MAX9708ETN+ Fast Delivery |IC PHOENIX CO.,LIMITED

MAX9708ETN+ ,20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D AmplifierBlock DiagramMAX9708MAX97082 2SYNCOUT SYNCOUTFS1, FS2 FS1, FS2SYNCSYNCRIGHTCHANNELAUDIOCLASS DCLASS ..
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MAX9708ETN+
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
EVALUATION KIT AVAILABLE
General Description
The MAX9708 mono/stereo, Class D audio power amplifi-
er delivers up to 2 x 21W into an 8Ωstereo mode and
1 x 42W into a 4Ωload in mono mode while offering up to
87% efficiency. The MAX9708 provides Class AB amplifi-
er performance with the benefits of Class D efficiency,
eliminating the need for a bulky heatsink and conserving
power. The MAX9708 operates from a single +10V to
+18V supply, driving the load in a BTL configuration.
The MAX9708 offers two modulation schemes: a fixed-
frequency modulation (FFM) mode, and a spread-spec-
trum modulation (SSM) mode that reduces
EMI-radiated emissions. The MAX9708 can be synchro-
nized to an external clock from 600kHz to 1.2MHz. A
synchronized output allows multiple units to be cascad-
ed in the system.
Features include fully differential inputs, comprehensive
click-and-pop suppression, and four selectable-gain set-
tings (22dB, 25dB, 29.5dB, and 36dB). A pin-program-
mable thermal flag provides seven different thermal
warning thresholds. Short-circuit and thermal-overload
protection prevent the device from being damaged
during a fault condition.
The MAX9708 is available in a 56-pin TQFN (8mm x
8mm x 0.8mm) package and is specified over the
extended -40°C to +85°C temperature range.
Applications
LCD TVsPDP TVs
AutomotivePC/HiFi Audio Solutions
Features2 x 21W Output Power in Stereo Mode
(8Ω, THD = 10%)1 x 42W Output Power in Mono Mode
(4Ω, THD = 10%)High Efficiency: Up to 87%Filterless Class D AmplifierUnique Spread-Spectrum ModeProgrammable Gain (+22dB, +25dB, +29.5dB,
+36dB)High PSRR (90dB at 1kHz)Differential Inputs Suppress Common-Mode
NoiseShutdown and Mute ControlIntegrated Click-and-Pop SuppressionLow 0.1% THD+NCurrent Limit and Thermal ProtectionProgrammable Thermal FlagSYNC Input/OutputAvailable in Thermally Efficient, Space-Saving
56-Pin TQFN Package
CLASS D
MODULATOR
SYNCOUT
TEMP
OUTPUT
PROTECTION
GAIN
CONTROL
FS1, FS2
MAX9708
STEREO MODE
G1, G22
SYNC
RIGHT
CHANNEL
LEFT
CHANNEL
MONO
TH0, TH1,
TH2
PARTTEMP RANGEPIN-
PACKAGE
PKG
CODE
MAX9708ETN+-40°C to +85°C56 TQFN-EP*T5688-3
MAX9708ETN/V+-40°C to +85°C56 TQFN-EP*T5688-3
Simplified Block Diagram
Ordering Information
+Denotes lead-free package.
/V denotes an automotive qualified part.
*EP = Exposed pad.Pin Configurations appear at end of data sheet.
CLASS D
MODULATOR
SYNCOUT
TEMP
OUTPUT
PROTECTION
GAIN
CONTROL
FS1, FS2
MAX9708
MONO MODE
G1, G22
SYNC
AUDIO
INPUT
VDIGITAL
MONO
TH0, TH1,
TH2
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(PVDD= VDD= +18V, PGND = GND = 0V, CSS= 0.47µF, CREG= 0.01µF, C1 = 0.1µF, C2 = 1µF, RLOAD = ∞, MONO = low (stereo
mode), SHDN= MUTE= high, G1 = low, G2 = high (AV= 22dB), FS1 = FS2 = high (SSM), SYNCIN = low. All load resistors (RL) are
connected between OUT_+ and OUT_-, unless otherwise stated. TA= TMINto TMAX, unless otherwise noted. Typical values are at TA
= +25°C.) (Note 1)
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, VDDto PGND, GND.......................................-0.3 to +30V
PVDDto VDD..........................................................-0.3V to +0.3V
OUTR+, OUTR-, OUTL+,
OUTL- to PGND, GND...........................-0.3V to (PVDD+ 0.3V)
C1N to GND.............................................-0.3V to (PVDD+ 0.3V)
C1P to GND..............................(PVDD- 0.3V) to (CPVDD+ 0.3V)
CPVDD to GND..........................................(PVDD - 0.3V) to +40V
All Other Pins to GND.............................................-0.3V to +12V
Continuous Input Current (except PVDD, VDD, OUTR+,
OUTR-, OUTL+, and OUTL-)...........................................20mA
Continuous Power Dissipation (TA= +70°C)
56-Pin TQFN (derate 47.6mW/°C above +70°C)............3.81W
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Junction Temperature......................................................+150°C
Thermal Resistance (θJC)
56-Pin TQFN….............................................................0.6°C/W
Lead Temperature (soldering, 10s).................................+300°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
Supply Voltage RangeVDDInferred from PSRR test1018V
Shutdown CurrentISHDNSHDN = low0.11µA
Shutdown to Full OperationtSON100ms
Mute to Full OperationtMUTE100ms
G1 = 0, G2 = 15085125
G1 = 1, G2 = 1406390
G1 = 1, G2 = 0254360Input ImpedanceRIN
G1= 0, G2 = 0122130
Output Pulldown ResistanceSHDN = GND600kΩ
Output Offset VoltageVOSAC-coupled input, measured between
OUT_+ and OUT_-±30mV
PVDD = 10V to 18V6890
fRIPPLE = 1kHz90Power-Supply Rejection RatioPSRR200mVP-P ripple
(Note 2)fRIPPLE = 20kHz50
DC, input referred5070Common-Mode Rejection RatioCMRRf = 20Hz to 20kHz, input referred70dB
Switch On-ResistanceRDSOne power switch0.30.75Ω
FS1FS201802002201 (SSM)2000160
Switching FrequencyfSW1250
kHz
Oscillator Spread BandwidthFS1 = FS2 = high (SSM)±2%
SYNCIN Lock RangeEqual to fSW x 46001200kHz
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(PVDD= VDD= +18V, PGND = GND = 0V, CSS= 0.47µF, CREG= 0.01µF, C1 = 0.1µF, C2 = 1µF, RLOAD = ∞, MONO = low (stereo
mode), SHDN= MUTE= high, G1 = low, G2 = high (AV= 22dB), FS1 = FS2 = high (SSM), SYNCIN = low. All load resistors (RL) are
connected between OUT_+ and OUT_-, unless otherwise stated. TA= TMINto TMAX, unless otherwise noted. Typical values are at TA
= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
G1 = 0, G2 = 121.622.022.3
G1 = 1, G2 = 124.925.025.6
G1 = 1, G2 = 029.229.529.9GainAV
G1 = 0, G2 = 035.936.036.6
TH2TH1TH000+8001+9010+10011+11000+12001+12910+139
TEMP Flag ThresholdTFLAG11+150
TEMP Flag AccuracyFrom +80°C to +140°C±6°C
TEMP Flag Hysteresis2°C
STEREO MODE (RLOAD = 8Ω)
MUTE = 1, RLOAD = ∞2030Quiescent CurrentMUTE = 0511mA
Output PowerPOUTf = 1kHz, THD = 10%, TA = +25°C,
RLOAD = 8Ω, PVDD = 18V2021W
Total Harmonic Distortion Plus
NoiseTHD+Nf = 1kHz, BW = 22Hz to 22kHz,
RLOAD = 8Ω, POUT = 8W0.1%
22Hz to 22kHz91Signal-to-Noise RatioSNRRLOAD = 8Ω, POUT = 10WA-weighted96dB
EfficiencyηRLOAD = 8Ω, L > 60µH , P OU T = 15W + 15W ,
f = 1kHz87%
Left-Right Channel Gain
MatchingPOUT = 10W0.02dB
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(PVDD= VDD= +18V, PGND = GND = 0V, CSS= 0.47µF, CREG= 0.01µF, C1 = 0.1µF, C2 = 1µF, RLOAD = ∞, MONO = low (stereo
mode), SHDN= MUTE= high, G1 = low, G2 = high (AV= 22dB), FS1 = FS2 = high (SSM), SYNCIN = low. All load resistors (RL) are
connected between OUT_+ and OUT_-, unless otherwise stated. TA= TMINto TMAX, unless otherwise noted. Typical values are at TA
= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
Output Short-Circuit Current
ThresholdISCRLOAD = 0Ω2.4A
Into shutdown-63
Click-and-Pop LevelKCP
Peak voltage, 32
samples/second,
A-weighted (Notes 2, 4)Out of shutdown-55
dBV
MONO MODE (RLOAD = 4Ω, MONO = High)
MUTE = 1, RLOAD = ∞20Quiescent CurrentMUTE = 05mA
RLOAD = 8Ω23Output PowerPOUTf = 1kHz,
THD = 10%RLOAD = 4Ω42W
Total Harmonic Distortion Plus
Noise
f = 1kHz, BW = 22Hz to 22kHz,
RLOAD = 4Ω, POUT = 17W0.12%
20Hz to 20kHz91Signal-to-Noise RatioSNRRLOAD = 4Ω,
POUT = 10WA-weighted95dB
EfficiencyηRLOAD = 4Ω, L > 40µH, POUT = 42W,
f = 1kHz85%
Output Short-Circuit Current
ThresholdISCRLOAD = 0Ω4.8A
Into shutdown-60
Click-and-Pop LevelKCP
Peak voltage, 32
samples/second,
A-weighted (Notes 2, 4)Out of shutdown-63
dBV
DIGITAL INPUTS (SHDN, MUTE, G1, G2, FS1, FS2, TH0, TH1, TH2, SYNCIN, MONO)
Logic-Input CurrentIIN0 to 12V1µA
Logic-Input High VoltageVIH2.5V
Logic-Input Low VoltageVIL0.8V
OPEN-DRAIN OUTPUTS (TEMP, SYNCOUT)
Open-Drain Output Low VoltageVOLISINK = 3mA0.4V
Leakage CurrentILEAKVPULLUP = 5.5V0.2µA
Note 1:All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
Note 2:Inputs AC-coupled to GND.
Note 3:The device is current limited. The maximum output power is obtained with an 8Ωload.
Note 4:Testing performed with an 8Ωresistive load in series with a 68µH inductive load connected across BTL outputs. Mode tran-
sitions are controlled by SHDN.
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
MAX9708 toc01
OUTPUT POWER PER CHANNEL (W)
THD+N (%)2015105
PVDD = 18V, 8Ω
STEREO MODE, 1kHz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
MAX9708 toc02
OUTPUT POWER PER CHANNEL (W)
THD+N (%)5
PVDD = 12V,
STEREO MODE,
fIN = 1kHz
RL = 8Ω
RL = 4Ω
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
MAX9708 toc03
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.1100k
PVDD = 18V,
8Ω STEREO MODE,
POUT = 8.3W PER
CHANNEL
EFFICIENCY vs. OUTPUT POWER
MAX9708 toc04
OUTPUT POWER PER CHANNEL (W)
EFFICIENCY (%)2015105
PVDD = 18V, 8Ω
STEREO MODE
OUTPUT POWER
vs. SUPPLY VOLTAGE
MAX9708 toc05
SUPPLY VOLTAGE (V)
OUTPUT POWER PER CHANNEL (W)141218
RL = 8Ω
STEREO MODE
10% THD+N
1% THD+N
NO-LOAD SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX9708 toc06
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)1816141222
STEREO MODE
TA = +25°CTA = +85°C
TA = -40°C
Typical Operating Characteristics
(PVDD= VDD= +18V, PGND = GND = 0V, CSS= 0.47µF, CREG= 0.01µF, C1 = 0.1µF, C2 = 1µF, RLOAD = ∞, SHDN= high, MONO
= low, MUTE= high, G1 = low, G2 = high, FS1 = FS2 = high (SSM), SYNCIN = low. All load resistors (RL) are between OUT_+ and
OUT_-, TA= +25°C, unless otherwise stated.)
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX9708 toc07
SUPPLY CURRENT (nA)18121416
SHDN = 0
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
MAX9708 toc08
THD+N (%)40302010
PVDD = 18V, 4Ω MONO MODE,
1kHz
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
MAX9708 toc10
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.1100k
PVDD = 18V,
4Ω MONO MODE,
POUT = 18W
WIDEBAND OUTPUT SPECTRUM
(SSM MODE)
MAX9708 toc11
FREQUENCY (Hz)
OUTPUT AMPLITUDE (dBV)
10M1M
100k100M
10kHz RBW
WIDEBAND OUTPUT SPECTRUM
(FFM MODE)
MAX9708 toc12
FREQUENCY (Hz)
OUTPUT AMPLITUDE (dBV)
10M1M100k100M
10kHz RBW
OUTPUT FREQUENCY SPECTRUM
(SSM MODE)
MAX9708 toc13
FREQUENCY (kHz)
OUTPUT AMPLITUDE (dBV)161284
OUTPUT FREQUENCY SPECTRUM
(FFM MODE)
MAX9708 toc14
FREQUENCY (kHz)
OUTPUT AMPLITUDE (dBV)161284
Typical Operating Characteristics (continued)
(PVDD= VDD= +18V, PGND = GND = 0V, CSS= 0.47µF, CREG= 0.01µF, C1 = 0.1µF, C2 = 1µF, RLOAD = ∞, SHDN= high, MONO
= low, MUTE= high, G1 = low, G2 = high, FS1 = FS2 = high (SSM), SYNCIN = low. All load resistors (RL) are between OUT_+ and
OUT_-, TA= +25°C, unless otherwise stated.)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER
MAX9708 toc09
OUTPUT POWER (W)
THD+N (%)15105
PVDD = 12V,
MONO MODE,
fIN = 1kHz
RL = 4Ω
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
EFFICIENCY vs. OUTPUT POWER
MAX9708 toc15
OUTPUT POWER (W)
EFFICIENCY (%)40302010
PVDD = 18V,
4Ω MONO MODE
OUTPUT POWER
vs. SUPPLY VOLTAGE
MAX9708 toc16
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)141218
RL = 4Ω,
MONO MODE,
10% THD+N
OUTPUT POWER
vs. LOAD RESISTANCE
MAX9708 toc17
LOAD RESISTANCE (Ω)
OUTPUT POWER (W)86
MONO MODE,
10% THD+N,
PVDD = 18V
OUTPUT POWER
vs. LOAD RESISTANCE
MAX9708 toc18
LOAD RESISTANCE (Ω)
OUTPUT POWER PER CHANNEL (W)1098
STEREO MODE,
10% THD+N,
PVDD = 18V
MUTE RESPONSE
MAX9708 toc19
40ms/div
MUTE
5V/div
OUTPUT
50mV/div
SHUTDOWN RESPONSE
MAX9708 toc20
40ms/div
SHDN
5V/div
OUTPUT
50mV/div
Typical Operating Characteristics (continued)
(PVDD= VDD= +18V, PGND = GND = 0V, CSS= 0.47µF, CREG= 0.01µF, C1 = 0.1µF, C2 = 1µF, RLOAD = ∞, SHDN= high, MONO
= low, MUTE= high, G1 = low, G2 = high, FS1 = FS2 = high (SSM), SYNCIN = low. All load resistors (RL) are between OUT_+ and
OUT_-, TA= +25°C, unless otherwise stated.)
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
MAX9708 toc21
FREQUENCY (Hz)
CMRR (dB)
10k1k100
-110100k
INPUT REFERRED
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX9708 toc22
FREQUENCY (Hz)
PSRR (dB)
10k1k100
-110100k
CROSSTALK vs. FREQUENCY
MAX9708 toc23
FREQUENCY (Hz)
CROSSTALK (dB)
10k1k100
-120100k
MAXIMUM STEADY-STATE OUTPUT POWER
vs. TEMPERATURE
MAX9708 toc24
AMBIENT TEMPERATURE (°C)
OUTPUT POWER PER CHANNEL (W)405070
PVDD = 18V, 8Ω
STEREO MODE, 1kHz,
FS1 = FS2 = 1
TH0 = TH1 = 1
TH2 = 0
MEASURED WITH THE EV KIT (TQFN
PACKAGE), JUNCTION TEMPERATURE
MAINTAINED AT +110°C
MAXIMUM STEADY-STATE OUTPUT POWER
vs. TEMPERATURE
MAX9708 toc25
AMBIENT TEMPERATURE (°C)
OUTPUT POWER (W)405070
PVDD = 18V, 4Ω
MONO MODE, 1kHz,
FS1 = FS2 = 1
TH0 = TH1 = 1
TH2 = 0
MEASURED WITH THE EV KIT (TQFN
PACKAGE), JUNCTION TEMPERATURE
MAINTAINED AT +110°C
Typical Operating Characteristics (continued)
(PVDD= VDD= +18V, PGND = GND = 0V, CSS= 0.47µF, CREG= 0.01µF, C1 = 0.1µF, C2 = 1µF, RLOAD = ∞, SHDN= high, MONO
= low, MUTE= high, G1 = low, G2 = high, FS1 = FS2 = high (SSM), SYNCIN = low. All load resistors (RL) are between OUT_+ and
OUT_-, TA= +25°C, unless otherwise stated.)
Pin Description
PINNAMEFUNCTION
1, 12, 42, 43,
44, 55, 56N.C.No Connection. Not internally connected.
2, 3, 4,
39, 40,
41, 49, 50
PGNDPower Ground
5, 6, 7,
36, 37, 38PVDDPositive Power Supply. Bypass to PGND with a 0.1µF and a 47µF capacitor with the smallest
capacitor placed as close to pins as possible.
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
Pin Description (continued)
PINNAMEFUNCTIONC1NCharge-Pump Flying Capacitor C1, Negative TerminalC1PCharge-Pump Flying Capacitor C1, Positive TerminalCPVDDCharge-Pump Power Supply. Bypass to PVDD with a 1µF capacitor as close to the pin as possible.SYNCOUTOpen-Drain, Slew-Rate Limited Clock Output. Pullup with a 10kΩ resistor to REG.SYNCINClock Synchronization Input. Allows for synchronization of the internal oscillator with an external clock.
SYNCIN is internally pulled up to VREG with a 100kΩ resistor.FS2Frequency Select 2FS1Frequency Select 1INL-Left-Channel Negative Input (Stereo Mode Only)INL+Left-Channel Positive Input (Stereo Mode Only)MONOMono/Stereo Mode Input. Drive logic-high for mono mode. Drive logic-low for stereo mode.
19, 20, 21REGInternal Regulator Output Voltage (6V). Bypass with a 0.01µF capacitor to GND.
22, 23GNDAnalog GroundSSSoft-Start. Connect a 0.47µF capacitor to GND to utilize soft-start power-up sequence.VDDAnalog Power Supply. Bypass to GND with a 0.1µF capacitor as close to pin as possible.INR-Right-Channel Negative Input. In mono mode, INR- is the negative input.INR+Right-Channel Positive Input. In mono mode, INR+ is the positive input.G1Gain Select Input 1G2Gain Select Input 2SHDNActive-Low Shutdown Input. Drive SHDN high for normal operation. Drive SHDN low to place the
device in shutdown mode.MUTE
Active-Low Mute Input. Drive logic-low to place the device in mute. In mute mode, Class D output
stage is no longer switching. Drive high for normal operation. MUTE is internally pulled up to VREG
with a 100kΩ resistor.TEMPThermal Flag Output, Open Drain. Pull up with a 10kΩ resistor to REG.TH2Temperature Flag Threshold Select Input 2TH1Temperature Flag Threshold Select Input 1TH0Temperature Flag Threshold Select Input 0
45, 46OUTR-Right-Channel Negative Output
47, 48OUTR+Right-Channel Positive Output
51, 52OUTL-Left-Channel Negative Output
53, 54OUTL+Left-Channel Positive OutputEPExposed Paddle. Connect to GND with multiple vias for best heat dissipation.
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
Typical Application Circuits/Functional Diagrams
OUTR+
OUTR-
OUTL-
OUTL+
SYNCIN
INL+
INL-
INR+
INR-
SHDN
SYNCOUT
PGND
RIN
RIN
RIN
RIN
VBIAS
VBIAS
TH0TH1TH2
TEMP
CPVDD
PVDD
PVDD
PVDD
PVDD
PVDD
VDD
VDD
C1P
C1N
REG
LEFT
CHANNEL
RIGHT
CHANNEL
VDIGITAL
1µF
0.1µF
0.1µF47µF*
1µF
1µF
1µF
1µF
CREG
0.01µF
CSS
0.47µFVDIGITAL
VDIGITAL
VDIGITAL
VDIGITAL
GND
MONO
FS1
FS2
10kΩ
10kΩ3433
19, 20, 21
51, 52
53, 54
45, 46
47, 48
22, 232–4, 39–41 49–505–7, 36–3825
MUTE31
*ADDITIONAL BULK CAPACITANCE
CONFIGURATION: TQFN STEREO MODE, SSM, INTERNAL OSCILLATOR, GAIN = 22dB, THERMAL SETTING = +120°C
MAX9708
GAIN
CONTROL
CONTROL
CHARGE
PUMP
REGULATOR
THERMAL SENSOR
MUX
CLASS D
MODULATOR
AND H-BRIDGE
CLASS D
MODULATOR
AND H-BRIDGE
Figure 1. Typical Application and Functional Diagram in Stereo Mode
MAX9708
20W/40W, Filterless, Spread-Spectrum,
Mono/Stereo, Class D Amplifier
Typical Application Circuits/Functional Diagrams (continued)
OUTR+
OUTR-
OUTL-
OUTL+
SYNCIN
INR+
INR-
SHDN
SYNCOUT
PGND
RIN
RIN
VBIAS
TH0TH1TH2
TEMP
CPVDD
PVDD
PVDD
PVDD
PVDD
PVDD
VDD
VDD
C1P
C1N
REG
AUDIO
INPUT
VDIGITAL
1µF
0.1µF
0.1µF
47µF*
1µF
1µF
CREG
0.01µF
0.1µF
CSS
0.47µFVDIGITAL
VDIGITAL
VDIGITAL
VDIGITAL
GND
MONO
FS1
FS2
10kΩ
10kΩ3433
19, 20, 21
51, 52
53, 54
45, 46
47, 48
22, 232–4, 39–41 49–505–7, 36–3825
MUTE31
VDIGITAL
MAX9708
GAIN
CONTROL
CHARGE
PUMP
REGULATOR
THERMAL SENSOR
MUX
CONTROL
CLASS D
MODULATOR
AND H-BRIDGE
CLASS D
MODULATOR
AND H-BRIDGE
*ADDITIONAL BULK CAPACITANCE
CONFIGURATION: TQFN MONO MODE, SSM, INTERNAL OSCILLATOR, GAIN = 22dB, THERMAL SETTING = +120°C
Figure 2. Typical Application and Functional Diagram in Mono Mode

Partno	Mfg	Dc	Qty	Available	Descript
MAX9708ETN+	MAXIM	N/a	338	avai	20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier