PAM8012

Document number: DSxxxxx Rev. 1 - 3

8 of 14

www.diodes.com

October 2012

© Diodes Incorporated

PAM8012

A Product Line of

Diodes Incorporated

equation:

C

R

2

1

f

I

I

C

Π

=

It is important to consider the value of CI as it directly affects the low frequency performance of the circuit. For example, the specification calls

for a flat bass response are down to 150Hz.

Equation is reconfigured as followed:

f

R

2

1

C

I

I

I

Π

=

voltage at the input to the amplifier that reduces useful headroom, especially in high gain applications. For this reason, a low-leakage tantalum

or ceramic capacitor is the best choice. When polarized capacitors are used, the positive side of the capacitor should face the amplifier input in

capacitor polarity in the application.

The PAM8012 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output total

harmonic distortion (THD) as low as possible. Power supply decoupling also prevents the oscillations causing by long lead length between the

amplifier and the speaker.

The optimum decoupling is achieved by using two different types of capacitors that target on different types of noise on the power supply leads.

For higher frequency transients, spikes, or digital hash on the line, a good low equivalentseries- resistance (ESR) ceramic capacitor, typically

10µF or greater placed near the audio power amplifier is recommended.

How to Reduce EMI

Most applications require a ferrite bead filter for EMI elimination shown at Figure 1. The ferrite filter reduces EMI around 1MHz and higher.

When selecting a ferrite bead, choose one with high impedance at high frequencies, but low impedance at low frequencies.

Figure 1: Ferrite Bead Filter to Reduce EMI

Shutdown Operation

In order to reduce power consumption while not in use, the PAM8012 contains shutdown circuitry that is used to turn off the amplifier’s bias

circuitry. This shutdown feature turns the amplifier off when logic low is placed on the EN pin. By switching the EN pin connected to GND, the

PAM8012 supply current draw will be minimized in idle mode.

Short Circuit Protection (SCP)

The PAM8012 has short circuit protection circuitry on the outputs to prevent the device from damage when output-to-output shorts or output-to-

GND shorts occur. When a short circuit occurs, the device immediately goes into shutdown state. Once the short is removed, the device will be

reactivated.