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3W FILTERLESS STEREO CLASS-D AUDIO AMPLIFIER WITH DC VOLUME CONTROL
Description
The PAM8603M is a 3W, sterero, Class-D audio amplifier with DC
volume control. It offers low THD+N, allowing it to produce highquality sound reproduction. The new filterless architecture allows the
device to drive the speaker directly, requiring no low-pass output
filters, which saves the system cost and PCB area.
With the same numbers of external components, the efficiency of the
PAM8603M is much better than class-AB cousins. It can extend the
battery life thus ideal for portable applications.
The PAM8603M is available in SSOP-24 and SOP-18 packages.
Features
3W Output at 10% THD with a 4 Load and 5V Power Supply
Filterless, Low Quiescent Current and Low EMI
Low THD+N
64-Step DC Volume Control from -75dB to +24dB
Superior Low Noise
Efficiency up to 89%
Short Circuit Protection
Thermal Shutdown
Few External Components to Save the Space and Cost
Pb-Free Package
Applications
Pin Assignments
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PAM8603M
LCD Monitors/TV Projectors
Notebook Computers
Portable Speakers
Portable DVD Players, Game Machines
Cellular Phones/Speaker Phones
PAM8603M
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Typical Applications Circuit
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Pin Descriptions
Pin
Name
+OUTL 1 1 Left Channel Positive Output
PGNDL 2, 3 2 Left Channel Power GND
-OUTL 4 3 Left Channel Negative Output
PVDDL 5 4 Left Channel Power Supply
MUTE 6 5 Mute Control Input (active low)
VDD 7 6 Analog Power Supply
INL 8 7 Left Channel Input
NC 9, 12, 13, 15, 16 8 No Connection
VDC 10 9 Analog reference for gain control section.
VOLUME 11 10 DC volume control to set the gain of Class-D.
VREF 14 11 Internal analog reference, connect a bypass capacitor from VREF to GND.
INR 17 12 Right Channel Input
GND 18 13 Analog Ground
SHDN 19 14 Shutdown Control Input (active low)
PVDDR 20 15 Right Channel Power Supply
-OUTR 21 16 Right Channel Negative Output
PGNDR 22, 23 17 Right Channel Power GND
+OUTR 24 18 Right Channel Positive Output
PAM8603M
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Package Name
SSOP-24 SOP-18
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Function
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Functional Block Diagram
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PAM8603M
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 300, 5sec
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)
SSOP-24
SOP-18 70
SSOP-24
SOP-18 16
JA
JC
96
18
°C/W
PAM8603M
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Electrical Characteristics (@T
Symbol Parameter Test Conditions Min Typ Max Units
VDD
PO
THD+N
PSRR Power Supply Ripple Rejection
CS
SNR Signal-to-Noise
VN
Dyn Dynamic Range
I
MUTE
ISD
R
DS(ON)
fsw Switching Frequency
VOS
VIH SD/MUTE Input High
VIL SD/MUTE Input Low
OTP Over Temperature Protection
OTH Over Temperature Hysterisis 30
PAM8603M
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Supply Power
Output Power
Total Harmonic Distortion Plus
Noise
Crosstalk
Output Noise
Efficiency
Quiescent Current
IQ
Muting Current
Shutdown Current
Static Drain-to-Source On-State
Resistor
Output Offset Voltage
= +25°C, VDD = 5V, Gain = 20dB, unless otherwise specified.)
A
= 5.0V
V
THD+N = 10%, f = 1kHz, R
= 4
L
THD+N = 1%, f = 1kHz, RL = 4
THD+N = 10%, f = 1kHz, RL = 8
THD+N = 1%, f = 1kHz, RL = 8
V
= 5.0V, Po = 0.5W, RL = 8
DD
V
= 3.6V, Po = 0.5W, RL = 8
DD
V
= 5.0V, Po = 1W, RL = 4
DD
V
= 3.6V, Po = 1W, RL = 4
DD
= 5.0V, Inputs AC-Grounded
V
DD
V
= 5.0V, Po = 0.5W, RL = 8, f = 1kHz
DD
V
= 5V, V
DD
V
= 5V, Inputs AC-Grounded with
DD
= 0.47F
C
IN
V
= 5V, THD = 1%, f = 1kHz
DD
R
= 8, THD = 10%
L
= 1V, f = 1kHz
O_RMS
RL = 4, THD = 10%
= 5.0V
V
DD
V
= 3.6V
DD
V
= 5.0V, V
DD
V
= 2.5V to 5.5V, VSD = 0.3V
DD
I
= 500mA,VGS = 5V
DS
= 3V to 5V
V
DD
V
= 0V, V
IN
= 5V
V
DD
V
= 5V
DD
DD
MUTE
= 5V
= 0.3V
No Load, Junction Temperature, V
DD
= 5V
DD
VDD = 3.6V
= 5.0V
V
DD
VDD = 3.6V
= 5.0V
V
DD
VDD = 3.6V
= 5.0V
V
DD
VDD = 3.6V
f = 1kHz
f = 1kHz
f = 100Hz -59 -50
f = 1kHz -58 -50
A-weighting 98 150
No A-weighting 120 300
f = 1kHz
No load
PMOS 240 500
NMOS 180 350
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2.8 5.5 V
2.85 3.2
1.55 1.8
2.35 2.6
1.25 1.5
1.55 1.8
0.75 0.9
1.15 1.4
0.5 0.72
0.15 0.3
0.11 0.25
0.15 0.3
0.11 0.25
W
W
W
W
%
%
dB
-58 dB
85 -95 -80 dB
µV
90 102 dB
85 89
80 85
13.5 20
8.5 15
%
mA
2.7 5 mA
1 µA
m
200 260 300 kHz
10 50 mV
1.45
0.65
135
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V
°C
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Typical Performance Characteristics (@T
Diodes Incorporated
= +25°C, unless otherwise specified.)
A
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PAM8603M
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Typical Performance Characteristics (cont.) (@T
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= +25°C, unless otherwise specified.)
A
PAM8603M
PAM8603M
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Typical Performance Characteristics (cont.) (@T
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= +25°C, unless otherwise specified.)
A
PAM8603M
PAM8603M
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PAM8603M
Table 1. DC Volume Control
Step Gain (dB) Step Gain (dB)
0 -75 32 11.6
1 -40 33 12.0
2 -34 34 12.4
3 -28 35 12.8
4 -22 36 13.2
5 -16 37 13.6
6 -10 38 14.0
7 -7.5 39 14.4
8 -5.0 40 14.8
9 -2.5 41 15.2
10 0 42 15.6
11 1.5 43 16.0
12 3.0 44 16.4
13 4.0 45 16.8
14 4.4 46 17.2
15 4.8 47 17.6
16 5.2 48 18.0
17 5.6 49 18.4
18 6.0 50 18.8
19 6.4 51 19.2
20 6.8 52 19.6
21 7.2 53 20.0
22 7.6 54 20.4
23 8.0 55 20.8
24 8.4 56 21.2
25 8.8 57 21.6
26 9.2 58 22.0
27 9.6 59 22.4
28 10.0 60 22.8
29 10.4 61 23.2
30 10.8 62 23.6
31 11.2 63 24.0
PAM8603M
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Application Information
1. When the PAM8603M works with LC filters, it should be connected with the speaker before it is powered on, otherwise it will be damaged
easily.
2. When the PAM8603M works without LC filters, it's better to add a ferrite chip bead at the outgoing line of speaker to suppress the possible
electromagnetic interference.
3. 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 PAM8603M has big gain, it will make the device damaged.
4. When testing the PAM8603M without LC filters by using resistor instead of speaker as the output load, the test results, e.g. efficiency, will be
worse than those using speaker as load.
Test Setup for Performance Testing
Notes: 1. The AP AUX-0025 low pass filter is necessary for class-D amplifier measurement done by AP analyzer.
2. Two 22µH inductors are used in series with load resistor to emulate the s mall speaker for efficiency measurement.
Mute Operation
The MUTE pin is an input for controlling the output state of the PAM8603M. 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 cur rent is listed in the electrical
characteristic table. The MUTE pin can be left floating due to the internal pull-up.
For better power-off pop performance, the amplifier should be placed in the mute mode prior to removing the power supply.
Shutdown Operation
In order to reduce power consumption while not in use, the PAM8603M 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 PAM8603M supply current
draw will be minimized in idle mode. The SHDN pin can be left floating due to the pull-up.
Power Supply Decoupling
The PAM8603M is a high performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output THD and
PSRR as low as possible. Power supply decoupling affects low frequency response. Optimum decoupling is achieved by using two capacitors of
different types that target different noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line, a good
low equivalent-series resistance (ESR) ceramic capacitor, typically 1.0µF, placed as close as possible to the device V
filtering lower-frequency noise signals, a large capacitor of 10µF (ceramic) or greater placed near the audio power amplifier is recommended.
terminal works best. For
DD
PAM8603M
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Application Information (cont.)
Input Capacitor (CI)
Large input capacitors are both expensive and space hungry for portable designs. Clearly, a certain sized capacitor is needed to couple in low
frequencies without severe attenu ation. But in many cases the speakers used in portable systems, whether internal or external, have little ability
to reproduce signals below 100Hz to 150Hz. Thus, using a large input capacitor may not increase actual s ystem performance. In t his case, input
capacitor (C
In addition to system cost and size, click and pop performance is affected by the size of the input coupling capacitor, C
capacitor requires more charge to reach its quiescent DC voltage (nominally 1/2 V
feedback and is apt to create pops upon device enable. Thus, by minimizing the capacitor size based on necessary low frequency response,
turn-on pops can be minimized.
The Analog Reference Bypass Capacitor (C
The Analog Reference Bypass Capacitor (C
from shutdown mode, C determines the rate at which the amplifier starts up. The second function is to reduce noise produced by the power
supply coupling in the output drive signal. This noise is from the internal analog reference to the amplifier which appears as degraded PSRR and
THD+N.
A ceramic bypass capacitor (C
capacitor reduces clicking and popping noise from power on/off and entering and leaving shutdown.
Under Voltage Lock-Out
The PAM8603M incorporates circuitry to detect low supply voltage. When the supply voltage drops to 1.8V or below, the PAM8603M outputs are
disable. The device resumes to normal functional once V
Short Circuit Protection (SCP)
The PAM8603M has short circuit protection circuitry on the outputs to prevent the device from damage when output-to -output or output-to-GND
short. When a short circuit is detected on the outputs, the outputs are disabled immediately. If the short was removed, the device activates again.
Over Temperature Protection
Thermal protection on the PAM8603M prevents the device from damage when the internal die temperature exceeds +135°C. There is a 15
degree tolerance on this trip point from device to device. Once the die temperature exceeds the thermal set point, the device outputs are
disabled. This is not a latched fault. The thermal fault is cleared once the temperature of the die is reduced by 30°C. This large hysteresis will
prevent motor boating sound well. The device begins normal operation at this point without external system interaction.
How to Reduce EMI (Electro Magnetic Interference)
A simple solution is to put an additional capacitor 1000µF at power supply terminal for power line coupling if the traces from amplifier to speakers
are short (< 20cm).
Most applications require a ferrite bead filter as shown at Figure 3. The ferrite filter reduces EMI of around 1 MHz and higher. When selecting a
ferrite bead, choose one with high impedance at high frequencies, and low impedance at low frequencies (MH2012HM221-T).
) and input resistance (RI) of the amplifier form a high-pass filter with the corner frequency determined equation below,
I
1
f
C
R2
C
I
I
. A larger input coupling
I
). This charge comes from the internal circuit via the
DD
)
BYP
) is the most critical capacitor and serves several important functions. During start-up or recovery
BYP
) of 0.47F to 1.0F is recommended for the best THD and noise performance. Increasing the bypass
BYP
2.0V.
DD
PAM8603M
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Figure 3. Ferrite Bead Folter to reduce EMI
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Application Information (cont.)
PCB Layout Guidelines Grounding
At this stage it is paramount to notice the necessity of separate grounds. Noise currents in the output power stage need to be returned to output
noise ground and nowhere else. Were these currents to circulate elsewhere, they may get into the power supply, the signal ground, etc, even
worse, they may form a loop and radiate noise. Any of these cases results in degraded amplifier performance. The logical returns for the output
noise currents associated with Class-D switching are the respective PGND pins for each channel. The switch state diagram illustrates that
PGND is instrumental in nearly every switch state. This is the perfect point to which the output noise ground trace should return. Also note that
output noise ground is channel specific. A two channel amplifier has two seperate channels and consequently must have two seperate output
noise ground traces. The layout of the PAM8603M offers separate PGND connections for each channel and in some cases each side of the
bridge. Output noise grounds must be tied to system ground at the power exclusively. Signal currents for the inputs, reference, etc need to be
returned to quite ground. This ground is only tied to the signal components and the GND pin, and GND then tied to system ground.
Ordering Information
Part Number Part Marking Package Type Standard Package
PAM8603MNHR
PAM8603MDER
PAM8603MDET
Marking Information
PAM8603M
XXXYWWLL
PAM8603M
XXXYWWLL
PAM8603M
XXXYWWLL
SSOP-24 2500 Units/Tape&Reel
SOP-18 1000 Units/Tape&Reel
SOP18 40 Units/Tube
PAM8603M
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Package Outline Dimensions (All dimensions in mm.)
SSOP-24
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PAM8603M
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Package Outline Dimensions (cont.) (All dimensions in mm.)
SOP-18
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PAM8603M
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1. are intended to implant into the body, or
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IMPORTANT NOTICE
LIFE SUPPORT
PAM8603M
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