MAX9768ETG+T ,10W Mono Class D Speaker Amplifier with Volume ControlELECTRICAL CHARACTERISTICS(V = 12V, V = 3.3V, V = V = 0, V = V , V = 0; Max volume setting; speaker ..
MAX976ESA ,Single/Dual/Quad / SOT23 / Single-Supply / High-Speed / Low-Power Comparatorsfeatures a' 1nA Shutdown Supply Currentlow-power shutdown mode that places the output in ahigh-impe ..
MAX976ESA+ ,Single/Dual/Quad, SOT23, Single-Supply, High-Speed, Low-Power ComparatorsELECTRICAL CHARACTERISTICS(V = +2.7V to +5.5V, V = 0V, T = -40°C to +85°C, unless otherwise noted. ..
MAX976ESA+T ,Single/Dual/Quad, SOT23, Single-Supply, High-Speed, Low-Power Comparatorsapplications. They achieve a20ns propagation delay while consuming only 225µA ♦ 225µA Supply Curren ..
MAX976EUA ,Single/Dual/Quad / SOT23 / Single-Supply / High-Speed / Low-Power ComparatorsELECTRICAL CHARACTERISTICS(V = +2.7V to +5.5V, V = 0V, T = -40°C to +85°C, unless otherwise noted. ..
MAX9770ETI ,1.2W Low-EMI / Filterless / Mono Class D Amplifier with Stereo DirectDrive Headphone AmplifiersELECTRICAL CHARACTERISTICS(V = PV = CPV = 3.3V, GND = PGND = CPGND = 0V, SHDN = 3.3V, C1 = C2 = 1µF ..
MB89475 ,F2MC-8L/Low Power/Low Voltage Microcontrollersapplications forconsumer product.2* : F MC stands for FUJITSU Flexible Microcontroller.n
MB89535A ,F2MC-8L/Low Power/Low Voltage MicrocontrollersFEATURES• Wide range of package options• Two types of QFP packages (1 mm pitch, 0.65 mm pitch) • LQ ..
MB89535A ,F2MC-8L/Low Power/Low Voltage MicrocontrollersFUJITSU SEMICONDUCTORDS07-12547-4EDATA SHEET8-bit Original Microcontroller CMOS2F MC-8L MB89530A Se ..
MB89537A , 8-bit Original Microcontroller CMOS, F-2MC-8L MB89530A Series
MB89537A , 8-bit Original Microcontroller CMOS, F-2MC-8L MB89530A Series
MB89537AC , 8-bit Original Microcontroller CMOS, F-2MC-8L MB89530A Series
MAX9768ETG+-MAX9768ETG+T
10W Mono Class D Speaker Amplifier with Volume Control
General DescriptionThe MAX9768 mono 10W Class D speaker amplifier
provides high-quality, efficient audio power with an inte-
grated volume control function.
The MAX9768 features a 64-step dual-mode (analog or
digitally programmable) volume control and mute func-
tion. The audio amplifier operates from a 4.5V to 14V
single supply and can deliver up to 10W into an 8Ω
speaker with a 14V supply.
A selectable spread-spectrum mode reduces EMI-radiat-
ed emissions, allowing the device to pass EMC testing
with ferrite bead filters and cable lengths up to 1m. The
MAX9768 can be synchronized to an external clock,
allowing synchronization of multiple Class D amplifiers.
The MAX9768 features high 77dB PSRR, low 0.08%
THD+N, and SNR up to 97dB. Robust short-circuit and
thermal-overload protection prevent device damage
during a fault condition. The MAX9768 is available in a
24-pin thin QFN-EP (4mm x 4mm x 0.8mm) package
and is specified over the extended -40°C to +85°C tem-
perature range.
Applications
Features10W Output (8Ω, PVDD= 14V, THD+N = 10%)Spread-Spectrum ModulationMeets EN55022B EMC with Ferrite Bead FiltersAmplifier Operation from 4.5V to 14V Supply64-Step Integrated Volume Control (I2C or Analog)Low 0.08% THD+N (RL= 8Ω, POUT= 6W)High 77dB PSRRTwo tONTimes Offered
MAX9768—220ms
MAX9768B—15msLow-Power Shutdown Mode (0.5µA)Short-Circuit and Thermal-Overload Protection
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control19-0854; Rev 2; 11/08
EVALUATION KIT
AVAILABLE
Pin Configuration located at end of data sheet.
Ordering Information
Note:All devices are specified over the -40°C to +85°C oper-
ating temperature range.
+Denotes a lead-free/RoHS-compliant package.
*EP = Exposed pad.
PARTPIN-PACKAGEtON (ms)MAX9768ETG+24 TQFN-EP*220
MAX9768BETG+24 TQFN-EP*15
MUTE
SHDN
SPEAKER
AUDIO
INPUT
FILTERLESS
CLASS D
SPEAKER
OUTPUT
ANALOG OR
I2C VOLUME
CONTROL
3.3V4.5V TO 14V
MAX9768
Simplified Block Diagram
MAX9768 EMI WITH FERRITE BEAD FILTERS
(VDD = 12V, 1m CABLE, 8Ω LOAD)FREQUENCY (MHz)
AMPLITUDE (dB
V/m)251000
OVER 20dB MARGIN
TO EN55022B LIMIT
Notebook Computers
Flat-Panel Displays
Multimedia Monitors
GPS Navigation
Systems
Security/Personal
Mobile Radio
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VSHDN= VDD, VMUTE= 0; Max volume setting; speaker load resistor connected
between OUT+ and OUT-, RL= ∞, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RF= 30kΩ,
SSM mode. Filterless modulation mode (see the Functional Diagram/Typical Application Circuit). 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.
PVDDto PGND........................................................-0.3V to +16V
VDDto GND..............................................................-0.3V to +4V
SCLK, SDA/VOL to GND..........................................-0.3V to +4V
FB, SYNCOUT............................................-0.3V to (VDD+ 0.3V)
BOOT_ to OUT_........................................................-0.3V to +4V
OUT_ to GND...........................................-0.3V to (PVDD+ 0.3V)
PGND to GND ......................................................-0.3V to +0.3V
Any Other Pin to GND..............................................-0.3V to +4V
OUT_ Short-Circuit Duration.......................................Continuous
Continuous Current (PVDD, PGND, OUT_) ..........................2.2A
Continuous Input Current (Any Other Pin) .......................±20mA
Continuous Input Current (FB_) .......................................±60mA
Continuous Power Dissipation (TA= +70°C)
Single-Layer Board:
24-Pin Thin QFN 4mm x 4mm,
(derate 20.8mW/°C above +70°C).................................1.67W
Multilayer Board:
24-Pin Thin QFN 4mm x 4mm,
(derate 27.8mW/°C above +70°C).................................2.22W
θJA, Single-Layer Board…...........................................….48°C/W
θJA, Multilayer Board...................................................….36°C/W
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) ................................+300°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
GENERALSpeaker Supply Voltage
RangePVDDInferred from PSRR test4.514.0V
Supply Voltage RangeVDDInferred from PSRR and UVLO test2.73.6V
IVDD714.2
Filterless modulation47.6Quiescent CurrentIPVDDClassic PWM modulation47.6
Shutdown CurrentISHDNISHDN = IPVDD + IDD, SHDN = GND, TA = +25°C0.550µA
Filterless modulation, VMUTE = VDD, TA = +25°C±2±12.5Output OffsetVOSFilterless modulation, VMUTE = 0V, TA = +25°C±2±14mV
MAX9768220Turn-On TimetONMAX9768B15ms
Common-Mode Bias VoltageVBIAS1.5V
Input Amplifier Output-
Voltage Swing HighVOHSpecified as
VDD - VOHRL = 2kΩ connect to 1.5V3.6100mV
Input Amplifier Output-
Voltage Swing LowVOLSpecified as
VOL - GNDRL = 2kΩ connect to 1.5V650mV
Input Amplifier Output
Short-Circuit Current Limit±60mA
Input Amplifier Gain-
Bandwidth ProductGBW1.8MHz
SPEAKER AMPLIFIERSInternal GainAVMAX
Max volume setting; from FB to amplifier outputs
|(OUT+) - (OUT-)|; excludes external gain
resistors
29.2730.131.00dB
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSFilterless modulation87Efficiency (Note 2)ηPOUT = 8W, fIN =
1kHz, RL = 8ΩClassic PWM modulation85%
RL = 8Ω, THD+N = 1%,
filterless modulation1.3
PVDD = 5V
RL = 8Ω, THD+N = 10%,
filterless modulation1.7
RL = 8Ω, THD+N = 10%,
classic PWM modulation9
PVDD = 12VRL = 8Ω, THD+N = 10%,
filterless modulation9
RL = 8Ω, THD+N = 10%,
classic PWM modulation10
Output Power (Note 2)POUT
PVDD = 14VRL = 8Ω, THD+N = 10%,
filterless modulation10
Soft Output Current LimitILIM1.752A
Hard Output Current LimitISC2.5A
Filterless modulation0.09Total Harmonic Distortion
Plus Noise (Note 2)THD+Nf = 1kHz, RL = 8Ω,
POUT = 5WClassic PWM modulation0.08%
FFM94UnweightedSSM93
FFM97
0dB = 8W, RL =
8Ω, BW = 22Hz to
22kHz, filterless
modulation modeA-weightedSSM97
FFM93UnweightedSSM89
FFM97
Signal-to-Noise Ratio
(Note 2)SNR
0dB = 8W, RL =
8Ω, BW = 22Hz to
22kHz, classic
PWM modulationA-weightedSSM91
MUTE Attenuation (Note 3)0dB = 8W, f = 1kHz115dB
VDD = 2.7V to 3.6V, filterless modulation,
TA = +25°C5268
PVDD = 4.5V to 14V, filterless modulation,
TA = +25°C6784
f = 1kHz, VRIPPLE = 200mVP-P on PVDD77
Power-Supply Rejection
RatioPSRR
f = 1kHz, VRIPPLE = 100mVP-P on VDD60
SYNC = GND106012001320
SYNC = unconnected129614401584Oscillator FrequencyfOCS
SYNC = VDD (spread-spectrum modulation
mode)
±30
kHz
ELECTRICAL CHARACTERISTICS (continued)(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VSHDN= VDD, VMUTE= 0; Max volume setting; speaker load resistor connected
between OUT+ and OUT-, RL= ∞, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RF= 30kΩ,
SSM mode. Filterless modulation mode (see the Functional Diagram/Typical Application Circuit). TA= TMINto TMAX, unless otherwise
noted. Typical values are at TA= +25°C.) (Note 1)
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
ELECTRICAL CHARACTERISTICS (continued)(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VSHDN= VDD, VMUTE= 0; Max volume setting; speaker load resistor connected
between OUT+ and OUT-, RL= ∞, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RF= 30kΩ,
SSM mode. Filterless modulation mode (see the Functional Diagram/Typical Application Circuit). TA= TMINto TMAX, unless otherwise
noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSSYNC = GND265300330
SYNC = unconnected324360396Class D Switching
FrequencySYNC = VDD (spread-spectrum modulation
mode)
±7.5
kHz
SYNC Frequency Lock
Range10001600kHz
Minimum SYNC Frequency
Lock Duty Cycle40%
Maximum SYNC Frequency
Lock Duty Cycle60%
Gain MatchingFull volume (ideal matching for RIN and RF)2%
Into shutdown52.6
Out of shutdown48
Into mute67
Click-and-Pop Level (Note 2)KCP
Peak voltage, 32 samples
per second, A-weighted, RIN
x CIN ≤ 10ms to guarantee
clickless/popless operationOut of mute57
dBV
Input ImpedanceDC volume control mode (SDA/VOL)100MΩ
Input HysteresisDC volume control mode (SDA/VOL)11mV
9.5dB Gain VoltageDC volume control mode (SDA/VOL)0.1 x VDDV
Full Mute VoltageDC volume control mode (SDA/VOL)0.9 x VDDV
DIGITAL INPUTS (SHDN, MUTE, ADDR1, ADDR2, SYNC)SYNC2.33Input-Voltage HighVIHAll other pins0.7 x VDDV
SYNC0.8Input-Voltage LowVILAll other pins0.3 x VDDV
ISYNCTA = +25°C±7.5±13Input Leakage CurrentILKAll other digital inputs, TA = +25°C±1µA
DIGITAL OUTPUT (SYNCOUT)Output-Voltage HighLoad = 1mAVDD - 0.3V
Output-Voltage LowLoad = 1mA0.3V
Rise/Fall TimeCL = 10pF5ns
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
ELECTRICAL CHARACTERISTICS (continued)(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VSHDN= VDD, VMUTE= 0; Max volume setting; speaker load resistor connected
between OUT+ and OUT-, RL= ∞, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RF= 30kΩ,
SSM mode. Filterless modulation mode (see the Functional Diagram/Typical Application Circuit). TA= TMINto TMAX, unless otherwise
noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
THERMAL PROTECTIONThermal Shutdown
Threshold150°C
Thermal Shutdown
Hysteresis15°C
DIGITAL INPUTS (SCLK, SDA/VOL)Input-Voltage HighVIH0.7 x VDDV
Input-Voltage LowVIL0.3 x VDDV
Input High Leakage CurrentIIHVIN = VDD, TA = +25°C±1µA
Input Low Leakage CurrentIILVIN = GND, TA = +25°C±1µA
Input Hysteresis0.1 x VDDV
Input CapacitanceCIN5pF
DIGITAL OUTPUTS (SDA/VOL)Output High CurrentIOHVOH = VDD1µA
Output Low VoltageVOLIOL = 3mA0.4V
I2C TIMING CHARACTERISTICS (Figure 3)Serial ClockfSCL400kHz
Bus Free Time Between a
STOP and START
Condition
tBUF1.3µs
Hold Time (Repeated)
START ConditiontHD,STA0.6µs
Repeated START Condition
Setup TimetSU,STA0.6µs
STOP Condition Setup TimetSU,STO0.6µs
Data Hold TimetHD,DAT00.9µs
Data Setup TimetSU,DAT100ns
SCL Clock Low PeriodtLOW1.3µs
SCL Clock High PeriodtHIGH0.6µs
Rise Time of SDA and SCL,
ReceivingtR(Note 4)20 +
0.1Cb300ns
Fall Time of SDA and SCL,
ReceivingtF(Note 4)20 +
0.1Cb300ns
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
Note 1:All devices are 100% production tested at TA= +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.
Note 3:Device muted by either asserting MUTE or minimum VOLsetting.
Note 4:Cb= total capacitance of one bus line in pF.
ELECTRICAL CHARACTERISTICS (continued)(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VSHDN= VDD, VMUTE= 0; Max volume setting; speaker load resistor connected
between OUT+ and OUT-, RL= ∞, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RF= 30kΩ,
SSM mode. Filterless modulation mode (see the Functional Diagram/Typical Application Circuit). TA= TMINto TMAX, unless otherwise
noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSFall Time of SDA,
TransmittingtF(Note 4)20 +
0.1Cb250ns
Pulse Width of Spike
SuppressedtSP050ns
Capacitive Load for Each
Bus LineCb400pF
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCYMAX9768 toc01
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01100k
PVDD = 12V
RL = 8Ω
FILTERLESS MODULATION
OUTPUT POWER = 6W
OUTPUT POWER = 2W
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCYMAX9768 toc02
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.01100k
PVDD = 12V
RL = 8Ω
PWM MODE
OUTPUT POWER = 5W
OUTPUT POWER = 2W
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCYMAX9768 toc03
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.001100k
PVDD = 5V
RL = 8Ω
FILTERLESS MODULATION
OUTPUT POWER = 1W
OUTPUT POWER = 300mW
Typical Operating Characteristics(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VMUTE= 0; 0dB volume setting; all speaker load resistors connected between OUT+
and OUT-, RL= 8Ω, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RFB= 30kΩ, spread-spec-
trum modulation mode.)
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCYMAX9768 toc04
FREQUENCY (Hz)
THD+N (%)
10k1k100
0.001100k
PVDD = 5V
RL = 8Ω
PWM MODE
OUTPUT POWER = 300mW
OUTPUT POWER = 800mW
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCYMAX9768 toc05
FREQUENCY (Hz)
THD+N (%)
PVDD = 12V
RL = 8Ω
FILTERLESS MODULATION
POUT = 4W
10k1k10010100k
FIXED-FREQUENCY
MODULATION
SPREAD-SPECTRUM
MODULATION
MAX9768 toc06
FREQUENCY (Hz)
THD+N (%)
PVDD = 12V
RL = 8Ω
PWM MODE
POUT = 4W
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY10k1k10010100k
FIXED-FREQUENCY
MODULATION
SPREAD-SPECTRUM
MODULATION
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWERMAX9768 toc07
OUTPUT POWER (W)
THD+N (%)8462
PVDD = 12V
RL = 8Ω
FILTERLESS MODULATION
fIN = 10kHz
fIN = 100HzfIN = 1kHz
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWERMAX9768 toc08
OUTPUT POWER (W)
THD+N (%)8462
PVDD = 12V
RL = 8Ω
PWM MODE
fIN = 10kHz
fIN = 100HzfIN = 1kHz
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWERMAX9768 toc09
OUTPUT POWER (W)
THD+N (%)
PVDD = 5V
RL = 8Ω
FILTERLESS MODULATION
fIN = 10kHz
fIN = 100HzfIN = 1kHz
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWERMAX9768 toc10
OUTPUT POWER (W)
THD+N (%)
PVDD = 5V
RL = 8Ω
PWM MODE
fIN = 10kHz
fIN = 100HzfIN = 1kHz
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWERMAX9768 toc11
OUTPUT POWER (W)
THD+N (%)4682
PVDD = 12V
RL = 8Ω
fIN = 1kHz
FILTERLESS MODULATION
FIXED-FREQUENCY
MODULATION
SPREAD-SPECTRUM
MODULATION
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWERMAX9768 toc12
OUTPUT POWER (W)
THD+N (%)4682
PVDD = 12V
RL = 8Ω
fIN = 1kHz
PWM MODE
FIXED-FREQUENCY
MODULATION
SPREAD-SPECTRUM
MODULATION
Typical Operating Characteristics (continued)(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VMUTE= 0; 0dB volume setting; all speaker load resistors connected between OUT+
and OUT-, RL= 8Ω, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RFB= 30kΩ, spread-spec-
trum modulation mode.)
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
EFFICIENCY vs. OUTPUT POWERMAX9768 toc13
OUTPUT POWER (W)
EFFICIENCY (%)4682
PWM MODE
PVDD = 12V
fIN = 1kHz
RL = 8Ω
FILTERLESS MODULATION
EFFICIENCY vs. OUTPUT POWERMAX9768 toc14
OUTPUT POWER (W)
EFFICIENCY (%)
PWM MODE
FILTERLESS MODULATION
PVDD = 5V
fIN = 1kHz
RL = 8Ω
EFFICIENCY vs. SUPPLY VOLTAGEMAX9768 toc15
SUPPLY VOLTAGE (V)
EFFICIENCY (%)
THD+N = 10%
THD+N = 1%
fIN = 1kHz
RL = 8Ω
FILTERLESS MODULATION
EFFICIENCY vs. SUPPLY VOLTAGEMAX9768 toc16
SUPPLY VOLTAGE (V)
EFFICIENCY (%)
fIN = 1kHz
RL = 8Ω
PWM MODULATION
THD+N = 10%
THD+N = 1%
OUTPUT POWER vs. SUPPLY VOLTAGEMAX9768 toc17
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)810126
RL = 8Ω
fIN = 1kHz
PWM MODE
THD+N = 10%
THD+N = 1%
OUTPUT POWER vs. SUPPLY VOLTAGEMAX9768 toc18
SUPPLY VOLTAGE (V)
OUTPUT POWER (W)810126
RL = 4Ω
fIN = 1kHz
PWM MODE
THD+N = 1%
THD+N = 10%
OUTPUT POWER vs. LOAD RESISTANCEMAX9768 toc19
LOAD RESISTANCE (Ω)
OUTPUT POWER (W)101525205
PVDD = 12V
f = 1kHz
PWM MODE
THD+N = 1%
THD+N = 10%
OUTPUT POWER vs. LOAD RESISTANCEMAX9768 toc20
LOAD RESISTANCE (Ω)
OUTPUT POWER (W)101525205
PVDD = 5V
f = 1kHz
PWM MODE
THD+N = 1%
THD+N = 10%
Typical Operating Characteristics (continued)(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VMUTE= 0; 0dB volume setting; all speaker load resistors connected between OUT+
and OUT-, RL= 8Ω, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RFB= 30kΩ, spread-spec-
trum modulation mode.)
CASE TEMPERATURE vs. OUTPUT POWERMAX9768 toc21
OUTPUT POWER (W)
CASE TEMPERATURE (
°C)461082
fIN = 1kHz
RL = 8Ω
PVDD = 14V
PVDD = 12V
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
POWER-SUPPLY REJECTION RATIO (PVDD)
vs. FREQUENCYMAX9768 toc22
FREQUENCY (Hz)
PSRR (dB)
100k1k10k100
PVDD = 12V
VRIPPLE = 100mVP-P
RL = 8Ω
PWM MODE
FILTERLESS MODULATION
POWER-SUPPLY REJECTION RATIO (VDD)
vs. FREQUENCYMAX9768 toc23
FREQUENCY (Hz)
PSRR (dB)
100k1k10k100
VDD = 3.3V
VRIPPLE = 100mVP-P
RL = 8Ω
PWM MODE
FILTERLESS MODULATION
OUTPUT WAVEFORM
(FILTERLESS MODULATION)MAX9768 toc24
1μs/div
5V/div
5V/div
OUTPUT WAVEFORM (PWM MODE)MAX9768 toc25
1μs/div
5V/div
5V/div
OUTPUT FREQUENCY SPECTRUMMAX9768 toc26
FREQUENCY (kHz)10515
FFM MODE
VIN = -60dBV
f = 1kHz
RL = 8Ω
UNWEIGHTED
OUTPUT MAGNITUDE (dBV)
OUTPUT FREQUENCY SPECTRUMMAX9768 toc27
FREQUENCY (kHz)10515
VIN = -60dBV
f = 1kHz
RL = 8Ω
UNWEIGHTED
OUTPUT MAGNITUDE (dBV)
WIDEBAND OUTPUT SPECTRUM
(FIXED-FREQUENCY MODULATION MODE)MAX9768 toc28
FREQUENCY (MHz)
RBW = 10kHz
INPUT AC GROUNDED
FILTERLESS MODULATION
OUTPUT AMPLITUDE (dBV)
WIDEBAND OUTPUT SPECTRUM
(FIXED-FREQUENCY MODULATION MODE)MAX9768 toc29
FREQUENCY (MHz)
RBW = 10kHz
INPUT AC GROUNDED
PWM MODE
OUTPUT AMPLITUDE (dBV)
WIDEBAND OUTPUT SPECTRUM
(SPREAD-SPECTRUM MODULATION MODE)MAX9768 toc30
FREQUENCY (MHz)
OUTPUT AMPLITUDE (dBV)
RBW = 10kHz
INPUT AC GROUNDED
FILTERLESS MODULATION
Typical Operating Characteristics (continued)(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VMUTE= 0; 0dB volume setting; all speaker load resistors connected between OUT+
and OUT-, RL= 8Ω, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RFB= 30kΩ, spread-spec-
trum modulation mode.)
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
WIDEBAND OUTPUT SPECTRUM
(SPREAD-SPECTRUM MODULATION MODE)MAX9768 toc31
FREQUENCY (MHz)
OUTPUT AMPLITUDE (dBV)
RBW = 10kHz
INPUT AC GROUNDED
PWM MODE
TURN-ON/OFF RESPONSE
(MAX9768)MAX9768 toc32
100ms/div
SHDN
2V/div
OUT
500mA/div
TURN-ON/OFF RESPONSE
(MAX9768B)MAX9768 toc33
40ms/div
SHDN
2V/div
OUT
500mA/div
VOLUME CONTROL LEVEL
vs. VOLUME CONTROL VOLTAGEMAX9768 toc34
VVOL (V)
VOLUME LEVEL (dB)
SUPPLY CURRENT (PVDD)
vs. SUPPLY VOLTAGEMAX9768 toc35
SUPPLY VOLTAGE (V)108612
SUPPLY CURRENT (mA)
PWM MODE
RL = ∞
FILTERLESS MODULATION
SUPPLY CURRENT (VDD)
vs. SUPPLY VOLTAGEMAX9768 toc36
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
PWM MODE
FILTERLESS MODULATION
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGEMAX9768 toc37
SUPPLY VOLTAGE (V)108612
SHUTDOWN CURRENT (
SHUTDOWN CURRENT = IPVDD + IDD
VDD = 3.3V
Typical Operating Characteristics (continued)(VPVDD= 12V, VDD= 3.3V, VGND= VPGND= 0, VMUTE= 0; 0dB volume setting; all speaker load resistors connected between OUT+
and OUT-, RL= 8Ω, unless otherwise noted. CBIAS= 2.2µF, C1 = C2 = 0.1µF, CIN= 0.47µF, RIN= 20kΩ, RFB= 30kΩ, spread-spec-
trum modulation mode.)
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
Pin Description
PINNAMEFUNCTION1, 2OUT+Positive Speaker Output
3, 16PVDDSpeaker Amplifier Power-Supply Input. Bypass with a 1µF capacitor to ground.BOOT+Positive Speaker Output Boost Flying-Capacitor Connection. Connect a 0.1µF ceramic capacitor
between BOOT+ and OUT+.SCLK2C Serial-Clock Input and Modulation Scheme Select. In I2C mode (ADDR1 and ADDR2 ≠ GND)
acts as I2C serial-clock input. Connect SCLK to VDD for classic PWM modulation, or connect
SCLK to ground for filterless modulation.SDA/VOLI2C Serial Data I/O and Analog Volume Control Input
7FBFeedback. Connect feedback resistor between FB and IN to set amplifier gain. See the Adjustable
Gain section.INAudio Input
9, 11GNDGroundBIASCommon-Mode Bias Voltage. Bypass with a 2.2µF capacitor to GND.SYNC
Frequency Select and External Clock Input.
SYNC = GND: Fixed-frequency mode with fS = 300kHz.
SYNC = Unconnected: Fixed-frequency mode with fS = 360kHz.
SYNC = VDD: Spread-spectrum mode with fS = 300kHz ±7.5kHz.
SYNC = Clocked: Fixed-frequency mode with fS = external clock frequency.SYNCOUTClock Signal OutputVDDPower-Supply Input. Bypass with a 1µF capacitor to GND.BOOT-Negative Speaker Output Boost Flying-Capacitor Connection. Connect a 0.1µF ceramic capacitor
between BOOTL- and OUTL-.
17, 18OUT-Negative Speaker OutputSHDNShutdown Input. Drive SHDN low to disable the audio amplifiers. Connect SHDN to VDD for normal
operationMUTEMute Input. Drive MUTE high to mute the speaker outputs. Connect MUTE to GND for normal
operation.
21, 22PGNDPower GroundADDR2Address Select Input 2. I2C address option, also selects volume control mode.ADDR1Address Select Input 1. I2C address option, also selects volume control mode.
—EPExposed Pad. Connect the exposed thermal pad to GND, and use multiple vias to a solid copper
area on the bottom of the PCB.
Detailed DescriptionThe MAX9768 10W, Class D audio power amplifier with
spread-spectrum modulation provides a significant step
forward in switch-mode amplifier technology. The
MAX9768 offers Class AB performance with Class D
efficiency and a minimal board space solution. This
device features a wide supply voltage operation (4.5V to
14V), analog or digitally adjusted volume control, exter-
nally set input gain, shutdown mode, SYNC input and
output, speaker mute, and industry-leading click-and-
pop suppression.
The MAX9768 features a 64-step, dual-mode (analog or2C programmed) volume control and mute function. In
analog volume control mode, voltage applied to
SDA/VOL sets the volume level. Two address inputs
(ADDR1, ADDR2) set the volume control function
between analog and I2C and set the slave address. In
I2C mode there are three selectable slave addresses
allowing for multiple devices on a single bus.
Spread-spectrum modulation and synchronizable
switching frequency significantly reduce EMI emis-
sions. The outputs use Maxim’s low-EMI modulation
scheme with minimum pulse outputs when the audio
inputs are at the zero crossing. As the input voltage
increases or decreases, the duration of the pulse at
one output increases while the other output pulse dura-
tion remains the same. This causes the net voltage
across the speaker (VOUT+- VOUT-) to change. The
minimum-width pulse topology reduces EMI and
increases efficiency.
MAX9768
10W Mono Class D Speaker
Amplifier with Volume ControlMUTE
VOLUME
CONTROL
CLASS D
SHUTDOWN
CONTROL
OSCILLATOR
SYNCOUT
BIAS
VDD
VDD
PVDD
CBIAS
2.2μF1, 2
17, 18
30kΩ
RIN
20kΩ
CIN
0.47μFC1
0.1μF
0.1μF
1μF1μF
GNDPGND
OUT+
BOOT+
OUT-
BOOT-
BIAS
3, 16
9, 1121, 22
2.7V to 3.6V4.5V to 14V
SYNC
MUTE
SHDN
SDA/VOL
SCLK
ADDR1
ADDR22C
ANALOG
CONTROL
MAX9768
(SHOWN IN ANALOG VOLUME CONTOL MODE, AV = 23.5dB, f-3dB = 17Hz, SPREAD-SPECTRUM MODULATION MODE, FILTERLESS MODULATION MODE, MUTE OFF)
Functional Diagram/Typical Application Circuit
Operating Modes
Fixed-Frequency ModeThe MAX9768 features two fixed-frequency modes:
300kHz and 360kHz. Connect SYNC to GND to select
300kHz switching frequency; leave SYNC unconnected
to select 360kHz switching frequency. The frequency
spectrum of the MAX9768 consists of the fundamental
switching frequency and its associated harmonics (see
the Wideband Output Spectrum graphs in the Typical
Operating Characteristics). For applications where
exact spectrum placement of the switching fundamen-
tal is important, program the switching frequency so the
harmonics do not fall within a sensitive frequency band
(Table 1). Audio reproduction is not affected by chang-
ing the switching frequency.
Spread-Spectrum ModeThe MAX9768 features a unique spread-spectrum
mode that flattens the wideband spectral components,
improving EMI emissions that may be radiated by the
speaker and cables. This mode is enabled by setting
SYNC = VDD(Table 1). In SSM mode, the switching fre-
quency varies randomly by ±7.5kHz around the center
frequency (300kHz). The modulation scheme remains
the same, but the period of the triangle waveform
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. A proprietary amplifier topology ensures this
does not corrupt the noise floor in the audio bandwidth.
External Clock ModeThe SYNC input allows the MAX9768 to be synchro-
nized to an external clock, or another Maxim Class D
amplifier, creating a fully synchronous system, minimiz-
ing clock intermodulation, and allocating spectral com-
ponents of the switching harmonics to insensitive
frequency bands. Applying a clock signal between
1MHz and 1.6MHz to SYNC synchronizes the
MAX9768. The Class D switching frequency is equal to
one-fourth the SYNC input frequency.
SYNCOUT is equal to the SYNC input frequency and
allows several Maxim amplifiers to be cascaded. The
synchronized output minimizes interference due to
clock intermodulation caused by the switching spread
between single devices. The modulation scheme
remains the same when using SYNCOUT, and audio
reproduction is not affected (Figure 1). Current flowing
between SYNCOUT of a master device and SYNC of a
slave device is low as the SYNC input is high imped-
ance (typically 200kΩ).
MAX9768
10W Mono Class D Speaker
Amplifier with Volume Control
Table 1. Operating Modes
SYNCOSCILLATOR FREQUENCY (kHz)CLASS D FREQUENCY (kHz)GNDFixed-frequency modulation with fOSC = 1200Fixed-frequency modulation with fOSC = 300
UnconnectedFixed-frequency modulation with fOSC = 1440Fixed-frequency modulation with fOSC = 360
VDDSpread-spectrum modulation with fOSC = 1200 ±30Spread-spectrum modulation with fOSC = 300 ±7.5
ClockedFixed-frequency modulation with fOSC = external clock
frequency
Fixed-frequency modulation with fOSC = external clock
frequency / 4
SYNCOUT
OUT+
OUT-
OUT+
OUT-SYNC
MAX9768
MAX9768
Figure 1. Cascading Two Amplifiers
