SC7315 2-CH OUTPUT STEREO AUDIO PROCESSOR DESCRIPTION The SC7315 is a volume, tone (bass and treble), balance (left/ right) and fader 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 I 2C bus microprocessor DIP-20-300-2.54 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. SOP-20-375-1.27 FEATURES * 2 stereo inputs * Two speaker attenuators: --2 independent speakers control in 1.25dB steps for balance and fader ORDERING INFORMATION facilities --Independent mute function Device Package * All functions programmable via serial I 2C Bus SC7315 DIP-20-300-2.54 * Loudness function SC7315S SOP-20-375-1.27 * Volume control in 1.25dB steps * Treble and bass control * Input and output for external equalizer ornoise reduction system BLOCK DIAGRAM HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 1 of 13 SC7315 ABSOLUTE MAXIMUM RATING Characteristics Symbol Ratings Unit VS 10.2 V Operating Temperature Tamb -40 ~ +85 °C Storage Temperature Tstg -55 ~ +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, f=1kHz THD 0.01 Signal to Noise Ratio S/N 106 Channel Separation, f=1kHz SC Supply Voltage Volume Control, 1.25dB Step Bass and Treble Control, 2dB step Fader and Balance Control, 1.25dB step Vrms 0.1 % dB 103 dB -78.75 0 dB -14 +14 dB -38.75 0 dB 0 11.25 dB Input Gain, 3.75dB Step Mute Attenuation 100 dB ELECTRICAL CHARACTERISTICS (Refer to the test circuit) (Tamb=25°C,VS=9.0V,RL=10kΩ Characteristics RG=600Ω Symbol all controls flat(G=0), f=1kHz,Unless otherwise specified) 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 dB 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 37.5 40 dB SPEAKER ATTENUATORS Control Range Crange 35 (To be continued) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 2 of 13 SC7315 (Continued) Characteristics Step Resolution Attenuation Set Error Output Mute Attenuation DC Steps Symbol Test conditions SSTEP Min. Typ. Max. Unit 0.5 1.25 1.75 dB 1.5 dB 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 Resistance Maximum boost/cut 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 BW=20 ~20kHz,flat output muted Output Noise Signal to Noise Ratio Distortion Channel Separation Left/Right eNO S/N d 5 A curve, all gains =0 dB 3 µV All gains=0dB; Vo=1Vrms 106 dB 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 80 15 µV BW=20 ~20kHz,flat All gains=0dB Sc Total Tracking Error µV 2.5 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 Acknowledge Vo V Io=1.6mA +5 µA 0.4 V 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 input is grounded through the 2.2µF capacitor. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 3 of 13 SC7315 PIN CONFIGURATIONS CREF 1 20 SCL VDD 2 19 SDA GND 3 18 DGND L 4 17 OUT L R 5 16 OUT R IN(R) 6 15 BOUT(R) LOUD R 7 14 BIN(R) NC 8 13 BOUT(L) LOUD L 9 12 BIN(L) BUS INPUTS TREBLE BASS NC 10 11 IN(L) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 4 of 13 SC7315 TYPICAL CHARACTERISTICS PERFORMANCE HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 5 of 13 SC7315 TYPICAL CHARACTERISTICS PERFORMANCE (continued) Fig.11 Supply Voltage Rejection vs. Frequency Fig.10 Input Separation vs. Frequency 100 100 VIN=1Vrms AV=0dB All controls Flat 90 80 90 Output Clipping Level (v) Channel Separation (dB) 110 Channel Separation (dB) Fig.12 Output Clipping Level vs. Supply Voltage 80 70 Vsvr=0.5Vrms All Input to GND AV=0dB All controls Flat 60 5.0 RL=10k ¸ f=1kHz THD=0.3% 4.0 3.0 2.0 70 1.0 2 10 3 10 4 10 1 10 2 10 3 10 4 10 4 6 8 10 12 Frequency (Hz) Frequency (Hz) Supply Voltage (V) Fig.13 Quiescent current vs. Supply Voltage Fig.14 Supply current vs. Temperature Fig.15 Bass resistance vs. Temperature 8.0 6.0 4.0 50 8.5 48 ) 9.0 Bass Resistance (k Quiescent Current (mA) Quiescent Current (mA) 1 10 8.0 Vs=9V 7.5 7.0 4 6 8 10 12 44 42 6.5 2.0 46 40 -60 -30 0 30 Temperature Supply Voltage (V) 60 90 -60 -30 0 30 Temperature ( ) 60 90 ( ) Fig.16 Typical Tone Response (with the Ext components indicated the test circuit) 15 AV=0dB Tone Response (dB) 10 5 0 -5 -10 -15 1 10 2 10 3 10 4 10 Frequency (Hz) HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 6 of 13 SC7315 APPLICATION NOTES 1. I2C BUS INTERFACE Data transmission from microprocessor to the SC7315 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 dtat 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. 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:1.0 2004.08.03 Page 7 of 13 SC7315 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 SC7315 address(the 8 th bit of the bytes must be 0). The SC7315 must always acknowledge at the end of each transmitted byte. • • A sequence of data(N-bytes + acknowledge) A stop condition (P) SC7315 address MSB LSB MSB S 1 0 0 0 0 0 0 0 ACK LSB DATA MSB ACK LSB DATA ACK P Data Transferred (N-Bytes + Acknowledge) ACK: Acknowledge S: Start P: Stop Max clock speed: 100kbits/sec 2. Chips address 1 (MSB) 0 0 0 0 0 0 0 (LSB) 3. Data bytes MSB LSB Function 0 0 B2 B1 B0 A2 A1 A0 Volume Control 1 0 0 B1 B0 A2 A1 A0 Speaker ATT L 1 0 1 B1 B0 A2 A1 A0 Speaker ATT R 0 1 0 * * L * * 0 1 1 0 C3 C2 C1 C0 Bass control 0 1 1 1 C3 C2 C1 C0 Treble control Loudness control Note: Ax=1.25dB steps;Bx=10dB steps;Cx=2dB steps;Gx=3.75dB steps;*=no effect. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 8 of 13 SC7315 DETAILED 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 0 0 B1 B0 A2 A1 A0 Speaker ATT L 1 0 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: 10110100 HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 9 of 13 SC7315 3.Loudness function MSB 0 1 0 * * L LSB Function * Loudness control * 0 Loudness ON 1 Loudness OFF Note:*=no effect 4.Bass and treble MSB LSB Function 0 1 1 0 C3 C2 C1 C0 Bass 0 1 1 1 C3 C2 C1 C0 Terble 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 8 bit string is: 01100010. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 10 of 13 SC7315 TEST AND TYPICAL APPLICATION CIRCUIT HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn REV:1.0 2004.08.03 Page 11 of 13 SC7315 PACKAGE OUTLINE DIP-20-300-2.54 UNIT: mm 2.54 1.27 15 degree 26.4±0.3 0.51MIN 0.51 HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http: www.silan.com.cn 9.525 7.6±0.3 UNIT: mm 10.2±0.4 SOP-20-375-1.27 REV:1.0 2004.08.03 Page 12 of 13 SC7315 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:1.0 2004.08.03 Page 13 of 13