2x30W Stereo Class-D Audio Amplifier With Low Idle Current and AGC

Features

Single supply voltage

4.5V ~ 26V for loudspeaker driver Built-in LDO output 5V for others

Supports Multiple Output Configurations BTL Mode: 30W/CH into 8 at 24 V BTL Mode: 30W/CH into 4 at 18 V

Loudspeaker performance

BTL Mode: 30W/CH into 8<1% THD+N@24V BTL Mode: 30W/CH into 4<1% THD+N@18V

>90% efficient Class-D operation eliminates need for heat sink

Energy Saving Class-D Operation Low Idle Current <23mA

Multiple Switching Frequencies AM Avoidance

Master/Slave Synchronization

300KHz to 1.2MHz Switching Frequency

Differential inputs

Four selectable, fixed gain settings

Internal oscillator

Short-Circuit protection with auto recovery

Under-Voltage detection

Over-Voltage protection

Pop noise and click noise reduction

Adjustable Automatic Gain Control or adjustable power limit function for speaker protection

Output DC detection for speaker protection

Thermal fold-back control

Over temperature protection with auto recovery

Description

The AD52070 is a high efficiency stereo class-D audio amplifier with adjustable power limit function. It can deliver 30W/CH output  power  into  4  or 8 loudspeaker within 1% THD+N at 24V supply voltage.

The AD52070 has low idle current mode for battery-powered audio system and helps to extend the batter life. The advanced oscillator/PLL circuit employs a multiple switching frequency option to avoid AM interferences. In order to achieve multi-channels application, which the clock slave mode design with, making it possible to synchronize multiple devices.

The Automatic Gain Control (AGC) is enabled to prevent output signal from distortion when the input signal exceeds a threshold level. The AGC allows adjustment of maximum output voltage without signal clipping for enhanced speaker protection and audio quality. The power-limit control can provide further limit output power level of amplifier. The adjustable power limit function allows user to set a voltage to limit the amount of current through the speaker. All these functions are performed automatically.

Output DC detection prevents speaker damage from long-time current stress. AD52070 output short circuit and over temperature protection include auto-recovery feature.

Applications

TV audio

Boom-Box

Powered speaker

Monitors

Consumer Audio Equipment

Simplified Application Circuit