PAM8404

Document number: DSxxxxx Rev. 1 - 1

12 of 18

www.diodes.com

November 2012

© Diodes Incorporated

PAM8404

A Product Line of

Diodes Incorporated

Application Information

Test Setup for Performance Testing

Notes:

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

2. Two 22μH inductors are used in series with load resistor to emulate the small speaker for efficiency measurement.

Gain Settin

The gain of PAM8404 can be selected as 6,12,18 or 24 dB utilizing the G0 and G1 gain setting pins. The gains showed in the following table are

realized by changing the input resistors inside the amplifier. The input impedance changes with the gain setting.

Table 1. Gain Setting

G1

G0

Gain

(V/V)

Gain

(dB)

Input

Impedance

(kΩ)

0

0

2

6

28.1

0

1

4

12

17.3

1

0

8

18

9.8

1

1

16

24

5.2

voltage at the input making the inputs less susceptible to noise. In addition to these features, lower value of Gain minimizes pop noise.

C

R

2

1

f

I

I

C





specification calls for a flat bass response are down to 200Hz, the equation is reconfigured as follows:

f

R

2

1

C

C

I

I





voltage at the input to the amplifier that reduces useful headroom, especially in high gain applications.