SA1140 FM RADIO IC FOR DIGITAL TUNING SYSTEM DESCRIPTION The SA1140 is an IF system IC designed for FM car stereo receivers. It features versatile muting characteristics which can be varied with external parts. FEATURES * Muting characteristics ZIP-16 a) Muting operation is performed under weak signal strength. b) Maximum muting attenuation can be selected to be approximately 6 to 40 dB. c) Input signal strength level which actuates the muting circuit can be set freely. * High limiting sensitivity ORDERING INFORMATION * High S/N (78 dB typ.) * Good AMR Device Package * Signal meter drive output proportional to the input signal strength in SA1140 ZIP-16 dB (suitable to control multiplex IC SA3370). APPLICATIONS * FM car stereo receivers, FM home radio BLOCK DIAGRAM HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.10.27 Page 1 of 6 SA1140 ABSOLUTE MAXIMUM RATING (Tamb=25°C) Characteristics Symbol Rating Unit Maximum Supply Voltage VCC max 16 V Maximum Supply Current ICC max 40 mA Allowable Power Dissipation Pd max 640 mW 460 mW VIN ±1 Vp-p I2 ±0.2 mA I3 ±0.2 mA I6 2 mA I5 1 mA I13 2 mA I14 2 mA I15 1 mA I16 1 mA Operating Temperature Topr -20 to +70 °C Storage Temperature Tstg -40 to +125 °C Input Voltage Flow-In Current Flow-Out Current ELECTRICAL CHARACTERISTICS (Tamb=25°C, VCC=8V, f=10.7MHz, see specified test circuit) Characteristics Recommended Supply Voltage Operating Supply Voltage Range Quiescent Current Symbol Test condition Min. VCC Current Drain ICC Demodulation Output VO Total Harmonic Distortion THD Signal-To-Noise Ratio S/N Input Limiting Voltage VIN (lim) Max. 8 VCCop ICCO Typ. Unit V 7.5 16 V VIN=0 15 21 27 mA VIN = 100 dBµ 20 25 30 mA 200 260 320 mVrms 0.05 0.2 % VIN = 100 dBµ, 400 Hz 100% mod. VIN = 100 dBµ, 400 Hz 100% mod. VIN = 100 dBµ, 400 Hz 100% mod. 72 VO: 3 dB down, 400 Hz 100% VIN (Mute) V14 = 2.0 V Muting Attenuation (1) Mute (ACC) Muting Attenuation (2) Mute (ACC) Muting Bandwidth BW (Mute) VIN = 100 dBµ, V14 = 2.0 V V6 = 2.0 V (22 kΩ), VIN = 100 dBµ, 400 Hz 100% mod. V6 = 5.0 V (22 kΩ), VIN = 100 dBµ, 400 Hz 100% mod. dB 25 29 dBµ 22 26 32 dBµ 10 15 20 dB 24 28 32 dB 140 210 370 kHz mod. Muting Sensitivity 78 (To be continued) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.10.27 Page 2 of 6 SA1140 (Continued) Characteristics Symbol Test condition Min. Typ. Max. Unit 50 63 3.5 4.2 5.0 V VIN = 100 dBµ 0 0 0.3 V 0 0.1 0.3 V VIN = 100 dBµ, FM 400 Hz. AM Rejection Ratio AMR 100% mod., AM 1 kHz 30% dB mod. Muting Drive Output(1) V14-0 Muting Drive Output（2） VIN=0 V14-100 Signal Meter Output (1) V15-0 VIN=0 Signal Meter Output (2) V15-50 VIN = 50 dBµ 0.8 1.4 2.0 V Signal Meter Output (3) V15-70 VIN = 70 dBµ 1.6 2.4 3.2 V Signal Meter Output (4) V15-100 VIN = 100 dBµ 4.5 5.3 6.0 V VIN=0 3.5 4.1 4.5 V 0 0.02 0.3 V AGC Output (1) V16-0 AGC Output (2) V16-100 VIN = 100 dBµ Offset Voltage (1) V7-13 VIN=0, pin 7 to 13 –0.25 0 +0.25 V Offset Voltage (2) V8-13 VIN=0, pin 8 to 13 –0.5 0 +0.5 V PIN CONFIGURATIONS PIN DESCRIPTIONS Pin No. Pin Name Description 1 IN+ Positive in 2 IN- Negative in 3 PREAMPOUT 4 GND1 5 ATTadj 6 MUTEIN 7 AFC AFC clamp 8 OUT Out of AF Out of IF preamp Gnd1 Resister connected between p5 and GND determines the maximum muting attenuation The higher the current flowing into p6,the lower the gain (the higher the attenuation ) (To be continued) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.10.27 Page 3 of 6 SA1140 (Continued) Pin No. Pin Name 9 IFOUT Out of IF 10 GND2 Gnd2 11 QUADIN 12 VCC 13 VREG 14 MUTEdrive 15 S-meter 16 AGC Description In of quadrature det Vcc Regulative voltage Connected to p6 through resister Signal meter Automatic gain control FUNCTION DESCRIPTION 1．Muting Characteristic The muting operation is performed by an AF preamplifier, the gain of which varies continuously with control current, and a muting drive output circuit which supplies the control current. The gain of the AF preamplifier decreases with increasing gain control current applied to pin 6. However, the gain does not decrease further when the control current reaches approximately 120 µA or greater. The lower limit of the gain under this condition depends upon a resistor connected between pin 5 and GND, and the higher the resistance the lower the gain (the higher the attenuation). Thus the maximum muting attenuation will be set by connecting the resistor between pin 5 and GND. 2．The muting drive output comes in three types: 1) Hole detector output which develops a voltage when C/N (carrier-to-noise ratio) lowers under weak signal input conditions. 2) A reversed output of the signal strength indicating output (output at pin 15) 3) A bandwidth limited muting drive output which develops a voltage when the AFC output becomes higher than ±VBE during tuning-off operation. All these outputs are led to an OR circuit and the processed output is developed at pin 14. 3．The general method to adjust the muting circuit of the SA1140 is: to set the signal input level required to actuate the muting circuit with the R16-G, to adjust the slope of the curve for the muting attenuation vs. antenna signal input with the R15-G, and to adjust the maximum muting attenuation (determined by setting the noise level at no signal) with the R5-G. The slope of the curve for the muting attenuation vs. antenna signal input level can also be adjusted by the resistor connected between pins 14 and 6 in addition to R15-G, however, selecting a resistor too high does not allow the muting control current flowing into pin 6 to reach 120 µA even though the maximum muting drive output (V14) is applied, namely the muting attenuation does not reach its maximum value. Accordingly a recommended value of the resistor between pins 14 and 6 is about 22 kΩ. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.10.27 Page 4 of 6 SA1140 TEST CIRCUITS TYPICAL APPLICATION CIRCUIT HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.10.27 Page 5 of 6 SA1140 PACKAGE OUTLINE ZIP-16 HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn UNIT: mm REV:1.0 2004.10.27 Page 6 of 6