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Description
The PAM8303D is a 3W mono filterless Class-D amplifier with high
PSRR and differential input that eliminate noise and RF rectification.
Features like 90% efficiency and small PCB area make the
PAM8303D Class-D amplifier ideal for cellular handsets. The filterless
architecture requires no external output filter, fewer external
components, less PCB area and lower system costs, and simplifies
application design.
The PAM8303D features short circuit protection and thermal
shutdown.
The PAM8303D is available in MSOP-8 and DFN3x3 8-pin packages.
MONO CLASS-D AUDIO POWER AMPLIFIER
Pin Assignments
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PAM8303D
ULTRA LOW EMI, 3W FILTERLESS
Features
• Ultra Low EMI, -20dB Better Than FCC Class-B @ 300MHz
• High Efficiency up to 90% @1W with an 8Ω Speaker
• Shutdown Current <1µA
• 3W@10% THD Output with a 4Ω Load at 5V Supply
• Demanding Few External Components
• Superior Low Noise without Input
• Supply Voltage from 2.8V to 5.5V
• Short Circuit Protection
• Thermal Shutdown
• Available in Space Saving Packages: MSOP-8, DFN3x3-8
• Pb-Free Package
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Applications
• Cellular Phones/Smart Phones
• MP4/MP3
• GPS
• Digital Photo Frame
• Electronic Dictionary
• Portable Game Machines
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Typical Applications Circuit
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PAM8303D
Pin Descriptions
Pin
Name
OUT+ 1 Positive BTL Output
PVDD 2 Power Supply
VDD 3 Analog Power Supply
IN- 4 Negative Differential Input
IN+ 5 Positive Differential Input
SD 6 Shutdown Terminal (active low)
GND 7 Ground
OUT- 8 Negative BTL Output
Pin
Number
Function
Functional Block Diagram
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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PAM8303D
Absolute Maximum Ratings (@T
These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may
affect device reliability. All voltages are with respect to ground.
Parameter Rating Unit
Supply Voltage 6.0
Input Voltage
Maximum Junction Temperature 150
Storage Temperature -65 to +150
Soldering Temperature 250, 10 sec
Recommended Operating Conditions (@T
Parameter Rating Unit
Supply Voltage Range 2.8 to 5.5 V
Ambient Temperature Range -40 to +85 °C
Junction Temperature Range -40 to +125 °C
= +25°C, unless otherwise specified.)
A
-0.3 to V
DD
+0.3
= +25°C, unless otherwise specified.)
A
V
°C
Thermal Information
Parameter Package Symbol Max Unit
Thermal Resistance (Junction to Ambient)
Thermal Resistance (Junction to Case) MSOP-8
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
MSOP-8
DFN3x3-8 47.9
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θ
JA
θ
JC
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180
75
°C/W
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PAM8303D
Electrical Characteristics (@T
Symbol Parameter Test Conditions Min Typ Max Units
VDD
PO
THD+N
PSRR Power Supply Ripple Rejection
Dyn Dynamic Range
VN
CMRR Common Mode Rejection Ratio
ISD
R
DS(ON)
RIN
fSW
GV
VOS
VIH
VIL
Supply Voltage
Output Power
Total Harmonic Distortion Plus
Noise
Output Noise Inputs AC-Grounded
η Peak Efficiency
Quiescent Current
IQ
Shutdown Current
Static Drain-to-Source
On-State Resistor
Input Resistance
Switching Frequency
Closed Loop Gain
Output Offset Voltage
Enable Input High Voltage
Enable Input Low Voltage
= +25°C, VDD = 5V, Gain = 2V/V, RL = L(33µH) + R + L(33µH), unless otherwise specified.)
A
THD+N = 10%, f = 1KHz, R = 4Ω
THD+N = 1%, f = 1KHz, R = 4Ω
THD+N = 10%, f = 1KHz, R = 8Ω
THD+N = 1%, f = 1KHz, R = 8Ω
= 5.0V, PO = 1W, R = 8Ω
V
DD
VDD = 3.6V, PO = 0.1W, R = 8Ω
VDD = 3.2V, PO = 0.1W, R = 8Ω
VDD = 5.0V, PO = 0.5W, R = 4Ω
VDD = 3.6V, PO = 0.2W, R = 4Ω
VDD = 3.2V, PO = 0.1W, R = 4Ω
V
= 3.6V, Inputs AC-Grounded
DD
with C
= 1µF
IN
V
= 5V, THD = 1%, R = 8Ω
DD
= 5.0V
V
DD
VDD = 3.6V
VDD = 3.2V
V
= 5.0V
DD
VDD = 3.6V
VDD = 3.2V
= 5.0V
V
DD
VDD = 3.6V
VDD = 3.2V
= 5.0V
V
DD
VDD = 3.6V
VDD = 3.2V
f = 1kHz
f = 1kHz
f = 217Hz -63 -55
f = 1kHz -62 -55
f = 10kHz -52 -40
f = 1kHz 85 95
2.8 5.5 V
2.85 3.00
1.65 1.80
1.20 1.35
2.50 2.66
1.15 1.30
0.85 1.0
1.65 1.80
0.75 0.90
0.55 0.70
1.3 1.5
0.55 0.72
0.40 0.55
0.28 0.35
0.40 0.45
0.55 0.60
0.20 0.25
0.35 0.40
0.5 0.55
No A-Weighting 50 100
A-Weighting 30 60
V
= 100m, VPP, f =1kHz
IC
R
= 8Ω, THD = 10%
L
RL = 4Ω, THD = 10%
= 5.0V
V
DD
VDD = 3.6V
f = 1kHz
R = 8Ω
VDD = 3.0V
VDD = 3.0V to 5.0V VSD = 0.3V
= 5.0V
V
CSP Package, High Side PMOS
plus Low Side NMOS,
I = 500mA
MSOP/DFN package,
High Side PMOS plus
Low Side NMOS, I = 500mA
DD
VDD = 3.6V
VDD = 3.0V
= 5.0V
V
DD
VDD = 3.6V
VDD = 3.0V
VDD = 3V to 5V
VDD = 3V to 5V
Input AC-Ground, VDD = 5V
VDD = 5V
VDD = 5V
40 63 dB
85 90
80 86 %
7.5 10
4.6 7.0
3.6 5.0 mA
0.5 2.0 µA
280 350
300 375
325 400
365 420
385 450
410 500
150 KΩ
200 250 300 KHz
300kΩ/R
dB
I
10 50 mV
1.5 V
0.3 V
W
W
W
W
%
%
dB
µV
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Typical Performance Characteristics (@T
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PAM8303D
= +25°C, VDD = 5V, f = 1kHz, Gain = 2V/V, unless otherwise specified.)
A
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Typical Performance Characteristics (cont.) (@T
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PAM8303D
= +25°C, VDD = 5V, f = 1kHz, Gain = 2V/V, unless otherwise specified.)
A
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Typical Performance Characteristics (cont.) (@T
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PAM8303D
= +25°C, VDD = 5V, f = 1kHz, Gain = 2V/V, unless otherwise specified.)
A
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Typical Performance Characteristics (cont.) (@T
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PAM8303D
= +25°C, VDD = 5V, f = 1kHz, Gain = 2V/V, unless otherwise specified.)
A
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Typical Performance Characteristics (cont.) (@T
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PAM8303D
= +25°C, VDD = 5V, f = 1kHz, Gain = 2V/V, unless otherwise specified.)
A
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Application Information
Test Setup for Performance Testing
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PAM8303D
Notes 1. The 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.
Input Resistance (RI)
The input resistors (RI) set the gain of the amplifier according to Equation 1.
Ω
V
k150x2
⎞
⎛
Resistor matching is very important in fully differential amplifiers. The balance of the output on the reference voltage depends on matched ratios
of the resistors. CMRR, PSRR, and cancellation of the second harmonic distortion diminish if resistor mismatch occurs. Therefore, it is
recommended to use 1% tolerance resistors or better to keep the performance optimized. Matching is more important than overall tolerance.
Resistor arrays with 1% matching can be used with a tolerance greater than 1%.
Place the input resistors very close to the PAM8303D to limit noise injection on the high impedance nodes.
For optimal performance the gain should be set to 2X (R
high voltage at the input making the inputs less susceptible to noise. In addition to these features, higher value of R
Gain
=
R
I
⎟
⎜
V
⎠
⎝
= 150k) or lower. Lower gain allows the PAM8303D to operate at its best, and keeps a
I
minimizes pop noise.
I
Input Capacitors (CI)
In the typical application, an input capacitor, Ci, is required to allow the amplifier to bias the input signal to the proper DC level for optimum
operation. In this case, Ci and the minimum input impedance R
equation:
1
It is important to consider the value of C
the specification calls for a flat bass response are down to 150Hz. Equation is reconfigured as followed:
When input resistance variation is considered, the C
capacitor is the leakage path from the input source through the input network (C
voltage at the input to the amplifier that reduces useful headroom, especially in high gain applications.
For this reason, a low-leakage tantalum or ceramic capacitor is the best choice. When polarized capacitors are used, the positive side of the
capacitor should face the amplifier input in most applications as the DC level is held at V
Please note that it is important to confirm the capacitor polarity in the application.
=
f
C
=
C
I
Π
R2
Π
C
I
I
as it directly affects the low frequency performance of the circuit. For example, when Ri is 150kΩ and
i
1
R2
F
CI
I
is 7nF, so one would likely choose a value of 10nF. A further consideration for this
I
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
form is a high-pass filter with the corner frequency determined in the follow
I
, RI + RF) to the load. This leakage current creates a DC offset
I
/2, which is likely higher than the source DC level.
DD
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Application Information (cont.)
Decoupling Capacitor (CS)
The PAM8303D is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output total
harmonic distortion (THD) as low as possible. Power supply decoupling also prevents the oscillations causing by long lead length between the
amplifier and the speaker.
The optimum decoupling is achieved by using two different types of capacitors that target on different types of noise on the power supply leads.
For higher frequency transients, spikes, or digital hash on the line, a good low equivalentseries- resistance (ESR) ceramic capacitor, typically
1µF, is placed as close as possible to the device each V
large ceramic capacitor of 10µF or greater placed near the audio power amplifier is recommended.
How to Reduce EMI
Most applications require a ferrite bead filter for EMI elimination shown at Figure 1. The ferrite filter reduces EMI around 1MHz and higher. When
selecting a ferrite bead, choose one with high impedance at high frequencies, but low impedance at low frequencies.
and PVDD pin for the best operation. For filtering lower frequency noise signals, a
DD
In order to reduce power consumption while not in use, the PAM8303D contains shutdown circuitry that is used to turn off the amplifier’s bias
circuitry. This shutdown feature turns the amplifier off when logic low is placed on the SD pin. By switching the shutdown pin connected to GND,
the PAM8303D supply current draw will be minimized in idle mode.
Figure 1: Ferrite Bead Filter to Reduce EMI
Shutdown Operation
In order to reduce power consumption while not in use, the PAM8303D contains shutdown circuitry that is used to turn off the amplifier’s bias
circuitry. This shutdown feature turns the amplifier off when logic low is placed on the pin. By switching the shutdown pin connected to GND, the
PAM8303D supply current draw will be minimized in idle mode.
Under Voltage Lock-Out (UVLO)
The PAM8303D incorporates circuitry designed to detect low supply voltage. When the supply voltage drops to 2.3V or below, the PAM8303D
goes into a state of shutdown, and the device comes out of its shutdown state and restore to normal function only when reset the power supply
or SD pin.
Thermal protection on the PAM8303D prevents the device from damage when the internal die temperature exceeds +135°C. There is a 15°C
tolerance on this trip point from device to device. Once the die temperature exceeds the set point, the device will enter the shutdown state and
the outputs are disabled. This is not a latched fault. The thermal fault is cleared once the temperature of the die decreased by 30°C. This large
hysteresis will prevent motor boating sound well and the device begins normal operation at this point with no external system interaction.
POP and Click Circuitry
The PAM8303D contains circuitry to minimize turn-on and turn-off transients or “click and pops”, where turn-on refers to either power supply turn-
on or device recover from shutdown mode. When the device is turned on, the amplifiers are internally muted. An internal current source ramps
up the internal reference voltage. The device will remain in mute mode until the reference voltage reach half supply voltage, 1/2 V
the reference voltage is stable, the device will begin full operation. For the best power-off pop performance, the amplifier should be set in
shutdown mode prior to removing the power supply voltage.
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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. As soon as
DD
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PAM8303D
Application Information (cont.)
PCB Layout Guidelines
Grounding
It is recommended to use plain grounding or separate grounds. Do not use one line connecting power GND and analog GND. Noise currents in
the output power stage need to be returned to output noise ground and nowhere else. When these currents circulate elsewhere, they may get
into the power supply, or the signal ground, etc, even worse, they may form a loop and radiate noise. Any of these instances results in degraded
amplifier performance. The output noise ground that the logical returns for the output noise currents associated with Class-D switching must tie
to system ground at the power exclusively. Signal currents for the inputs, reference need to be returned to quite ground. This ground only ties to
the signal components and the GND pin. GND then ties to system ground.
Power Supply Line
As same to the ground, VDD and PVDD need to be separately connected to the system power supply. It is recommended that all the trace could
be routed as short and thick as possible. For the power line layout, just imagine water stream, any barricade placed in the trace (shown in Figure
2) could result in the bad performance of the amplifier.
Figure 2. Power Line
Components Placement
Decoupling capacitors-As previously described, the high-frequency 1µF decoupling capacitors should be placed as close to the power supply
terminals (V
on the PV
Input resistors and capacitors need to be placed very close to input pins.
Output filter - The ferrite EMI filter should be placed as close to the output terminals as possible for the best EMI performance, and the capacitors
used in the filters should be grounded to system ground.
and PVDD) as possible. Large bulk power supply decoupling capacitors (10µF or greater) should be placed near the PAM8303D
DD
terminal.
DD
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Ordering Information
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PAM8303D
Part Number Part Marking Package Type Standard Package
PAM8303DBYC
PAM8303DBSC
Marking Information
P8303D
XXXYW
P8303D
XXXYW
DFN3x3-8 3000 Units/Tape&Reel
MSOP-8 2500 Units/Tape&Reel
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Package Outline Dimensions (All dimensions in mm.)
MSOP-8
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PAM8303D
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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Package Outline Dimensions (cont.) (All dimensions in mm.)
DFN3x3-8
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PAM8303D
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
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without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or
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This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the
final and determinative format released by Diodes Incorporated.
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express
written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the
labeling can be reasonably expected to result in significant injury to the user.
B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and
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Copyright © 2012, Diodes Incorporated
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IMPORTANT NOTICE
LIFE SUPPORT
PAM8303D
Document number: DSxxxxx Rev. 1 - 7
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