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. SSOP-20-225-0.65 FEATURES * BICMOS technology * Dual power supply (+5V/-12V) * Built-in voltage regulation module * Low distortion * Standby function APPLICATIONS * Mute function * Audio amplification system, such as * ON/OFF POP noise suppression VCD/DVD ORDERING INFORMATION Part No. Package Marking SD7401 SSOP-20-225-0.65 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) Symbol Rating Unit 1 VCC/VSS +6/-- V Operating Temperature Topr -20~85 °C Storage Temperature Tstg -40~125 °C Note 1: Tolerable voltage is decided by external resistor because of built-in voltage regulator at negative power supply. ELECTRICAL CHARACTERISTIC (Unless otherwise specified, VCC = 5V, VSS = -12V, RL = 10kΩ, Tamb = 25°C, f = 1kHz) Characteristics Operating Voltage Operating Current Symbol Min. Typ. Max. Unit VCC -- 5 -- V VSS -- -12 -- V ICC 2.0 2.2 2.5 mA 14.7 14.8 14.9 mA 550 600 640 µA 2.50 2.51 2.53 Vrms 7.7 8.3 8.5 dB -- 11.5 -- dB -- 0.05 0.06 dB 75 76 78 dB 78 79 80 dB 75 77 80 dB 62 65 70 dB -- -- 0.2 dB -- 27.6 -- Ω ISS Standby Current ISTBY Max. Output Voltage Vomax Audio Amplitude Response Voltage Gain External resistor 470Ω at negative power supply STBY_N connect toVSS fin=1kHz; RL=10kΩ; THD=0.1% 20Hz~20kHz, Vo=2Vrms G Total Harmonic Distortion THD Signal-Noise Ratio SNR Dynamic Range Test Condition DR Mute Restrain MR Channel Separation CT Channel Balance CB Input Impedance Ri 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 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. Pin Name I/O Pin Description 1 VCC -- 2 PMUTE I/O 3 MIC IN I Microphone input 4 MUTE I Mute control 5 CENT IN I Center input 6 LS IN I Left surround input 7 L IN I Left channel input 8 R IN I Right channel input 9 SUB IN I Subwoofer input 10 RS IN I Right surround input 11 RS OUT O Right surround output 12 SUB OUT O Subwoofer output 13 R OUT O Right channel output 14 L OUT O Left channel output 15 LS OUT O Left surround output 16 CENT OUT O Center output 17 MIC OUT O Microphone output 18 STBY_N I Standby control 19 VSS -- Negative power supply 20 GND -- Ground Positive power supply POP restrain control 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 MICOUT + VSS 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 UNIT: mm 1 10 +0.08 0.127 -0.04 +0.10 -0.05 0°～8° 0.10 1.45MAX 1.20±0.05 4.40±0.10 6.40±0.20 11 0.60±0.15 6.50±0.20 20 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: z The operator must put on wrist strap which should be earthed to against electrostatic. z Equipment cases should be earthed. z All tools used during assembly, including soldering tools and solder baths, must be earthed. z 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 REV:1.0 2008.07.07 Page 7 of 7