LM1894 ,Dynamic Noise Reduction System DNRLM1894DynamicNoiseReductionSystemDNRDecember1994LM1894DynamicNoiseReductionSystemDNRÉYCompatible wi ..
LM1894M ,Dynamic Noise Reduction System DNRFeaturesn Video disc playback noise reductionn Non-complementary noise reduction, “single ended”n L ..
LM1894MT ,Dynamic Noise Reduction System DNRGeneral Descriptionn 10 dB effective tape noise reduction CCIR/ARMThe LM1894 is a stereo noise redu ..
LM1894MX ,Dynamic Noise Reduction System DNRApplicationsand an adaptive bandwidth scheme allow the DNR toachieve 10 dB of noise reduction. DNR ..
LM1894N ,Dynamic Noise Reduction System DNRLM1894 Dynamic Noise Reduction System DNRDecember 1994LM1894®Dynamic Noise Reduction System DNRn Co ..
LM1894N. ,Dynamic Noise Reduction System DNRGeneral Descriptionn 10 dB effective tape noise reduction CCIR/ARMThe LM1894 is a stereo noise redu ..
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LM1894
Dynamic Noise Reduction System DNR
TL/H/7918
LM1894
Dynamic
Noise
Reduction
System
DNR
December 1994
LM1894 Dynamic Noise Reduction System DNRÉ
General Description
The LM1894isa stereo noise reduction circuitforusewith
audio playback systems. The DNR systemis non-comple-
mentary, meaningit doesnot require encoded source mate-
rial. The systemis compatible with virtuallyall prerecorded
tapesandFM broadcasts. Psychoacoustic masking,andan
adaptive bandwidth scheme allowthe DNRto achieve10of noise reduction. DNR can save circuit board space
and cost becauseofthe few additional componentsre-
quired.
Features Non-complementary noise reduction, ‘‘single ended’’ Low cost external components,no critical matching Compatible withall prerecorded tapesandFM10dB effective tape noise reduction CCIR/ARM
weighted Wide supply range, 4.5Vto 18V1 Vrms input overload
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
*R1aR2e 1kXtotal.
See Application Hints. TL/H/7918–1
FIGURE1. ComponentHook-Upfor Stereo DNR System
OrderNumber LM1894Mor LM1894N
SeeNSPackage Number M14Aor N14A
DNRÉisa registeredtrademarkof National SemiconductorCorporation.
TheDNRÉ systemis licensed toNationalSemiconductorCorporationunderU.S. patent3,678,416and3,753,159.
Trademarkandlicense agreement requiredforuseof thisproduct.
C1995National SemiconductorCorporation RRD-B30M115/PrintedinU.S.A.
