TDA7448 6 CHANNEL VOLUME CONTROLLER PRODUCT PREVIEW ■ ■ ■ ■ ■ ■ 6 CHANNEL INPUTS 6 CHANNEL OUTPUTS VOLUME ATTENUATION RANGE OF 0 TO -79dB VOLUME CONTROL IN 1.0dB STEPS 6 CHANNEL INDEPENDENT CONTROL ALL FUNCTION ARE PROGRAMMABLE VIA SERIAL BUS SO20 ORDERING NUMBER: TDA7448 DESCRIPTIO The TDA7448 is a 6 channel volume controller for quality audio applications in Multi-Channels Audio Systems Low Distortion, Low Noise and DC stepping are obtained. Thanks to the used BIPOLAR/CMOS Technology, BLOCK DIAGRAM IN1 7 2 VOLUME OUT1 50K IN2 14 19 VOLUME OUT2 50K IN3 6 3 VOLUME OUT3 50K IN4 15 18 VOLUME OUT4 50K IN5 5 4 VOLUME OUT5 50K IN6 16 17 VOLUME OUT6 50K GND CREF 11 I2C BUS DECODER SUPPLY 10 9 12 20 1 VS SCL SDA ADDR D02AU1396 December 2002 This is preliminary information on a new product now in development. Details are subject to change without notice. 1/13 TDA7448 ABSOLUTE MAXIMUM RATINGS Symbol VS Parameter Value Unit 10.5 V Operating Supply Voltage Tamb Operating Ambient Temperature -10 to 85 °C Tstg Storage Temperature Range -55 to 150 °C Value Unit 150 °C/W PIN CONNECTION VS 1 20 CREF IN1 2 19 IN2 IN3 3 18 IN4 IN5 4 17 IN6 OUT5 5 16 OUT6 OUT3 6 15 OUT4 OUT1 7 14 OUT2 N.C. 8 13 N.C. SDA 9 12 ADDR SCL 10 11 GND D02AU1397 THERMAL DATA Symbol Rth j-pin Parameter thermal Resistance junction-pins QUICK REFERENCE DATA Symbol Parameter Typ. Max. Unit 4.75 9 10 V VS Supply Voltage VCL Max Input Signal Handling THD Total Harmonic Distortion V = 1Vrms f =1KHz 0.01 S/N Signal to Noise Ratio Vout = 1Vrms 100 dB SC Channel Separation f = 1KHz 90 dB Volume Control (1dB step) Mute Attenuation 2/13 Min. 2 Vrms -79 0.1 0 90 % dB dB TDA7448 ELECTRICAL CHARACTERISTCS (refer to the test circuit Tamb = 25°C, VS = 9V, RL = 10KΩ, RG = 600Ω, unless otherwise specified) Symbol Parameter Test Condition Min. Typ. Max. Unit 4.75 9 10 V SUPPLY VS Supply Voltage IS Supply Current 7 mA Ripple Rejection 80 dB SVR INPUT STAGE RIN Input Resistance 35 50 VCL Clipping Level THD = 0.3% SIN Input Separation The selected input is grounded through a 2.2µ capacitor 65 KΩ 2 2.5 Vrms 90 dB Control Range 79 dB AVMAX Max. Attenuation 79 dB ASTEP Step Resolution VOLUME CONTROL CRANGE EA Attenuation Set Error 0.5 1 1.5 dB -1 0 1 dB -2.0 0 2.0 dB AV = 0 to -24dB -1 0 1 dB AV = -24 to -79dB -2 0 2 dB adyacent attenuation steps -3 0 3 mV AV = 0 to -24dB AV = -24 to -79dB ET VDC Amute Tracking Error DC Step Mute Attenuation 90 db 2.5 Vrms AUDIO OUTPUTS VCLIP RL VDC Clipping Level THD = 0.3% Output Load Resistance 2 2 DC Voltage Level KΩ 4.5 V GENERAL Output Noise BW = 20Hz to 20KHz All gains = 0dB, Flat 10 S/N Signal to Noise Ratio All gains = 0dB; VO = 1Vrms 100 dB SC Channel Separation left/Right 90 dB THD Distortion 80 AV = 0; VI = 1Vrms 0.01 15 µV ENO 0.1 % 1 V BUS INPUT VIl Input Low Voltage VIH Input High Voltage IIN Input Current VIN = 0.4V VO Output Voltage SDA Achnowledge IO = 1.6mA 2.5 V -5 0.4 5 µA 0.8 V 3/13 TDA7448 Figure 1. Test circuit 0.47µF IN1 IN1 7 2 VOLUME OUT1 50K 0.47µF IN2 IN2 14 19 VOLUME OUT2 50K 0.47µF IN3 IN3 6 3 VOLUME OUT3 50K 0.47µF IN4 IN4 15 18 VOLUME OUT4 50K 0.47µF IN5 IN5 5 4 VOLUME OUT5 50K 0.47µF IN6 IN6 16 17 VOLUME OUT6 50K GND CREF 11 I2C BUS DECODER SUPPLY APPLICATION SUGGESTIONS 9 11 20 10µF 10 1 VS SCL SDA ADDR D02AU1406 Figure 3. THD vs. R LOAD The volume control range is 0 to -79dB, by 1dB step resolution. The very high resolution allows the implementation of systems free from any noise acoustical effect. CREF The suggested 10µF reference capacitor (CREF) value can be reduced to 4.7µF if the application requires faster power ON. Figure 2. THD vs. frequency Figure 4. Channel separation vs. frequency 4/13 TDA7448 I2C BUS INTERFACE Data transmission from microprocessor to the TDA7448 and vice versa takes place through the 2 wires I2C BUS interface, consisting of the two lines SDA and SCL (pull-up resistors to positive supply voltage must be connected). Data Validity As shown in fig. 1, the data on 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. Start and Stop Conditions As shown in fig. 2 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. Byte Format Every byte transferred on the SDA line must contain 8 bits. Each byte must be followed by an acknowledge bit. The MSB is transferred first. Acknowledge The master (µP) puts a resistive HIGH level on the SDA line during the acknowledge clock pulse (see fig. 5). The peripheral (audio processor) that acknowledges has to pull-down (LOW) the SDA line during this clock pulse. The audio processor which has been addressed has to generate an acknowledge after the reception of each byte, otherwise the SDA line remains 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. Transmission without Acknowledge Avoiding to detect the acknowledge of the audio processor, the µP can use a simpler transmission: simply it waits one clock without checking the slave acknowledging, and sends the new data. This approach of course is less protected from misworking. Figure 5. Data Validity on the I2CBUS SDA SCL DATA LINE STABLE, DATA VALID CHANGE DATA ALLOWED D99AU1031 Figure 6. Timing Diagram of I2CBUS SCL I2CBUS SDA D99AU1032 START STOP Figure 7. Acknowledge on the I2CBUS SCL 1 2 3 7 8 9 SDA MSB START D99AU1033 ACKNOWLEDGMENT FROM RECEIVER 5/13 TDA7448 SOFTWARE SPECIFICATION Interface Protocol The interface protocol comprises: ■ A start condition (S) ■ A chip address byte, containing the TDA7448 address ■ A subaddress bytes ■ A sequence of data (N byte + acknowledge) ■ A stop condition (P)) SUBADDRESS CHIP ADDRESS MSB S 1 LSB 0 0 0 1 0 0 0 MSB ACK X DATA 1 to DATA n LSB X X B DATA MSB ACK LSB DATA ACK P D96AU420 ACK = Acknowledge; S = Start; P = Stop; A = Address; B = Auto Increment EXAMPLES No Incremental Bus The TDA7448 receives a start condition, the correct chip address, a subaddress with the B = 0 (no incremental bus), N-data (all these data concern the subaddress selected), a stop condition. SUBADDRESS CHIP ADDRESS MSB S 1 LSB 0 0 0 1 0 0 0 MSB ACK X DATA LSB X X 0 D3 D2 D1 D0 MSB ACK LSB DATA ACK P D96AU421 Incremental Bus The TDA7448 receivea start conditions, the correct chip address, a subaddress with the B = 1 (incremental bus): now it is in a loop condition with an autoincrease of the subaddress whereas SUBADDRESS from "XXX1000" to "XXX1111" of DATA are ignored.The DATA 1 concern the subaddress sent, and the DATA 2 concern the subaddress sent plus one in the loop etc, and at the end it receivers the stop condition. SUBADDRESS CHIP ADDRESS MSB S 1 LSB 0 0 0 1 0 0 0 MSB ACK X DATA 1 to DATA n LSB X X 1 D3 D2 D1 D0 MSB ACK LSB DATA ACK P D96AU422 DATA BYTES Address= 88 (HEX) (10001000): ADDR open; 8A (HEX) (10001010): connect to supply FUNCTION SELECTION: subaddress MSB D7 X X X X X X X X D6 X X X X X X X X D5 X X X X X X X X B=1: INCREMENTAL BUS; ACTIVE B=0: NO INCREMENTAL BUS X= DON’T CARE 6/13 D4 B B B B B B B B D3 0 0 0 0 0 0 0 0 D2 0 0 0 0 1 1 1 1 D1 0 0 1 1 0 0 1 1 LSB D0 0 1 0 1 0 1 0 1 SUBADDRESS SPEAKER ATTENUATION OUT 1 SPEAKER ATTENUATION OUT 2 SPEAKER ATTENUATION OUT 3 SPEAKER ATTENUATION OUT 4 SPEAKER ATTENUATION OUT 5 SPEAKER ATTENUATION OUT 6 NOT USED” NOT USED TDA7448 In Incremental Bus Mode, the three “not used” functions must be addressed in any case. For example to refresh “ Speaker Attenuation 3 = 0dB and Speaker Attenuation 6 = -40 dB”; the following bytes must be sent: SUBADDRESS XXX10010 SPEAKER ATTENUATION OUT 1 XXXXXXXX SPEAKER ATTENUATION OUT 2 XXXXXXXX SPEAKER ATTENUATION OUT 3 00000000 SPEAKER ATTENUATION OUT 4 XXXXXXXX SPEAKER ATTENUATION OUT 5 XXXXXXXX SPEAKER ATTENUATION OUT 6 00101111 SPEAKER ATTENUATION SELECTION MSB LSB SPEAKER ATTENUATION D7 D6 D5 D4 D3 D2 D1 D0 0 0 0 0dB 0 0 1 -1dB 0 1 0 -2dB 0 1 1 -3dB 1 0 0 -4dB 1 0 1 -5dB 1 1 0 -6dB 1 1 1 -7dB 0 0 0 0 0 -0dB 0 0 0 0 1 -8dB 0 0 0 1 0 -16dB 0 0 0 1 1 -24dB 0 0 1 0 0 -32dB 0 0 1 0 1 -40dB 0 0 1 1 0 -48dB 0 0 1 1 1 -56dB 0 1 -64dB 1 0 -72dB 1 1 MUTE value = 0 to -79dB and MUTE 7/13 TDA7448 Figure 8. PIN:20 Figure 11. PINS: 10 VS VS 20µA 20K SCL CREF 20K D96AU424 D96AU430 Figure 9. PINS: 5, 6, 7, 14, 15, 16 Figure 12. PINS: 9 VS 20µA 24 OUT1 to OUT6 SDA 20µA D96AU423 D02AU1398 Figure 10. PINS: 2, 3, 4, 17, 18, 19 VS 20µA IN 100K VREF 8/13 D96AU425 TDA7448 Figure 13. Test and Application Circuit J1 J2 IN1 OUT1 J3 IC1 GND 7 OUT6 C10 5 0.47µF C12 17 C13 IN6 15 0.47µF 4 C11 + 6 OUT5 + IN6 IN5 C8 18 C9 + 5 OUT4 0.47µF 16 OUT1 2 OUT2 3 OUT3 4 OUT4 5 OUT5 6 OUT6 7 GND 22µF 16V 22µF 16V + IN5 C7 IN4 C6 6 1 22µF 16V 22µF 16V + 4 OUT3 14 0.47µF 3 22µF 16V 22µF 16V + IN4 IN3 C4 19 C5 OUT2 0.47µF 10µF 16V 20 8 13 CREF SCL N.C. SDA N.C. ADDR + C14 100µF 16V GND 3 IN2 7 10 9 12 J5 JP1 R1 11 IN3 C3 1 VS 2 DGND 3 SCL 4 SDA 10 C15 0.1µF I2C VS 1 2 OUT1 VS IN2 IN1 1 1 J4 C2 2 + IN1 TDA7448 0.47µF 2 C1 J6 R2 R3 1K 1K GND 9/13 TDA7448 Figure 14. Component Layout (65 x 72mm) Figure 15. PC Board (Component side) 10/13 TDA7448 Figure 16. PC Board (Solder side) 11/13 TDA7448 mm inch OUTLINE AND MECHANICAL DATA DIM. MIN. TYP. MAX. MIN. TYP. MAX. A 2.35 2.65 0.093 0.104 A1 0.1 0.3 0.004 0.012 B 0.33 0.51 0.013 0.020 C 0.23 0.32 0.009 0.013 D 12.6 13 0.496 0.512 E 7.4 7.6 0.291 0.299 e 1.27 0.050 H 10 10.65 0.394 0.419 h 0.25 0.75 0.010 0.030 L 0.4 1.27 0.016 0.050 SO20 K 0˚ (min.)8˚ (max.) L h x 45˚ A B e A1 K H D 20 11 E 1 0 1 SO20MEC 12/13 C TDA7448 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. 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