PAM8403 Datasheet, PDF (10/12 Pages) Power Analog Micoelectronics – Filterless 3W Class-D Stereo Audio Amplifier

PAM8403
Filterless 3W Class-D Stereo Audio Amplifier
Under Voltage Lock-out (UVLO)
The PAM8403 incorporates circuitry designed to
detect low supply voltage. When the supply
voltage drops to 2.0V or below, the PAM8403
outputs are disabled, and the device comes out of
this state and starts to normal function when V_DD
≥2.2V.
Short Circuit Protection (SCP)
The PAM8403 has short circuit protection
circuitry on the outputs to prevent damage to the
device when output-to-output or output-to-GND
short occurs. 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 PAM8403 prevents the
device from damage when the internal die
temperature exceeds 140°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 and the device begins normal
operation at this point without external system
intervention.
How to Reduce EMI (Electro Magnetic
Interference)
A simple solution is to put an additional capacitor
1000μF at power supply terminal for power line
coupling if the traces from amplifier to speakers
are short (<20cm).
Most applications require a ferrite bead filter as
shown in Figure 2. The ferrite filter reduces EMI of
around 1 MHz and higher. When selecting a
ferrite bead, choose one with high impedance at
high frequencies, and low impedance at low
frequencies.
OUT+
Ferrite Bead
OUT-
Ferrite Bead
220pF
220pF
Figure 2: Ferrite Bead Filter to reduce EMI
Power Analog Microelectronics,Inc
www.poweranalog.com
10
09/2008 Rev 1.3