Diodes PAM8603A - Manual (Page 11)

PAM8603A
Document number: DSxxxxx Rev. 1 - 2
11 of 16
www.diodes.com
November 2012
© Diodes Incorporated
PAM8603A
A Product Line of
Diodes Incorporated
Application Information
Test Setup for Performance Testing (Class D)
1. When the PAM8603A works with LC filters, it should be connected with the speaker before it's powered on, otherwise it will be damaged
easily.
2. When the PAM8603A works without LC filters, it's better to add a ferrite chip bead at the outgoing line of speaker for suppressing the
possible electromagnetic interference.
3. The absolute maximum rating of the PAM8603A operation voltage is 6V. When the PAM8603A is powered with four battery cells, it should
be noted that the voltage of four new dry or alkaline batteries is over 6V, higher than its maximum operation voltage, which probably make
the device damaged. Therefore, it's recommended to use either four Ni-MH (Nickel Metal Hydride) rechargeable batteries or three dry or
alkaline batteries.
4. The input signal should not be too high, if too high, it will cause the clipping of output signal when increasing the volume. Because the DC
volume control of the PAM8603A has big gain, it will make the device damaged.
5. When testing the PAM8603A without LC filters by using resistor instead of speaker as the output load, the test results, e.g. THD or efficiency,
will be worse than those using speaker as load.
Notes: 1. The Audio Precision (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.
Anti-saturation Function
If the preset gain is haigher than 12dB, Anti-saturation is active by detecting the duty cycle of the PWM output when the mode been detected,
the gain is automatcally adjusted to the value that the output is not clip step by step. The maximum attenuation is -12dB (preset gain = 24dB).
The attach is immediately and the released time is 250ms per step.
Mute Operation
The MUTE pin is an input for controlling the output state of the PAM8603A. A logic low on this pin disables the outputs, and a logic high enables
the outputs. This pin may be used as a quick disable or enable of the outputs without a volume fade. Quiescent current is listed in the electrical
characteristic table. The
MUTE pin can be left floating due to the internal pull-up.
Shutdown Operation
In order to reduce power consumption while not in use, the PAM8603A contains shutdown circuitry to turn off the amplifier's bias circuitry. The
amplifier is turned off when logic low is placed on the
SHDN pin. By switching the SHDN pin connected to GND, the PAM8603A supply current
draw will be minimized in idle mode. The SHDN pin can be left floating due to the pull-up.
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.