基于MAX97001設計的單片音頻系統方案

Maxim公司的MAX97001是單聲道音頻子系統,包括單聲道揚聲器放大器,立體聲耳機放大器和模擬DPST開關. 揚聲器和立體聲耳機放大器是單獨音量控制,4個輸入可配置成兩個差分輸入或4個單端輸入.2.7V-5.5V揚聲器電源,輸出700mW,1.6V-2V耳機電源,每路輸出37mW.主要用在手機和PMP.本文介紹MAX97001主要特性, 功能方框圖與應用框圖,MAX97001評估板主要特性,電路圖和材料清單(BOM).

The MAX97001 mono audio subsystem combines a mono speaker amplifier with a stereo headphone amplifier and an analog DPST switch. The headphone and speaker amplifiers have independent volume control and on/off control. The 4 inputs are configurable as 2 differential inputs or 4 single-ended inputs.

The entire subsystem is designed for maximum efficiency. The high-efficiency, 700mW, Class D speaker amplifier operates directly from the battery and consumes no more than 1μA in shutdown mode. The Class H headphone amplifier utilizes a dual-mode charge pump to maximize efficiency while outputting a ground-referenced signal that does not require output coupling capacitors.

The speaker amplifier incorporates a distortion limiter to automatically reduce the volume level when excessive clipping occurs. This allows high gain for low-level signals without compromising the quality of large signals.

All control is performed using the 2-wire I2C interface. The MAX97001 operates over the extended -40℃ to +85℃ temperature range, and is available in the 2mm x 2.5mm, 20-bump, WLP package (0.5mm pitch).

MAX97001主辦要特性:

2.7V to 5.5V Speaker Supply Voltage

1.6V to 2V Headphone Supply Voltage

700mW Speaker Output (V_PVDD = 3.7V, Z_SPK = 8Ω + 68μH)

37mW/Channel Headphone Output (R_HP = 16Ω)

Low-Emission Class D Amplifier

Efficient Class H Headphone Amplifier

Ground-Referenced Headphone Outputs

2 Stereo Single-Ended/Mono Differential Inputs

Integrated Distortion Limiter (Speaker Outputs)

Integrated DPST Analog Switch

No Clicks and Pops

TDMA Noise Free

2mm x 2.5mm, 20-Bump, 0.5mm Pitch WLP Package

MAX97001應用:

Cell Phones

Portable Multimedia Players


圖1.MAX97001簡化方框圖

圖2.MAX97001功能方框圖與應用框圖

MAX97001評估板

The MAX97001 evaluation kit (EV kit) is a fully assembled and tested PCB that evaluates the MAX97001 mono Class D audio power amplifier and stereo Class H DirectDriveM headphone amplifier communicating over a 2-wire I2C interface. The EV kit features an on-board microcontroller for communicating with the I2C interface of the MAX97001. PCB pads are provided for accessing the analog inputs and amplifier outputs.

The MAX97001 EV kit requires a 2.7V to 5.5V supply for PVDD and a 1.8V supply for VDD.

WindowsM 2000-, Windows XPM-, and Windows VistaMcompatible software is provided to facilitate configuration.

The software controls an on-board microcontroller over USB, which generates I2C commands.

MAX97001評估板:

Proven Audio PCB Layout

On-Board USB Interface Circuit Generates I2CCompatible Signals

PCB Pads for User-Supplied I2C-Compatible Signals

Surface-Mount Components

Windows 2000-, Windows XP-, and Windows Vista (32-Bit)-Compatible Software

Fully Assembled and Tested

圖3.MAX97001評估板電路圖(1)

圖4.MAX97001評估板電路圖(2)

MAX97001評估板元件清單: