_______________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX98304
Mono 3.2W Class D Amplifier
General Description
The MAX98304 mono 3.2W Class D amplifier provides
Class AB audio performance with Class D efficiency.
This device offers five selectable gain settings (0dB,
3dB, 6dB, 9dB, and 12dB) set by a single gain-select
input (GAIN).
Active emissions-limiting, edge-rate, and overshoot con-
trol circuitry greatly reduces EMI. A filterless spread-
spectrum modulation scheme eliminates the need for
output filtering found in traditional Class D devices. These
features reduce application component count.
The IC's 0.95mA at 3.7V (1.2mA at 5V) quiescent current
extends battery life in portable applications.
The IC is available in a 9-bump (1.0mm x 1.0mm) WLP
with 0.3mm pitch that is specified over the extended
-40NC to +85NC temperature range.
Applications
Notebook and Netbook Computers
Cellular Phones
Tablets
MP3 Players
Portable Audio Players
VoIP Phones
Features
S Low Quiescent Current: 0.95mA at 3.7V
S Spread Spectrum and Active Emissions Limiting
S Five Pin-Selectable Gains
S 19µVRMS Ultra-Low Noise
S 90dB PSRR
S Click-and-Pop Suppression
S Thermal and Overcurrent Protection
S Low-Current Shutdown Mode
S 1.0mm x 1.0mm, 9-Bump WLP (0.3mm Pitch)
Space-Saving Package
19-5519; Rev 0; 9/10
+Denotes a lead(Pb)-free/RoHS-compliant package.
Ordering Information
Typical Application Circuit Bump Configuration
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-
PACKAGE
TOP
MARK
MAX98304EWL+ -40NC to +85NC9 WLP AIR
0.47µF
0.1µF
0.47µF
+2.5V TO +5.5V
IN+
*SYSTEM BULK CAPACITANCE
IN-
PVDD
+2.5V TO +5.5V
PGND
SHDN
GAIN MAX98304
10µF*
OUT+
OUT-
WLP
(1mm x 1mm x 0.64mm
0.3mm PITCH)
TOP VIEW
BUMP SIDE DOWN MAX98304
+
OUT-
PGND
SHDN IN- IN+
N.C. GAIN
PVDDOUT+
1 2 3
B
C
A
WLP
(1mm x 1mm x 0.64mm
0.3mm PITCH)
TOP VIEW
BUMP SIDE DOWN
MAX98304
+
OUT-
PGND
SHDN IN- IN+
N.C. GAIN
PVDDOUT+
1 2 3
B
C
A
2 ______________________________________________________________________________________
MAX98304
Mono 3.2W Class D Amplifier
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
PVDD, IN+, IN-, SHDN, GAIN to PGND ..................-0.3V to +6V
All Other Pins to PGND .........................-0.3V to (VPVDD + 0.3V)
Continuous Current Into/Out of PVDD, PGND, OUT_ ... Q750mA
Continuous Input Current (all other pins) ........................ Q20mA
Duration of Short Circuit Between
OUT_ and PVDD, PGND .......................................Continuous
OUT+ and OUT- ....................................................Continuous
Continuous Power Dissipation (TA = +70NC) for Multilayer Board
9-Bump WLP (derate 10.6mW/NC) ..............................848mW
Junction Temperature .....................................................+150NC
Operating Temperature Range .......................... -40NC to +85NC
Storage Temperature Range ............................ -65NC to +150NC
Soldering Temperature (reflow) ......................................+260NC
ELECTRICAL CHARACTERISTICS
(VPVDD = VSHDN = 5.0V, VPGND = 0V, AV = 12dB (GAIN = PGND), RL = J, RL connected between OUT+ to OUT-, AC measurement
bandwidth 20Hz to 22kHz, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Notes 1, 2)
ABSOLUTE MAXIMUM RATINGS
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage Range PVDD Inferred from PSRR test 2.5 5.5 V
Undervoltage Lockout UVLO PVDD falling 1.5 1.8 2.2 V
Quiescent Supply Current IDD TA = +25NC1.2 1.8 mA
VPVDD = 3.7V 0.95
Shutdown Supply Current ISHDN VSHDN = 0V, TA = +25NC< 0.1 10 FA
Turn-On Time tON 3.4 10 ms
Bias Voltage VBIAS VPVDD
/2 V
Input Resistance RIN TA = +25°C,
single-ended
AV = 12dB 45 70
kI
AV = 9dB 64 100
AV = 6dB 90 140
AV = 3dB 128 200
AV = 0dB 180 280
Voltage Gain AV
Connect GAIN to PGND 11.5 12 12.5
dB
Connect GAIN to PGND
through 100kI ±5% 8.5 9 9.5
Connect GAIN to PVDD 5.5 6 6.5
Connect GAIN to PVDD
through 100kI ±5% 2.5 3 3.5
GAIN unconnected -0.5 0 +0.5
Output Offset Voltage VOS TA = +25°C (Note 3) Q1Q4.5 mV
Click and Pop KCP
Peak voltage,
A-weighted, 32
samples per second,
RL = 8I (Notes 3, 4)
Into shutdown -74
dBV
Out of shutdown -60
Common-Mode Rejection Ratio CMRR fIN = 1kHz, input referred 80 dB
_______________________________________________________________________________________ 3
MAX98304
Mono 3.2W Class D Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(VPVDD = VSHDN = 5.0V, VPGND = 0V, AV = 12dB (GAIN = PGND), RL = J, RL connected between OUT+ to OUT-, AC measurement
bandwidth 20Hz to 22kHz, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Notes 1, 2)
Note 1: This device is 100% production tested at +25NC. All temperature limits are guaranteed by design.
Note 2: Testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For RL = 4I,
L = 33FH. For RL = 8I, L = 68FH.
Note 3: Amplifier inputs AC-coupled to ground.
Note 4: Mode transitions controlled by SHDN.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Power-Supply Rejection Ratio
(Note 3) PSRR
VPVDD = 2.5V to 5.5V, TA = +25NC72 90
dB
VRIPPLE = 200mVP-P
f = 217Hz 80
f = 1kHz 84
f = 20kHz 84
Output Power POUT
THD+N = 10%,
f = 1kHz,
RL = 4I + 33FH
VPVDD = 5.0V 3.2
W
VPVDD = 4.2V 2.2
VPVDD = 3.7V 1.7
THD+N = 1%,
f = 1kHz,
RL = 4I + 33FH
VPVDD = 5.0V 2.6
VPVDD = 4.2V 1.8
VPVDD = 3.7V 1.4
THD+N = 10%,
f = 1kHz,
RL = 8I + 68FH
VPVDD = 5.0V 1.8
VPVDD = 4.2V 1.2
VPVDD = 3.7V 0.96
THD+N = 1%,
f = 1kHz,
RL = 8I + 68FH
VPVDD = 5.0V 1.4
VPVDD = 4.2V 1
VPVDD = 3.7V 0.8
Total Harmonic Distortion
Plus Noise THD+N fIN = 1kHz
RL = 4I
POUT = 1W 0.03 0.1
%
RL = 8I
POUT = 0.7W 0.03
Oscillator Frequency fOSC 300 kHz
Spread-Spectrum Bandwidth ±12.5 kHz
Efficiency EPOUT = 1.75W, RL = 8I93 %
Noise VNA-weighted (Note 3)
AV = 12dB 31
FVRMS
AV = 9dB 26
AV = 6dB 23
AV = 3dB 21
AV = 0dB 19
Output Current Limit ILIM 2.8 A
Thermal Shutdown Level 155 NC
Thermal Shutdown Hysteresis 15 NC
DIGITAL INPUT (SHDN)
Input-Voltage High VINH VPVDD = 2.5V to 5.5V 1.4 V
Input-Voltage Low VINL VPVDD = 2.5V to 5.5V 0.4 V
Input Leakage Current TA = +25NCQ1FA
4 ______________________________________________________________________________________
MAX98304
Mono 3.2W Class D Amplifier
Typical Operating Characteristics
(VPVDD = VSHDN = 5.0V, VPGND = 0V, AV = 6dB, RL = J, RL connected between OUT+ to OUT-, AC measurement bandwidth 20Hz
to 22kHz, TA = +25NC, unless otherwise noted.)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX98304 toc04
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01
0.1
1
10
0.001
10 100k
VPVDD = 5V
ZLOAD = 8I + 68µH
POUT = 1.2W
POUT = 0.2W
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX98304 toc07
OUTPUT POWER (W)
THD+N (%)
3.53.02.52.01.51.00.5
0.01
0.1
1
10
100
0.001
0 4.0
VPVDD = 5V
ZLOAD = 4I + 33µH
f = 6000Hz
f = 1000Hz
f = 100Hz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX98304 toc01
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01
0.1
1
10
0.001
10 100k
VPVDD = 5V
ZLOAD = 4I + 33µH
POUT = 2W
POUT = 1.5W
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX98304 toc05
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01
0.1
1
10
0.001
10 100k
VPVDD = 4.2V
ZLOAD = 8I + 68µH
POUT = 0.6W
POUT = 0.3W
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX98304 toc08
OUTPUT POWER (W)
THD+N (%)
2.01.51.00.5
0.01
0.1
1
10
100
0.001
0 2.5
VPVDD = 4.2V
ZLOAD = 4I + 33µH
f = 6000Hz
f = 1000Hz
f = 100Hz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX98304 toc02
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01
0.1
1
10
0.001
10 100k
VPVDD = 4.2V
ZLOAD = 4I + 33µH
POUT = 1W
POUT = 0.5W
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX98304 toc06
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01
0.1
1
10
0.001
10 100k
VPVDD = 3.7V
ZLOAD = 8I + 68µH
POUT = 0.2W
POUT = 0.4W
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX98304 toc09
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
OUTPUT POWER (W)
THD+N (%)
1.51.00.50
0.01
0.1
1
10
100
0.001
2.0
VPVDD = 3.7V
ZLOAD = 4I + 33µH
f = 6000Hz
f = 1000Hz
f = 100Hz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
MAX98304 toc03
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01
0.1
1
10
0.001
10 100k
VPVDD = 3.7V
ZLOAD = 4I + 33µH
POUT = 0.8W
POUT = 0.2W
_______________________________________________________________________________________ 5
MAX98304
Mono 3.2W Class D Amplifier
Typical Operating Characteristics (continued)
(VPVDD = VSHDN = 5.0V, VPGND = 0V, AV = 6dB, RL = J, RL connected between OUT+ to OUT-, AC measurement bandwidth 20Hz
to 22kHz, TA = +25NC, unless otherwise noted.)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX98304 toc10
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
OUTPUT POWER (W)
THD+N (%)
1.51.00.50
0.01
0.1
1
10
100
0.001
2.0
VPVDD = 5V
ZLOAD = 8I + 68µH
f = 6000Hz
f = 1000Hz
f = 100Hz
OUTPUT POWER vs. LOAD RESISTANCE
MAX98304 toc13
RLOAD (I)
OUTPUT POWER (W)
10010
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0
1 1000
VPVDD = 5.0V
THD+N = 10%
THD+N = 1%
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX98304 toc16
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)
5.04.54.03.53.0
0.5
1.0
1.5
2.0
2.5
0
2.5 5.5
f = 1kHz
ZLOAD = 8I + 68µH
THD+N = 10%
THD+N = 1%
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX98304 toc11
OUTPUT POWER (W)
THD+N (%)
1.20.90.60.3
0.01
0.1
1
10
100
0.001
0 1.5
VPVDD = 4.2V
ZLOAD = 8I + 68µH
f = 6000Hz
f = 1000Hz
f = 100Hz
OUTPUT POWER vs. LOAD RESISTANCE
MAX98304 toc14
RLOAD (I)
OUTPUT POWER (W)
10010
0.5
1.0
1.5
2.0
2.5
0
1 1000
VPVDD = 3.7V
THD+N = 10%
THD+N = 1%
FREQUENCY (Hz)
1k 100k
AMPLITUDE (dB)
10k10010
GAIN vs. FREQUENCY
MAX98304 toc17
-30
-20
-10
0
10
20 GAIN = PGND GAIN = 100kI TO PGND
GAIN = 100kI TO PVDD
GAIN = UNCONNECTED
-40
GAIN = PVDD
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWER
MAX98304 toc12
OUTPUT POWER (W)
THD+N (%)
1.00.80.60.40.2
0.01
0.1
1
10
100
0.001
0 1.2
VPVDD = 3.7V
ZLOAD = 8I + 68µH
f = 6000Hz
f = 1000Hz
f = 100Hz
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX98304 toc15
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)
5.04.54.03.53.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
0
2.5 5.5
f = 1kHz
ZLOAD = 4I + 33µH
THD+N = 10%
THD+N = 1%
EFFICIENCY vs. OUTPUT POWER
MAX98304 toc18
OUTPUT POWER (W)
EFFICIENCY (%)
3.02.51.5 2.01.00.5
10
20
30
40
50
60
70
80
90
100
0
0 3.5
VPVDD = 5.0V
ZLOAD = 8I + 68µH
ZLOAD = 4I + 33µH
6 ______________________________________________________________________________________
MAX98304
Mono 3.2W Class D Amplifier
Typical Operating Characteristics (continued)
(VPVDD = VSHDN = 5.0V, VPGND = 0V, AV = 6dB, RL = J, RL connected between OUT+ to OUT-, AC measurement bandwidth 20Hz
to 22kHz, TA = +25NC, unless otherwise noted.)
POWER-SUPPLY REJECTION
RATIO vs. SUPPLY VOLTAGE
MAX98304 toc22
SUPPLY VOLTAGE (V)
PSRR (dB)
5.04.54.03.53.0
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-100
2.5 5.5
f = 1kHz
VRIPPLE = 200mVP-P
STARTUP RESPONSE
MAX98304 toc24
ISPEAKER
100mA/div
1ms/div
VSHDN
2V/div
EFFICIENCY vs. OUTPUT POWER
MAX98304 toc19
OUTPUT POWER (W)
EFFICIENCY (%)
1.51.00.5
10
20
30
40
50
60
70
80
90
100
0
0 2.0
VPVDD = 3.7V
ZLOAD = 8I + 68µH
ZLOAD = 4I + 33µH
FREQUENCY (Hz)
10k1k10010 100k
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
MAX98304 toc23
CMRR (dB)
10
20
30
40
50
60
70
80
90
100
0
ZLOAD = 8I + 68µH
AV = 0dB
AV = 6dB
AV = 9dB
AV = 3dB
AV = 12dB
SHUTDOWN RESPONSE
MAX98304 toc25
ISPEAKER
100mA/div
1ms/div
VSHDN
2V/div
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX98304 toc20
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.04.54.03.53.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0
2.5 5.5
POWER-SUPPLY REJECTION
RATIO vs. FREQUENCY
MAX98304 toc21
FREQUENCY (Hz)
PSRR (dB)
10k1k100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-100
10 100k
VRIPPLE = 200mVP-P
ZLOAD = 8I + 68µH
_______________________________________________________________________________________ 7
MAX98304
Mono 3.2W Class D Amplifier
Bump Description
Bump Configuration
Typical Operating Characteristics (continued)
(VPVDD = VSHDN = 5.0V, VPGND = 0V, AV = 6dB, RL = J, RL connected between OUT+ to OUT-, AC measurement bandwidth 20Hz
to 22kHz, TA = +25NC, unless otherwise noted.)
WLP
(1mm x 1mm x 0.64mm
0.3mm PITCH)
TOP VIEW
BUMP SIDE DOWN MAX98304
+
OUT-
PGND
SHDN IN- IN+
N.C. GAIN
PVDDOUT+
1 2 3
B
C
A
WLP
(1mm x 1mm x 0.64mm
0.3mm PITCH)
TOP VIEW
BUMP SIDE DOWN
MAX98304
+
OUT-
PGND
SHDN IN- IN+
N.C. GAIN
PVDDOUT+
1 2 3
B
C
A
FREQUENCY (MHz)
OUTPUT MAGNITUDE (dBV)
1010.1 100
WIDEBAND vs. FREQUENCY
MAX98304 toc26
-80
-60
-40
-20
0
20 RBW = 100Hz
-100
IN-BAND vs. FREQUENCY
MAX98304 toc27
FREQUENCY (Hz)
OUTPUT MAGNITUDE (dBV)
10k1k100
-120
-100
-80
-60
-40
-20
0
-140
10 100k
f = 1kHz
VOUT = -60dBV
BUMP NAME FUNCTION
A1 OUT- Negative Speaker Output
A2 OUT+ Positive Speaker Output
A3 PVDD Power Supply. Bypass PVDD to PGND with 0.1FF || 10FF.
B1 PGND Ground
B2 N.C. No Connection. Can be left unconnected, or connected to PGND.
B3 GAIN Gain Select. See Table 1 for GAIN settings.
C1 SHDN Active-Low Shutdown Input. Drive SHDN low to place the device in shutdown.
C2 IN- Inverting Audio Input
C3 IN+ Noninverting Audio Input
8 ______________________________________________________________________________________
MAX98304
Mono 3.2W Class D Amplifier
Detailed Description
The MAX98304 features low quiescent current, a low-
power shutdown mode, comprehensive click-and-pop
suppression, and excellent RF immunity.
The device offers Class AB audio performance with
Class D efficiency in a minimal board-space solution.
The Class D amplifier features spread-spectrum modula-
tion, edge-rate, and overshoot control circuitry that offers
significant improvements to switch-mode amplifier radi-
ated emissions.
The amplifier features click-and-pop suppression that
reduces audible transients on startup and shutdown.
The amplifier includes thermal overload and short-circuit
protection.
Class D Speaker Amplifier
The filterless Class D amplifier offers much higher effi-
ciency than Class AB amplifiers. The high efficiency of
a Class D amplifier is due to the switching operation of
the output stage transistors. Any power loss associated
with the Class D output stage is mostly due to the I2R
loss of the MOSFET on-resistance and quiescent current
overhead.
Ultra-Low EMI Filterless Output Stage
Traditional Class D amplifiers require the use of external
LC filters, or shielding, to meet EN55022B electromag-
netic-interference (EMI) regulation standards. Maxim’s
patented active emissions-limiting edge-rate control
circuitry and spread-spectrum modulation reduces EMI
emissions, while maintaining up to 93% efficiency.
Maxim’s patented spread-spectrum modulation mode
flattens wideband spectral components, while propri-
etary techniques ensure that the cycle-to-cycle varia-
tion of the switching period does not degrade audio
reproduction or efficiency. The IC’s spread-spectrum
modulator randomly varies the switching frequency by
Q12.5kHz around the center frequency (300kHz). Above
10MHz, the wideband spectrum looks like noise for EMI
purposes (Figure 1).
Speaker Current Limit
If the output current of the speaker amplifier exceeds the
current limit (2.8A typ), the IC disables the outputs for
approximately 100Fs. At the end of 100Fs, the outputs
are reenabled. If the fault condition still exists, the IC
continues to disable and reenable the outputs until the
fault condition is removed.
Selectable Gain
The IC offers five programmable gain selections through
a single gain input (GAIN).
Figure 1. EMI with 60cm of Speaker Cable and No Output Filtering
Table 1. Gain Control Configuration
90
70
50
30
10
-10
0 100 200 300 400 500 600 700 800 900 1000
EMISSIONS LEVEL (dBµV/m)
FREQUENCY (MHz)
EN55022B LIMIT
HORIZONTAL
VERTICAL
GAIN PIN MAXIMUM GAIN (dB)
Connect to PGND 12
Connect to PGND through
100kW ±5% resistor 9
Connect to PVDD 6
Connect to PVDD through
100kW ±5% resistor 3
Unconnected 0
_______________________________________________________________________________________ 9
MAX98304
Mono 3.2W Class D Amplifier
Shutdown
The IC features a low-power shutdown mode, drawing
less than 0.1FA (typ) of supply current. Drive SHDN low
to put the IC into shutdown.
Click-and-Pop Suppression
The IC speaker amplifier features Maxim’s comprehen-
sive click-and-pop suppression. During startup, the
click-and-pop suppression circuitry reduces any audible
transient sources internal to the device. When entering
shutdown, the differential speaker outputs ramp down to
PGND quickly and simultaneously.
Applications Information
Filterless Class D Operation
Traditional Class D amplifiers require an output filter.
The filter adds cost, size, and decreases efficiency
and THD+N performance. The IC’s filterless modulation
scheme does not require an output filter.
Because the switching frequency of the IC is well
beyond the bandwidth of most speakers, voice coil
movement due to the switching frequency is very small.
Use a speaker with a series inductance > 10FH. Typical
8I speakers exhibit series inductances in the 20FH to
100FH range.
Component Selection
Power-Supply Input (PVDD)
PVDD powers the speaker amplifier. PVDD ranges
from 2.5V to 5.5V. Bypass PVDD with a 0.1FF and 10FF
capacitor to PGND. Apply additional bulk capacitance
at the device if long input traces between PVDD and the
power source are used.
Input Filtering
The input-coupling capacitor (CIN), in conjunction with the
amplifier’s internal input resistance (RIN), forms a high-
pass filter that removes the DC bias from the incoming
signal. These capacitors allow the amplifier to bias the
signal to an optimum DC level.
Assuming zero source impedance CIN is:
IN
IN 3dB
2 R
C [ F]
f−
π ×
=F
where f-3dB is the -3dB corner frequency and RIN is the
input resistance shown in the Electrical Characteristics
table. Use capacitors with adequately low voltage-coef-
ficient for best low-frequency THD performance.
Layout and Grounding
Proper layout and grounding are essential for optimum
performance. Good grounding improves audio perfor-
mance and prevents switching noise from coupling into
the audio signal.
Use wide, low-resistance output traces. As the load
impedance decreases, the current drawn from the
device increases. At higher current, the resistance of the
output traces decreases the power delivered to the load.
For example, if 2W is delivered from the device output
to a 4I load through 100mI of total speaker trace,
1.904W is being delivered to the speaker. If power is
delivered through 10mI of total speaker trace, 1.99W
is being delivered to the speaker. Wide output, supply,
and ground traces also improve the power dissipation of
the device.
The IC is inherently designed for excellent RF immunity.
For best performance, add ground fills around all signal
traces on top or bottom PCB planes.
WLP Applications Information
For the latest application details on WLP construction,
dimensions, tape carrier information, PCB techniques,
bump-pad layout, and recommended reflow tempera-
ture profile, as well as the latest information on reliability
testing results, refer to Application Note 1891: Wafer-
level packaging (WLP) and its applications. Figure 2
shows the dimensions of the WLP balls used on the IC.
Figure 2. MAX98304 WLP Ball Dimensions
0.18mm
0.18mm
10 _____________________________________________________________________________________
MAX98304
Mono 3.2W Class D Amplifier
Functional Diagram
Chip Information
PROCESS: CMOS
C2IN-
0.47µF
C3IN+
B3GAIN
C1
A3
PVDD
SHDN
0.47µF
CLASS D
MODULATOR
LOW-EMI
DRIVER
PVDD
A1
A2
OUT-
OUT+
PGND
LOW-EMI
DRIVER
PVDD
PGND
PGND
B1
UVLO/POWER
MANAGEMENT
CLICK-AND-POP
SUPPRESSION
2.5V TO 5.5V
10µF*
*SYSTEM BULK CAPACITANCE
0.1µF
MAX98304
______________________________________________________________________________________ 11
MAX98304
Mono 3.2W Class D Amplifier
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the
package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the
package regardless of RoHS status.
PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
9 WLP W91D1+1 21-0486 —
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
12 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX98304
Mono 3.2W Class D Amplifier
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 9/10 Initial release —
