PAM8302A User Guide

PAM8302A
EVB User Guide
PAM8302A-EV Board User Guide
AE Department
1. Revision Information
Date
2008/06/12
2008/11/14
Revision
V1.0
V2.0
Description
Initial Release
PCB Change
Comment
2. EV Board Schematic
Figure 1 Demo Board Schematic
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
PAM8302A
EVB User Guide
3. PAM8302A EB85AA Description
PAM8302A CB81AS is design for PAM8302A demo and evaluation, targeted to be used in providing a
simple and convenient evaluation environment for the PAM8302A. Requires parts, potentiometer for
standard RCA jacks for audio inputs, pin jacks for power supply and signal outputs, low-pass RC output
filter for each channel, etc. on the board make it easy to be evaluated.
4. EV Board View
Test Point
(Sine-Wave
Class-D BTL Output
Power In:
2.5V to 5.5V
Shutdown Jump
Differential/
Single-Ended
Input Selection
Audio
Input
Figure 2 Demo Board Top View
EV Board Operational Sequence:
a. Preset the power supply to between 2.5V and 5.5V.
b. Connect power supply to EV board power.
c. Connect audio input from audio input jack.
d. Connect the SPKs to the BTL output jack, 8ohm speaker recommend.
e. Turn on the power supply and verify that the sound quality of speaker.
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
PAM8302A
EVB User Guide
EV Board BOM List
Item
Value
Type
Rating
Description
C3, C5
100nF
X5R/X7R, Ceramic/0603
10V
Input CAP
C1
10µF
X5R/X7R, Ceramic/1210
10V
VDD coupling CAP
C2
1µF
X5R/X7R, Ceramic/0603
10V
VDD coupling CAP
R1, R2
Bead1/2
C4, C6
10K
120Ω/1A
220pF
1%
Input Resistor
EMI
EMI
0603
X5R/X7R, Ceramic/0603
10V
Vender and Part
Number
Murata
GRM21R71C104B
Murata
GRM21R71C106B
Murata
GRM21R71C105B
5. External Components Selection
Input Capacitors (C3, C5)
(1) Form a high pass filter with Ri, and the cut off frequency is fc=1/2ΠRi*Ci.
(2) Have a tolerance of 10% or better for matching: any mismatch in capacitance causes an importance
mismatch at the corner frequency.
(3) Low leakage current needed 0.1µF.
Input Resistors (R1, R2)
(1) Limit the closed-loop gain.
(2) Form a high pass filter with Ci, and the cut off frequency is fc=1/2*Π*Ri*Ci.
(3) 1% tolerance needed for resistor matching to improve CMRR, PSRR.
Power Supply decoupling Caps (C1, C2)
(1). Low ESR for good THD, PSRR.
(2) C2, 1.0µF ceramic for higher frequency transients, spikes.
(3) C1, Additional 10uF or greater for low frequency noise filtering and serves as a local storage capacitor
for supplying current during large signal transients on the amplifier outputs.
(4) Need place very closed to the IC.
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.
PAM8302A
EVB User Guide
6. PCB Layout Guidelines
Grounding
(1) Use plane grounding or separate grounds
(2) Do not use one line connecting power GND and analog GND
(3) Output noise grounds must tie to system ground at the power in exclusively.
(4) Signal currents for the inputs need to be returned to quite ground. This ground only ties to the signal
components and the GND pin.
Others
(1) The power supply de coupling capacitors (C1, C2) need to place very close to the PAM8302A’s pins.
(2) The output route should be far away from audio input route.
7. PCB Layout Example
Top Layer
Bottom Layer
Figure 3
Figure 4
This application note contains new product information. Diodes, Inc. reserves the right to modify the product specification without notice.
No liability isassumed as a result of the use of this product. No rights under any patent accompany the sale of the product.