25°C, unless otherwise specified.)
Symbol
ESD HBM
ESD CDM
ESD MM
V
CC
V
I
V
o
I
IK
I
OK
I
OK
I
O
I
CC
I
GND
T
J
T
STG
P
TOT
Notes:
Parameter
Human Body Model ESD Protection
Charged Device Model ESD Protection
Machine Model ESD Protection
Supply Voltage Range
Input Voltage Range
Voltage applied to output in high or low state
Input Clamp Current
Output Clamp Current
Output Clamp Current
V
I
< -0.5V
V
O
<-0.5V
V
O
> V
CC
+0.5V
Rating
2
1
200
-0.5 to +7.0
-0.5 to +7.0
-0.3 to V
CC
+0.5
-20
-20
20
±25
75
-75
-40 to +150
-65 to +150
500
Unit
KV
KV
V
V
V
V
mA
mA
mA
mA
mA
mA
°C
°C
mW
Continuous output current
Continuous current through Vcc
Continuous current through GND
Operating Junction Temperature
Storage Temperature
Total Power Dissipation
4. Stresses beyond the absolute maximum may result in immediate failure or reduced reliability. These are stress values and device
operation should be within recommend values.
74AHCT594
Document number: DS35485 Rev. 2 - 2
3 of 10
www.diodes.com
June 2013
© Diodes Incorporated
74AHCT594
Recommended Operating Conditions
(Note 5) (@T
A
= +25°C, unless otherwise specified.)
Symbol
V
CC
V
I
V
O
t/V
T
A
Note:
Parameter
Supply Voltage
Input Voltage
Output Voltage
Input transition Rise or Fall Rate
Operating Free-Air Temperature
Active Mode
Conditions
Min
4.5
0
0
-40
Max
5.5
5.5
V
CC
20
+125
Unit
V
V
V
ns/V
°C
V
CC
= 4.5V to 5.5V
5. Unused inputs should be held at V
CC
or Ground.
Electrical Characteristics
(@T
A
= +25°C, unless otherwise specified.)
Symbol
V
IH
V
IL
V
OH
V
OL
I
I
I
CC
∆I
CC
C
i
Parameter
High-level Input
Voltage
Low-level input
voltage
High Level
Output Voltage
Low-level
Output Voltage
Input Current
Supply Current
Additional
Supply Current
per Input
Input
Capacitance
I
OH
= -50μA
I
OH
= -8mA
I
OL
= 50μA
I
OL
= 8mA
V
I
= GND or 5.5V
V
I
= GND or V
CC
I
O
= 0
V
I
= V
CC
-2.1V
I
O
= 0
V
i
= V
CC
or GND
Test Conditions
V
CC
4.5V to 5.5V
4.5V to 5.5V
4.5V
4.5V
4.5V
4.5V
0V to 5.5V
5.5V
4.5V to 5.5V
5.5V
T
A
= +25°C
Min Typ Max
2.0
4.4
3.94
4.5
0
0.1
3.5
0.8
0.1
0.36
±0.1
4.0
1.35
10
T
A
= -40°C to +85°C T
A
= -40°C to +125°C
Min
Max
Min
Max
2.0
4.4
3.80
0.8
0.1
0.44
±1
40
1.5
10
2.0
4.4
3.70
0.8
0.1
0.55
±2
80
1.5
10
Unit
V
V
V
V
μA
μA
mA
pF
74AHCT594
Document number: DS35485 Rev. 2 - 2
4 of 10
www.diodes.com
June 2013
© Diodes Incorporated
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