This article refers to the address: http://
National Semiconductor Corporation (NS) has announced the launch of two high-performance, low-power Boomer® Class D audio subsystems to further expand the product lineup of this family of chips. The new products are the LM49352 mixed-signal audio subsystem and the LM49151 analog subsystem, which feature simplified system design for portable products, especially for smart mobile phones, multifunction phones, portable video game consoles, and portable global positioning. Applications such as systems.The LM49352 is a mixed-signal audio subsystem with an audio codec, a ground-referenced headphone amplifier, a small handset driver, a Class D speaker, and an audio digital signal processor. These circuits are all built into 3.3mm x 3.3mm Inside the mini package. The built-in speaker is extremely efficient, with an efficiency of up to 93% when outputting 970mW from a 4.2V supply. The headphone amplifier can support low-power (18mW) MP3 playback, which further extends battery life.
The LM49151 analog subsystem has a built-in handset driver, a Class D speaker, a ground referenced headphone amplifier, and an automatic level controller (ALC). These circuits are all built into the ultra-small package of 2.2mm x 2.6mm. The power consumption of the LM49151 analog subsystem is lower than that of similar products. If operating at 3.3V, the quiescent current of the speaker and headphones can be as low as 7.3mA. Mobile phone manufacturers can take full advantage of the automatic level control function of this subsystem to flexibly control the distortion level of the audio signal to avoid speaker damage.
Main technical specifications and features -- LM49352 mixed signal audio subsystem
The full-featured LM49352 audio subsystem is available in a 36-bump micro SMDxt package with built-in circuitry including 24-bit stereo digital/analog converter, 24-bit stereo analog/digital converter, stereo headphone amplifier and low Class D loudspeakers with electromagnetic interference. In addition, the audio subsystem also has a built-in two-wire bidirectional I2S interface and PCM audio bridge circuit for easy connection to peripheral devices such as Bluetooth® modules. Moreover, this system can also set different gains and modes through the I2C compatible interface.
If the 24-bit, 48kHz signal is input to the LM49352 subsystem, the built-in stereo analog/digital converter can achieve a signal-to-noise ratio of 97dB; in the same case, the digital-to-analog converter can achieve a signal-to-noise ratio of 103dB. The speaker can deliver up to 970mW of output power from a 4.2V supply to drive a 8Ohm load with less than 1% total harmonic distortion and noise.
The LM49352 subsystem's digital signal processor includes special effects circuitry that supports digital/analog converters and analog/digital converters for volume control, automatic level control (to compress and level signal spikes), and 5-band signal equalization ( In order to improve the audio processing effect and other functions. In addition, the built-in analog/digital converter itself has a flexible wind noise filter, so it can support voice or high fidelity recording modes.
Main technical specifications and features -- LM49151 analog audio subsystem
The LM49151 audio subsystem is available in a 20-bump micro SMD package with built-in circuitry including a mono D-class speaker amplifier with enhanced emission suppression (E2S), a Class AB headphone driver, and a ground-referenced stereo headphone driver. Volume control, input mixer/multiplexer, and speaker protection circuitry. The Class D amplifier features a patented ultra-low EMI pulse width modulation (PWM) architecture that dramatically reduces the amount of RF signal radiation to ensure better sound quality.
The Automatic Level Control (ALC) circuit of the LM49151 audio subsystem has many advantages. For example, the Chopper-free automatic level control function allows small signals to be amplified in multiples. Therefore, even if the battery voltage gradually drops, the signal will not be distorted, and the spike of the high level signal will not be flattened. In addition, the LM49151 chip can select the automatic level control function of chopping level, which can not only output very high power, but also control the distortion level. In addition, the automatic level control function of the power level can be selected to protect the speaker.
Price and availability
The LM49352 chip is priced at $7.55 each, and the LM49151 chip is priced at $1.60. Both chips are priced at 1,000 units and are available in volume.
Stainless Steel Table Lamp,Laser-Cutted Lamps,Mirror Pendant Lamp
Table Lamp Wall Lamp Co.,Ltd , http://www.nspendantlamp.com