Wireless Audio Link IC

Transcription

1 Wireless Audio Link IC BH5S / BH5F BH5S / BH5F The BH5S/F are FM stereo transmitter ICs that transmit simple configuration. The ICs consist 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 3kHz oscillator. The FM transmitter radiates FM wave on the air by modulating the carrier signal with a composite signal. Applications CD changer, Car T, Car navigation, Wireless speakers, Personal computer (sound board), Game machine Features ) It is possible to improve the timbre because it has the pre-emphasis circuit, limiter circuit, and the low-pass filter circuit. ) Built-in pilot-tone system FM stereo modulator circuit. 3) The transmission frequency is stable because it has a PLL system FM transmitter circuit. ) PLL data input (CE, CK, DA) by serial input. Absolute maximum ratings (Ta = 5 C, In measurement circuit.) Parameter Symbol Limits Unit Conditions Supply voltage cc 7.0 Pin, input voltage IN-D 0.3~cc0.3 Pin5,,7, comparator output voltage OUT-P 0.3~cc0.3 Power dissipation BH5S 000 Pd BH5F Storage temperature Tstg 55~5 * Derating : 0mW/ C for operation above Ta=5 C. * Derating :.5mW/ C for operation above Ta=5 C. mw C Pin7 Recommended operating conditions (Ta=5 C) Parameter Symbol Min. Typ. Max. Unit Conditions Operating supply voltage cc.0.0 Pin, Operating temperature Topr.0 5 C Audio input level IN-A 0 db Pin, Audio input frequency band fin-a 0 5k Hz Pin, time constant set up range τ PRE 55 µsec Pin, Transmission frequency ftx 70 0 MHz Pin9, Control terminal "H" level input voltage IH 0.cc cc Pin5,,7, Control terminal "L" level input voltage IL 0.cc Pin5,,7,

2 BH5S / BH5F Block diagram L-ch INPUT PRE-EMPHASIS TIME CONSTANT TIME CONSTANT PILOT SIGNAL ADJUST AUDIO MUTING DATA CLOCK CHIP ENABLE X'tal OSCILLATOR X'tal OSCILLATOR PLL PLL 9 OSC RF RF R-ch INPUT PRE-EMPHASIS TIME CONSTANT TIME CONSTANT FILTER COMPOSITE SIGNAL OUTPUT PLL PHASE DETECTOR OUTPUT RF OSCILLATOR RF RF OUTPUT

3 BH5S / BH5F Pin descriptions Pin No. Pin descriptions Equivalent circuit DC () R-ch audio source input terminal It cuts DC with the capacitor and it inputs R-ch audio signal. L-ch audio source input terminal or cc 3k.7k cc It cuts DC with the capacitor and it inputs L-ch audio signal. k, time constant terminal It connects a capacitor for the time constant of pre-emphasis. τ =.7kΩ C or cc 3,0 time constant terminal This is 5kHz. It connects a pf capacitor. 00k 00k - cc cc 00k p 0 3 or Filter terminal It is a ripple filter for the reference voltage of the audio part. k k cc 5 Composite signal output terminal It connects to the FM modulator. 5 cc 7 PLL phase output terminal It connects to the PLL circuit. 7 Power supply terminal cc

4 BH5S / BH5F Pin No. Pin descriptions Equivalent circuit DC () 9 RF oscillator terminal This is the base terminal of the colpitts oscillator. It connects time constant of the oscillation. 9 5k p p 7 cc 0k 30p 0 0 RF RF transmission output terminal It connects to the antenna through BPF. cc PLL power supply terminal cc 3, X'tal oscillator terminal It connects a 7.MHz crystal oscillator. k 3 M 5 terminal The terminal to make high level in serial data input. input terminal The clock which takes data and synchronization in serial data input. 7 input terminal 5 7 or or or The input terminal of the serial data which is forwarded from the controller Audio mute terminal 0.cc Pin : Mute ON 0.cc Pin : Mute OFF 9 Pilot signal adjust terminal 9 5k cc

5 BH5S / BH5F Electrical characteristics (Unless otherwise noted Ta = 5 C, =5.0, Signal source : fin=00hz) Parameter Symbol Min. Typ. Max. Unit Conditions Measurement circuit Quiescent current IQ 0 ma Fig. Channel separation Sep 5 0 db IN=0dB L R,R L Fig. Total harmonic distortion Channel balance THD C.B % db IN=0dB LR IN=0dB LR Fig.3 Fig. Input output gain Gv 0 db IN=0dB LR Pilot modulation rate MP 5 % IN=0dB,LR Pin5 Fig.3 Fig.3 Sub carrier rejection ratio SCR 30 0 db IN=0dB LR Fig.3 time constant Limiter input level τ PRE IN(LIM) µsec db IN=0dB LR Output level at db gain compression Fig.3 Fig. cut off frequency Mute attenuation volume fc() O() 5 khz db O=3dB Pin,Open IN=0dB LR Fig.5 Fig.3 Transmission output level "H" level input current TX IIH dbµ µa ftx=00mhz Pin5,,7, IN=5 Fig. Fig.7 "L" level input current IIL.0 µa Pin5,,7, IN=0 Fig.7 "H" level output voltage OH cc-.0 cc- 0.5 Pin7 IOUT=.0mA Fig.7 "L" level output voltage "off" level leak current OL IOFF na Pin7 IOUT=.0mA Pin7 OUT=5 Fig.7 Fig. "off" level leak current IOFF 00 na Pin7 OUT= Fig.

6 Measurement circuits Quiescent current 7.MHz BH5S / BH5F PLL 9 OSC RF RF p p 0µ 00p p Muting 7p 7p 0.0µ 0.0µ 00µ 5 IQ A Fig.

7 Channel separation Channel balance BH5S / BH5F 7.MHz 0µ 00p p 70p Muting 7p 7p 0.0µ L-ch PLL fin = 00Hz IN = -0dB R-ch 0µ 9 OSC RF RF p p 0µ 0µ 0k 0.0µ 00µ Stereo signal demodulator 5 L-ch ~ ~ R-ch Sep, C.B Fig.

8 BH5S / BH5F Total harmonic distortion Input output gain Pilot index of modulation Sub carrier rejection ratio time constant Mute attenuation volume 0 5 (Mute ON) 7.MHz 0µ 00p p 70p 7p 7p 0.0µ L-ch PLL ~ fin=00hz IN=0dB R-ch 0µ OSC RF RF p p 0µ 0µ 0.0µ 00µ 9 0k Spectrum analyzer SCR G, MP τ PRE IHF BPF 00Hz~5kHz 5 THD, O() 0 Output response (db) SCR k 0k 30k 0k k Frequency (Hz) Fig.3

9 BH5S / BH5F Limiter input level 7.MHz 0µ 00p p 70p Muting 7p 7p 0.0µ L-ch PLL ~ fin=00hz R-ch 0µ OSC RF RF p p 0µ 0µ 0.0µ 00µ 9 0k IN (LIM) 5 Output level (db) db Input level (db) IN(LIM) Fig.

10 BH5S / BH5F cut off frequency 7.MHz 0µ p 70p Muting 7p 7p 0.0µ L-ch PLL ~ fin=00hz IN=0dB R-ch 0µ OSC RF RF p 0µ 0µ 0.0µ 00µ 9 0k fc () 5 Output response (db) 3dB Frequency (Hz) Fig.5 fc()

11 BH5S / BH5F Transmission output level 7.MHz Muting 7p 7p 0.0µ PLL 0k 0.0µ 9 0p OSC p RF RF µ 00µ FEM0C-3F (SUMIDA) 33p 000p 0k K-7E (TOKO) TX Spectrum analyzer Zin=Ω ftx=00mhz 0.07µ 5.k 00 33µ 0k 5 SC0S (ROHM) 000p Fig.

12 BH5S / BH5F H level input current L level input current H level output voltage L level output voltage 0, 5 A IIH, IIL 7.MHz Muting 7p 7p 0.0µ PLL 0.0µ 9 OSC RF RF µ OH, OL OH OL ma ma 5 Fig.7

13 BH5S / BH5F off level leak input current 7.MHz Muting 7p 7p 0.0µ PLL 0.0µ 9 OSC RF RF µ IOFF, IOFF A 0, 5 5 Fig.

14 BH5S / BH5F Circuit operations Input of the serial data t, t, t3, t.5µsec t5 <.5µsec (X'tal : 7.MHZ) t t t3 t t5 CE CK DA D0 D D D3 D PD T0 T Internal data Composition of the serial data DA D0 D () PR-CTL () OM-CTL (3) PD-CTL D () TEST D3 D D5 D D7 D D9 D0 MONO PD0 PD T0 T Explanation of the serial data No. Control unit / Contents () PROGRAM COUNTER D0 ~ D0 It is the data which sets the program counter number of the dividing.this data can set a transmission frequency. It is a binary value. It sets D0 with MSB and it sets D0 with LSB. Example In case of 99.7MHz oscillation 99.7MHZ 00kHZ(fref) = 997 3E5(HEX) 5 E D0 D D D3 D D5 D D7 D D9 D0 LSB MSB

15 BH5S / BH5F No. Control unit / Contents () MULTIPLEXER It changes a stereo and monaural operation. MONO MONO 0 Condition of the composite signal Monaural operation LR, Pilot OFF Stereo operation LR(L-R),sinωstPsin t ωs () PHASE DETECTOR It controls charge pump output by the phase comparator compulsorily. PD0, PD PD0 PD Charge pump output Usual operation Compulsion by Low 0 Compulsion by High High impedance (3) TEST MODE T0, T It is data for the LSI test. Always in T0 Input "". Always in T Input "0". External dimensions (Units : mm) BH5S BH5F 9. ± ± ± ± Min..5 ± ± ~ ± ± 0.3. ± ± ± Min. 0.5 ± SDIP SOP