The MAX1894/MAX1924 are lithium-ion/lithium-polymer (Li+) battery-pack protector ICs for 3- or 4-series Li+ bat tery packs. The MAX1894/MAX1924 enhance the useful operating life of Li+ batteries by monitoring individual cell voltages and preventing over/undervoltage conditions. The MAX1894/MAX1924 also protect the battery pack against charge current, discharge current, and pack short fault conditions.
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.