BH1415F Audio ICs Wireless Audio Link IC BH1415F The BH1415F is a FM stereo transmitter IC that transmits simple configuration. The IC consists of a stereo modulator for generating stereo composite signals and a FM transmitter for broadcasting a FM signal on the air. The stereo modulator generates a composite signal which consists of the MAIN, SUB, and pilot signal from a 38kHz oscillator. The FM transmitter radiates FM wave on the air by modulating the carrier signal with a composite signal. Applications CD changer, Car TV, Car navigation, Wireless speakers, Personal computer (sound board), Game machine Features 1) It is possible to improve the timbre because it has the pre-emphasis circuit, limiter circuit, and the low-pass filter circuit. 2) Built-in pilot-tone system FM stereo modulator circuit. 3) The transmission frequency is stable because it has a PLL system FM transmitter circuit. 4) PLL data input (CE, CK, DA) by serial input. Absolute maximum ratings (Ta = 25C, In measurement circuit.) Parameter Symbol Limits Unit Conditions Supply voltage VCC +7.0 V Pin8,12 Data input voltage VIN-D 0.3 to VCC+0.3 V Pin15,16,17,18 Phase comparator output voltage VOUT-P 0.3 to VCC+0.3 V Pin7 Power dissipation Pd 450 mW Storage temperature Tstg 55 to +125 C Derating : 4.5mW/C for operation above Ta=25C. Recommended operating conditions (Ta = 25C) Max. Parameter Symbol Min. Typ. Unit Conditions 6.0 Operating supply voltage VCC 4.0 V Pin8,12 40 +85 Operating temperature Topr C 10 Audio input level VIN-A dBV Pin1,22 Audio input frequency band fIN-A 20 15k Hz Pin1,22 Pre-emphasis time constant set up range t PRE 155 sec Pin2,21 Transmission frequency fTX 70 120 MHz Pin9,11 Control terminal level input voltage VIH 0.8VCC VCC V Pin15,16,17,18 Control terminal level input voltage VIL GND 0.2VCC V Pin15,16,17,18 1/3 BH1415F Audio ICs Block diagram 22 21 20 19 18 17 16 15 14 13 12 PLL VCC Shift register LPF + 1 1 Pre-emphasis 50 4 MPX and Limiter MUTE 1 1 + 2 19 LPF Program counter Phase detector OSC RF + VCC 2 GND VCC RF GND 123456789 10 11 2/3 R-ch INPUT L-ch INPUT PRE-EMPHASIS TIME CONSTANT PRE-EMPHASIS TIME CONSTANT LPF TIME CONSTANT LPF TIME CONSTANT FILTER PILOT SIGNAL ADJUST COMPOSITE SIGNAL OUTPUT AUDIO MUTING GND DATA PLL PHASE DETECTOR OUTPUT CLOCK VCC CHIP ENABLE RF OSCILLATOR X tal OSCILLATOR RF GND X tal OSCILLATOR RF OUTPUT PLL VCC