PAM8008

Document number: DSxxxxx Rev. 1 - 0

9 of 14

www.diodes.com

October 2012

© Diodes Incorporated

PAM8008

A Product Line of

Diodes Incorporated

Application Information

Power Limit Function

When connect Pin 4 to GND or floating, the PAM8008 power is limited at 2.5W. Different from other company’s power limit, the power limit circuit

10% when power limit works. When the PAM8008 enters in power limit mode, the gain changes depending on the input audio signal amplitude

and the attack, release time. The gain changes constantly as the audio signal increase or decrease. Every gain step size is about 0.4dB. If the

audio signal has near-constant amplitude or the maximum attenuation is 20dB, the gain does not change.

Anti-Saturation Function

Table 2. PAM8008 Power Limit and Anti-Saturation Varible Description

Varible

Description

Value

Gain

The max gain when the PAM8008 is not in power limit

and anti-saturation mode.

20dB

(Maximum)

Attack Time

The minimum time between two gain decrements.

128µs

Release Time

The minimum time between two gain increments.

256mS

Table 3. PAM8008 Power Limit and Anti-Saturation Mode Setting

PL

Mode

PL = Floating or

PL = 0V to 0.2V

Power Limit

PL = 0.8V to VDD/2

Power Limit and

Anti-Saturation Off

PL = 3.8V to VDD

Noise Reduction Function

The gain of PAM8008 will reduce 6dB when there is no audio at the input of the amplifier for 8s. The gain will recover until the input signal is

above the noise threshold.The noise threshold is set by internal voltage.

Mute Operation

The MUTE pin is an input for controlling the Class-D output state of the PAM8008. A logic low on this pin enables the outputs, and a logic high

on this pin disables the outputs. This pin may be used as a quick disable or enable of the outputs without a volume fade. Quiescent current is

listed in the electrical characteristic table. The MUTE pin can be left floating due to the internal pull-down.

Shutdown Operation

In order to reduce power consumption while not in use, the PAM8008 contains shutdown circuit to tur n off the amplifier's bias circuit. The

amplifier is turned off when logic low is placed on the SD pin. By connecting the SD pin to GND, the PAM8008 supply current will be minimized

in idle mode. The SD pin can be left floating due to the internal pull-up.

For the best power on/off pop performance, the amplifier should be placed in the Mute mode prior to turning on/off the

power supply.