Editing 555 timer IC (section)

==Derivatives==
Numerous companies have manufactured one or more variants of the 555, 556, 558 timers over the past decades, under many different part numbers.  The following is a partial list:

{| class="wikitable sortable" style="text-align: center;"
|-
! Manufacturer !! Part<br/>number !! Production<br/>status !! IC<br/>process !! Timers<br/>total !! Supply<br/>min. ([[volt]]) !! Supply<br/>max. (volt) !! [[Quiescent current|''I''<sub>q</sub>]] ([[Electric current|μA]])<br/>at 5&nbsp;V<br/>supply<br/> !! Frequency<br/>max. ([[MHz]]) || class="unsortable" | Remarks || class="unsortable" | Datasheet
|-
| [https://customsiliconsolutions.com Custom Silicon Solutions (CSS)]|| CSS555 || {{Yes|Active}} || [[CMOS]] || 1 || 1.2 || 5.5 || 4.3 || 1.0 || Internal [[EEPROM]], requires programmer ||<ref name="CSS_CSS555_Datasheet">{{cite web |title=CSS555 Datasheet |url=http://www.customsiliconsolutions.com/downloads/Revised%20Standard%20products/CSS555_Spec_2.pdf |date=July 2012 |website=Custom Silicon Solutions |archive-url=https://web.archive.org/web/20170629194001/http://www.customsiliconsolutions.com/downloads/Revised%20Standard%20products/CSS555_Spec_2.pdf |archive-date=June 29, 2017 |url-status=live}}</ref><ref>{{cite web |title=CSS555 Part Search |url=https://www.jameco.com/shop/StoreCatalogDrillDownView?langId=-1&storeId=10001&catalogId=10001&freeText=css555&search_type=jamecoall |website=Jameco Electronics }}</ref><ref>{{cite journal |first=James |last=Senft |title=The Remarkable CSS555 |url=https://www.nutsvolts.com/magazine/article/february2016_CSS555TimerICs |journal=Nuts & Volts Magazine |archive-url=https://web.archive.org/web/20200527061138/https://www.nutsvolts.com/magazine/article/february2016_CSS555TimerICs |archive-date=May 27, 2020 |date=February 2016 |url-status=live}}</ref>
|-
| [[Diodes Incorporated|Diodes Inc]] || ZSCT1555 || {{No|Discontinued}} || Bipolar || 1 || 0.9 || 6 || 150 || 0.33 || Designed by [[Hans Camenzind]] || <ref name="DiodesInc_ZSCT1555_Datasheet">{{cite web |title=ZSCT1555 Datasheet |url=https://www.diodes.com/assets/Datasheets/ZSCT1555.pdf |date=July 2006 |website=[[Diodes Incorporated]] |archive-url=https://web.archive.org/web/20170629181234/https://www.diodes.com/assets/Datasheets/ZSCT1555.pdf |archive-date=June 29, 2017 |url-status=live}}</ref>
|-
| [[Japan Radio Company]] (JRC) || NJM555 || {{No|Discontinued}} || Bipolar || 1 || 4.5 || 16 || 3000 || 0.1* || Also available in [[Single in-line package|SIP]]-8 package. || <ref name="JRC_NJM555_Datasheet">{{cite web |title=NJM555 Datasheet |url=http://www.njr.com/semicon/PDF/NJM555_E.pdf |date=November 2012 |website=[[Japan Radio Company]] |archive-url=https://web.archive.org/web/20170629170934/http://www.njr.com/semicon/PDF/NJM555_E.pdf |archive-date=June 29, 2017 |url-status=dead}}</ref>
|-
| [[Microchip Technology|Microchip]] || MIC1555/7 || {{Yes|Active}} || CMOS || 1* || 2.7 || 18 || 240 || 5.0* || Reduced pins & features (only astable & monostable & no reset for MIC1555, astable only for MIC1557), only available in [[Small-outline transistor#SOT23-5|SOT23-5]], TSOT23-5, [[Flat no-leads package|UTDFN]]-10 packages. || <ref name="Microchip_MIC1555_Datasheet">{{cite web |title=MIC1555 Datasheet |url=http://ww1.microchip.com/downloads/en/DeviceDoc/20005730A.pdf |date=March 2017 |website=[[Microchip Technology]] |archive-url=https://web.archive.org/web/20210421210319/http://ww1.microchip.com/downloads/en/DeviceDoc/20005730A.pdf |archive-date=April 21, 2021 |url-status=live}}</ref>
|-
| [[ON Semiconductor|ON]] || MC1455 || {{Yes|Active}} || Bipolar || 1 || 4.5 || 16 || 3000 || 0.1* || {{sdash}} || <ref name="ON_MC1455_Datasheet">{{cite web |title=MC1455 Datasheet |url=https://www.onsemi.com/pub/Collateral/MC1455-D.PDF |date=December 2009 |website=ON Semiconductor |archive-url=https://web.archive.org/web/20200522114538/https://www.onsemi.com/pub/Collateral/MC1455-D.PDF |archive-date=May 22, 2020 |url-status=live}}</ref>
|-
| [[Renesas Electronics|Renesas]] || ICM7555 || {{Yes|Active}} || CMOS || 1 || 2 || 18 || 40 || 1.0 ||  ||<ref name="Intersil_ICM7555-556_Datasheet">{{cite web |title=ICM7555-556 Datasheet |url=http://www.intersil.com/content/dam/Intersil/documents/icm7/icm7555-56.pdf |date=June 2016 |website=[[Intersil]] |archive-url=https://web.archive.org/web/20170629211905/http://www.intersil.com/content/dam/Intersil/documents/icm7/icm7555-56.pdf |archive-date=June 29, 2017 |url-status=dead}}</ref>
|-
| Renesas || ICM7556 || {{Yes|Active}} || CMOS || 2 || 2 || 18 || 80 || 1.0 ||  ||<ref name="Intersil_ICM7555-556_Datasheet"/>
|-
| '''[[Signetics]]''' || '''NE555''' || {{Yes|Active (TI)}} || Bipolar || 1 || 4.5 || 16 || 3000 || 0.1* || '''First 555 timer''', [[Dual in-line package|DIP]]-8 or [[TO-5|TO5]]-8 packages. || <ref name="Signetics_1972_Linear1_Databook">{{cite web |title=Linear Vol1 Databook |url=https://archive.org/details/bitsavers_signeticsdcsLinearVol1_11470058 |date=1972 |website=[[Signetics]]}}</ref><ref name="Signetics_1973_555-556_Databook">{{cite web |title=555/556 Timers Databook |url=https://www.rfcafe.com/miscellany/cool-products/Signetics-555-556-Timer-1973-Databook.pdf |date=1973 |website=[[Signetics]] |archive-url=https://web.archive.org/web/20210511041359/https://www.rfcafe.com/miscellany/cool-products/Signetics-555-556-Timer-1973-Databook.pdf |archive-date=May 11, 2021 |url-status=live}}</ref><ref name="Signetics_1979_App_Manual">{{cite web |title=Analog Applications Manual |url=https://archive.org/details/bitsavers_signeticsdcsAnalogApplications_33415016 |date=1979 |website=[[Signetics]]}}</ref><ref name="Signetics_1985_Linear_Databook">{{cite web |title=Linear LSI Data and Applications Manual |url=https://archive.org/details/bitsavers_signeticsdcsLinearLSI_66682786 |date=1985 |website=[[Signetics]]}}</ref>
|-
| '''Signetics''' || '''NE556''' || {{Yes|Active (TI)}}  || Bipolar || 2 || 4.5 || 16 || 6000 || 0.1* || '''First 556 timer''', DIP-14 package. || <ref name="Signetics_1973_555-556_Databook"/><ref name="Signetics_1985_Linear_Databook"/>
|-
| '''Signetics''' || '''NE558''' || {{No|Discontinued}} || Bipolar || 4* || 4.5 || 16 || 4800* || 0.1* || '''First 558 timer''', DIP-16 package. || <ref name="Signetics_1985_Linear_Databook"/>
|-
| [[STMicroelectronics]] (ST) || TS555 || {{Yes|Active}} || CMOS || 1 || 2 || 16 || 110 || 2.7 || {{sdash}} || <ref name="ST_TS555_Datasheet">{{cite web |title=TS555 Datasheet |url=https://www.st.com/resource/en/datasheet/ts555.pdf |date=June 2015 |website=[[STMicroelectronics]]  |archive-url=https://web.archive.org/web/20200526095316/https://www.st.com/content/ccc/resource/technical/document/datasheet/45/d5/c6/11/46/d3/4b/a3/CD00000893.pdf/files/CD00000893.pdf/jcr:content/translations/en.CD00000893.pdf |archive-date=May 26, 2020 |url-status=live}}</ref>
|-
| [[Texas Instruments]] (TI) || LM555 || {{Yes|Active}} || Bipolar || 1 || 4.5 || 16 || 3000 || 0.1 ||  || <ref name="TI_LM555_Datasheet">{{cite web |title=LM555 Datasheet |url=http://www.ti.com/lit/ds/symlink/lm555.pdf |date=January 2015 |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20170629043122/http://www.ti.com/lit/ds/symlink/lm555.pdf |archive-date=June 29, 2017 |url-status=live}}</ref>
|-
| Texas Instruments || LM556 || {{No|Discontinued}} || Bipolar || 2 || 4.5 || 16 || 6000 || 0.1 ||  || <ref name="TI_LM556_Datasheet">{{cite web |title=LM556 Datasheet |url=http://www.ti.com/lit/ds/symlink/lm556.pdf |date=October 2015 |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20170629111822/http://www.ti.com/lit/ds/symlink/lm556.pdf |archive-date=June 29, 2017 |url-status=dead }}</ref>
|-
| Texas Instruments || LMC555 || {{Yes|Active}} || CMOS || 1 || 1.5 || 15 || 100 || 3.0 || Also available in [[Ball grid array|DSBGA]]-8 package. || <ref name="TI_LMC555_Datasheet">{{cite web |title=LMC555 Datasheet |url=http://www.ti.com/lit/ds/symlink/lmc555.pdf |date=July 2016 |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20170628232001/http://www.ti.com/lit/ds/symlink/lmc555.pdf |archive-date=June 28, 2017 |url-status=live}}</ref>
|-
| Texas Instruments || NE555 || {{Yes|Active}} || Bipolar || 1 || 4.5 || 16 || 3000 || 0.1* || {{sdash}} || <ref name="TI_NE555_Datasheet">{{cite web |title=NE555 Datasheet |url=http://www.ti.com/lit/ds/symlink/ne555.pdf |date=September 2014 |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20170628232239/http://www.ti.com/lit/ds/symlink/ne555.pdf |archive-date=June 28, 2017 |url-status=live}}</ref>
|-
| Texas Instruments || NE556 || {{Yes|Active}} || Bipolar || 2 || 4.5 || 16 || 6000 || 0.1* || {{sdash}} || <ref name="TI_NE556_Datasheet">{{cite web |title=NE556 Datasheet |url=http://www.ti.com/lit/ds/symlink/ne556.pdf |date=June 2006 |website=[[Texas Instruments]]  |archive-url=https://web.archive.org/web/20170629045640/http://www.ti.com/lit/ds/symlink/ne556.pdf |archive-date=June 29, 2017 |url-status=live}}</ref>
|-
| Texas Instruments || TLC551 || {{Yes|Active}} || CMOS || 1 || 1 || 15 || 170 || 1.8 ||  ||<ref name="TI_TLC551_Datasheet">{{cite web |title=TLC551 Datasheet |url=http://www.ti.com/lit/ds/symlink/tlc551.pdf |date=September 1997 |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20170629111015/http://www.ti.com/lit/ds/symlink/tlc551.pdf |archive-date=June 29, 2017 |url-status=live}}</ref>
|-
| Texas Instruments || TLC552 || {{Yes|Active}} || CMOS || 2 || 1 || 15 || 340 || 1.8 ||  ||<ref name="TI_TLC552_Datasheet">{{cite web |title=TLC552 Datasheet |url=http://www.ti.com/lit/ds/symlink/tlc552.pdf |date=May 1988 |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20170629111022/http://www.ti.com/lit/ds/symlink/tlc552.pdf |archive-date=June 29, 2017 |url-status=live}}</ref>
|-
| Texas Instruments || TLC555 || {{Yes|Active}} || CMOS || 1 || 2 || 15 || 170 || 2.1 || {{sdash}} || <ref name="TI_TLC555_Datasheet">{{cite web |title=TLC555 Datasheet |url=http://www.ti.com/lit/ds/symlink/tlc555.pdf |date=August 2016 |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20170628232326/http://www.ti.com/lit/ds/symlink/tlc555.pdf |archive-date=June 28, 2017 |url-status=live}}</ref>
|-
| Texas Instruments || TLC556 || {{Yes|Active}} || CMOS || 2 || 2 || 15 || 340 || 2.1 || {{sdash}} || <ref name="TI_TLC556_Datasheet">{{cite web |title=TLC556 Datasheet |url=http://www.ti.com/lit/ds/symlink/tlc556.pdf |date=September 1997 |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20170629111759/http://www.ti.com/lit/ds/symlink/tlc556.pdf |archive-date=June 29, 2017 |url-status=live}}</ref>
|-
| X-REL || XTR655 || {{Yes|Active}} || [[Silicon on insulator|SOI]] || 1 || 2.8 || 5.5 || 170 || 4.0 || Extreme (−60&nbsp;°[[Celsius|C]] to +230&nbsp;°C), ceramic DIP-8 package or bare die. || <ref name="X-REL_XTR655_Datasheet">{{cite web |title=XTR655 Datasheet |url=https://www.easii-ic.com/wp-content/uploads/2021/08/EASii-IC-DS-XTR650-Versatile-Timer-Rev-3-August-21-DS-00100-11.pdf |date=August 2021 |website=X-REL Semiconductor |archive-url=https://web.archive.org/web/20230710152544/https://www.easii-ic.com/wp-content/uploads/2021/08/EASii-IC-DS-XTR650-Versatile-Timer-Rev-3-August-21-DS-00100-11.pdf |archive-date=July 10, 2023 |url-status=live}}</ref>
|}

; Table notes
* All information in the above table was pulled from references in the datasheet column, except where denoted below.
* For the "Total timers" column, a "*" denotes parts that are missing 555 timer features.
* For the "''I''<sub>q</sub>" column, a 5-volt supply was chosen as a common voltage to make it easier to compare. The value for Signetics NE558 is an estimate because NE558 datasheets don't state ''I''<sub>q</sub> at 5&nbsp;V.<ref name="Signetics_1985_Linear_Databook"/> The value listed in this table was estimated by comparing the 5&nbsp;V to 15&nbsp;V ratio of other bipolar datasheets, then derating the 15&nbsp;V parameter for the NE558 part, which is denoted by the "*".
* For the "Frequency max." column, a "*" denotes values that may not be the actual maximum frequency limit of the part. The MIC1555 datasheet discusses limitations from 1 to 5&nbsp;MHz.<ref name="Microchip_MIC1555_Datasheet"/> Though most bipolar timers don't state the maximum frequency in their datasheets, they all have a maximum frequency limitation of hundreds of kHz across their full temperature range.  Section 8.1 of the Texas Instruments NE555 datasheet<ref name="TI_NE555_Datasheet"/> states a value of 100&nbsp;kHz, and their website shows a value of 100&nbsp;kHz in timer comparison tables. Signetics App Note 170 states that most devices will oscillate up to 1&nbsp;MHz; however, when considering temperature stability, it should be limited to about 500&nbsp;kHz.<ref name="Signetics_1985_Linear_Databook"/> The application note from [[Halbleiterwerk Frankfurt (Oder)|HFO]] mentions that at higher supply voltages the maximum power dissipation of the circuit might limit the operating frequency, as the supply current increases with frequency.<ref name=b555>{{cite book |title=Zeitgeber-IS B 555 / B 556 |first=Ullrich |last=Reick |language=de |publisher=Halbleiterwerk Frankfurt (Oder) |date=1986-03-01 |url=http://datasheet.datasheetarchive.com/originals/scans/Scans-048/DSAGER000125.pdf}}</ref>
* For the "Manufacturer" column, the following associates historical 555 timer manufacturers to current company names.
** [[Fairchild Semiconductor]] was sold to [[ON Semiconductor]] in 2016.<ref>{{cite web |title=ON Semiconductor Successfully Completes Acquisition of Fairchild Semiconductor |url=https://www.businesswire.com/news/home/20160919005796/en/Semiconductor-Successfully-Completes-Acquisition-Fairchild-Semiconductor-2.4 |website=[[Business Wire]] |archive-url=https://web.archive.org/web/20200128124808/https://www.businesswire.com/news/home/20160919005796/en/Semiconductor-Successfully-Completes-Acquisition-Fairchild-Semiconductor-2.4 |archive-date=January 28, 2020 |date=September 19, 2016 |url-status=live}}</ref>  ON Semiconductor was founded in 1999 as a spinoff of [[Motorola]] Semiconductor Components Group.<ref>{{cite web |title=Former Motorola group emerges as ON Semiconductor |url=https://www.eetimes.com/former-motorola-group-emerges-as-on-semiconductor/# |publisher=[[EE Times]] |archive-url=https://web.archive.org/web/20200608011400/https://www.eetimes.com/former-motorola-group-emerges-as-on-semiconductor/ |archive-date=June 8, 2020 |date=August 5, 1999 |url-status=live}}</ref>  The MC1455 started as a Motorola product.
** [[Intersil]] was sold to [[Renesas Electronics]] in 2017.<ref>{{cite web |title=Renesas and Intersil Announce Final Regulatory Approval for Renesas' Acquisition of Intersil |url=https://www.renesas.com/us/en/about/press-center/news/2017/news20170222.html |website=[[Renesas Electronics]] |archive-url=https://web.archive.org/web/20200613181551/https://www.renesas.com/us/en/about/press-center/news/2017/news20170222.html |archive-date=June 13, 2020 |date=February 22, 2017 |url-status=live}}</ref>  The ICM7555 and ICM7556 started as Intersil products.
** Micrel was sold to [[Microchip Technology]] in 2015.<ref>{{cite web |title=Microchip Technology Completes Micrel Acquisition |url=https://www.powerelectronics.com/news/industry/article/21862805/microchip-technology-completes-micrel-acquisition |website=Power Electronics |archive-url=https://web.archive.org/web/20200522100320/https://www.powerelectronics.com/news/industry/article/21862805/microchip-technology-completes-micrel-acquisition |archive-date=May 22, 2020 |date=August 12, 2015 |url-status=live}}</ref>  The MIC1555 started as a Micrel product.
** [[National Semiconductor]] was sold to [[Texas Instruments]] in 2011.<ref>{{cite web |title=Texas Instruments completes acquisition of National Semiconductor |url=https://investor.ti.com/news-releases/news-release-details/texas-instruments-completes-acquisition-national-semiconductor |website=[[Texas Instruments]] |archive-url=https://web.archive.org/web/20200522101031/https://investor.ti.com/news-releases/news-release-details/texas-instruments-completes-acquisition-national-semiconductor |archive-date=May 22, 2020 |date=September 23, 2011 |url-status=live}}</ref>  The LM555 and LM556 started as a National Semiconductor products.
** [[Signetics]] was sold to [[Philips|Philips Semiconductor]] in 1975, later to [[NXP Semiconductors]] in 2006.<ref>{{cite web |title=NXP Semiconductors history |url=https://www.siliconvalleyhistorical.org/nxp-semiconductors-history |website=Silicon Valley Historical Association |archive-url=https://web.archive.org/web/20200321080200/https://www.siliconvalleyhistorical.org/nxp-semiconductors-history |archive-date=March 21, 2020 |date=2008 |url-status=live}}</ref>
** [[Zetex Semiconductors]] was sold to [[Diodes Incorporated]] in 2008.<ref>{{cite web |title=Diodes Incorporated closes acquisition of Zetex |url=https://www.ledsmagazine.com/leds-ssl-design/driver-ics/article/16697918/diodes-incorporated-closes-acquisition-of-zetex-plc |website=LEDs Magazine |archive-url=https://web.archive.org/web/20200522102057/https://www.ledsmagazine.com/leds-ssl-design/driver-ics/article/16697918/diodes-incorporated-closes-acquisition-of-zetex-plc |archive-date=May 22, 2020 |date=June 13, 2008 |url-status=live}}</ref>  The ZSCT1555 started as a Zetex product.<ref name="Redesigning">{{cite journal |first=H.R. |last=Camenzind |title=Redesigning the old 555 [timer circuit] |journal=IEEE Spectrum |volume=34 |issue=9 |pages=80–85 |date=September 1997 |doi=10.1109/6.619384 }}</ref>

=== 556 dual timer ===
{{stack|[[File:STM-NE556-HD.jpg|thumb|[[Die (integrated circuit)|Die]] of a NE556 dual timer manufactured by [[STMicroelectronics]]]]}}
{{stack|[[File:NE556 pennen.svg|thumb|Pinout of 556 dual timer<ref name="TI_NE556_Datasheet"/><ref name="Signetics_1973_555-556_Databook"/>]]}}

The dual version is called 556. It features two complete 555 timers in a 14-pin package; only the two power-supply pins are shared between the two timers.<ref name="TI_NE556_Datasheet"/><ref name="Signetics_1973_555-556_Databook"/> In 2020, the bipolar version was available as the NE556,<ref name="TI_NE556_Datasheet"/> and the CMOS versions were available as the Intersil ICM7556 and Texas Instruments TLC556 and TLC552. See [[#Derivatives|derivatives table]] in this article.<ref name="Intersil_ICM7555-556_Datasheet"/><ref name="TI_TLC556_Datasheet"/><ref name="TI_TLC552_Datasheet"/>

{{clear}}

=== 558 quad timer ===
{{stack|[[File:Signetics Corporation NE558D 0136O07 9331KK KOREA.jpg|thumb|Die of a NE558 quad timer manufactured by [[Signetics]]]]}}
{{stack|[[File:NE558 pennen.svg|thumb|Pinout of 558 quad timer<ref name="Signetics_1985_Linear_Databook"/>]]}}
{{stack|[[File:NE558 intern.svg|thumb|558 internal block diagram. It is different from 555 and 556 timers.<ref name="Signetics_1985_Linear_Databook"/>]]}}

The quad version is called 558 and has four reduced-functionality timers in a 16-pin package designed primarily for [[monostable multivibrator]] applications.<ref>{{Cite book |last=Horn |first=Delton |title=Amplifiers, waveform generators, and other low-cost IC projects |publisher=TAB Books |year=1994 |isbn=0-07-030415-7 |location=New York |pages=27 |oclc=28676554 |quote=Not all functions are brought out to the 558's pins. This chip is designed primarily for monostable multivibrator applications}}</ref><ref name="Signetics_1985_Linear_Databook"/> By 2014, many versions of 16-pin NE558 have become obsolete.<ref name=":0">{{Cite book |last1=Platt |first1=Charles |url=https://books.google.com/books?id=FgRYBQAAQBAJ&pg=PT213 |series=Encyclopedia of Electronic Components |volume=2 |title=LEDs, LCDs, Audio, Thyristors, Digital Logic, and Amplification |last2=Jansson |first2=Fredrik |date=2014-11-13 |publisher=Maker Media |isbn=978-1-4493-3414-7 |language=en}}</ref>

Partial list of differences between 558 and 555 chips:<ref name="Signetics_1985_Linear_Databook"/><ref name=":0" />
* One ''V''<sub>CC</sub> and one GND, similar to 556 chip.
* Four "Reset" are tied together internally to one external pin (558).
* Four "Control Voltage" are tied together internally to one external pin (558).
* Four "Triggers" are falling-edge sensitive (558), instead of level sensitive (555).
* Two resistors in the voltage divider (558), instead of three resistors (555). 
* One comparator (558), instead of two comparators (555).
* Four "Output" are [[open-collector]] (O.C.) type (558), instead of [[Push–pull output|push–pull]] (P.P.) type (555).