SA1021 FM RADIO RECEIVER FOR PORTABLE SYSTEM DESCRIPTION The SA1021 integrated radio receiver circuit is for portable radios, stereo as well as mono, where a minimum of periphery is important in terms of small dimensions and low cost. It is fully compatible for applications using the low-voltage micro tuning system (MTS). The IC has a frequency locked loop (FLL) system with an intermediate frequency of 76kHz. The selectivity is obtained by active RC filters. The only function to be tuned is the resonant frequency of the SOP-16-225-1.27 oscillator.Interstation noise as well as noise from receiving weak signals is reduced by a correlation mute system. Special precautions have been taken to meet local oscillator radiation requirements. Because of the low intermediate frequency, low pass filtering of the MUX signal is required to avoid noise when receiving stereo. 50kHz roll-off compensation, needed because of the low pass characteristic of the FLL, is performed by the integrated LF ORDERING INFORMATION amplifier. For mono application this amplifier can be used to directly Part No. Package drive an earphone. The field-strength detector enables field-strength SA1021 SOP-16-225-1.27 dependent channel separation control. * Mixer * IF amplifier/limiter FEATURES * Mute circuit * RF input stage * Loop amplifier * Local oscillator * LF amplifier for mono earphone * Frequency detector amplifier or MUX filter * MTS compatible * Internal reference circuit * Field-strength dependent channel separation control facility. BLOCK DIAGRAM 12 13 RF 5 11 7 10 MIX AMP VCO MUTE 8 Buffer IF Filter OSC CLIM Demodulation AF 14 AMP 16 15 6 IF limiter STAB 2 1 3 4 9 Fig.1 Block diagram HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:2.0 2004.07.31 Page 1 of 7 SA1021 ABSOLUTE MAXIMUM RATINGS Characteristics Symbol Min. Max. Unit Vp= V4-3 -- 7.0 V Oscillator Voltage V5-4 Vp-0.5 Vp+0.5 V Operating Ambient Temperature Range Tamb -10 +70 °C Storage Temperature Range Tstg -55 +150 °C Supply Voltage(pin 4) QUICK REFERENCE DATA Characteristics Supply Voltage (pin 4) Symbol Supply Current I4 RF Input Frequency frf Sensitivity (e.m.f.) for –3 dB Limiting Signal Handling (e.m.f.) AF Output Voltage Conditions Min. Typ. Max. Unit 1.8 -- 6.0 V -- 6.3 -- mA Vp= V4-3 Vp=3V 1.5 -- 110 MHz EMF Sourceimpedance=75Ω;Mut -- 4 -- µV EMF e disabled -- 200 -- mV Source impedance=75Ω -- 90 -- mV Vo THERMAL RESISTANCE From junction to ambient Rth j-a 300 K/W DC ELECTRICAL CHARACTERISTICS(Tamb=25°C,Vp=3V , Unless otherwise specified) Characteristics Symbol Test conditions Min. Typ. Max. Unit Vp= V4-3 -- 1.8 3.0 6.0 V Supply Current I4 Vp=3V -- 6.3 -- mA Oscillator current I5 -- -- 250 -- µA Voltage at Pin 13 V13-3 -- -- 0.9 -- V Output Voltage(pin 14) V14-3 -- -- 1.3 -- V Supply Voltage(pin 4) AC ELECTRICAL CHARACTERISTICS(MONO OPERATION)Tamb=25°C, Vp=3V,mea sured in Fig.5, frf=96MHz modulated with ∆f=±22.5kHz, fm=1kHz, EMF=0.3mV (e.m.f. at a source impedance of 75Ω), r.m.s. noise voltage measured unweighted (f=300Hz to 20kHz), Unless otherwise specified Characteristics Sensitivity (e.m.f.) Symbol for –3 dB limiting EMF for –3 dB muting EMF for (S+N)/N=26dB EMF Signal Handling (e.m.f.) Signal-to-noise Ratio Total Harmonic Distortion EMF (S+N)/N THD Test conditions Min. Typ. Max. Unit -- 4.0 -- µV -- 5.0 -- µV -- 7.0 -- µV THD<10%, ∆f=±75kHz -- 200 -- mV -- -- 60 -- dB ∆f=22.5kHz -- 0.7 -- % ∆f=±75kHz -- 2.3 -- % See Fig.3 Muting disabled To be continued HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:2.0 2004.07.31 Page 2 of 7 SA1021 (continued) Characteristics Symbol Test conditions Min. Typ. Max. Unit -- 50 -- dB -- 30 -- dB -- 250 -- mV -- 5 -- KHz/°C Ratio of AM signal AM Suppression of Output Voltage AMS (fm=1kHz; m=80% ) to FM signal (fm=1kHz; ∆f=±75kHz) Ripple Rejection Oscillator Voltage (r.m.s. value) Variation of Oscillator Frequency with Temperature RR ∆Vp=100mV, f=1kHz V5-4(rms) -∆fosc/∆Tamb Vp= 1V S+300 see Fig.9 -- 46 -- dB S-300 no modualtion -- 30 -- dB AFC Range ±∆frf -- -- 160 -- kHz Mute Range ±∆frf -- -- 120 -- kHz -- 10 -- kHz -- 90 -- mV -100 -- +100 µA -- 3 -- mA Selectivity Audio Bandwidth AF Output Voltge(r.m.s. value) Max.d.c. load AF Output Max.a.c. load (peak value) B Vo(rms) ∆Vo=3dB,measured with 50µs pre-emphasis RL(pin 14)=100Ω Io(dc) -- Io(ac) THD=10% Fig.2 Supply current as a function of the supply voltage Fig.3 Field strength voltage (V9-3) at Rsource=1kΩ; f=96.75MHz;Vp=3V Fig.4 Mono operation: AF output voltage (Vo) and total harmonic distortion (THD) as functions of input e.m.f. (EMF); Rsource=75Ω; frf=96MHz; 0dB=90mV. For S+N and noise curves (1) is with muting enabled and (2) is with muting disabled; signal ∆f=±22.5kHz and fm=1kHz. For THD curve,∆f=±75kHz and fm=1kHz. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:2.0 2004.07.31 Page 3 of 7 SA1021 Fig.6 Stereo operation: signal/noise and channel separation of SA1021 when used in the circuit of Fig.8. Fig.7 Stereo operation: channel separation as a Function of audio frequency in the circuit of Fig.8. TEST AND APPLICATION CIRCUITS Fig.5 Test circuit for mono operation. AC ELECTRICAL CHARACTERISTICS(STEREO OPERATION)Tamb=25°C; Vp=3V; measured in Fig.8; frf=96MHz modulated with pilot ∆f=±6.75kHz and AF signal ∆f=±22.5kHz; fm=1kHz; EMF=1mV(e.m.f. at a source impedance of 75Ω); r.m.s. noise voltage measured unweighted (f=300Hz to 20kHz); Unless otherwise specified. Characteristics Sensitivity (e.m.f.) for (S+N)/N=26dB Selectitvity Signal-to-noise Ratio Symbol EMF S+300 S-300 (S+N)/N α Channel Separation α Test conditions See Fig.8,pilot off See Fig.9.no modulation -Vi=L-signal; at frf =97MHz fm=1kHz,pilot on: at frf =87.5MHz and 108MHz HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn Min. Typ. Max. Unit -- 11 -- µV -- 40 -- dB -- 22 -- dB -- 50 -- dB -- 26 -- dB -- 14 -- dB REV:2.0 2004.07.31 Page 4 of 7 SA1021 TEST AND APPLICATION CIRCUIT Fig.8: Stereo application in combination with a low voltage PLL stereo decoder (UTC7040) and a low voltage Mono/stereo power amplifier (UTC7050). Fig.9 test set-up; Vi=30mV; fi=76kHz; selective voltmeter at output has Ri≥1MΩ and Ci≤8pF; fo=fi. This test set-up is to incorporate the circuit of Fig.5 for mono operation or the circuit of Fig.8 for stereo operation. For either circuit, replace the 100µF capacitor at pin 6 with R6(100kΩ) as shown above. SELECTIVITY S+300=20 Vo | (300KhZ - fi) Vo | fi S-300=20 Vo | (300KhZ + fi) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn Vo | fi REV:2.0 2004.07.31 Page 5 of 7 SA1021 PACKAGE OUTLINE SOP-16-225-1.27 HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn UNIT: mm REV:2.0 2004.07.31 Page 6 of 7