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 ..
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 ..
MAX9770ETI+T ,1.2W, Low-EMI, Filterless, Mono Class D Amplifier with Stereo DirectDrive Headphone Amplifiersfeatures THD+N as low as 0.025%, high 70dB PackagesPSRR, and SNR in excess of 90dB.The headphone am ..
MAX9776ETJ+ ,2 x 1.5W, Stereo Class D Audio Subsystem with DirectDrive Headphone AmplifierELECTRICAL CHARACTERISTICS2(V = PV = CPV = 3.3V, V = V = V = 0V, SHDN = V , I C settings (INA gain ..
MAX977EEE ,Single/Dual / +3V/+5V Dual-Speed Comparators with Auto-StandbyELECTRICAL CHARACTERISTICS(V = +2.7V to +5.25V, specifications are for high-speed mode, T = -40°C t ..
MAX977ESD ,Single/Dual / +3V/+5V Dual-Speed Comparators with Auto-Standbyfeatures independently adjustable timeout periods foreach comparator using separate capacitors.¤ µM ..
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
MAX9770ETI
1.2W Low-EMI / Filterless / Mono Class D Amplifier with Stereo DirectDrive Headphone Amplifiers
General DescriptionThe MAX9770 combines a mono, filterless, Class D
speaker amplifier and stereo DirectDrive headphone
amplifiers in a single device. The MAX9770 operates
from a single 2.5V to 5.5V supply and includes features
that reduce external component count, system cost,
board space, and offer improved audio reproduction.
The speaker amplifier makes use of Maxim’s patented
Class D architecture, providing Class AB performance
with Class D efficiency, conserving board space, and
extending battery life. The speaker amplifier delivers
1.2W into an 8Ωload while offering efficiencies above
85%. A spread-spectrum scheme reduces radiated
emissions caused by the modulation frequency.
Furthermore, the MAX9770 oscillator can be synchro-
nized to an external clock through the SYNC input,
avoiding possible problem frequencies inside a system.
The speaker amplifier features a low 0.025% THD+N,
high 70dB PSRR, and SNR in excess of 90dB.
The headphone amplifiers feature Maxim’s patented
DirectDrive architecture that produces a ground-refer-
enced output from a single supply, eliminating the need
for large DC-blocking capacitors. The headphone ampli-
fiers deliver up to 80mW into a 16Ωload, feature low
0.015% THD+N, high 80dB PSRR, and ±8kV ESD-pro-
tected outputs. A headphone sense input detects the
presence of a headphone, and automatically configures
the amplifiers for either speaker or headphone mode.
The MAX9770 includes internally set, logic-selectable
gain, and a comprehensive input multiplexer/mixer, allow-
ing multiple audio sources to be selected and for true
mono reproduction of a stereo source in speaker mode.
Industry-leading click-and-pop suppression eliminates
audible transients during power and shutdown cycles. A
low-power shutdown mode decreases supply current
consumption to 0.1µA, further extending battery life.
The MAX9770 is offered in space-saving, thermally effi-
cient 28-pin TQFN (5mm x 5mm x 0.8mm) and 28-pin
TSSOP packages. The MAX9770 features thermal-over-
load and output short-circuit protection, and is specified
over the extended -40°C to +85°C temperature range.
ApplicationsCellular Phones
PDAs
Compact Notebooks
Features1.2W Filterless Class D Amplifier Passes FCC
Class B Radiated Emissions Standards with
100mm of CableUnique Spread-Spectrum Mode Offers 5dB
Emissions Improvement Over Conventional
Methods80mW DirectDrive Headphone Amplifier
Eliminates Bulky DC-Blocking CapacitorsHigh 80dB PSRR at 217Hz85% EfficiencyLow 0.015% THD+NIndustry-Leading Click-and-Pop SuppressionIntegrated 3-Way Input Mixer/MultiplexerLogic-Selectable GainShort-Circuit and Thermal Protection±8kV ESD-Protected Headphone Outputs
Low-Power Shutdown ModeAvailable in Space-Saving, Thermally Efficient
Packages
28-Pin TQFN (5mm x 5mm x 0.8mm)
28-Pin TSSOP
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiers
Simplified Block Diagram19-3134; Rev 0; 5/04
Pin Configuration appears at end of data sheet.Lead-free package.
*EP = Exposed paddle.
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiers
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VDD= PVDD= CPVDD= 3.3V, GND = PGND = CPGND = 0V, SHDN=3.3V, C1 = C2 = 1µF, CBIAS= 0.047µF, SYNC = GND, RL= ∞,
speaker load connected between OUT+ and OUT-, headphone load connected between HPOUT_ and GND, TA= TMINto TMAX,
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.
GND to PGND to CPGND......................................-0.3V to +0.3V
VDDto PVDDto CPVDD..........................................-0.3V to +0.3V
VDDto GND..............................................................................6V
PVDDto PGND.........................................................................6V
CPVDDto CPGND....................................................................6V
CPVSSto CPGND....................................................................-6V
SVSSto GND...........................................................................-6V
C1N..........................................(PVSS- 0.3V) to (CPGND + 0.3V)
HPOUT_ to GND....................................................................±3V
All other pins to GND..................................-0.3V to (VDD+ 0.3V)
Continuous Current Into/Out of:
PVDD, PGND, OUT_......................................................600mA
PVSS..............................................................................260mA
Duration of HPOUT_ Short Circuit to VDD, PVDD,
GND, PGND...........................................................Continuous
Duration of Short Circuit between
HPOUTL and HPOUTR..........................................Continuous
Duration of OUT_ Short Circuit to VDD, PVDD, GND, PGND..10s
Duration of Short Circuit Between OUT+ and OUT-...............10s
Continuous Power Dissipation (TA= +70°C)
28-Pin TQFN (derate 20.8mW/°C above +70°C).......1667mW
28-Pin TSSOP (derate 12.8mW°C above +70°C)......1026mW
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
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiers
ELECTRICAL CHARACTERISTICS (continued)(VDD= PVDD= CPVDD= 3.3V, GND = PGND = CPGND = 0V, SHDN= 3.3V, C1 = C2 = 1µF, CBIAS= 0.047µF, SYNC = GND, RL= ∞,
speaker load connected between OUT+ and OUT-, headphone load connected between HPOUT_ and GND, TA= TMINto TMAX,
unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)
Typical Operating Characteristics(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiers
ELECTRICAL CHARACTERISTICS (continued)(VDD= PVDD= CPVDD= 3.3V, GND = PGND = CPGND = 0V, SHDN= 3.3V, C1 = C2 = 1µF, CBIAS= 0.047µF, SYNC = GND, RL= ∞,
speaker load connected between OUT+ and OUT-, headphone load connected between HPOUT_ and GND, TA= TMINto TMAX,
Note 1:All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
Note 2:Speaker amplifier testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For= 4Ω, L = 47µH. For RL= 8Ω, L = 68µH.
Note 3:Guaranteed by design, not production tested.
Note 4:PSRR is specified with the amplifier inputs connected to GND through CIN.
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiersypical Operating Characteristics (continued)(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiersypical Operating Characteristics (continued)(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiersypical Operating Characteristics (continued)(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiersypical Operating Characteristics (continued)(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiersypical Operating Characteristics (continued)(VDD= 3.3V, BW = 22Hz to 22kHz, GAIN1 = 1, GAIN2 = 0, spread-spectrum mode, headphone outputs in phase.)
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiers
Detailed DescriptionThe MAX9770 combines a mono 1.2W Class D speaker
amplifier and stereo 80mW DirectDrive headphone
amplifiers with integrated headphone sensing and
comprehensive click-and-pop suppression. A
mixer/multiplexer allows for selection and mixing
between two stereo input sources and a single mono
source. The MAX9770 features a high 80dB PSRR, low
0.015% THD+N, industry-leading click/pop perfor-
mance, and a low-power shutdown mode.
Class D Speaker AmplifierThe MAX9770 Class D amplifier features a true filter-
less, low EMI, switch-mode architecture that provides
Class AB-like performance with Class D efficiency.
Comparators monitor the MAX9770 input and compare
the input voltage to a sawtooth waveform. The com-
parators trip when the input magnitude of the sawtooth
exceeds the corresponding input voltage. The com-
parator resets at a fixed time after the rising edge of the
second comparator trip point, generating a minimum-
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone AmplifiersFigure 1. MAX9770 Outputs with an Input Signal Applied
width pulse tON(min)at the output of the second com-
parator (Figure 1). As the input voltage increases or
decreases, the duration of the pulse at one output
increases (the first comparator trip point) while the
other output pulse duration remains at tON(min). This
causes the net voltage across the speaker (VOUT+-
VOUT-) to change.
Operating ModesThe switching frequency of the charge pump is 1/2 the
switching frequency of the Class D amplifier, regard-
less of the operating mode. When SYNC is driven exter-
nally, the charge pump switches at 1/2 fSYNC. When
SYNC = VDD, the charge pump switches with a spread-
spectrum pattern.
Fixed-Frequency Modulation (FFM) ModeThe MAX9770 features two FFM modes. The FFM
modes are selected by setting SYNC = GND for a
1.1MHz switching frequency, and SYNC = FLOAT for a
1.45MHz switching frequency. In FFM mode, the fre-
quency spectrum of the Class D output consists of the
fundamental switching frequency and its associated
harmonics (see the Wideband FFT graph in the Typical
Operating Characteristics). The MAX9770 allows the
switching frequency to be changed by +32% should
the frequency of one or more harmonics fall in a sensi-
tive band. This can be done during operation and does
not affect audio reproduction.
Spread-Spectrum Modulation (SSM) ModeThe MAX9770 features a unique, patented spread-
spectrum mode that flattens the wideband spectral
components, improving EMI emissions radiated by the
speaker and cables by 5dB. Proprietary techniques
ensure that the cycle-to-cycle variation of the switching
period does not degrade audio reproduction or effi-
ciency (see the Typical Operating Characteristics).
Select SSM mode by setting SYNC = VDD. In SSM
mode, the switching frequency varies randomly by
±120kHz around the center frequency (1.22MHz). The
modulation scheme remains the same, but the period
of the sawtooth waveform changes from cycle-to-cycle
(Figure 2). 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 MHz, the wideband spec-
trum looks like white noise for EMI purposes (Figure 3).
MAX9770
1.2W Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone AmplifiersFigure2. MAX9770 Output with an Input Signal Applied (SSM mode)
