PAM8001

Document number: DSxxxxx Rev. 1 - 0

12 of 17

www.diodes.com

February 2013

© Diodes Incorporated

PAM8001

A Product Line of

Diodes Incorporated

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.

Power Supply Decoupling

The PAM8001 is a high performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output THD and

PSRR are as low as possible. Power supply decoupling affects low frequency on the power supply leads. For higher frey response, optimum

decoupling is achieved by using two capacitors of different types that target different types of noise frequency transients, spikes, or digital hash

terminal works best. For filtering lower-frequecny noise signals, a large capacitor of 10µF (ceramic) or greater placed near the audio power

amplifier is recommended.

Large input capacitors are both expensive and space hungry for portable designs. Clearly, a certain sized capacitor is needed to couple in low

frequencies without severe attenuation. But in many cases the speakers used in portable systems, whether internal or external have little ability

to reproduce signals below 100Hz to 150Hz. Thus, using a large input capacitor may not increase actual system performance. In this case,

I

R

2

1

fc





feedback and is apt to create pops upon device enable. Thus, by minimizing the capacitor size based on necessary low frequency response,

turn-on pops can be minimized.

produced by the power supply caused by coupling into the output drive signal. The noise is from the internal analog reference to the amplifier,

which appears as degraded PSRR and THD+N.

A ceramic bypass capacitor (CBYP) of 0.47µF to 1.0µF is recommended for the best THD and noise performance. Increasing the bypass

capacitor reduces clicking and popping noise from power on/off and entering leaving shutdown.

Under Voltage Lock-Out (UVLO)

The PAM8001 incorporates circuitry designed to detect when supply voltage is low. When the supply voltage drops to 1.8V or below, the

Short Circuit Protection (SCP)

The PAM8001 has short circuit protection circuitry on the outputs that prevents the device from damage when output-to-output and output-to-

GND short. When a short circuit is detected on the outputs, the outputs are disabled immediately. If the short was removed, the device

activates again.

Over Temperature Protection

Thermal protection on the PAM8001 prevents the device from damage when the internal die temperature exceeds 150°C. There is a 15 degree

tolerance on this trip point from device to device. Once the die temperature exceeds the thermal set point, the device outputs are disabled. This

is not a latched fault. The thermal fault is cleared once the temperature of the die is reduced by 30°C. This large hysteresis will prevent motor

boating sound well. The device begins normal operation at this point without external system interaction.