Features Direct replacement for SE556/NE556 Timing from microseconds through hours Operates in both astable and monostable modes Replaces two 555 timers Adjustable duty cycle Output can source or sink 200mA Output and supply TTL compatible Temperature stability better than 0.005% per °C Normally on and normally off output Description The LM556 Dual timing circuit is a highly stable controller capable of producing accurate time delays or oscillation. The 556 is a dual 555. Timing is provided by an external resistor and capacitor for each timing function. The two timers operate independently of each other sharing only VCC and ground. The circuits may be triggered and reset on falling waveforms. The output structures may sink or source 200mA. Applications Precision timing Pulse generation Sequential timing Time delay generation Pulse width modulation Pulse position modulation Linear ramp generator

Datasheets

Title		Size	Date	Other Language
	LM556 Dual Timer	216 Kbytes	29-Mar-00
	LM556 Mil-Aero Datasheet MNLM556-X	11 Kbytes

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM556CM/NOPB LM556CM RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 1210 AVNET-EM Worldwide 391 DIGI-KEY Worldwide 543 FARNELL Europe and Asia 1471 MOUSER Worldwide 749 NEWARK Americas 365 RS COMPONENTS Worldwide 240 TAYLOR Americas 1210	$0.50 each at 1K+ pcs	rail of 55
LM556CMX/NOPB LM556CMX RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 2772 AVNET-EM Worldwide 4917 DIGI-KEY Worldwide 30434 MOUSER Worldwide 2465 TAYLOR Americas 2772	$0.50 each at 1K+ pcs	reel of 2500
LM556CN/NOPB LM556CN RoHS Status	MDIP	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 935 AVNET-EM Worldwide 565 BRITESTONE South Korea 43 DIGI-KEY Worldwide 1109 FARNELL Europe and Asia 1001 MOUSER Worldwide 1629 RS COMPONENTS Worldwide 490 TAYLOR Americas 2615	$0.51 each at 1K+ pcs	rail of 25
LM556 MWC RoHS Status		Full production Lead Time: N/A	Contact your distributor	CALL	wafer jar of N/A

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM556J-MIL	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM556.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM556 is located at RoHS Status.

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM556CM/NOPB LM556CM	129.551 130.001	SOIC NARROW	14	1 1	260 235	Detail	N/A	N/A	NSUZXYTTE# LM556CM
LM556CMX/NOPB LM556CMX	129.551 130.001	SOIC NARROW	14	1 1	260 235	Detail	N/A	N/A	NSUZXYTTE# LM556CM
LM556CN/NOPB LM556CN	986.751 990.002	MDIP	14	1 1	NA NA	Detail	N/A	N/A	NSUZXYYTTE# LM556CN
LM556 MWC	32300	Wafer				N/A	-

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM556.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM556 is located at RoHS Status.

Reference Design

RD-168 - Ambient Light Adaptive LED Driver

CAD Symbols and Models N/A

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM556 MWC	SLM	0	44046	0	0	3532500	1	1002356520
LM556CM	SLM	0	44046	0	0	3532500	1	1002356520
LM556CMX	SLM	0	44046	0	0	3532500	1	1002356520
LM556CN	SLM	0	44046	0	0	3532500	1	1002356520

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM556.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM556 is located at RoHS Status.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM556J-MIL	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008