digital tuning indicator

digit•al t.uning indicator Although the Japanese manufacturer, OKI, is less well known than some others, they are nevertheless important among the Japanese suppliers. One of their important contributions is the development of the electronics for the increasingly popular digital tuning indicators for Hi-fi tuners. These circuits are now integrated onto a single chip. This is a typical application for the MSM 5526, a directly monolithic 40-pin CMOS IC which drives digit LCD. A crystal oscillator with a fre- a 31/2 quency of 6.5536 MHz is used for timing. As w as the internal clock, this oscillator produces an accurate 50 Hz output signal, and a 1 = AM 2 = FM 3 = freq. counter 4 = pulse counter frequency meter, or as a pulse FM and mum display indication is "2999". Up to 6 AM frequencies can be preset when the IC is used as a tuning indicator. The circuit diagram shows that very few com- osc. I R3 1 C3 1P Xtal = 6,5536 MHz AM 0---2-11 I 81604 00n ell to drive the LCD. A number of d...