PAM8008 User Guide

PAM8008
EVB User Guide
PAM8008-EV Board User Guide
AE Department
1. Revision Information
Date
2012/06/28
Revision
V1.0
Description
Initial Release
Comment
2. PAM8008 General Description
The PAM8008 is a 2.4W, class-D audio amplifier. Advanced 64-step DC volume control minimizes external
components and allows speaker volume control.
Integrated power limit technology which suppress the output signal clip automatically due to the over
level input signal. It offers low THD+N, to produce high-quality sound reproduction.
PAM8008 has an additional noise reduction circuit which achieve 6dB noise attenuation. This circuit may
help eliminate external filtering, thereby saving the board space and components cost.
3. Key Features
 2.4W Output at 1% THD with a 4Ω Load and 5V
Power Supply
 6dB Effective Noise Reduction
 Superior Low Noise: 60µV
 Filter less , Low Quiescent Current and Low EMI
 Minimize Pop/Clip Noise
 Low THD+N
 High Efficiency up to 90%
 Power Limit Function to Protect Speaker when
 Auto Recovery Short Circuit Protection
Occuring large Input
 64-step DC Volume Control from -80dB to 20dB
 Thermal Shutdown
 Pb-Free Package
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.
PAM8008
EVB User Guide
4. EV Board Schematic
C9
TP1
R5
FB1
IC1
SD
1
Vin
2
SD
3
2
C4
Vin
C1
Rin
R1
R3
C2
1
Vin
2
MUTE
3
4
R4
MUTE
1
C3
Lin
R2
Volume
5
6
7
3
MUTE
8
SD
ROUTP
BYPASS
VDD
RINN
PL
GND
LINN
VOLUME
MUTE
ROUTN
PAM8008
SD
GND
GND
LOUTN
VDD
LOUTP
16
RoutP
RoutP
FB2
15
14
Vin
RoutN
C5
C6
12
C7
1
R6
C10
C8
2
1
C14
C11
TP3
R7
FB3
LoutN
10
9
2
TP2
13
11
RoutN
C13
Rout
Vin
LoutP
FB4
LoutP
LoutN
R8
C12
C15
Lout
2
1
2
1
C16
TP4
Figure 1
5. PAM8008 EVB TB21AA Description
PAM8008 TB21AA is an evaluation board for the PAM8008, a stereo class-D audio power amplifier. The
board is targeted to be used in providing a simple and convenient evaluation
environment for the PAM8008. Requires parts, the standard RCA jacks for audio inputs, pin jacks for power
supply and signal outputs etc. on the board make it easy to be evaluated.
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.
PAM8008
EVB User Guide
6. EV Board View and Jack Description
SD Control
Power Supply
Top View
R-CH Output
Audio Input
L-CH Output
Volume Control
Mute Control
EV Board Operational Sequence:
a) Connect SD to a high for normal operation
b) Connect audio input from audio input jack
c) Connect the loading(speaker or power resistor) to the output jack
d) Power on: 2.5V to 5.5V DC power supply
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.
PAM8008
EVB User Guide
7. EV Board BOM List
Item
C1,C2
C5,C7
C6,C8
C3
C4
R1, R2
R3, R4
VR1
FB1,FB2,FB3,FB4
C13,C14,C15,C16
Value
0.1µF
1µF
10µF
1µF
1µF
0
0Ω
50kΩ
200Ω
220pF
Type
X5R/X7R, Ceramic/0603
X5R/X7R, Ceramic/0603
X5R/X7R, Ceramic/0805
X5R/X7R, Ceramic/0603
X5R/X7R, Ceramic/0603
0805
Rating
10V
25V
10V
16V
16V
1%
5%
0805
0603
2A
25V
Description
Input coupling CAP
PVDD coupling CAP,
PVDD main coupling CAP,
BYPASS CAP
Decoupling CAP
Input Resistor
PL select resistor
Volume setting
For EMI eliminate components
form a FB-CAP filter
Vender and port
LMK063BJ104KP-F
TMK107B7105KA-T
LMK107BBJ106MALT
EMK107B7105KA-T
EMK107B7105KA-T
8. External Components Selection
Input Capacitors (C1, C2)
(1) Form a high pass filter with Ri, and the cut off frequency is fc = 1/2*Π*Ri*Ci
(2) Have a tolerance of 10% or better for matching : any mismatch in capacitance causes an importance
mismatch at the corner frequency and below
(3) Low leakage current needed, 0.1µF, X5R/X7R ceramic recommend
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 (C5, C6, C7, C8 )
(1) Low ESR for good THD, PSRR
(2) 1uF ceramic for higher frequency transients, spikes, or digital hash on the line of PVDD/AVCC
(3) Additional 10µF 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
Bias Voltage Capacitor (C3)
(1) Internal power supply for pre-amplifier,
(2) 1uF, X5R/X7R ceramic recommend
(3) Place very closed to the device
EMI Eliminate Filter (FB1, FB2, FB3 and FB4)
(1) High impedance at high frequency and very low impedance at low frequency
(2) The current rating is higher than 2A
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.
PAM8008
EVB User Guide
9. 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.
Power Supply
Others
(1). The power supply capacitors (C5, C6, C7, C8, ) need to place very close to the PAM8008’s pins.
(2). Input capacitors (C1, C2) place closed to input pin as near as possible
10. PCB Layout Example
Top Layer
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.
PAM8008
EVB User Guide
Bottom Layer
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.