SC7314 4-CH OUTPUT STEREO AUDIO PROCESSOR WITH 4 STEREO INPUTS AND TONE/VOLUME CONTROL DESCRIPTION The SC7314 is a volume, tone (bass and treble), balance (left/ right) and fader (front/rear) processor for quality audio applications in car radio and Hi-Fi systems. Selectable input gain and external loudness function are provided. Control is accomplished by serial I2C bus microprocessor interface. The AC signal settings is obtained by resistor networks and switches combined with operational amplifiers. Due to the Used CMOS technology, low distortion, low noise and low DC stepping are obtained. FEATURES * Input multiplexer: --4 stereo inputs --Selectable input gain for optimal adaptation to different ORDERING INFORMATION sources Device * Four speaker attenuators: --4 independent speakers control in 1.25dB steps for Package SC7314 DIP-28-600-2.54 balance and fader facilities SC7314S SOP-28-375-1.27 --Independent mute function SC7314D SDIP-28-400-1.778 2 * All functions programmable via serial I C Bus * Loudness function * Volume control in 1.25dB steps * Treble and bass control * Input and output for external equalizer or noise reduction system BLOCK DIAGRAM 18 6 17 12 20 19 3 24 L 16 L1 L2 15 L3 14 L4 13 R1 8 R2 9 10 11 28 Volume & Loudness Bass Treble Speaker ATT/Mute SCL Input Selection & Gain Control SDA Serial Bus Decoder + Latches DGND R3 27 26 25 R4 CREF Supply Volume & Loudness 1 5 Bass Treble Speaker ATT/Mute 4 23 R 2 7 22 21 HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 1 of 14 SC7314 ABSOLUTE MAXIMUM RATINGS Characteristics Symbol Ratings Unit VS 10.5 V Operating Temperature Tamb -20 ~ +75 °C Storage Temperature Tstg -40 ~ +150 °C Supply Voltage QUICK REFERENCE DATA Characteristics Symbol Min. Typ. Max. Unit Vs 6 9 10 V Maximum Input Signal Handling VCL 2 Total Harmonic Distortion ,V=1Vrms, THD 0.01 Signal To Noise Ratio S/N 106 dB Channel Separation, f=1kHz Sc 103 dB Supply Voltage Vrms 0.1 % f=1kHz Volume Control, 1.25dB Step -78.75 0 dB -14 +14 dB -38.75 0 dB 0 11.25 dB Bass And Treble Control, 2dB Step Fader And Balance Control, 1.25dB Step Input Gain, 3.75dB Step Mute Attenuation 100 dB ELECTRICAL CHARACTERISTICS (Refer to the test circuit) (Tamb=25°C,VS=9.0V,RL=10kΩ RG=600Ω all controls flat(G=0), f=1kHz,Unless otherwise specified) Characteristics Symbol Test conditions Min. Typ. Max. Unit 6 9 10.0 V 20.0 35.0 mA SUPPLY VOLTAGE Operating Supply Voltage VS Operating Supply Current IS Ripple Rejection Of Supply Voltage SVR 60 80 35 50 dB INPUTS SELECTORS Input Resistance RII Input 1, 2, 3, 4 Clipping Level VCL 2 2.5 Vrms Input Separation (note 2) SIN 80 100 dB Output Load Resistance RL Pin 6,18 70 4 kΩ Minimum Input Gain GIN(MIN) Maximum Input Gain GIN(MAX) 11.25 dB GSTEP 3.75 dB G=11.25dB 2 µV Adjacent gain steps 4 G=18.75 to MUTE 4 Step Resolution Input Noise eIN DC Steps VDC -1 kΩ 0 1 20 dB mV mV (To be continued) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 2 of 14 SC7314 (Continued) Characteristics Symbol Test conditions Min. Typ. Max. Unit RIV 20 33 50 kΩ Control Range Crange 70 75 80 dB Minimum Attenuation AV(min) -1 0 1 dB Maximum Attenuation AV(max) 70 75 80 dB Step Resolution ASTEP 0.5 1.25 1.75 dB -1.25 0 1.25 VOLUME CONTROL Input Resistance Attenuation Set Error EA Tracking Error ET DC Steps VDC AV=0 to –20dB AV=-20 to –60dB -3 Adjacent attenuation steps From 0dB to AV max 2 dB 2 dB 0 3 mV 0.5 7.5 mV SPEAKER ATTENUATORS Control Range Crange 35 37.5 40 dB Step Resolution SSTEP 0.5 1.25 1.75 dB 1.5 dB Attenuation Set Error Output Mute Attenuation DC Steps EA AMUTE VDC 80 100 dB Adjacent attenuation steps 0 3 mV From 0dB to MUTE 1 10 mV ±12 ±14 ±16 dB BASS CONTROL (note 1) Control Range GB Step Resolution BSTEP 1 2 3 dB RB 34 44 58 kΩ ±13 ±14 ±15 dB 1 2 3 dB 2 2.5 Internal Feedback Maximum boost/cut Resistance TREBLE CONTROL (note 1) Control Range Gt Step Resolution TSTEP Maximum boost/cut AUDIO OUTPUTS Clipping Level VOCL Output Load Resistance RL Output Load Capacitance CL THD=0.3% Vrms 4 kΩ 10 nF Output Resistance ROUT 30 75 120 Ω DC Voltage Level VOUT 4.2 4.5 4.8 V GENERAL Output Noise Signal To Noise Ratio eNO S/N µV BW=20 ~20kHz,flat output muted 2.5 BW=20 ~20kHz,flat All gains=0dB 5 A curve, all gains =0 dB 3 µV All gains=0dB; Vo=1Vrms 106 dB 15 µV (To be continued) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 3 of 14 SC7314 (Continued) Characteristics Distortion Channel Separation Symbol d Test conditions Typ. Max. Unit AV=0,VIN=10mV 0.01 0.1 % AV=-20dB, VIN=1Vrms 0.09 0.3 % AV=-20dB,VIN=0.3Vrms 0.04 % 103 dB Sc Min. 80 Left/Right Total Tracking Error AV=0 to –20 dB 0 1 dB AV=-20 to –60 dB 0 2 dB 1 V BUS INPUTS Input Low Voltage VIL Input High Voltage VIH 3 Input Current IIN -5 Output Voltage SDA Vo V Io=1.6mA +5 µA 0.4 V Acknowledge NOTES: (1) Bass and treble response see Figure 16. The center frequency and quality of the response behavior can be chosen by the external circuitry. A standard first order bass response can realized by a standard feedback network. (2) The selected input is grounded through the 2.2µF capacitor. PIN CONFIGURATIONS HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 4 of 14 SC7314 HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn Loudness (dB) THD & Noise (%) Channel Separation (dB) Noise (¦ÌV£© THD (%) THD & Noise (%) Noise (¦ÌV£© Loudness (dB) Loudness (dB) TYPICAL CHARACTERISTICS PERFORMANCE REV:1.1 2007.09.25 Page 5 of 14 SC7314 TYPICAL CHARACTERISTICS PERFORMANCE (continued) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 6 of 14 SC7314 APPLICATION NOTES 1. I2c bus interface Data transmission from microprocessor to the SC7314 and viceversa takes place through the 2 wires I 2C BUS interface, consisting of the two lines SDA and SCL(pull-up resistors to positive supply voltage must be connected). 2.Data validity As shown in Figure 17, the data of the SDA line must be stable during the high period of the clock. The HIGH and LOW state of the data line can only change when the clock signal on the SCL line is LOW. Fig. 17 Data Validity on the I2C BUS 3. Start and stop conditions As shown in Figure 18, a start condition is a HIGH to LOW transition of the SDA line while SCL is HIGH. The stop condition is a LOW to HIGH transition of the SDA line while SCL is HIGH. SCL I2C BUS // SDA // start stop Fig. 18 Timing diagram of I2C BUS 4. Byte format Every byte transferred on the SDA line must obtain 8 bits. Each byte must be followed by the an acknowledge bit. The MSB is transferred first. 5. Acknowledge The master (microprocessor) puts a resistive HIGH level on the SDA line during the acknowledge clock pulse(see Figure 19). The peripheral (audioprocessor) that acknowledges has to pull-down (LOW) the SDA line during the acknowledge clock pulse, so that the SDA line is stable LOW during this clock pulse. The audioprocessor which has been addressed has to generate an acknowledge after the reception of each byte, otherwise the SDA line remain at the HIGH level during the ninth clock pulse time. In this case the master transmitter can generate the STOP information in order to abort the transfer. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 7 of 14 SC7314 Fig. 19 Acknowledge on the I2C BUS 6. Transmission without acknowledge Avoiding to detect the acknowledge of the audioprocessor, the microprocessor can use a simpler transmission: simply it waits one clock without checking the slave acknowledgig, and sends the new data. This approach of course is less protected from mis-working and decreases the noise immunity. SOFTWARE SPECIFICATION 1. Interface protocol The interface protocol comprises: • • A start conditions A chip address byte, containing the SC7314 address (the 8 th bit of the bytes must be 0). The SC7314 must always acknowledge at the end of each transmitted byte. • • A sequence of data(N-bytes + acknowledge) A stop condition (P) 2. Chips address 1 (MSB) 0 0 0 1 0 0 0 (LSB) 3. Data bytes MSB LSB Function 0 0 B2 B1 B0 A2 A1 A0 Volume Control 1 1 0 B1 B0 A2 A1 A0 Speaker ATT L 1 1 1 B1 B0 A2 A1 A0 Speaker ATT R 0 1 0 G1 G0 S2 S1 S0 Audio switch 0 1 1 0 C3 C2 C1 C0 Bass control 0 1 1 1 C3 C2 C1 C0 Treble control Note: Ax=1.25dB steps;Bx=10dB steps;Cx=2dB steps;Gx=3.75dB steps HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 8 of 14 SC7314 SDETAILED DESCRIPTION OF DATA BYTES 1. Volume MSB 0 0 0 0 B2 B1 B0 LSB Function A2 A1 A0 Volume 1.25dB steps 0 0 0 0 0 0 1 -1.25 0 1 0 -2.5 0 1 1 -3.75 1 0 0 -5 1 0 1 -6.25 1 1 0 -7.5 1 1 1 -8.75 A2 A1 A0 Volume 10dB steps B2 B1 B0 0 0 0 0 0 0 1 -10 0 1 0 -20 0 1 1 -30 1 0 0 -40 1 0 1 -50 1 1 0 -60 1 1 1 -70 For example, a volume of –45dB is given by: 00100100 2. Speaker attenuators MSB LSB Function 1 1 0 B1 B0 A2 A1 A0 Speaker ATT L 1 1 1 B1 B0 A2 A1 A0 Speaker ATT R 0 0 0 0 0 0 1 -1.25 0 1 0 -2.5 0 1 1 -3.75 1 0 0 -5 1 0 1 -6.25 1 1 0 -7.5 1 1 1 -8.75 0 0 0 0 1 -10 1 0 -20 1 1 -30 1 1 1 1 1 MUTE For example, attenuation of 25dB on speaker R is given by: 11110100 HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 9 of 14 SC7314 3.Audio switch MSB 0 1 0 G1 G0 S2 LSB Function S1 S0 Audio switch 0 0 Stereo 1 0 1 Stereo 2 1 0 Stereo 3 1 1 Stereo 4 0 Loudness ON 1 Loudness OFF 0 0 +11.25dB 0 1 +7.5dB 1 0 +3.75dB 1 1 0dB For example, to select the stereo 2 input with a gain of +7.5dB Loudness ON the 8bit string is: 01001001 4.Bass and treble MSB LSB Function 0 1 1 0 C3 C2 C1 C0 Bass 0 1 1 1 C3 C2 C1 C0 Treble 0 0 0 0 -14 0 0 0 1 -12 0 0 1 0 -10 0 0 1 1 -8 0 1 0 0 -6 0 1 0 1 -4 0 1 1 0 -2 0 1 1 1 0 1 1 1 1 0 1 1 1 0 2 1 1 0 1 4 1 1 0 0 6 1 0 1 1 8 1 0 1 0 10 1 0 0 1 12 1 0 0 0 14 C3=Sign For Example, bass at –10dB is obtained by the following 8bit string is: 01100010. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 10 of 14 SC7314 TEST AND TYPICAL APPLICATION CIRCUIT 5.6k 2.2 F MCU 100 nF 100 nF 25 2.2 F 26 11 R1 DGND SDA AM/FM TUNER 27 18 SCL 17 12 20 LOUD BOUT (L) (L) OUT(L) IN(L) 100 nF 19 2.7nF 3 BIN TREBLE (L) (L) 16 L1 2.2 F 10 F 2.2 F 10 R2 CD PLAYER OUT L 24 OUT R 23 15 L2 2.2 F SC7314 2.2 F 9 10 F R3 TAPE 14 L3 2.2 F 2.2 F 8 R4 AUDIO 13 L4 2.2 F VDD GND CREF 1 2 28 OUT(R) IN(R) 6 5 2.2 F HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn 7 22 100 nF 22 F VDD LOUD BOUT (R) (R) BIN (R) TREBLE (R) 21 100 nF 4 100 nF 2.7nF 5.6k REV:1.1 2007.09.25 Page 11 of 14 SC7314 PACKAGE OUTLINE UNIT: mm 2.8 MAX 9.525 SOP-28-375-1.27 7.6±0.3 UNIT: mm 10.2±0.4 DIP-28-600-2.54 HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 12 of 14 SC7314 PACKAGE OUTLINE : mm SDIP-28-400-1.778 1.778 1.0 15 Degree 25.6±0.1 0.25 HANDLING MOS DEVICES: Electrostatic charges can exist in many things. All of our MOS devices are internally protected against electrostatic discharge but they can be damaged if the following precautions are not taken: • Persons at a work bench should be earthed via a wrist strap. • Equipment cases should be earthed. • All tools used during assembly, including soldering tools and solder baths, must be earthed. • MOS devices should be packed for dispatch in antistatic/conductive containers. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.1 2007.09.25 Page 13 of 14