Wireless Audio Link IC

Transcription

1 BH5F Wireless Audio Link IC BH5F The BH5F 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 3kHz 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 ) 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 Supply voltage input voltage comparator output voltage Power dissipation Storage temperature VIN-D VOUT-P Pd Tstg Derating :.5mW/ C for operation above Ta=5 C. 7.0 V 0.3~0.3 V 0.3~0.3 V mw 55~5 C Conditions Pin, Pin5,,7, Pin7 Recommended operating conditions (Ta = 5 C) Parameter Symbol Min. Typ. Max. Unit Operating supply voltage Operating temperature Audio input level Audio input frequency band time constant set up range Transmission frequency Control terminal "H" level input voltage Control terminal "L" level input voltage Topr VIN-A fin-a t PRE ftx VIH VIL k V C dbv Hz µsec MHz V V Conditions Pin, Pin, Pin, Pin, Pin9, Pin5,,7, Pin5,,7,

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

4 BH5F Pin No. Pin descriptions Equivalent circuit DC (V) 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 0k 30p 0 0 RF RF transmission output terminal It connects to the antenna through BPF..9 0 PLL power supply terminal 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. Pin : Mute ON 0. Pin : Mute OFF 9 Pilot signal adjust terminal 9 5k

5 BH5F Electrical characteristics (Unless otherwise noted Ta = 5 C, = 5.0V, 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 VIN=0dBV L R,R L Fig. Total harmonic distortion Channel balance THD C.B % db VIN=0dBV LR VIN=0dBV LR Fig.3 Fig. Input output gain Gv 0 db VIN=0dBV LR Pilot modulation rate MP 5 % VIN=0dBV,LR Pin5 Fig.3 Fig.3 Sub carrier rejection ratio SCR 30 0 db VIN=0dBV LR Fig.3 time constant Limiter input level τ PRE VIN(LIM) µsec dbv VIN=0dBV LR Output level at db gain compression Fig.3 Fig. cut off frequency Mute attenuation volume fc() VO() 5 khz db VO=3dB Pin,Open VIN=0dBV LR Fig.5 Fig.3 Transmission output level "H" level input current VTX IIH dbµv µa ftx=00mhz Pin5,,7, VIN=5V Fig. Fig.7 "L" level input current IIL.0 µa Pin5,,7, VIN=0V Fig.7 "H" level output voltage VOH V Pin7 IOUT=.0mA Fig.7 "L" level output voltage "off" level leak current VOL IOFF V na Pin7 IOUT=.0mA Pin7 VOUT=5V Fig.7 Fig. "off" level leak current IOFF 00 na Pin7 VOUT= Fig.

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

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

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

9 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 VIN (LIM) 5V Output level (dbv) db Input level (dbv) VIN(LIM) Fig.

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

11 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 KV-7E (TOKO) VTX Spectrum analyzer Zin=Ω ftx=00mhz 0.07µ 5.k 00 33µ 0k 5V SC0S (ROHM) 000p Fig.

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

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

14 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 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) 3. ± 0.. ± ± ± ± Min. 0.5 ± SOP