PAM8012

Mono 2.0W Anti-saturation Class D

Audio Power Amplifier with Power Limit

7

,

Power Analog Microelectronics Inc

www.poweranalog.com

06/2012 Rev1.3

Notes

1. The AP AUX-0025 low pass filter is necessary for class-D amplifier measurement with AP analyzer.

2. Two 33µH inductors are used in series with load resistor to emulate the small speaker for efficiency

measurement.

Test Setup for Performance Testing

AP System One

Generator

PAM8012 Demo Board

+OUT

Input

Load

AP

Low Pass

Filter

AUX-0025

AP System Two

Analyzer

GND

-OUT

VDD

Power Supply

Anti-saturation

The Anti-saturation feature provides continuous automatic gain adjustment to the amplifiier through an

internal circuit. This feature enhances the perceived audio loudness and at the same time prevents

speaker damage from occurring.

Table 1. PAM8012 Anti-saturation Variable Description

VARIABLE

DE SCRIP TI ON

V alue

Gain

The pre-set gain of the device when the Anti-saturation is inactive.

The fixed gain is also the initial gain when the device c omes out of

shutdown mode or when the Anti-s aturation is disabled

18dB

(Max imum)

Attack Time

The minimum time between two gain dec rements .

128uS

Release Time

The minimum time between two gain increments.

256mS

The Anti-saturation works by detecting the output. The gain changes depending on the supply voltage ,

and the attack and release time. The gain changes constantly as the audio signal increases and/or

decreases. The gain step size for the

is 0.4 dB. If the audio signal has near-constant

amplitude, the gain does not change. Table 1 shows the Anti-saturation variable description.

Anti-saturation

PL Terminal Function

able 2

The voltage value of PL sets the PAM8012 maximum output by an external resistor. Refer to t

for

anti-saturation and power limit selection.

Table 2. PAM8012 Anti-saturation and Power Limit Variable Description

Application Information

0

30K<Rpl<120K

Open

VDD

PL: OFF

Anti-sat: OFF

PL: ON

Anti-sat: ON

PL: OFF

Anti-sat: ON

VDD/2

PL: OFF

Anti-sat: OFF

PL: ON

Anti-sat: OFF

PL: ON

Anti-sat: OFF

EN

Rpl