基于TPA2028D1設計的3W無濾波器D類音頻放大器設計

TI 公司的TPA2028D1是單聲道 3W 無濾波器D類音頻功率放大器,集成了音量控制,動態范圍壓縮(DRC)和自動增益控制(AGC).DRV/AGC功能可通過數字I2C接口進行編程.5V電源時能向4歐姆負載提供3W功率(THD+N為10%),工作電壓從2.5 V 到5.5 V,工作電流1.8mA,關斷電流0.2uA,主要用在無線或蜂窩手機與PDA,PND,DVD播放器,筆記本電腦,手提無線電和游戲機以及教育類玩具.本文介紹TPA2028D1主要特性,功能方框圖, 指標測試方框圖,以及TPA2028D1YZFEVM評估板性能,電路圖和材料清單(BOM).

The TPA2028D1 is a mono, filter-free Class-D audio power amplifier with volume control, dynamic range compression (DRC) and automatic gain control (AGC). It is available in a 1,63 mm x 1,63 mm wafer chip-scale package (WCSP).

The DRC/AGC function in the TPA2028D1 is programmable via a digital I2C interface. The DRC/AGC function can be configured to automatically prevent distortion of the audio signal and enhance quiet passages that are normally not heard. The DRC/AGC can also be configured to protect the speaker from damage at high power levels and compress the dynamic range of music to fit within the dynamic range of the speaker. The gain can be selected from –28 dB to +30 dB in 1-dB steps.

TPA2028D1主要特性:

Fast AGC Start-up Time: 5 ms

Pin-out Compatible with TPA2018D1

Filter-Free Class-D Architecture

3 W Into 4

880 mW Into 8

Power Supply Range: 2.5 V to 5.5 V

Flexible Operation With/Without I2C

Programmable DRC/AGC Parameters

Digital I2C Volume Control

Selectable Gain from –28 dB to 30 dB in 1-dB Steps (when compression is used)

Selectable Attack, Release and Hold Times

4 Selectable Compression Ratios

Low Supply Current: 1.8 mA

Low Shutdown Current: 0.2 µA

High PSRR: 80 dB

AGC Enable/Disable Function

Limiter Enable/Disable Function

Short-Circuit and Thermal Protection

Space-Saving Package

1,63 mm × 1,63 mm Nano-Free WCSP (YZF)

TPA2028D1應用:

• Wireless or Cellular Handsets and PDAs

• Portable Navigation Devices

• Portable DVD Player

• Notebook PCs

• Portable Radio

• Portable Games

• Educational Toys

• USB Speakers

圖1.TPA2028D1功能方框圖

圖2.TPA2028D1指標測試方框圖

圖3.TPA2028D1簡化應用方框圖

TPA2028D1YZFEVM評估板

The TPA2028D1 evaluation module (EVM) is a complete, stand-alone audio board. It contains the TPA2028D1 WCSP (YZF) Class-D audio power amplifier.

TPA2028D1YZFEVM評估板指標:

圖4.TPA2028D1YZFEVM評估板外形圖

圖5.TPA2028D1YZFEVM評估板電路圖(1)

圖6.TPA2028D1YZFEVM評估板電路圖(2)

TPA2028D1YZFEVM評估板材料清單(BOM):