PAM8302 Datasheet, PDF (6/8 Pages) List of Unclassifed Manufacturers – Tiny Package 2 Watt Class-D Audio Amplifiers With Enable

PAM8302
Tiny Package 2 Watt Class-D Audio Amplifiers With Enable
Input
Enable
0.47 F 10K
Vdd
C1
C2
VDD
+OUT
IN
-OUT
GND
33 H
0.47 F
33 H
0.47 F
Speaker
Fig. 1
Setting Amplifier voltage gain
It is very important to know the maximum output level (0dB) of the signal source connected to a power amplifier in
order to prevent hard clipping during operation.
Gain (max) = Vsupply/ Vin (p-p)
Insufficient voltage gain will cause low output level and maybe not enough to drive speaker properly. On the
other hand, the distortion will be very high if the voltage gain is too high in an audio system.
There is a 10k input resistor integrated in side IN (input) node, and since the integrated feedback resistor is 100k ,
so the maximum voltage gain of PAM8302 is limited at 10V/V (100k/10k, one output). With an external input resistor
(Rin) placed between signal source & input node, the voltage gain will be
Gain = 100k/ (10k + Rin) = Vsupply/ Vin (p-p)
Actual voltage gain is two times of this calculation because of BTL connection.
Decouple capacitor
PAM8302 is a high performance, high speed class D amplifier, and it requires a 1 F, X7R ceramic decouple
capacitor (C1) placed very close between VDD & GND pins to ensure the total harmonic distortion plus noise
(THD+N) performance is as designed. This is also very important for efficiency and lowering noise floor. Another
100 F to 1000 F main decouple capacitor (C2) should be placed close to supply pin for low frequency
Ecoupling.
Input capacitor
Input capacitor (Cin) blocks the DC voltage between signal source & amplifier to ensure the DC balancing will not
be broken between two systems. It also form a high-pass-filter (HPF) with input resistors (Rin + 10k), the lower corner
frequency (FCL) is determine by equation below.
Power Analog Microelectronics, Inc.
CONFIDENTIAL. DO NOT DISTRIBUTE OR REPRODUCE WITHOUT PERMISSION FROM P.A.M.
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CONFIDENTIAL INFORMATION