Currently, global mobile phone shipments continue to grow steadily. In the Chinese mobile phone market, Feature Phone and Smart Phone music playback speakers are already a standard configuration, and music phones are increasingly demanding high-quality audio output. When designing the audio module of the mobile phone solution, how to resist audio breakout output and reasonable audio gain control is the most concerned by mobile phone hardware design engineers. I hope that the audio output of the audio volume has good sound quality and high volume without breaking. It takes a lot of time to test and adjust the hardware system of the solution.
Orient-Chip Semiconductor Co., Ltd introduced innovative, audio-power amplifier IC OCA7220 with proprietary technology and automatic gain adjustment anti-breaking output to the market in Q3 2010-anti-breaking, ultra-low EMI, Class D audio power amplifier with output power of 3W; its innovative and unique AnTI-Crack ProtecTIon (ACP) technology can effectively resist the dilemma of audio output and gain control, the dilemma of mobile phone audio output. OCA7220 has been put in several large mobile phones including Shanghai Wentai
Main features of audio power amplifier OCA7220 with anti-breaking sound, ultra-low EMI, and output power of 3W:
Maximum output power is 3W; maximum battery life and minimum heat generation
Unique and innovative anti-breaking sound (ACP) function, NCN1, NCN2, NCNOFF 3 modes are available
Quiescent current 4Ma, 0.5μA in shutdown mode
Built-in over current protection, over temperature protection and under voltage protection.
Ideal PWM output stage without LC output filter
Built-in 250KHz oscillator, no additional capacitance and resistance required
Wide range of operating voltage (2.5V ~ 5.5V)
Fully differential design reduces RF rectification without bypass capacitors
Excellent power supply voltage rejection ratio (-75dB), excellent common mode rejection ratio, no input coupling capacitor required
Package: micro SMD (CSP9)
The principle of the occurrence of broken sound is that when the music volume is large, the output power will exceed the limit value that the PA can withstand when the gain of the control output is unchanged, and the sound source will appear clipped distortion, causing the output audio to be broken sound. OCS's proprietary ACP technology is a technical innovation based on this problem. When the volume of the input sound source is large, the gain factor set inside the PA is automatically reduced, so that the output sound source can achieve maximum output power without distortion. OCS anti-breaking technology (ACP) uses compression / limiting technology in professional audio systems, with important parameters such as threshold threshold, start-up time and release time.
Threshold Threshold: The threshold voltage for starting the anti-breaking sound (ACP) function is the maximum undistorted output amplitude allowed by the system.
Start-up time: the time from when the detected signal exceeds the threshold voltage to when the compression function is fully expanded. The start-up time depends largely on the type of sound signal being processed and the desired characteristics: a short start-up time usually makes the sound "rounded", and soon the sound can be fully compressed; a long start-up time can be better Reflect the long, slowly changing signal. Typical start-up time is 1ms-100ms
Release time: The choice of release time also depends on the type of sound signal being processed and the desired characteristics. Short release time can respond well to rapidly changing sound signals, such as rapid gunfire and sharp short alarm sounds. Long release time will make the sound smooth and soft. Typical release time is 20ms-5s
The following are the waveform characteristics of music under different functions:
original signal:
Audio output signal without anti-breaking function
Audio output signal with anti-breaking function
From the above audio output signal diagram, we can see that the output with anti-breaking output technology-ACP function is obviously smooth, and the output power reaches the ultimate without distortion, improving the overall sound quality and volume of music .
Orient-Chip Semiconductor Co., Ltd-OCS is the world's leading analog, digital, and mixed-signal IC design company. Focus on providing customers with the most diversified and most cost-effective IC products, complete solutions and the best quality services. Since its establishment, OCS has been continuously devoted to the development of a new generation of ICs that integrate advanced energy efficiency ratio and controllable cost, and also provides customers with the most complete customized system design support and services. For more information, please log in to the electronic enthusiast website (http: //)
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Short circuit protection:The following test shall be performed. Charge batteriesas specified in ; use of 4.6.3 is permitted. Measure and record the OCV. Short each battery across all the positive and negative terminals with a total external resistance not greater than 50 milliohms. After one hour remove the short from across the terminals. Measure and record the OCV. Stabilize batteries at the normal conditions of 4.3.1 for not less than 2 hours. Chargebatteries in accordance with 4.6; use of 4.6.3 is permitted. Stabilize batteries at normal conditions for not less than 2 hours, then discharge the battery in accordance with 4.7.2.3. The battery shall meet the requirements of 3.7.2.3.
Li-Ion Battery With Lcd Display
Charge voltage: 16.8V
Nominal voltage : 14.8V (4S7P)
Initial impedance : 120mΩ
Nominal capacity: 19.6Ah
Minimum capacity: 19.4Ah
Communication methods : SMBUS data communication
Electricity quantity show: LCD Electricity quantity show
Charge current: Standard Charging::0.2C5A (3.9A)
Rapid charge: 0.5C5A C(9.8A) Max
Standard Charging method : 3.9A(0.2C5A) CC(constant current)charge to 16.8V,then CV(constant voltage 16.8V)charge till charge current decline to ≤196mA(≈0.01C5A)
Charging time:Standard Charging: 6.5hours(Ref.)
Rapid charge: 3.5 hours(Ref.)
Max.discharge current: 9.8A(0.5C5A)
Discharge cut-off voltage: 10.0V
Cycle life (0.2C5A/0.2C5A) : 500 items,≧80%DOD; 300 times,≧80%DOD
Operating temperature : Charging: 0℃~45℃
Discharging:-20℃~+60℃
Li-ion Battery With LCD Display
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YFJ TECHNOLOGY (HK) CO.,LIMITED , http://www.yfjpower.com