BU1920 Datasheet | ROHM

Audio ICs RDS / RBDS decoder BU1920 / BU1920F / BU1920FS The BU1920, BU1920F and BU1920FS are RDS / RBDS decoders that employ a digital PLL. It has a built-in anti-aliasing filter and an eight-stage BPF (switched-capacitor filter). Linear CMOS circuitry is used for low current dissipation. FApplications RDS / RBDS patible FM receivers for Europe and North America, car stereo systems, home stereo systems and FM pagers. FFeatures 1) Low current dissipation. 2) Two-stage anti-aliasing filter. 3) 57k Hz bandpass filter. 4) DSB demodulation (digital PLL). 5) ARI signal discrimination. 6) Quality indication output for demodulated data. FAbsolute maximum ratings (Ta = 25_C) FRemended operating conditions (Ta = 25_C) Audio ICs FBlock diagram Application example BU1920 / BU1920F / BU1920FS Pin assignments Audio ICs FPin descriptions BU1920 / BU1920F / BU1920FS Audio ICs FInput / output circuits BU1920 / BU1920F / BU1920FS Audio ICs BU1920 / BU1920F / BU1920FS FElectrical characteristics (unless otherwise noted, Ta = 25_C, VDD = 5.0V and GND = 0.0V) Filter block Demodulator block Audio ICs FOutput data timing BU1920 / BU1920F / BU1920FS The clock (RCLK) frequency is 1187.5Hz. Depending on the state of the internal PLL clock, the data (RDATA) is replaced in synchronous with either the rising or falling edge of the clock. To read the data, you may choose either the rising or falling edge of the clock as the reference. The data is valid for 416.7µs, after the reference clock edge. QUAL pin operation: Indicates the quality of the demodulated data. (1) Good data : HI (2) Poor data : LO ARI pin operation: ARI / RDS discrimination. (1) ARI : LO (2) RDS + ARI : LO (3) RDS : HI (4) No signal : unstable FElectrical characteristics...