NS LM49153 G类耳机放大器解决方案
NS 公司的LM49153是全集成音频子系统，包括高效25mW的G类耳机放大器（THD+N ≤ 1%）和高效的1.35W D类扬声器放大器（RL = 8Ω, THD+N < 1%），通过I2C进行音量，模式选择和关断控制，主要用在手机和智能手机。本文介绍了LM49153主要指标，主要特性，典型音频放大器应用电路以及演示板电路图和材料清单，元件布局图。
The LM49153 is a fully integrated audio subsystem designed for portable handheld applications such as cellular phones.
Part of National’s PowerWise family of products, the LM49153 combines an earpiece switch, a high efficiency 25mW class G headphone amplifier, and a high efficiency 1.35W class D loudspeaker into a single device.
The headphone amplifiers feature National’s class G ground referenced architecture that creates a ground-referenced output with dynamic supply rails for optimum efficiency. The
class D amplifier features an ALC (Automatic Level Control) with a noise gate that provides both no-clip and speaker protection.
Mode selection, shutdown control, and volume are controlled through an I2C compatible interface. Click and pop suppression eliminates audible transients on power-up/down and during shutdown. The LM49153 is available in an ultra-small 25-bump 0.4mm pitch micro SMD package (2.30mm x 2.42mm).
LM49153主要指标：
■ Class G Headphone Amplifier,..
