MAX9714ETJ ,6W, Filterless, Spread-Spectrum Mono/Stereo Class D AmplifiersMAX9713/MAX971419-3039; Rev 2; 9/046W, Filterless, Spread-SpectrumMono/Stereo Class D Amplifiers
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MAX9714ETJ+T ,6W, Filterless, Spread-Spectrum Mono/Stereo Class D AmplifiersMAX9713/MAX971419-3039; Rev 6; 12/066W, Filterless, Spread-SpectrumMono/Stereo Class D Amplifiers
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 ..
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MAX9715ETE+T ,2.8W, Low-EMI, Stereo, Filterless Class D Audio AmplifierELECTRICAL CHARACTERISTICS(V = PV = 5.0V, GND = PGND = 0V, V = V , C = 1μF, speaker impedance = 8Ω ..
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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 ..
MB89193PF ,8-bit Proprietary MicrocontrollerFUJITSU SEMICONDUCTORDS07-12512-7EDATA SHEET8-bit Proprietary MicrocontrollerCMOS2F MC-8L MB89190/1 ..
MAX9713ETJ-MAX9714ETJ
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
patent-protected modulation and switching schemes
render the traditional 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 100dB. 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 2; 9/04
Ordering Information*EP = Exposed paddle.
LCD Monitors
LCD TVs
Desktop PCs
LCD Projectors
High-End Notebook
Audio
Hands-Free Car
Phone Adaptors
Pin Configurations appear at end of data sheet.
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)
MAX9713 32-Pin TQFN (derate 21.3mW/°C
above +70°C)..........................................................1702.1mW
MAX9714 32-Pin TQFN (derate 33.3mW/°C
above +70°C)..........................................................2666.7mW
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= CREG= 0.47µF, C1 = 100nF, C2 = 1µF, FS1 = FS2 = GND
(fS= 330kHz), RLconnected between OUTL+ and OUTL- and OUTR+ and OUTR-, TA= TMINto TMAX, unless otherwise noted.
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= CREG= 0.47µF, 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)
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
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
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
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
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 associ-
ated harmonics (see the Wideband FFT 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, patented
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 FS1 = FS2 = H. In SSM mode, the
switching frequency varies randomly by ±1.7%kHz
around the center frequency (335kHz). The modulation
scheme remains the same, but the period of the trian-
gle 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 (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 I*R 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
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 180nF.
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 Amplifiers
