NA555, NE555, SA555, SE555

www.ti.com SLFS022J – SEPTEMBER 1973 – REVISED FEBRUARY 2025

7.2.3.2 Detailed Design Procedure

The nominal output frequency and duty cycle are determined using the formulas in Section 6.3.2. RL improves
VOH, but RL is not required for TTL compatibility.

ÎÎÎÎÎ
7.2.3.3 Application Curve

ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
RA = 3 kΩ
RB = 500 Ω

ÎÎÎÎÎÎÎ
ÎÎÎÎÎ
RL = 1 kΩ

ÎÎÎÎÎÎÎ
See Figure 20

ÎÎÎÎÎÎÎ
Voltage − 2 V/div
ÎÎÎÎÎÎÎ Modulation Input Voltage

ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎÎ
Output Voltage

ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
Capacitor Voltage

Time − 0.1 ms/div

Figure 7-6. Pulse-Position-Modulation Waveforms

7.2.4 Sequential Timer

Many applications, such as computers, require signals for initializing conditions during start-up. Other
applications, such as test equipment, require activation of test signals in sequence. These timing circuits can
be connected to provide such sequential control. The timers can be used in various combinations of astable
or monostable circuit connections, with or without modulation, for extremely flexible waveform control. Figure
7-7 shows a sequencer circuit with possible applications in many systems, and Figure 7-8 shows the output
waveforms.
VCC

4 8 RA 33 kΩ 4 8 RB 33 kΩ 4 8 RC
RESET VCC RESET VCC RESET VCC
3 3 3
2 OUT 2 OUT 2 OUT
TRIG TRIG TRIG
0.001 0.001
7
S
DISCH
7 µF DISCH 7 µF DISCH
5 5 5
CONT 6 CONT 6 CONT 6
THRES THRES THRES
GND GND GND
0.01 1 0.01 1 0.01 1
CA CB CC
µF µF µF

CA = 10 µF CC = 14.7 µF
RA = 100 kΩ Output A Output B RC = 100 kΩ Output C
CB = 4.7 µF
RB = 100 kΩ
Pin numbers shown are for the D, JG, P, PS, and PW packages.
NOTE A: S closes momentarily at t = 0.

Figure 7-7. Sequential Timer Circuit

7.2.4.1 Design Requirements

The sequential timer application chains together multiple mono-stable timers. The joining components are the
33kΩ resistors and 0.001µF capacitors. The output high to low edge passes a 10µs start pulse to the next
monostable.

Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 17

Product Folder Links: NA555 NE555 SA555 SE555
NA555, NE555, SA555, SE555
SLFS022J – SEPTEMBER 1973 – REVISED FEBRUARY 2025 www.ti.com

7.2.4.2 Detailed Design Procedure

The timing resistors and capacitors can be chosen using this formula. tw = 1.1 × R × C.

ÏÏÏÏÏ
7.2.4.3 Application Curve

ÏÏÏÏÏ
ÏÏÏÏ
ÏÏÏ ÏÏÏÏÏ
ÏÏÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏ ÏÏÏÏÏ
ÏÏÏ
See Figure 22

ÏÏÏÏÏÏÏ ÏÏÏÏÏ
ÏÏÏ twA

ÏÏÏÏ ÏÏÏ
ÏÏÏÏÏ
Output A twA = 1.1 RACA

ÏÏÏÏ ÏÏÏ
ÏÏÏÏÏ twB

ÏÏÏÏ ÏÏÏÏÏ
Voltage − 5 V/div
ÏÏÏÏ
twB = 1.1 RBCB
Output B

ÏÏÏÏ
ÏÏÏÏ ÏÏ
ÏÏ ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏ ÏÏ ÏÏÏÏÏ
ÏÏÏ
Output C twC twC = 1.1 RCCC

ÏÏÏ
ÏÏÏ
ÏÏÏ
t=0

t − Time − 1 s/div

Figure 7-8. Sequential Timer Waveforms

7.3 Power Supply Recommendations

The Nx555 and Sx555 precision timers are designed to operate from an input voltage supply range between
4.5V and 16V (18V for SE555). A bypass capacitor is highly recommended from VCC to the ground pin; a
ceramic 0.1µF capacitor is sufficient.

18 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated

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 NA555, NE555, SA555, SE555
www.ti.com SLFS022J – SEPTEMBER 1973 – REVISED FEBRUARY 2025

8 Device and Documentation Support

8.1 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on
Notifications 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.
8.2 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.
8.3 Trademarks
TI E2E™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
8.4 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.

8.5 Glossary
TI Glossary This glossary lists and explains terms, acronyms, and definitions.

9 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision I (September 2014) to Revision J (February 2025) Page
• Updated list of end equipment in Applications ...................................................................................................1
• Updated Device Information table...................................................................................................................... 1
• Deleted package thermal impedance specifications from Absolute Maximum Ratings and added Thermal
Information table with updated per-package thermal specifications...................................................................4
• Deleted Handling Ratings and moved storage temperature specification to Absolute Maximum Ratings ........ 4
• Added ESD Ratings table...................................................................................................................................4
• Deleted redundant input voltage specification in Recommended Operating Conditions ...................................4
• Changed Operating Characteristics title to Switching Characteristics, and clarified that values are specified by
design or characterization and are not production tested...................................................................................7
• Deleted initial error of timing interval specification in Switching Characteristics and clarified that output rise
and fall times are 20% to 80% and 80% to 20%, respectively........................................................................... 7
• Changed functional block diagram to simplified schematic and moved to Overview....................................... 10
• Updated Functional Block Diagram ................................................................................................................. 10
• Added CONT pin table note to Table 6-1, Function Table ............................................................................... 13

Changes from Revision H (June 2010) to Revision I (September 2014) Page

• Updated document to new TI enhanced data sheet format................................................................................1
• Deleted Ordering Information table.................................................................................................................... 1
• Added Military Disclaimer to Features ...............................................................................................................1
• Added Applications ............................................................................................................................................1

Copyright © 2025 Texas Instruments Incorporated Submit Document Feedback 19

Product Folder Links: NA555 NE555 SA555 SE555
NA555, NE555, SA555, SE555
SLFS022J – SEPTEMBER 1973 – REVISED FEBRUARY 2025 www.ti.com

• Added Device Information table......................................................................................................................... 1

• Added DISCH switch on-state voltage parameter.............................................................................................. 5
• Added Mechanical, Packaging, and Orderable Information section................................................................. 20

10 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-side navigation.

20 Submit Document Feedback Copyright © 2025 Texas Instruments Incorporated

Product Folder Links: NA555 NE555 SA555 SE555

 PACKAGE OPTION ADDENDUM

www.ti.com 26-Jun-2025

PACKAGING INFORMATION

Orderable part number Status Material type Package | Pins Package qty | Carrier RoHS Lead finish/ MSL rating/ Op temp (°C) Part marking
(1) (2) (3) Ball material Peak reflow (6)
(4) (5)

JM38510/10901BPA Active Production CDIP (JG) | 8 50 | TUBE No SNPB N/A for Pkg Type -55 to 125 JM38510
/10901BPA
JM38510/10901BPA.A Active Production CDIP (JG) | 8 50 | TUBE No SNPB N/A for Pkg Type -55 to 125 JM38510
/10901BPA
NA555D Obsolete Production SOIC (D) | 8 - - Call TI Call TI -40 to 105 NA555
NA555DR Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM -40 to 105 NA555
NA555DR.A Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM -40 to 105 NA555
NA555P Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU | SN N/A for Pkg Type -40 to 105 NA555P
NA555P.A Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type -40 to 105 NA555P
NA555PE4 Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type -40 to 105 NA555P
NA555PE4.A Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type -40 to 105 NA555P
NE555D Obsolete Production SOIC (D) | 8 - - Call TI Call TI 0 to 70 NE555
NE555DR Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU | SN Level-1-260C-UNLIM 0 to 70 NE555
NE555DR.A Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM 0 to 70 NE555
NE555DR1G4 Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM 0 to 70 NE555
NE555DR1G4.A Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM 0 to 70 NE555
NE555DRG4 Obsolete Production SOIC (D) | 8 - - Call TI Call TI 0 to 70 NE555
NE555P Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU | SN N/A for Pkg Type 0 to 70 NE555P
NE555P.A Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type 0 to 70 NE555P
NE555PE4 Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type 0 to 70 NE555P
NE555PE4.A Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type 0 to 70 NE555P
NE555PS Active Production SO (PS) | 8 80 | TUBE Yes NIPDAU Level-1-260C-UNLIM - N555
NE555PS.A Active Production SO (PS) | 8 80 | TUBE Yes NIPDAU Level-1-260C-UNLIM 0 to 70 N555
NE555PSR Active Production SO (PS) | 8 2000 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM 0 to 70 N555
NE555PSR.A Active Production SO (PS) | 8 2000 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM 0 to 70 N555
NE555PW Obsolete Production TSSOP (PW) | 8 - - Call TI Call TI 0 to 70 N555
NE555PWR Active Production TSSOP (PW) | 8 2000 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM 0 to 70 N555
NE555PWR.A Active Production TSSOP (PW) | 8 2000 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM 0 to 70 N555
SA555D Obsolete Production SOIC (D) | 8 - - Call TI Call TI -40 to 85 SA555
SA555DR Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU | SN Level-1-260C-UNLIM -40 to 85 SA555

Addendum-Page 1
 PACKAGE OPTION ADDENDUM

www.ti.com 26-Jun-2025

Orderable part number Status Material type Package | Pins Package qty | Carrier RoHS Lead finish/ MSL rating/ Op temp (°C) Part marking
(1) (2) (3) Ball material Peak reflow (6)
(4) (5)

SA555DR.A Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM -40 to 85 SA555
SA555DRG4 Obsolete Production SOIC (D) | 8 - - Call TI Call TI -40 to 85 SA555
SA555P Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type -40 to 85 SA555P
SA555P.A Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type -40 to 85 SA555P
SE555D Obsolete Production SOIC (D) | 8 - - Call TI Call TI -55 to 125 SE555
SE555DG4 Obsolete Production SOIC (D) | 8 - - Call TI Call TI -55 to 125 SE555
SE555DR Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM -55 to 125 SE555
SE555DR.A Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM -55 to 125 SE555
SE555DRG4 Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM -55 to 125 SE555
SE555DRG4.A Active Production SOIC (D) | 8 2500 | LARGE T&R Yes NIPDAU Level-1-260C-UNLIM -55 to 125 SE555
SE555FKB Active Production LCCC (FK) | 20 55 | TUBE No SNPB N/A for Pkg Type -55 to 125 SE555FKB
SE555FKB.A Active Production LCCC (FK) | 20 55 | TUBE No SNPB N/A for Pkg Type -55 to 125 SE555FKB
SE555JG Active Production CDIP (JG) | 8 50 | TUBE No SNPB N/A for Pkg Type -55 to 125 SE555JG
SE555JG.A Active Production CDIP (JG) | 8 50 | TUBE No SNPB N/A for Pkg Type -55 to 125 SE555JG
SE555JGB Active Production CDIP (JG) | 8 50 | TUBE No SNPB N/A for Pkg Type -55 to 125 SE555JGB
SE555JGB.A Active Production CDIP (JG) | 8 50 | TUBE No SNPB N/A for Pkg Type -55 to 125 SE555JGB
SE555P Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type -55 to 125 SE555P
SE555P.A Active Production PDIP (P) | 8 50 | TUBE Yes NIPDAU N/A for Pkg Type -55 to 125 SE555P

(1)
Status: For more details on status, see our product life cycle.

(2)
Material type: When designated, preproduction parts are prototypes/experimental devices, and are not yet approved or released for full production. Testing and final process, including without limitation quality assurance,
reliability performance testing, and/or process qualification, may not yet be complete, and this item is subject to further changes or possible discontinuation. If available for ordering, purchases will be subject to an additional
waiver at checkout, and are intended for early internal evaluation purposes only. These items are sold without warranties of any kind.

(3)
RoHS values: Yes, No, RoHS Exempt. See the TI RoHS Statement for additional information and value definition.

(4)
Lead finish/Ball material: Parts may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two lines if the finish value exceeds the maximum
column width.

(5)
MSL rating/Peak reflow: The moisture sensitivity level ratings and peak solder (reflow) temperatures. In the event that a part has multiple moisture sensitivity ratings, only the lowest level per JEDEC standards is shown.
Refer to the shipping label for the actual reflow temperature that will be used to mount the part to the printed circuit board.

Addendum-Page 2
 PACKAGE OPTION ADDENDUM

www.ti.com 26-Jun-2025

(6)
Part marking: There may be an additional marking, which relates to the logo, the lot trace code information, or the environmental category of the part.

Multiple part markings will be inside parentheses. Only one part marking contained in parentheses and separated by a "~" will appear on a part. If a line is indented then it is a continuation of the previous line and the two
combined represent the entire part marking for that device.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and
makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative
and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers
and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

OTHER QUALIFIED VERSIONS OF SE555, SE555M :

• Catalog : SE555
• Military : SE555M
• Space : SE555-SP, SE555-SP

NOTE: Qualified Version Definitions:

• Catalog - TI's standard catalog product

• Military - QML certified for Military and Defense Applications
• Space - Radiation tolerant, ceramic packaging and qualified for use in Space-based application

Addendum-Page 3
 PACKAGE MATERIALS INFORMATION

www.ti.com 13-Jun-2025

TAPE AND REEL INFORMATION

REEL DIMENSIONS TAPE DIMENSIONS

K0 P1

B0 W
Reel
Diameter
Cavity A0
A0 Dimension designed to accommodate the component width
B0 Dimension designed to accommodate the component length
K0 Dimension designed to accommodate the component thickness
W Overall width of the carrier tape
P1 Pitch between successive cavity centers

Reel Width (W1)

QUADRANT ASSIGNMENTS FOR PIN 1 ORIENTATION IN TAPE

Sprocket Holes

Q1 Q2 Q1 Q2

Q3 Q4 Q3 Q4 User Direction of Feed

Pocket Quadrants

*All dimensions are nominal

Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1
Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant
(mm) W1 (mm)
NA555DR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1
NE555DR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1
NE555DR1G4 SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1
NE555PSR SO PS 8 2000 330.0 16.4 8.35 6.6 2.4 12.0 16.0 Q1
NE555PWR TSSOP PW 8 2000 330.0 12.4 7.0 3.6 1.6 8.0 12.0 Q1
SA555DR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1
SA555DR SOIC D 8 2500 330.0 12.8 6.4 5.2 2.1 8.0 12.0 Q1
SE555DR SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1
SE555DRG4 SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1

Pack Materials-Page 1