Silan Semiconductors SC1088 FM RECEIVER CIRCUIT FOR BATTERY SUPPLY DESCRIPTION The SC1088 is a bipolar integrated circuit for use in mono portable and pocket radios. It is used when a minimum of perpheral components (of small dimensions and low costs) is important. The circuit contains a frequency-locked-loop(FLL) system with an intermediate frequency(IF) of about 70kHz. Selectivity is achieved by active RC-filters. De-tuning related to the IF and too weak input signal is suppressed by the mute circuit. FEATURES * Equipped with all stages of a mono receiver from antenna to audio output. * Mute Circuit * Search tuning with a single varicap diode * Mechanical tuning with integrating AFC * AM application supported * Power supply polarity protection * Power supply voltage down to 1.8V SOP-16 APPLICATION 1. Mechanical tuning: This is possible with or without integrated AFC circuit 2. Electrical tuning: This is realized by one directional(band-up) search tuning facility, including RESET to the lower-band limit. PIN CONFIGURATIONS MUTE 1 16 TUNE VOAF 2 15 CAP LOOP 3 14 GND VP 4 13 CLIM SC1088 OSC 5 12 VIRF IF FB 6 11 VIRF CLP1 7 10 CLP2 VOIF 8 9 VIIF HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD 1 V101 10kΩ 2 70nH 68nF +3V 0.1µF Searching tuning VCO Mixer 2.2kΩ 6 7 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD V2 +1 180pF V2 8 9 6kΩ 10 330pF 1 V3 RUN 1.8nF 2 AF 6kΩ 22nF 3 VoAF V2 Loop Filter 22kΩ -1 All pass Filter 15 470pF 5.4kΩ Demodulator AF MUTE IF Limter 0.1µF 13 SC1088 VP 3.9nF Fig.1 Block Dirgram and Application Circuit for Search Tuning. S R & 2.2kΩ 3.3nF Note: V1,V2 and V3 are internal voltages. 16 14 4 5 12 V1 11 10nF 78nH 220pF 68pF 82pF RESET 5.6kΩ 680pF 5kΩ Silan Semiconductors SC1088 BLOCK DIAGRAM Silan Semiconductors SC1088 ABSOLUTE MAXIMUM RATINGS Characteristic Supply Voltage Operating Temperature Storage Temperature Symbol Value Unit Vp Tamb Tstg 5 -10 ~ +70 -55 ~ +150 V °C °C DC ELECTRICAL CHARACTERISTICS (Tamb=25°C,Vp=3V ,Unless otherwise specified) Parameter Symbol Test conditions Min Typ Max Unit Supply Voltage(pin 4) Supply Current(Pin 4) DC voltage of pin 1 DC voltage of pin 3 DC voltage of pin 6 and 7 DC voltage of pin 8 DC voltage of pin 9,10 and 13 DC voltage of pin 11 and 12 DC voltage of pin 15 AF output current on pin 2 Oscillator current on pin 5 1.8 4.2 2.50 2.64 2.38 1.60 2.42 0.91 2.06 45 275 3.0 5.2 2.55 2.69 2.44 1.67 2.47 0.94 2.12 60 375 5.0 6.6 2.60 2.74 2.50 1.74 2.52 0.98 2.18 80 500 V mA V V V V V V V µA µA Vp Ip V1 V3 V6,7 V8 V9,10,13 V11,12 V15 I2 I5 AC ELECTRICAL CHARACTERISTICS Tamb=25°C,Vp=3V,Firf=96MHz modulated with ∆f=±22.5kHz and fm=1kHz deviation;EMF=0.3mV(e.m.f. at a sourse impedance of 75Ω),and measurement taken in fig.3 Unless otherwise specified Parameter RF Sensitivityinput voltage Signal handling Signal-to -noise ratio Total Harmonic distortion AM suppression of output voltage Ripple rejection Audio output signal Symbol Vi(rms) (S+N)/N THD AMS RR Vo(rms) Test conditions VoAF=-3dB;VoAF=0dB at Vi=1mV;see Fig. 2 Mute OFF Mute ON (S+N)/N=26dB THD<10%,∆f=±75kHz See fig.2 ∆f=±22.5kHz ∆f=±75kHz FM: 1kHz; ±75kHz AM: 1kHz; MOD=80% ∆Vp=100mVrms,f=1kHz RL=22kΩ Min Typ Max Unit 6 12 10 1.4 3.3 47 3 6 5 200 56 1 2.4 52 µV µV µV mV dB % % dB 7 60 10 85 95 1.25 4.75 Vp1.85 210 2.83 9.5 3 120 dB mV Search Tuning(with V101 and C16=0.1µF) See Fig.1 Minimum output voltage on pin 16 Tuning steepness Oscillator steepness AFC steepness V16 ∆V/∆t ∆fosc/∆ t ∆IAFC/∆V3 Limiting point Voltage at pin 16 Voltage at pin 3 V 420 mV/sec 5.6 MHz/sec µs 19 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD 3 Silan Semiconductors SC1088 PIN DESCRIPTIONS Pin No. Symbol 1 MUTE 2 VOAF 3 4 Description LOOP Vp Mute output Audio frequency output signal AF loop filter Supply voltage 5 OSC 6 IF FB 7 CLP1 8 VOIF Pin No. Symbol 9 ViIF 10 CLP2 11 12 VIRF VIRF Oscillator resonat circuit 13 CLIM IF feedback Low-pass capacitor of 1dB amplifier IF output to external coupling capacitor(high-pass) 14 GND 15 CAP 16 TUNE Description IF input to limiter amplifier Low-pass capacitor of IF limiter amplifier Radio frequency input Radio frequency input Limiter offset voltage capacitor Ground All-pass filter capacitor.input for search tuning Electrical tuning/AFC output 20 VOAF (dB) 0 2 S+N 2 -20 1 1 Noise -40 -60 -80 -6 10 -5 10 -4 10 -3 10 -2 10 EMF (V) 1: Mute ON 2: Mute OFF Fig. 2 Input sensitivity HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD 4 Silan Semiconductors SC1088 TEST AND APPLICATION CIRCUIT Rs=75Ω 220pF 10kΩ ViRF EMF 330pF 3,9nF 82pF 0.1µF 470pF 68pF 70nH 16 15 14 13 12 11 10 9 TUNE CAP GND CLIM VIRF VIRF CLP2 VIIF MUTE VOAF LOOP VP OSC IF FB CLP1 VOIF 1 2 3 4 5 6 7 8 SC1088 78nH 22nF 3.3nF 180pF 22kΩ 0.1µF 1.8nF MUTE Disable 1.2kΩ +3V 27pF 18pF 10nF VOAF C1 10kΩ 330pF ViRF 68pF 3.9nF 82pF 0.1µF 470pF 220pF Fig. 3 Test circuit and application for mechanical tuning 70nH 16 15 14 13 12 11 10 9 TUNE CAP GND CLIM VIRF VIRF CLP2 VIIF MUTE VOAF LOOP VP IF FB CLP1 VOIF 1 2 3 4 6 7 8 OSC 5 3.3nF 1.2kΩ +3V 180pF 78nH 22nF 22kΩ 1.8nF 0.1µF SC1088 27pF 18pF 10nF VOAF C1 C2 68nF D1 V101 Fig. 4 Application circuit with AFC for mechanical tuning HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD 5 6 Oscillator resonat circuit 4.7nF 3.9nF AM IF 100kΩ 10nF UTC7642 BAW62 2.7kΩ AM FM AM 12pF 33pF 0.1µF 1µF 10kΩ 10 9 33pF 12 VIRF 33pF AF VP 13 CLIM VOAF CAP 15 LOOP GND 14 AF 2 3 22nF Fig.5 AM application circuit AM antenna 11 VIRF OSC IF FB 4 SC1088 5 6 330pF CLP2 CLP1 V OIF V IIF 7 180pF 8 4.7nF VP 4.7nF FM 22kΩ 1 1µF 470pF 16 TUNE MUTE 47nF AF Amplifier 12Ω 27kΩ Volume High Low 10nF earphone 22µF ON OFF 5.1Ω Battery switch +3V AF Transformer Silan Semiconductors SC1088 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD Silan Semiconductors SC1088 PACKAGE OUTLINE SOP-16-225-1.27 UNIT:mm 5.72 3.95 6.00 0.41 1.27 10.20 1.95 9.80 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD 7