National Semiconductor Corporation announced the industry's first analog audio subsystem with integrated noise suppression technology for smart phones and multifunction phones. The analog audio subsystem of the PowerWise® LM49155 features a significant improvement in the talker's speech/background noise ratio while ensuring a clear, natural voice. Whether you are calling or answering, mobile phone users can enjoy clearer call quality even in noisy environments. The LM49155 analog audio subsystem filters out background noise as much as possible to improve the accuracy of the speech recognition system. This article refers to the address: http:// The LMV1099 noise processing IC is also available in volume quantities and is priced at $1.50 each in 1,000-unit quantities. Spiral Rotor Flowmeter,marine helical rotor flowmeter,lzx type marine helical rotor flowmeter Taizhou Jiabo Instrument Technology Co., Ltd. , https://www.taizhoujbcbyq.com
National's LM49155 analog audio subsystem implements noise suppression with minimal power consumption. When the phone is in quiescent mode, the signal path of the headphone amplifier and microphone amplifier consumes only 3.7 mA. Because the subsystem is so easy to use, engineers can easily add noise suppression to their handsets without the need for additional development time to write and test voice processor code for digital signal processors or microprocessors.
The LM49155 subsystem suppresses uplink noise and improves the signal-to-noise ratio of the downlink. It is available in a 36-bump ultra-small micro SMD package measuring only 3.4mm x 3.4mm. In addition, the subsystem includes a 1.35W high-efficiency Class D speaker driver that supports automatic level control (ALC), a headphone amplifier with switching/switching noise suppression and reference to ground voltage, and a mix Frequency and volume control.
The uplink noise suppression technology of the LM49155 subsystem utilizes a unique dual microphone amplifier design to reject far-field noise. The clarity of the downlink speech signal is improved by increasing the signal-to-noise ratio (SNR) between the handset headset signal and ambient noise. The LM49155 subsystem can store uplink voice signals in close range, while also filtering out background noise from the microphone 0.5 meters away. In addition, the subsystem continuously adjusts the downlink signal so that the voice of the other party can be clearly heard regardless of the environment in which the listener is located.
In addition, National's newly developed noise suppression technology is also used in the discrete noise processing IC model LMV1099. If the input frequency is 1kHz, the chip can provide 34dB uplink far-field noise suppression, its near-field signal-to-noise ratio (SNR) can be increased from 6dB to 18dB, and the downlink signal-to-noise ratio is improved by 16dB. Other features of the LMV1099 chip include: 0.1% up/downlink total harmonic distortion and noise (THD+N), 0.07uA shutdown current, and 3.7mA supply current. The chip operates from a 2.7V to 5.5V supply and is available in a 25-bump micro SMD package.
The LM49155 analog audio subsystem is available now in volume quantities and is priced at $2.25 each in 1,000-unit quantities.