SD7401

SD7401 SIX-CHANNEL AUDIO AMPLIFIER DESCRIPTION SD7401 is a 6-channel audio amplifier with built-in microphone input amplifier. High quality audio output is available through simple peripheral circuit and the amplifier gain can be adjusted flexibly by external resistor. It is widely used as pre-amplification in various multi-channel audio systems. FEATURES * BICMOS technology * Dual power supply (+5V/-12V) * Built-in voltage regulation module * Low distortion * Standby function * Mute function * ON/OFF POP noise suppression SSOP-20-225-0.65 APPLICATIONS * Audio amplification system, such as VCD/DVD ORDERING INFORMATION Part No. SD7401 Package SSOP-20-225-0.65 Marking SD7401 BLOCK DIAGRAM HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.0 2008.07.07 Page 1 of 7 SD7401 ABSOLUTE MAXIMUM RATINGS (Unless otherwise specified, Tamb = 25°C) Characteristics Supply Voltage (VCC-Vss) Operating Temperature Storage Temperature supply. Symbol VCC/VSS Topr Tstg Rating +6/-1 Unit V °C °C -20~85 -40~125 Note 1: Tolerable voltage is decided by external resistor because of built-in voltage regulator at negative power ELECTRICAL CHARACTERISTIC (Unless otherwise specified, VCC = 5V, VSS = -12V, RL = 10kΩ, Tamb = 25°C, f = 1kHz) Characteristics Operating Voltage Symbol VCC VSS ICC Operating Current Standby Current Max. Output Voltage Audio Amplitude Response Voltage Gain Total Harmonic Distortion Signal-Noise Ratio Dynamic Range Mute Restrain Channel Separation Channel Balance Input Impedance G THD SNR DR MR CT CB Ri ISS ISTBY Vomax External resistor 470Ω at negative power supply STBY_N connect toVSS fin=1kHz; RL=10kΩ; THD=0.1% 20Hz~20kHz, Vo=2Vrms No input resistor, THD=0.1% fin=1kHz; RL=10kΩ; Vo=2Vrms fin=1kHz; RL=10kΩ; Vo=2Vrms fin=1kHz, Vin=-60dB fin=1kHz; RL=10kΩ; Vo=2Vrms fin=1kHz; RL=10kΩ; Vo=2Vrms fin=1kHz; RL=10kΩ; Vo=2Vrms fin=1kHz, RL=10kΩ Test Condition Min. --2.0 14.7 550 2.50 7.7 --75 78 75 62 --Typ. 5 -12 2.2 14.8 600 2.51 8.3 11.5 0.05 76 79 77 65 -27.6 Max. --2.5 14.9 640 2.53 8.5 -0.06 78 80 80 70 0.2 -Unit V V mA mA µA Vrms dB dB dB dB dB dB dB dB Ω HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.0 2008.07.07 Page 2 of 7 SD7401 PIN CONFIGURATION PIN DESCRIPTION Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Pin Name VCC PMUTE MIC IN MUTE CENT IN LS IN L IN R IN SUB IN RS IN RS OUT SUB OUT R OUT L OUT LS OUT CENT OUT MIC OUT STBY_N VSS GND I/O -I/O I I I I I I I I O O O O O O O I --Pin Description Positive power supply POP restrain control Microphone input Mute control Center input Left surround input Left channel input Right channel input Subwoofer input Right surround input Right surround output Subwoofer output Right channel output Left channel output Left surround output Center output Microphone output Standby control Negative power supply Ground HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.0 2008.07.07 Page 3 of 7 SD7401 FUNCTION DESCRIPTION 1. Channel amplifier The second-order filter structure shown as above is adopted for 6-channel audio amplifier, with in-band gain of about 12dB and -3dB bandwidth of 40kHz above which is well meet audio requirements. As principle structure, in-band gain is decided by: G = − R 2 , thus, gain can be adjusted by changing R1. R1 2. Microphone amplifier R2 C VCC R1 MICIN + VSS MICOUT AGND The proportional amplifier shown as above is adopted for microphone amplifier with setting gain of about 29dB, and capacitor c is used for high frequency signal filtering. As described above, the gain can be also adjusted by changing R1. 3. Mute & ON/OFF POP noise control Mute control pin (pin 4) controls 6-channel as mute by internal switches. It comes to mute mode when pin 4 is HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.0 2008.07.07 Page 4 of 7 SD7401 connected to Vcc (high level) and comes to normal mode when connected to ground. Pin 2 is used for POP noise restrain by connecting an external capacitor which can be increased appropriately for better POP noises restrain effect. In general, POP noise restrain is realized by mute control. Mute pulse is generated when turned on for zero output and ended after powered on for normal output; mute pulse is also generated when power supply is threshold value below during turned off for zero output. Thus, pop noise is restrained during power on/down. 4. Power supply The built-in voltage regulator for negative power supply is shown as below. An external resistor R guarantees voltage stability near -5 V on pin 19 and the chip power supply is ±5V for normal operation. Because the negative power to provide current is decided by this resistance, if the system output is light load, this resistance can be properly increased to reduce operate current, but the voltage of PIN 19 must be maintained and can not drop significantly. 5. System standby The pin STBY_N controls system entering standby mode by turning off internal amplifier bias circuit. When this pin is connected to Vss, system enters standby mode, and when floated, system works normally. Note: internal voltage regulating circuit still works in standby mode and supplies working current. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.0 2008.07.07 Page 5 of 7 SD7401 TYPICAL APPLICATION CIRCUIT HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http://www.silan.com.cn REV:1.0 2008.07.07 Page 6 of 7 SD7401 PACKAGE OUTLINE SSOP-20-225-0.65 6.50±0.20 20 11 UNIT: mm 6.40±0.20 1 10 1.20±0.05 0°～8° +0.10 -0.05 +0.08 0.127 -0.04 1.45MAX 4.40±0.10 0.65 0.25 MOS DEVICES OPERATE NOTES: Electrostatic charges may exist in many things. Please take following preventive measures to prevent effectively the MOS electric circuit as a result of the damage which is caused by discharge: The operator must put on wrist strap which should be earthed to against electrostatic. Equipment cases should be earthed. All tools used during assembly, including soldering tools and solder baths, must be earthed. MOS devices should be packed in antistatic/conductive containers for transportation. Note：Silan reserves the right to make changes without notice in this specification for the improvement of the design and performance. Silan will supply the best possible product for customers. HANGZHOU SILAN MICROELECTRONICS CO.,LTD Http://www.silan.com.cn 0.10 0.60±0.15 REV:1.0 2008.07.07 Page 7 of 7