MAX9714 ,6W, Filterless, Spread-Spectrum Mono/Stereo Class D AmplifiersFeatures♦ Filterless Class D AmplifierThe MAX9713/MAX9714 mono/stereo Class D audiopower amplifiers ..
MAX9714ETJ ,6W, Filterless, Spread-Spectrum Mono/Stereo Class D AmplifiersMAX9713/MAX971419-3039; Rev 2; 9/046W, Filterless, Spread-SpectrumMono/Stereo Class D Amplifiers
MAX9714ETJ+ ,6W, Filterless, Spread-Spectrum Mono/Stereo Class D AmplifiersFeatures♦ Filterless Class D AmplifierThe MAX9713/MAX9714 mono/stereo Class D audiopower amplifiers ..
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MAX9715ETE+ ,2.8W, Low-EMI, Stereo, Filterless Class D Audio AmplifierBlock DiagramTOP VIEW4.5V TO 5.5V SUPPLY12 11 10 9BIAS 138 SHDNOUTR+INRVOUTR-DD 147 GNDMAX9715GAINC ..
MAX9715ETE+ ,2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifierfeatures high PSRR (71dB at 1kHz),allowing for operation from noisy supplies without addi- ♦ Low-Po ..
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MB89193 ,8-bit Proprietary MicrocontrollerFUJITSU SEMICONDUCTORDS07-12512-7EDATA SHEET8-bit Proprietary MicrocontrollerCMOS2F MC-8L MB89190/1 ..
MB89193A ,8-bit Proprietary MicrocontrollerFUJITSU SEMICONDUCTORDS07-12512-7EDATA SHEET8-bit Proprietary MicrocontrollerCMOS2F MC-8L MB89190/1 ..
MB89193AP ,8-bit Proprietary MicrocontrollerFEATURES • Minimum execution time: 0.95 m s at 4.2 MHz (VCC = 2.7 V) 2•F MC-8L family CPU core•Two ..
MAX9714
6W, Filterless, Spread-Spectrum Mono/Stereo Class D Amplifiers
General DescriptionThe MAX9713/MAX9714 mono/stereo Class D audio
power amplifiers provide Class AB amplifier performance
with Class D efficiency, conserving board space and
eliminating the need for a bulky heatsink. Using a Class
D architecture, these devices deliver up to 6W while
offering greater than 85% efficiency. Proprietary and pro-
tected modulation and switching schemes render the tra-
ditional Class D output filter unnecessary.
The MAX9713/MAX9714 offer two modulation schemes:
a fixed-frequency mode (FFM), and a spread-spectrum
mode (SSM) that reduces EMI-radiated emissions due
to the modulation frequency. The device utilizes a fully
differential architecture, a full bridged output, and com-
prehensive click-and-pop suppression.
The MAX9713/MAX9714 feature high 76dB PSRR, low
0.07% THD+N, and SNR in excess of 95dB. Short-cir-
cuit and thermal-overload protection prevent the
devices from being damaged during a fault condition.
The MAX9713 is available in a 32-pin TQFN (5mm x
5mm x 0.8mm) package. The MAX9714 is available in a
32-pin TQFN (7mm x 7mm x 0.8mm) package. Both
devices are specified over the extended -40°C to
+85°C temperature range.
Applications
FeaturesFilterless Class D AmplifierUnique Spread-Spectrum Mode Offers 5dB
Emissions Improvement Over Conventional
MethodsUp to 85% Efficient6W Output Power into 8ΩLow 0.07% THD+NHigh PSRR (76dB at 1kHz)10V to 25V Single-Supply OperationDifferential Inputs Minimize Common-Mode NoisePin-Selectable Gain Reduces Component CountIndustry-Leading Integrated Click-and-Pop
SuppressionLow Quiescent Current (18mA)Low-Power Shutdown Mode (0.2µA)Short-Circuit and Thermal-Overload ProtectionAvailable in Thermally Efficient, Space-Saving
Packages
32-Pin TQFN (5mm x 5mm x 0.8mm)–MAX9713
32-Pin TQFN (7mm x 7mm x 0.8mm)–MAX9714
MAX9713/MAX9714
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers19-3039; Rev 6; 12/06
EVALUATION KIT
AVAILABLE
Ordering Information
PARTTEMP RANGEPIN-PACKAGEAMP
MAX9713ETJ+-40oC to +85oC32 TQFN-EP*Mono
MAX9714ETJ+-40oC to +85oC32 TQFN-EP*Stereo
*EP = Exposed paddle.
+Denotes lead-free package.
LCD Monitors
LCD TVs
Desktop PCs
LCD Projectors
High-End Notebook
Audio
Hands-Free Car
Phone Adaptors
MAX97140.47μFINL+OUTL+
OUTL-INL-
0.47μFH-BRIDGE
0.47μFINR+OUTR+
OUTR-INR-0.47μFH-BRIDGE
Pin Configurations appear at end of data sheet.MAX9713
0.47μFIN+OUT+
OUT-IN-
0.47μFH-BRIDGE
Block Diagrams
MAX9713/MAX9714
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
ABSOLUTE MAXIMUM RATINGSStresses 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.
(All voltages referenced to GND.)
VDDto PGND, AGND.............................................................30V
OUTR_, OUTL_, C1N..................................-0.3V to (VDD+ 0.3V)
C1P............................................(VDD- 0.3V) to (CHOLD + 0.3V)
CHOLD........................................................(VDD- 0.3V) to +40V
All Other Pins to GND.............................................-0.3V to +12V
Duration of OUTR_/OUTL_
Short Circuit to GND, VDD......................................Continuous
Continuous Input Current (VDD, PGND, AGND)...................1.6A
Continuous Input Current (all other pins)..........................±20mA
Continuous Power Dissipation (TA= +70°C)
Single-Layer Board:
MAX9713 32-Pin TQFN (derate 21.3mW/°C
above +70°C)..........................................................1702.1mW
MAX9714 32-Pin TQFN (derate 27mW/°C
above +70°C)..........................................................2162.2mW
Multilayer Board:
MAX9713 32-Pin TQFN (derate 34.5mW/°C
above +70°C)..........................................................2758.6mW
MAX9714 32-Pin TQFN (derate 37mW/°C
above +70°C)..........................................................2963.0mW
Junction Temperature......................................................+150°C
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
ELECTRICAL CHARACTERISTICS(VDD= 15V, GND = PGND = 0V, SHDN≥VIH, AV= 16dB, CSS= CIN= 0.47µF, CREG= 0.01µF, C1 = 100nF, C2 = 1µF, FS1 = FS2 =
GND (fS= 330kHz), RLconnected between OUTL+ and OUTL- and OUTR+ and OUTR-, TA= TMINto TMAX, unless otherwise noted.
Typical values are at TA= +25°C.) (Notes 1, 2)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
GENERALSupply Voltage RangeVDDInferred from PSRR test1025V
MAX97131017.5Quiescent CurrentIDDRL = ∞MAX97141823mA
Shutdown CurrentISHDN0.21.5µA
CSS = 470nF100Turn-On TimetONCSS = 180nF50ms
Amplifier Output Resistance in
ShutdownSHDN = GND150330kΩ
AV = 13dB355880
AV = 16dB304865
AV = 19.1dB233955Input ImpedanceRIN
AV = 22.1dB203142
G1 = L, G2 = L21.922.122.3
G1 = L, G2 = H18.919.119.3
G1 = H, G2 = L12.81313.2Voltage GainAV
G1 = H, G2 = H15.91616.3
Gain MatchingBetween channels (MAX9714)0.5%
Output Offset VoltageVOS±6±30mV
Common-Mode Rejection RatioCMRRfIN = 1kHz, input referred60dB
VDD = 10V to 25V5476
fRIPPLE = 1kHz76Power-Supply Rejection Ratio
(Note 3)PSRR200mVP-P ripplefRIPPLE = 20kHz60
MAX9713/MAX9714
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
ELECTRICAL CHARACTERISTICS (continued)(VDD= 15V, GND = PGND = 0V, SHDN≥VIH, AV= 16dB, CSS= CIN= 0.47µF, CREG= 0.01µF, C1 = 100nF, C2 = 1µF, FS1 = FS2 =
GND (fS= 330kHz), RLconnected between OUTL+ and OUTL- and OUTR+ and OUTR-, TA= TMINto TMAX, unless otherwise noted.
Typical values are at TA= +25°C.) (Notes 1, 2)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSRL = 16Ω8Output PowerPOUTTH D + N = 10%,
f = 1kH zRL = 8Ω6W
Total Harmonic Distortion Plus
NoiseTHD+NfIN = 1kHz, either FFM or SSM, RL = 8Ω,
POUT = 4W0.07%
FFM94BW = 22Hz to
22kHzSSM88
FFM97Signal-to-Noise RatioSNRRL = 8Ω, POUT =
4W, f = 1kHz
A-weightedSSM91
FS1 = L, FS2 = L300335370
FS1 = L, FS2 = H460
FS1 = H, FS2 = L236Oscillator FrequencyfOSC
FS1 = H, FS2 = H (spread-spectrum mode)335
kHz
POUT = 5W, fIN = 1kHz, RL = 16Ω85EfficiencyηPOUT = 4W, f = 1kHz, RL = 8Ω75%
DIGITAL INPUTS (SHDN, FS_, G_)VIH2.5Input ThresholdsVIL0.8V
Input Leakage Current±1µA
Note 1:All devices are 100% production tested at +25°C. 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= 8Ω, L = 68µH.
For RL= 16Ω, L = 136µH.
Note 3:PSRR is specified with the amplifier inputs connected to GND through CIN.
MAX9713/MAX9714
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCYMAX9713 toc01
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01100k
VDD = +15V
AV = 13dB
RL = 8Ω
POUT = 4W
POUT = 100mW
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCYMAX9713 toc02
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01100k
VDD = +20V
AV = 13dB
RL = 8Ω
POUT = 4W
POUT = 100mW
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCYMAX9713 toc03
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01100k
VDD = +15V
AV = 13dB
RL = 16Ω
POUT = 5W
POUT = 55mW
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCYMAX9713 toc04
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01100k
VDD = +20V
AV = 13dB
RL = 16Ω
POUT = 7.5W
POUT = 120mW
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWERMAX9713 toc07
OUTPUT POWER (W)
THD+N (%)23456
VDD = 20V
AV = 13dB
RL = 8Ω
f = 100Hz
f = 1kHz
f = 10kHzf = 10kHz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCYMAX9713 toc05
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01100k
VDD = +15V
AV = 13dB
POUT = 4W
RL = 8Ω
SSM
FFM
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWERMAX9713 toc06
OUTPUT POWER (W)
THD+N (%)321
VDD = 15V
AV = 13dB
RL = 8Ω
f = 100Hz
f = 1kHz
f = 10kHz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWERMAX9713 toc08
OUTPUT POWER (W)
THD+N (%)42
VDD = 15V
AV = 13dB
RL = 16Ω
f = 100Hz
f = 1kHz
f = 10kHz
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWERMAX9713 toc09
OUTPUT POWER (W)
THD+N (%)5
VDD = 20V
AV = 13dB
RL = 16Ω
f = 100Hz
f = 1kHz
f = 10kHz
Typical Operating Characteristics(136µH with 16Ω, 68µH with 8Ω, part in SSM mode, unless otherwise noted.)
MAX9713/MAX9714
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. OUTPUT POWERMAX9713 toc10
OUTPUT POWER (W)
THD+N (%)42
VDD = 15V
AV = 13dB
f = 1kHz
RL = 8Ω
SSM
FFM
EFFICIENCY vs. OUTPUT POWERMAX9713 toc11
OUTPUT POWER (W)
EFFICIENCY (%)642
RL = 16Ω
RL = 8Ω
VDD = 15V
AV = 13dB
EFFICIENCY vs. OUTPUT POWERMAX9713 toc12
OUTPUT POWER (W)
EFFICIENCY (%)63
RL = 16Ω
RL = 8Ω
VDD = 20V
AV = 13dB
OUTPUT POWER
vs. SUPPLY VOLTAGEMAX9713 toc13
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)19161325
AV = 13dB
THD+N = 10%
RL = 8Ω
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCYMAX9713 toc16
FREQUENCY (Hz)
PSRR (dB)
10k1k100
-70100k
VDD = 15V
AV = 13dB
VRIPPLE = 200mVP-P
RL = 16Ω10100
OUTPUT POWER
vs. LOAD RESISTANCEMAX9713 toc14
LOAD RESISTANCE (Ω)
OUTPUT POWER (W)
VDD = 15V
AV = 13dB
THD+N = 10%
THD+N = 1%
COMMON-MODE REJECTION RATIO
vs. FREQUENCYMAX9713 toc15
FREQUENCY (Hz)
CMRR (dB)
10k1k100
-90100k
VDD = 15V
AV = 13dB
RL = 8Ω
CROSSTALK vs. FREQUENCYMAX9713 toc17
FREQUENCY (Hz)
CROSSTALK (dB)10.1
LEFT TO RIGHT
RIGHT TO LEFT
OUTPUT REFERRED
AV = 13dB
OUTPUT FREQUENCY SPECTRUMMAX9713 toc18
FREQUENCY (Hz)
OUTPUT MAGNITUDE (dB)105
FFM MODE
POUT = 5W
f =1kHz
RL = 8Ω
UNWEIGHTED
Typical Operating Characteristics (continued)(136µH with 16Ω, 68µH with 8Ω, part in SSM mode, unless otherwise noted.)
MAX9713/MAX9714
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
OUTPUT FREQUENCY SPECTRUMMAX9713 toc19
FREQUENCY (Hz)
OUTPUT MAGNITUDE (dB)
15k10k5k
-14020k
SSM MODE
POUT = 5W
f = 1kHz
RL = 8Ω
UNWEIGHTED
OUTPUT FREQUENCY SPECTRUMMAX9713 toc20
FREQUENCY (Hz)
OUTPUT MAGNITUDE (dB)
15k10k5k
-2020k
SSM MODE
POUT = 5W
f = 1kHz
RL = 8Ω
A-WEIGHTED
RBW = 10kHz
-10010M100M
WIDEBAND OUTPUT SPECTRUM
(FFM MODE)MAX1973toc21
FREQUENCY (Hz)
OUTPUT AMPLITUDE (dB)
-10RBW = 10kHz
-10010M100M
WIDEBAND OUTPUT SPECTRUM
(SSM MODE)MAX9713toc22
FREQUENCY (Hz)
OUTPUT AMPLITUDE (dB)
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX9713 toc25
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (161412
TURN-ON/TURN-OFF RESPONSE
MAX9713 toc23
20ms/div
MAX9714
OUTPUT
1V/div
5V/divSHDN
f = 1kHz
RL = 8Ω
CSS = 180pF
SUPPLY CURRENT
vs. SUPPLY VOLTAGEMAX9713
toc24
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)16141220
Typical Operating Characteristics (continued)(136µH with 16Ω, 68µH with 8Ω, part in SSM mode, unless otherwise noted.)
MAX9713/MAX9714
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
PIN
MAX9713MAX9714
NAMEFUNCTION1, 2, 23, 241, 2, 23, 24PGNDPower Ground
3, 4, 21, 223, 4, 21, 22VDDPower-Supply Input5C1NCharge-Pump Flying Capacitor Negative Terminal6C1PCharge-Pump Flying Capacitor Positive TerminalCHOLDCharge-Pump Hold Capacitor. Connect a 1µF capacitor from CHOLD to VDD.
8, 17, 20, 25,
26, 31, 328N.C.No Connection. Not internally connected.14REG6V Internal Regulator Output. Bypass with a 0.01µF capacitor to PGND.13AGNDAnalog Ground—IN-Negative Input—IN+Positive Input12SSSoft-Start. Connect a 0.47µF capacitor from SS to GND to enable soft-start feature.11SHDNActive-Low Shutdown. Connect SHDN to GND to disable the device. Connect to
VDD for normal operation.17G1Gain-Select Input 118G2Gain-Select Input 219FS1Frequency-Select Input 120FS2Frequency-Select Input 2
27, 28—OUT-Negative Audio Output
29, 30—OUT+Positive Audio Output9INL-Left-Channel Negative Input10INL+Left-Channel Positive Input15INR-Right-Channel Negative Input16INR+Right-Channel Positive Input25, 26OUTR-Right-Channel Negative Audio Output27, 28OUTR+Right-Channel Positive Audio Output29, 30OUTL-Left-Channel Negative Audio Output31, 32OUTL+Left-Channel Positive Audio Output—EPExposed Paddle. Connect to GND.
Pin Description
MAX9713/MAX9714
Detailed DescriptionThe MAX9713/MAX9714 filterless, Class D audio power
amplifiers feature several improvements to switch-
mode amplifier technology. The MAX9713 is a mono
amplifier, the MAX9714 is a stereo amplifier. These
devices offer Class AB performance with Class D effi-
ciency, while occupying minimal board space. A
unique filterless modulation scheme and spread-spec-
trum switching mode create a compact, flexible, low-
noise, efficient audio power amplifier. The differential
input architecture reduces common-mode noise pick-
up, and can be used without input-coupling capacitors.
The devices can also be configured as a single-ended
input amplifier.
Comparators monitor the device inputs and compare
the complementary input voltages to the triangle wave-
form. The comparators trip when the input magnitude of
the triangle exceeds their corresponding input voltage.
Operating Modes
Fixed-Frequency Modulation (FFM) ModeThe MAX9713/MAX9714 feature three FFM modes with
different switching frequencies (Table 1). In FFM mode,
the frequency spectrum of the Class D output consists of
the fundamental switching frequency and its associated
harmonics (see the Wideband Output Spectrum (FFM
Mode) graph in the Typical Operating Characteristics).
The MAX9713/ MAX9714 allow the switching frequency
to be changed by ±35%, should the frequency of one or
more of the harmonics fall in a sensitive band. This can
be done at any time and not affect audio reproduction.
Spread-Spectrum Modulation (SSM) ModeThe MAX9713/MAX9714 feature a unique spread-spec-
trum mode that flattens the wideband spectral compo-
nents, improving EMI emissions that may be radiated
by the speaker and cables. This mode is enabled by
setting FS1 = FS2 = H. In SSM mode, the switching fre-
quency varies randomly by ±1.7%kHz around the cen-
ter frequency (335kHz). The modulation scheme
remains the same, but the period of the triangle wave-
form changes from cycle to cycle. Instead of a large
amount of spectral energy present at multiples of the
switching frequency, the energy is now spread over a
bandwidth that increases with frequency. Above a few
megahertz, the wideband spectrum looks like white
noise for EMI purposes (Figure 2).
EfficiencyEfficiency of a Class D amplifier is attributed to the
region of operation of the output stage transistors. In a
Class D amplifier, the output transistors act as current-
steering switches and consume negligible additional
power. Any power loss associated with the Class D out-
put stage is mostly due to the I2R loss of the MOSFET
on-resistance, and quiescent current overhead.
The theoretical best efficiency of a linear amplifier is
78%, however that efficiency is only exhibited at peak
output powers. Under normal operating levels (typical
music reproduction levels), efficiency falls below 30%,
whereas the MAX9714 still exhibits >80% efficiencies
under the same conditions (Figure 3).
ShutdownThe MAX9713/MAX9714 have a shutdown mode that
reduces power consumption and extends battery life.
Driving SHDNlow places the device in low-power
(0.2µA) shutdown mode. Connect SHDNto a logic high
for normal operation.
Click-and-Pop SuppressionThe MAX9713/MAX9714 feature comprehensive click-
and-pop suppression that eliminates audible transients
on startup and shutdown. While in shutdown, the H-
bridge is pulled to GND through 300kΩ. During startup,
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D Amplifiers
Table 1. Operating Modes
FS1FS2SWITCHING MODE
(kHz)L335H460L236H335 ±7%
Figure 1. MAX9714 Outputs with No Input Signal Applied
VIN = 0V
OUT-
OUT+
or power-up, the input amplifiers are muted and an
internal loop sets the modulator bias voltages to the
correct levels, preventing clicks and pops when the H-
bridge is subsequently enabled. Following startup, a
soft-start function gradually un-mutes the input ampli-
fiers. The value of the soft-start capacitor has an impact
on the click/pop levels. For optimum performance, CSS
should be at least 0.18µF.
Mute FunctionThe MAX9713/MAX9714 feature a clickless/popless
mute mode. When the device is muted, the outputs
stop switching, muting the speaker. Mute only affects
the output state, and does not shut down the device. To
mute the MAX9713/MAX9714, drive SSto GNDby
using a MOSFET pulldown (Figure 4). Driving SSto
GND during the power-up/down or shutdown/turn-on
cycle optimizes click-and-pop suppression.
Applications Information
Filterless OperationTraditional Class D amplifiers require an output filter to
recover the audio signal from the amplifier’s PWM out-
put. The filters add cost, increase the solution size of
the amplifier, and can decrease efficiency. The tradi-
tional PWM scheme uses large differential output
swings (2 ✕VDDpeak-to-peak) and causes large ripple
currents. Any parasitic resistance in the filter compo-
nents results in a loss of power, lowering the efficiency.
The MAX9713/MAX9714 do not require an output filter.
The devices rely on the inherent inductance of the
speaker coil and the natural filtering of both the speak-
er and the human ear to recover the audio component
of the square-wave output. Eliminating the output filter
results in a smaller, less costly, more efficient solution.
Because the frequency of the MAX9713/MAX9714 out-
put is well beyond the bandwidth of most speakers,
voice coil movement due to the square-wave frequency
MAX9713/MAX9714
6W, Filterless, Spread-Spectrum
Mono/Stereo Class D AmplifiersFigure 3. MAX9714 Efficiency vs. Class AB Efficiency
EFFICIENCY vs. OUTPUT POWER
OUTPUT POWER (W)
EFFICIENCY (%)
MAX9714
VDD = 15V
f = 1kHz
RL = 16Ω
CLASS AB
Figure 2. SSM Radiated Emissions
MAX9713/
MAX9714
0.18µFGPIO
MUTE SIGNAL
Figure 4. MAX9713/MAX9714 Mute Circuit
