NXP SA58670立体声2.1WD类音频放大方案

NXP公司的SA58670是每路输出2.1W的立体声D类音频放大器,能对每路进行单独的关断控制.增益可选择为6dB, 12dB, 18dB或24dB. SA58670工作电压2.5V到5.5V,5V时能向4欧姆负载提供2.1W/路, 向8欧姆负载提供1.4W/路,217Hz时的SVRR高达77dB,可用在无线和蜂窝手机与PDA,手提DVD播放器,USB扬声器,笔记本电脑和手提收音机和游戏机.本文介绍了SA58670主要特性,方框图和应用电路.

SA58670: 2.1 W/channel stereo class-D audio amplifier

The SA58670 is a stereo, filter-free class-D audio amplifier which is available in an HVQFN20 package with the exposed Die Attach Paddle (DAP).

The SA58670 features independent shutdown controls for each channel. The gain may be set at 6 dB, 12 dB, 18 dB or 24 dB with gain select pins G0 and G1. Improved immunity to noise and RF rectification is increased by high PSRR and differential circuit topology. Fast start-up time and small package makes it an ideal choice for both cellular handsets and PDAs.

The SA58670 delivers 1.4 W/channel at 5.0 V and 720 mW/channel at 3.6 V into 8ohm. It delivers 2.1 W/channel at 5.0 V into 4 ohm. The maximum power efficiency is excellent at 70 % to 74 % into 4 ohm and 84 % to 88 % into 8 ohm. The SA58670 provides thermal and short-circuit shutdown protection.

SA58670主要特性:

Output power:

2.1 W/channel into 4 ohm at 5.0 V

1.4 W/channel into 8 ohm at 5.0 V

720 mW/channel into 8 ohm at 3.6 V

Supply voltage: 2.5 V to 5.5 V

Independent shutdown control for each channel

Selectable gain: 6 dB, 12 dB, 18 dB and 24 dB

High SVRR: 77 dB at 217 Hz

Fast start-up time: 3.5 ms

Low supply current

Low shutdown current

Short-circuit and thermal protection

Space savings with 4 mm x4 mm HVQFN20 package

Low junction to ambient thermal resistance of 24 K/W with exposed DAP

SA58670应用:

Wireless and cellular handset and PDA

Portable DVD player

USB speaker

Notebook PC

Portable radio and gaming


图1.SA58670方框图

图2.SA58670应用电路图