Features Non-complementary noise reduction, "single ended" Low cost external components, no critical matching Compatible with all prerecorded tapes and FM 10 dB effective tape noise reduction CCIR/ARM weighted Wide supply range, 4.5V to 18V 1 Vrms input overload Description The LM1894 is a stereo noise reduction circuit for use with audio playback systems. The DNR system is non-complementary, meaning it does not require encoded source material. The system is compatible with virtually all prerecorded tapes and FM broadcasts. Psychoacoustic masking, and an adaptive bandwidth scheme allow the DNR to achieve 10 dB of noise reduction. DNR can save circuit board space and cost because of the few additional components required. Applications Automotive radio/tape players Compact portable tape players Quality HI-FI tape systems VCR playback noise reduction Video disc playback noise reduction

Typical Application click for larger image	Block Diagram click for larger image
Typical Performance click for larger image

Datasheets

Title		Size	Date	Other Language
	LM1894 Dynamic Noise Reduction System DNR	340 Kbytes	14-Oct-04	日本語

Application Notes

Title		Size	Date	Other Language
	AN-384: Application Note 384 Audio Noise Reduction and Masking	163 Kbytes	23-Sep-02
	AN-386: Application Note 386 A Non-Complementary Audio Noise Reduction System	376 Kbytes	23-Sep-02
	AN-390: Application Note 390 DNR - Applications Of The LM1894	304 Kbytes	25-Sep-02

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM1894MX/NOPB LM1894MX RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 2500 DIGI-KEY Worldwide 0 TAYLOR Americas 2500	$0.91 each at 1K+ pcs	reel of 2500

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM1894M	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM1894MTBD	NONE	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM1894N	NONE	NONE	01 Dec 2004

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 LM1894.

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 LM1894 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
LM1894MX/NOPB LM1894MX	129.551 130.001	SOIC NARROW	14	1 1	260 235	Detail	N/A	N/A	NSUZXYTT LM1894M

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 LM1894.

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 LM1894 is located at RoHS Status.

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)
LM1894MX	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 LM1894.

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 LM1894 is located at RoHS Status.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM1894M	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM1894MTBD	NONE	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM1894N	NONE	NONE	01 Dec 2004