SN74HCT595-Q1
SCLS883A – OCTOBER 2021 – REVISED DECEMBER 2021
SN74HCT595-Q1 Automotive 8-Bit Shift Registers with 3-State Output Registers
1 Features
3 Description
•
The SN74HCT595-Q1 device contains an 8-bit, serialin, parallel-out shift register that feeds an 8-bit D-type
storage register. The storage register has parallel
3-state outputs. Separate clocks are provided for
both the shift and storage register. The shift register
has a direct overriding clear (SRCLR) input, serial
(SER) input, and a serial output (QH') for cascading.
When the output-enable (OE) input is high, the
storage register outputs are in a high-impedance
state. Internal register data and serial output (QH') are
not impacted by the operation of the OE input.
•
•
•
•
•
AEC-Q100 qualified for automotive applications:
– Device temperature grade 1:
• –40°C to +125°C, TA
– Device HBM ESD Classification Level 2
– Device CDM ESD Classifcation Level C6
LSTTL input logic compatible
– VIL(max) = 0.8 V, VIH(min) = 2 V
CMOS input logic compatible
– II ≤ 1 µA at VOL, VOH
4.5 V to 5.5 V operation
Supports fanout up to 10 LSTTL loads
Shift register has direct clear
Device Information(1)
2 Applications
•
•
•
•
Output expansion
LED matrix control
7-segment display control
8-bit data storage
PART NUMBER
PACKAGE
SN74HCT595PW-Q1
TSSOP (16)
(1)
OE
RCLK
SRCLR
SRCLK
SER
BODY SIZE (NOM)
5.00 mm × 4.40 mm
For all available packages, see the orderable addendum at
the end of the data sheet.
13
12
10
11
14
D
Q
D
Q
15
QA
R
D
Q
D
Q
1
QB
R
2
QC
3
QD
4
QE
5
QF
6
QG
D
Q
D
Q
7
QH
R
9
QH’
Logic Diagram (Positive Logic)
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
SN74HCT595-Q1
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SCLS883A – OCTOBER 2021 – REVISED DECEMBER 2021
Table of Contents
1 Features............................................................................1
2 Applications..................................................................... 1
3 Description.......................................................................1
4 Revision History.............................................................. 2
5 Pin Configuration and Functions...................................3
6 Specifications.................................................................. 4
6.1 Absolute Maximum Ratings........................................ 4
6.2 ESD Ratings............................................................... 4
6.3 Recommended Operating Conditions.........................4
6.4 Thermal Information....................................................4
6.5 Electrical Characteristics.............................................5
6.6 Timing Characteristics.................................................5
6.7 Switching Characteristics............................................6
6.8 Typical Characteristics................................................ 8
7 Parameter Measurement Information............................ 9
8 Detailed Description......................................................10
8.1 Functional Block Diagram......................................... 10
8.2 Feature Description...................................................10
8.3 Device Functional Modes..........................................12
9 Application and Implementation.................................. 13
9.1 Application Information............................................. 13
9.2 Typical Application.................................................... 14
10 Power Supply Recommendations..............................17
11 Layout........................................................................... 17
11.1 Layout Guidelines................................................... 17
11.2 Layout Example...................................................... 17
12 Device and Documentation Support..........................18
12.1 Documentation Support.......................................... 18
12.2 Receiving Notification of Documentation Updates..18
12.3 Support Resources................................................. 18
12.4 Trademarks............................................................. 18
12.5 Electrostatic Discharge Caution..............................18
12.6 Glossary..................................................................18
13 Mechanical, Packaging, and Orderable
Information.................................................................... 18
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision * (October 2021) to Revision A (December 2021)
Page
• Updated the status of the data sheet from: Advanced Information to: Production Data ....................................1
2
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5 Pin Configuration and Functions
QB
1
16
VCC
QC
2
QA
QD
QE
3
15
14
4
13
QF
5
12
RCLK
QG
QH
6
11
SRCLK
7
8
10
SRCLR
QH¶
GND
9
SER
OE
Figure 5-1. PW Package
16-Pin TSSOP
Top View
Table 5-1. Pin Functions
PIN
(1)
TYPE(1)
DESCRIPTION
NAME
NO.
QB
1
O
QB O
QC
2
O
QC O
QD
3
O
QD O
QE
4
O
QE O
QF
5
O
QF O
QG
6
O
QG O
QH
7
O
QH O
GND
8
—
Ground
QH'
9
O
Serial O, can be used for cascading
SRCLR
10
I
Shift register clear, active low
SRCLK
11
I
Shift register clock, rising edge triggered
RCLK
12
I
O register clock, rising edge triggered
OE
13
I
O Enable, active low
SER
14
I
Serial I
QA
15
O
QA O
VCC
16
—
Positive supply
Signal Types: I = Input, O = Output, I/O = Input or Output.
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6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
MIN
MAX
UNIT
VCC
Supply voltage
–0.5
7
V
IIK
Input clamp current(2)
VI < 0 or VI >VCC + 0.5 V
–20
20
mA
IOK
Output clamp current(2)
VO < 0 or VO > VCC + 0.5 V
–20
20
mA
IO
Continuous output current
VO = 0 to VCC
–35
35
mA
ICC
Continuous output current through VCC or GND
TJ
Junction temperature
Tstg
Storage temperature
(1)
(2)
–70
–65
70
mA
150
°C
150
°C
Operation outside the Absolute Maximum Ratings may cause permanent device damage. Absolute maximum ratings do not imply
functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions.
If briefly operating outside the Recommended Operating Conditions but within the Absolute Maximum Ratings, the device may not
sustain damage, but it may not be fully functional. Operating the device in this manner may affect device reliability, functionality,
performance, and shorten the device lifetime.
The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
Electrostatic discharge
Human body model (HBM), per AEC
HBM ESD Classification Level 2
Q100-002(1)
UNIT
±4000
V
Charged device model (CDM), per AEC Q100-011
CDM ESD Classification Level C4B
±1500
AEC Q100-002 indicate that HBM stressing shall be in accordrance with the ANSI/ESDA/JEDEC JS-001 specification.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
VCC
Supply voltage
VIH
High-level input voltage
VCC = 4.5 V to 5.5V
VIL
Low-level input voltage
VCC = 4.5 V to 5.5V
VI
Input voltage
VO
Output voltage
Δt/Δv
Input transition rise and fall rate
TA
Ambient temperature
MIN
NOM
MAX
4.5
5
5.5
2
UNIT
V
V
0.8
V
0
VCC
V
0
VCC
V
500
ns/V
125
°C
VCC = 4.5 V to 5.5V
–40
6.4 Thermal Information
SN74HCT595-Q1
THERMAL
METRIC(1)
PW (TSSOP)
UNIT
16 PINS
4
RθJA
Junction-to-ambient thermal resistance
131.8
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
69.8
°C/W
RθJB
Junction-to-board thermal resistance
76.5
°C/W
ΨJT
Junction-to-top characterization parameter
20.9
°C/W
YJB
Junction-to-board characterization parameter
76.1
°C/W
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6.4 Thermal Information (continued)
SN74HCT595-Q1
THERMAL
METRIC(1)
PW (TSSOP)
UNIT
16 PINS
RθJC(bot)
(1)
Junction-to-case (bottom) thermal resistance
N/A
°C/W
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
6.5 Electrical Characteristics
over operating free-air temperature range (unless otherwise noted)
PARAMETER
VOH
High-level output
voltage
TA = 25°C
TEST CONDITIONS
VI = VIH or VIL
MIN
TYP
-40°C to 125°C
MAX
MIN
TYP
MAX
UNI
T
IOH = -20 uA, VCC =
4.5 V
4.4
4.4
V
IOH = -6 mA, VCC =
4.5 V
3.98
3.84
V
IOL = 20 uA, VCC =
4.5 V
0.1
0.1
V
IOL = 6 mA, VCC =
4.5 V
0.26
0.33
V
VI = VCC or 0
VCC = 5.5 V
±100
±1000
nA
Off-State (HighImpedance State)
Output Current
VO = VCC or 0, QAQH
VCC = 5.5 V
±0.5
±5
µA
ICC
Supply current
VI = VCC or 0, IO = 0 VCC = 5.5 V
8
80
µA
VI = VCC - 2.1V
VCC = 4.5V to 5.5V
126.2
157.5
µA
ΔICC
Additional
Quiescent Device
Current Per Input
Pin
VI = 0.5 V or 2.4V
VCC = 5.5V
2.4
2.9 mA
Ci
Input capacitance
VCC = 4.5V to 5.5V
VCC = 4.5V to 5.5V
10
pF
CO
Output capacitance VCC = 4.5V to 5.5V
VCC = 4.5V to 5.5V
20
pF
Cpd
Power dissipation
capacitance per
gate
50
pF
Low-level output
voltage
VI = VIH or VIL
II
Input leakage
current
IOZ
VOL
No load
6.6 Timing Characteristics
over recommended operating free-air temperature range (unless otherwise noted)
PARAMETER
fclock
CONDITION
VCC
Clock frequency
MIN
4.5 V
SRCLK or RCLK high or
low
tw
TA = 25°C
Pulse duration
SRCLR low
-40°C to 125°C
MAX
MIN
31
MAX
25
4.5 V
16
20
5.5 V
16
20
4.5 V
16
20
5.5 V
16
20
UNIT
MHz
ns
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6.6 Timing Characteristics (continued)
over recommended operating free-air temperature range (unless otherwise noted)
PARAMETER
CONDITION
SER before SRCLK↑
SRCLK↑ before RCLK↑
tsu
Setup time
SRCLR low before RCLK↑
SRCLR high (inactive)
before SRCLK↑
th
Hold time
TA = 25°C
VCC
SER after SRCLK↑
MIN
-40°C to 125°C
MAX
MIN
4.5 V
20
25
5.5 V
20
25
4.5 V
16
20
5.5 V
16
20
4.5 V
10
13
5.5 V
10
13
4.5 V
10
12
5.5 V
10
12
4.5 V
0
0
5.5 V
0
0
MAX
UNIT
ns
ns
6.7 Switching Characteristics
over operating free-air temperature range (unless otherwise noted)
PARAMETER
FROM (INPUT)
TO (OUTPUT)
fmax
4.5 V
SRCLK
tpd
TA = 25°C
MIN
TYP
-40°C to 125°C
MAX
31
MIN
TYP
MAX
25
42
53
5.5 V
42
53
4.5 V
40
50
5.5 V
40
50
4.5 V
40
50
5.5 V
40
50
4.5 V
35
44
5.5 V
35
44
4.5 V
30
38
5.5 V
30
38
Any output
4.5 V
12
15
Any output
5.5 V
14
17
QA - QH
tPHL Propogation delay SRCLR
QH'
ten
Enable time
OE
QA - QH
tdis
Disable time
OE
QA - QH
tt
Transition-time
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UNI
T
MHz
4.5 V
QH'
Propogation delay
RCLK
6
VCC
ns
ns
ns
ns
ns
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SRCLK
SER
RCLK
SRCLR
OE
QA
QB
QC
QD
QE
QF
QG
QH
QH’
NOTE:
implies that the output is in 3-State mode.
Figure 6-1. Timing Diagram
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6.8 Typical Characteristics
TA = 25°C
4.5
0.3
VOL Ou tpu t Low Voltage (V)
VOH Ou tpu t High Voltage (V)
4.45
4.4
4.35
4.3
4.25
4.2
4.15
0.25
0.2
0.15
0.1
0.05
0
0
1
2
3
4
IOH Ou tpu t High Cu rrent (mA )
5
6
0
1
2
3
4
IOL Ou tpu t Low Cu rrent ( mA )
5
6
Figure 6-2. Typical Output Voltage in the High State Figure 6-3. Typical Output Voltage in the Low State
(VOH)
(VOL)
8
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7 Parameter Measurement Information
Phase relationships between waveforms were chosen arbitrarily. All input pulses are supplied by generators
having the following characteristics: PRR ≤ 1 MHz, ZO = 50 Ω, tt < 6 ns.
For clock inputs, fmax is measured when the input duty cycle is 50%.
The outputs are measured one at a time with one input transition per measurement.
VCC
Test
Point
Test
Point
S1
RL
From Output
Under Test
From Output
Under Test
CL(1)
CL(1)
S2
(1) CL includes probe and test-fixture capacitance.
(1) CL includes probe and test-fixture capacitance.
Figure 7-2. Load Circuit for Push-Pull Outputs
Figure 7-1. Load Circuit for 3-State Outputs
tw
VCC
Clock
Input
VCC
Input
50%
50%
50%
0V
0V
th
tsu
Figure 7-3. Voltage Waveforms, Pulse Duration
VCC
Data
Input
50%
50%
0V
Figure 7-4. Voltage Waveforms, Setup and Hold
Times
VCC
Input
50%
VCC
Output
Control
50%
50%
50%
0V
tPLH
(1)
tPHL
0V
(1)
tPZL
VOH
Output
50%
VOL
50%
10%
VOL
tPZH(3)
VOH
Output
50%
tPLH(1)
tPHL(1)
Output
Waveform 2
S1 at GND(2)
50%
VOL
tPLZ
(4)
§ 9CC
Output
Waveform 1
S1 at VLOAD(1)
50%
(3)
tPHZ(4)
90%
VOH
50%
§0V
Figure 7-6. Voltage Waveforms Propagation Delays
(1) The greater between tPLH and tPHL is the same as tpd.
Figure 7-5. Voltage Waveforms Propagation Delays
90%
VCC
90%
Input
10%
10%
tr(1)
0V
tf(1)
90%
VOH
90%
Output
10%
10%
tr(1)
tf(1)
VOL
(1) The greater between tr and tf is the same as tt.
Figure 7-7. Voltage Waveforms, Input and Output Transition Times
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8 Detailed Description
8.1 Functional Block Diagram
OE
RCLK
SRCLR
SRCLK
SER
13
12
10
11
14
D
Q
D
Q
15
QA
R
D
Q
D
Q
1
QB
R
2
QC
3
QD
4
QE
5
QF
6
QG
D
Q
D
Q
7
QH
R
9
QH’
Figure 8-1. Logic Diagram (Positive Logic) for the SN74HCT595-Q1
8.2 Feature Description
8.2.1 Balanced CMOS 3-State Outputs
This device includes balanced CMOS 3-State outputs. The three states that these outputs can be in are driving
high, driving low, and high impedance. The term balanced indicates that the device can sink and source similar
currents. The drive capability of this device may create fast edges into light loads so routing and load conditions
should be considered to prevent ringing. Additionally, the outputs of this device are capable of driving larger
currents than the device can sustain without being damaged. It is important for the output power of the device
to be limited to avoid damage due to overcurrent. The electrical and thermal limits defined in the Absolute
Maximum Ratings must be followed at all times.
When placed into the high-impedance mode, the output will neither source nor sink current, with the exception of
minor leakage current as defined in the Electrical Characteristics table. In the high-impedance state, the output
voltage is not controlled by the device and is dependent on external factors. If no other drivers are connected
to the node, then this is known as a floating node and the voltage is unknown. A pull-up or pull-down resistor
can be connected to the output to provide a known voltage at the output while it is in the high-impedance state.
The value of the resistor will depend on multiple factors, including parasitic capacitance and power consumption
limitations. Typically, a 10 kΩ resistor can be used to meet these requirements.
Unused 3-state CMOS outputs should be left disconnected.
10
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8.2.2 Balanced CMOS Push-Pull Outputs
This device includes balanced CMOS push-pull outputs. The term balanced indicates that the device can sink
and source similar currents. The drive capability of this device may create fast edges into light loads so routing
and load conditions should be considered to prevent ringing. Additionally, the outputs of this device are capable
of driving larger currents than the device can sustain without being damaged. It is important for the output power
of the device to be limited to avoid damage due to overcurrent. The electrical and thermal limits defined in the
Absolute Maximum Ratings must be followed at all times.
Unused push-pull CMOS outputs should be left disconnected.
8.2.3 TTL-Compatible CMOS Inputs
This device includes TTL-compatible CMOS inputs. These inputs are specifically designed to interface with TTL
logic devices by having a reduced input voltage threshold.
TTL-compatible CMOS inputs are high impedance and are typically modeled as a resistor in parallel with
the input capacitance given in the Electrical Characteristics. The worst case resistance is calculated with the
maximum input voltage, given in the Absolute Maximum Ratings, and the maximum input leakage current, given
in the Electrical Characteristics, using Ohm's law (R = V ÷ I).
TTL-compatible CMOS inputs require that input signals transition between valid logic states quickly, as defined
by the input transition time or rate in the Recommended Operating Conditions table. Failing to meet this
specification will result in excessive power consumption and could cause oscillations. More details can be found
in the Implications of Slow or Floating CMOS Inputs application report.
Do not leave TTL-compatible CMOS inputs floating at any time during operation. Unused inputs must be
terminated at VCC or GND. If a system will not be actively driving an input at all times, a pull-up or pull-down
resistor can be added to provide a valid input voltage during these times. The resistor value will depend on
multiple factors; however, a 10-kΩ resistor is recommended and will typically meet all requirements.
8.2.4 Latching Logic
This device includes latching logic circuitry. Latching circuits commonly include D-type latches and D-type
flip-flops, but include all logic circuits that act as volatile memory.
When the device is powered on, the state of each latch is unknown. There is no default state for each latch at
start-up.
The output state of each latching logic circuit only remains stable as long as power is applied to the device within
the supply voltage range specified in the Recommended Operating Conditions table.
8.2.5 Clamp Diode Structure
The inputs and outputs to this device have both positive and negative clamping diodes as depicted in Figure 8-2.
CAUTION
Voltages beyond the values specified in the Absolute Maximum Ratings table can cause damage
to the device. The input and output voltage ratings may be exceeded if the input and output clampcurrent ratings are observed.
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VCC
Device
+IIK
+IOK
Logic
Input
Output
-IIK
-IOK
GND
Figure 8-2. Electrical Placement of Clamping Diodes for Each Input and Output
8.3 Device Functional Modes
Function Table lists the functional modes of the SN74HCT595-Q1.
Table 8-1. Function Table
INPUTS
SER
12
SRCLK
FUNCTION
SRCLR
RCLK
OE
H
Outputs QA – QH are disabled
X
X
X
X
X
X
X
X
L
Outputs QA – QH are enabled.
X
X
L
X
X
Shift register is cleared.
L
↑
H
X
X
First stage of the shift register goes low.
Other stages store the data of previous stage,
respectively.
H
↑
H
X
X
First stage of the shift register goes high.
Other stages store the data of previous stage,
respectively.
X
X
H
↑
X
Shift-register data is stored in the storage register.
X
↑
H
↑
X
Data in shift register is stored in the storage
register, the data is then shifted through.
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9 Application and Implementation
Note
Information in the following applications sections is not part of the TI component specification,
and TI does not warrant its accuracy or completeness. TI’s customers are responsible for
determining suitability of components for their purposes, as well as validating and testing their design
implementation to confirm system functionality.
9.1 Application Information
In this application, the SN74HCT595-Q1 is used to control seven-segment displays. Utilizing the serial output
and combining a few of the input signals, this implementation reduces the number of I/O pins required to
control the displays from sixteen to four. Unlike other I/O expanders, the SN74HCT595-Q1 does not need a
communication interface for control. It can be easily operated with simple GPIO pins.
The OE pin is used to easily disable the outputs when the displays need to be turned off or connected to a
PWM signal to control brightness. However, this pin can be tied low and the outputs of the SN74HCT595-Q1
can be controlled accordingly to turn off all the outputs reducing the I/O needed to three. There is no practical
limitation to how many SN74HCT595-Q1 devices can be cascaded. To add more, the serial output will need to
be connected to the following serial input and the clocks will need to be connected accordingly. With separate
control for the shift registers and output registers, the desired digit can be displayed while the data for the next
digit is loaded into the shift register.
At power-up, the initial state of the shift registers and output registers are unknown. To give them a defined state,
the shift register needs to be cleared and then clocked into the output register.
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9.2 Typical Application
VCC
VCC
C1
MCU
Seven Segment
QA
g
QB
f
QC
a
SER
QD
b
SRCLK
QE
DP
RCLK
QF
c
QG
d
QH
e
R1
SRCLR
OE
GND
a
f
b
g
e
c
d
DP
QH’
VCC
VCC
Seven Segment
QA
g
QB
f
QC
a
SER
QD
b
SRCLK
QE
DP
RCLK
QF
c
QG
d
QH
e
R2
SRCLR
C2
OE
GND
a
f
b
g
e
c
d
DP
QH’
Figure 9-1. Typical Application Block Diagram
9.2.1 Design Requirements
9.2.1.1 Power Considerations
Ensure the desired supply voltage is within the range specified in the Recommended Operating Conditions. The
supply voltage sets the device's electrical characteristics as described in the Electrical Characteristics.
The positive voltage supply must be capable of sourcing current equal to the total current to be sourced by all
outputs of the SN74HCT595-Q1 plus the maximum static supply current, ICC, listed in Electrical Characteristics
and any transient current required for switching. The logic device can only source as much current as is provided
by the positive supply source. Be sure not to exceed the maximum total current through VCC listed in the
Absolute Maximum Ratings.
14
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The ground must be capable of sinking current equal to the total current to be sunk by all outputs of the
SN74HCT595-Q1 plus the maximum supply current, ICC, listed in Electrical Characteristics, and any transient
current required for switching. The logic device can only sink as much current as can be sunk into its ground
connection. Be sure not to exceed the maximum total current through GND listed in the Absolute Maximum
Ratings.
The SN74HCT595-Q1 can drive a load with a total capacitance less than or equal to 50 pF while still meeting
all of the data sheet specifications. Larger capacitive loads can be applied; however, it is not recommended to
exceed 50 pF.
The SN74HCT595-Q1 can drive a load with total resistance described by RL ≥ VO / IO, with the output voltage
and current defined in the Electrical Characteristics table with VOH and VOL. When outputting in the high state,
the output voltage in the equation is defined as the difference between the measured output voltage and the
supply voltage at the VCC pin.
Total power consumption can be calculated using the information provided in CMOS Power Consumption and
Cpd Calculation.
Thermal increase can be calculated using the information provided in Thermal Characteristics of Standard Linear
and Logic (SLL) Packages and Devices.
CAUTION
The maximum junction temperature, TJ(max) listed in the Absolute Maximum Ratings, is an additional
limitation to prevent damage to the device. Do not violate any values listed in the Absolute Maximum
Ratings. These limits are provided to prevent damage to the device.
9.2.1.2 Input Considerations
Input signals must cross VIL(max) to be considered a logic LOW, and VIH(min) to be considered a logic HIGH. Do
not exceed the maximum input voltage range found in the Absolute Maximum Ratings.
Unused inputs must be terminated to either VCC or ground. These can be directly terminated if the input is
completely unused, or they can be connected with a pull-up or pull-down resistor if the input is to be used
sometimes, but not always. A pull-up resistor is used for a default state of HIGH, and a pull-down resistor is used
for a default state of LOW. The resistor size is limited by drive current of the controller, leakage current into the
SN74HCT595-Q1, as specified in the Electrical Characteristics, and the desired input transition rate. A 10-kΩ
resistor value is often used due to these factors.
The SN74HCT595-Q1 has CMOS inputs and thus requires fast input transitions to operate correctly, as defined
in the Recommended Operating Conditions table. Slow input transitions can cause oscillations, additional power
consumption, and reduction in device reliability.
Refer to the Feature Description section for additional information regarding the inputs for this device.
9.2.1.3 Output Considerations
The positive supply voltage is used to produce the output HIGH voltage. Drawing current from the output will
decrease the output voltage as specified by the VOH specification in the Electrical Characteristics. The ground
voltage is used to produce the output LOW voltage. Sinking current into the output will increase the output
voltage as specified by the VOL specification in the Electrical Characteristics.
Push-pull outputs that could be in opposite states, even for a very short time period, should never be connected
directly together. This can cause excessive current and damage to the device.
Two channels within the same device with the same input signals can be connected in parallel for additional
output drive strength.
Unused outputs can be left floating. Do not connect outputs directly to VCC or ground.
Refer to Feature Description section for additional information regarding the outputs for this device.
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9.2.2 Detailed Design Procedure
1. Add a decoupling capacitor from VCC to GND. The capacitor needs to be placed physically close to the
device and electrically close to both the VCC and GND pins. An example layout is shown in the Layout
section.
2. Ensure the capacitive load at the output is ≤ 50 pF. This is not a hard limit, however it will ensure
optimal performance. This can be accomplished by providing short, appropriately sized traces from the
SN74HCT595-Q1 to one or more of the receiving devices.
3. Ensure the resistive load at the output is larger than (VCC / IO(max)) Ω. This will ensure that the maximum
output current from the Absolute Maximum Ratings is not violated. Most CMOS inputs have a resistive load
measured in MΩ; much larger than the minimum calculated above.
4. Thermal issues are rarely a concern for logic gates; the power consumption and thermal increase, however,
can be calculated using the steps provided in the application report, CMOS Power Consumption and Cpd
Calculation.
9.2.3 Application Curve
SER
QA
QB
QC
QC
QD
QE
QF
Output Registers
QB
Serial Registers
Output Registers
QA
Serial Registers
SER
QD
QE
QF
QG
QG
QH
QH
QH¶
QH¶
SRCLK rising edge shifts data
in the serial registers only
RCLK rising edge shifts data
to the output registers
Figure 9-2. Simplified Functional Diagram Showing Clock Operation
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10 Power Supply Recommendations
The power supply can be any voltage between the minimum and maximum supply voltage rating located in the
Recommended Operating Conditions. Each VCC terminal should have a good bypass capacitor to prevent power
disturbance. A 0.1-μF capacitor is recommended for this device. It is acceptable to parallel multiple bypass caps
to reject different frequencies of noise. The 0.1-μF and 1-μF capacitors are commonly used in parallel. The
bypass capacitor should be installed as close to the power terminal as possible for best results, as shown in
given example layout image.
11 Layout
11.1 Layout Guidelines
When using multiple-input and multiple-channel logic devices inputs must not ever be left floating. In many
cases, functions or parts of functions of digital logic devices are unused; for example, when only two inputs of a
triple-input AND gate are used or only 3 of the 4 buffer gates are used. Such unused input pins must not be left
unconnected because the undefined voltages at the outside connections result in undefined operational states.
All unused inputs of digital logic devices must be connected to a logic high or logic low voltage, as defined by the
input voltage specifications, to prevent them from floating. The logic level that must be applied to any particular
unused input depends on the function of the device. Generally, the inputs are tied to GND or VCC, whichever
makes more sense for the logic function or is more convenient.
11.2 Layout Example
Recommend GND flood fill for
improved signal isolation, noise
reduction, and thermal dissipation
Unused inputs tie to GND or VCC
Avoid 90°
corners for
signal lines
GND VCC
0.1 F
Bypass capacitor
placed close to
the device
QB
1
16
VCC
QC
2
15
QA
QD
3
14
SER
QE
4
13
OE
QF
5
12
RCLK
QG
6
11
SRCLK
QH
7
10
SRCLR
GND
8
9
QH¶
Unused output
left floating
Figure 11-1. Example Layout for the SN74HCT595-Q1
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12 Device and Documentation Support
TI offers an extensive line of development tools. Tools and software to evaluate the performance of the device,
generate code, and develop solutions are listed below.
12.1 Documentation Support
12.1.1 Related Documentation
For related documentation, see the following:
•
•
•
Texas Instruments, HCMOS Design Considerations application report
Texas Instruments, CMOS Power Consumption and Cpd Calculation application report
Texas Instruments, Designing With Logic application report
12.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on
Subscribe to updates to register and receive a weekly digest of any product information that has changed. For
change details, review the revision history included in any revised document.
12.3 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight
from the experts. Search existing answers or ask your own question to get the quick design help you need.
Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do
not necessarily reflect TI's views; see TI's Terms of Use.
12.4 Trademarks
TI E2E™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
12.5 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled
with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric changes could cause the device not to meet its published
specifications.
12.6 Glossary
TI Glossary
This glossary lists and explains terms, acronyms, and definitions.
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
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PACKAGE OPTION ADDENDUM
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6-Jan-2022
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)
SN74HCT595QPWRQ1
ACTIVE
TSSOP
PW
16
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 125
HT595Q
(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
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