LM1894

LM1894 Dynamic Noise Reduction System DNR December 1994 LM1894 Dynamic Noise Reduction System DNR ® General 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. n Compatible with all prerecorded tapes and FM n 10 dB effective tape noise reduction CCIR/ARM weighted n Wide supply range, 4.5V to 18V n 1 Vrms input overload Applications n n n n n Automotive radio/tape players Compact portable tape players Quality HI-FI tape systems VCR playback noise reduction Video disc playback noise reduction Features n Non-complementary noise reduction, “single ended” n Low cost external components, no critical matching Typical Application DS007918-1 *R1 + R2 = 1 kΩ total. See Application Hints. Order Number LM1894M or LM1894N See NS Package Number M14A or N14A FIGURE 1. Component Hook-Up for Stereo DNR System DNR ® is a registered trademark of National Semiconductor Corporation. The DNR ® system is licensed to National Semiconductor Corporation under U.S. patent 3,678,416 and 3,753,159. Trademark and license agreement required for use of this product. © 1999 National Semicon...