View MAX9708_388222.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-3678; Rev 2; 3/06
KIT ATION EVALU ABLE AVAIL
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
General Description
The MAX9708 mono/stereo, Class D audio power amplifier delivers up to 2 x 21W into an 8 stereo mode and 1 x 42W into a 4 load in mono mode while offering up to 87% efficiency. The MAX9708 provides Class AB amplifier 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 fixedfrequency modulation (FFM) mode, and a spread-spectrum modulation (SSM) mode that reduces EMI-radiated emissions. The MAX9708 can be synchronized to an external clock from 600kHz to 1.2MHz. A synchronized output allows multiple units to be cascaded in the system. Features include fully differential inputs, comprehensive click-and-pop suppression, and four selectable-gain settings (22dB, 25dB, 29.5dB, and 36dB). A pin-programmable 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 56-pin TQFN (8mm x 8mm x 0.8mm) and 64-pin TQFP (10mm x 10mm x 1.4mm) packages, and is specified over the extended -40C to +85C temperature range.
Features
2 x 21W Output Power in Stereo Mode (8, THD = 10%) 1 x 42W Output Power in Mono Mode (4, THD = 10%) High Efficiency: Up to 87% Filterless Class D Amplifier Unique Patented Spread-Spectrum Mode Programmable Gain (+22dB, +25dB, +29.5dB, +36dB) High PSRR (90dB at 1kHz) Differential Inputs Suppress Common-Mode Noise Shutdown and Mute Control Integrated Click-and-Pop Suppression Low 0.1% THD+N Current Limit and Thermal Protection Programmable Thermal Flag SYNC Input/Output Available in Thermally Efficient, Space-Saving Packages: 56-Pin TQFN and 64-Pin TQFP
MAX9708
Ordering Information
PART MAX9708ETN+ MAX9708ECB* TEMP RANGE -40C to +85C -40C to +85C PIN-PACKAGE 56 TQFN-EP** 64 TQFP-EP** PKG CODE T5688-3 C64E-6
Applications
LCD TVs Automotive PDP TVs PC/HiFi Audio Solutions
Pin Configurations appear at end of data sheet.
+Denotes lead-free package. *Future product--Contact factory for availability. **EP = Exposed paddle.
Simplified Block Diagram
FS1, FS2 SYNC RIGHT CHANNEL LEFT CHANNEL MONO 2
2
MAX9708
SYNCOUT
FS1, FS2 SYNC AUDIO INPUT
2
MAX9708
SYNCOUT
CLASS D MODULATOR GAIN CONTROL OUTPUT PROTECTION
CLASS D MODULATOR GAIN CONTROL 2 3 TEMP OUTPUT PROTECTION
VDIGITAL
MONO 3 TEMP G1, G2 TH0, TH1, TH2
G1, G2 TH0, TH1, TH2
STEREO MODE
MONO MODE
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
ABSOLUTE MAXIMUM RATINGS
PVDD, VDD to PGND, GND .......................................-0.3 to +30V PVDD to 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 = +70C) 56-Pin Thin QFN (derate 47.6mW/C above +70C) ......3.81W 64-Pin TQFP (derate 43.5mW/C above +70C).............3.48W Operating Temperature Range ...........................-40C to +85C Storage Temperature Range .............................-65C to +150C Junction Temperature ......................................................+150C Thermal Resistance (JC) 56-Pin Thin QFN... .......................................................0.6C/W 64-Pin TQFP....................................................................2C/W Lead Temperature (soldering, 10s) .................................+300C
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.
ELECTRICAL CHARACTERISTICS
(PVDD = VDD = +18V, PGND = GND = 0V, CSS = 0.47F, CREG = 0.01F, C1 = 0.1F, C2 = 1F, 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 = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER Supply Voltage Range Shutdown Current Shutdown to Full Operation Mute to Full Operation SYMBOL VDD ISHDN tSON tMUTE G1 = 0, G2 = 1 Input Impedance RIN G1 = 1, G2 = 1 G1 = 1, G2 = 0 G1= 0, G2 = 0 Output Pulldown Resistance Output Offset Voltage VOS SHDN = GND AC-coupled input, measured between OUT_+ and OUT_PVDD = 10V to 18V Power-Supply Rejection Ratio PSRR 200mVP-P ripple (Note 2) DC, input referred f = 20Hz to 20kHz, input referred One power switch FS1 0 Switching Frequency fSW 1 1 0 Oscillator Spread Bandwidth SYNCIN Lock Range Equal to fSW x 4 FS2 0 1 (SSM) 0 1 600 180 200 200 160 250 2 1200 % kHz 220 kHz fRIPPLE = 1kHz fRIPPLE = 20kHz 50 68 90 90 50 70 70 0.3 0.75 dB dB 50 40 25 12 SHDN = low CONDITIONS Inferred from PSRR test MIN 10 0.1 100 100 85 63 43 21 600 30 125 90 60 30 k mV k TYP MAX 18 1 UNITS V A ms ms
Common-Mode Rejection Ratio Switch On-Resistance
CMRR RDS
FS1 = FS2 = high (SSM)
2
_______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(PVDD = VDD = +18V, PGND = GND = 0V, CSS = 0.47F, CREG = 0.01F, C1 = 0.1F, C2 = 1F, 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 = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER SYMBOL G1 = 0, G2 = 1 Gain AV G1 = 1, G2 = 1 G1 = 1, G2 = 0 G1 = 0, G2 = 0 TH2 0 0 0 TEMP Flag Threshold TFLAG 0 1 1 1 1 TEMP Flag Accuracy TEMP Flag Hysteresis STEREO MODE (RLOAD = 8) Quiescent Current MUTE = 1, RLOAD = MUTE = 0 POUT f = 1kHz, THD = 10%, TA = +25C, RLOAD = 8, PVDD = 18V f = 1kHz, BW = 22Hz to 22kHz, RLOAD = 8, POUT = 8W RLOAD = 8, POUT = 10W 22Hz to 22kHz A-weighted 20 20 5 21 30 11 mA TH1 0 0 1 1 0 0 1 1 TH0 0 1 0 1 0 1 0 1 +80 +90 +100 +110 +120 +129 +139 +150 6 2 C C C CONDITIONS MIN 21.6 24.9 29.2 35.9 TYP 22.0 25.0 29.5 36.0 MAX 22.3 25.6 29.9 36.6 dB UNITS
MAX9708
From +80C to +140C
Output Power
W
Total Harmonic Distortion Plus Noise Signal-to-Noise Ratio Efficiency Left-Right Channel Gain Matching
THD+N SNR
0.1 91 96 87 0.02
% dB % dB
RLOAD = 8, L > 60H, POUT = 15W + 15W, f = 1kHz POUT = 10W
_______________________________________________________________________________________
3
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
ELECTRICAL CHARACTERISTICS (continued)
(PVDD = VDD = +18V, PGND = GND = 0V, CSS = 0.47F, CREG = 0.01F, C1 = 0.1F, C2 = 1F, 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 = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1)
PARAMETER Output Short-Circuit Current Threshold Click-and-Pop Level SYMBOL ISC RLOAD = 0 Peak voltage, 32 samples/second, A-weighted (Notes 2, 4) MUTE = 1, RLOAD = MUTE = 0 POUT f = 1kHz, THD = 10% RLOAD = 8 RLOAD = 4 Into shutdown Out of shutdown CONDITIONS MIN TYP 2.4 -63 dBV -55 MAX UNITS A
KCP
MONO MODE (RLOAD = 4, MONO = High) Quiescent Current Output Power Total Harmonic Distortion Plus Noise Signal-to-Noise Ratio Efficiency Output Short-Circuit Current Threshold Click-and-Pop Level SNR ISC 20 5 23 42 0.12 91 95 85 4.8 Into shutdown Out of shutdown -60 dBV -63 1 2.5 0.8 ISINK = 3mA VPULLUP = 5.5V 0.2 0.4 A V V V A mA W % dB % A
f = 1kHz, BW = 22Hz to 22kHz, RLOAD = 4, POUT = 17W RLOAD = 4, POUT = 10W 20Hz to 20kHz A-weighted
RLOAD = 4, L > 40H, POUT = 42W, f = 1kHz RLOAD = 0 Peak voltage, 32 samples/second, A-weighted (Notes 2, 4)
KCP
DIGITAL INPUTS (SHDN, MUTE, G1, G2, FS1, FS2, TH0, TH1, TH2, SYNCIN, MONO) Logic-Input Current IIN 0 to 12V Logic-Input High Voltage Logic-Input Low Voltage Open-Drain Output Low Voltage Leakage Current VIH VIL VOL ILEAK
OPEN-DRAIN OUTPUTS (TEMP, SYNCOUT)
Note 1: Note 2: Note 3: Note 4:
All devices are 100% production tested at +25C. All temperature limits are guaranteed by design. Inputs AC-coupled to GND. The device is current limited. The maximum output power is obtained with an 8 load. Testing performed with an 8 resistive load in series with a 68H inductive load connected across BTL outputs. Mode transitions are controlled by SHDN.
4
_______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Typical Operating Characteristics
(PVDD = VDD = +18V, PGND = GND = 0V, CSS = 0.47F, CREG = 0.01F, C1 = 0.1F, C2 = 1F, 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 = +25C, unless otherwise stated.)
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER
MAX9708 toc01
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER
MAX9708 toc02
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY
PVDD = 18V, 8 STEREO MODE, POUT = 8.3W PER CHANNEL THD+N (%)
MAX9708 toc03
100 PVDD = 18V, 8 STEREO MODE, 1kHz 10 THD+N (%)
100 PVDD = 12V, STEREO MODE, fIN = 1kHz RL = 8 1
1
10 THD+N (%)
1
0.1
0.1
0.1
RL = 4
0.01 0 5 10 15 20 25 30 OUTPUT POWER PER CHANNEL (W)
0.01 0 5 10 15 OUTPUT POWER PER CHANNEL (W)
0.01 10 100 1k FREQUENCY (Hz) 10k 100k
EFFICIENCY vs. OUTPUT POWER
MAX9708 toc04
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX9708 toc05
NO-LOAD SUPPLY CURRENT vs. SUPPLY VOLTAGE
STEREO MODE 22 SUPPLY CURRENT (mA) 20 18 16 14 12 10 TA = -40C TA = +85C TA = +25C
MAX9708 toc06
100 90 80 EFFICIENCY (%) 70 60 50 40 30 20 10 0 5 10 15 20 25 PVDD = 18V, 8 STEREO MODE
30 OUTPUT POWER PER CHANNEL (W) 25 20 15 10
RL = 8 STEREO MODE
24
10% THD+N
1% THD+N 5 0
30
10
12
14 SUPPLY VOLTAGE (V)
16
18
10
12
14
16
18
20
22
OUTPUT POWER PER CHANNEL (W)
SUPPLY VOLTAGE (V)
SHUTDOWN SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX9708 toc07
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER
PVDD = 18V, 4 MONO MODE, 1kHz 10 THD+N (%)
MAX9708 toc08
4.0 3.5 SUPPLY CURRENT (nA) 3.0 2.5 2.0 1.5 1.0 0.5 0 10 12 14 16 18 20 SHDN = 0
100
1
0.1
0.01 22 0 10 20 30 40 50 60 SUPPLY VOLTAGE (V) OUTPUT POWER (W)
_______________________________________________________________________________________
5
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Typical Operating Characteristics (continued)
(PVDD = VDD = +18V, PGND = GND = 0V, CSS = 0.47F, CREG = 0.01F, C1 = 0.1F, C2 = 1F, 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 = +25C, unless otherwise stated.)
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER
MAX9708 toc09
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY
PVDD = 18V, 4 MONO MODE, POUT = 18W
MAX9708 toc10
WIDEBAND OUTPUT SPECTRUM (SSM MODE)
20 OUTPUT AMPLITUDE (dBV) 10 0 -10 -20 -30 -40 -50 -60 10kHz RBW
MAX9708 toc11
100 PVDD = 12V, MONO MODE, fIN = 1kHz RL = 4
1
30
10 THD+N (%)
1
THD+N (%)
0.1
0.1
0.01 0 5 10 15 20 25 OUTPUT POWER (W)
0.01 10 100 1k FREQUENCY (Hz) 10k 100k
-70 100k 1M 10M 100M FREQUENCY (Hz)
WIDEBAND OUTPUT SPECTRUM (FFM MODE)
MAX9708 toc12
OUTPUT FREQUENCY SPECTRUM (SSM MODE)
MAX9708 toc13
OUTPUT FREQUENCY SPECTRUM (FFM MODE)
MAX9708 toc14
30 20 OUTPUT AMPLITUDE (dBV) 10 0 -10 -20 -30 -40 -50 -60 -70 100k 1M 10M 10kHz RBW
0 -20 OUTPUT AMPLITUDE (dBV) -40 -60 -80 -100 -120
0 -20 OUTPUT AMPLITUDE (dBV) -40 -60 -80 -100 -120
100M
0
4
8
12
16
20
24
0
4
8
12
16
20
24
FREQUENCY (Hz)
FREQUENCY (kHz)
FREQUENCY (kHz)
6
_______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Typical Operating Characteristics (continued)
(PVDD = VDD = +18V, PGND = GND = 0V, CSS = 0.47F, CREG = 0.01F, C1 = 0.1F, C2 = 1F, 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 = +25C, unless otherwise stated.)
EFFICIENCY vs. OUTPUT POWER
MAX9708 toc15
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX9708 toc16
OUTPUT POWER vs. LOAD RESISTANCE
MONO MODE, 10% THD+N, PVDD = 18V
MAX9708 toc17
100 90 80 EFFICIENCY (%) 70 60 50 40 30 20 10 0 10 20 30 40 50 PVDD = 18V, 4 MONO MODE
60 50 OUTPUT POWER (W) 40 30 20 10 0 RL = 4, MONO MODE, 10% THD+N
60 50 OUTPUT POWER (W) 40 30 20 10 0
60
10
12
14 SUPPLY VOLTAGE (V)
16
18
4
6
8
10
12
OUTPUT POWER (W)
LOAD RESISTANCE ()
OUTPUT POWER vs. LOAD RESISTANCE
STEREO MODE, 10% THD+N, PVDD = 18V
MAX9708 toc18
MUTE RESPONSE
MAX9708 toc19
SHUTDOWN RESPONSE
MAX9708 toc20
30 OUTPUT POWER PER CHANNEL (W) 25 20 15 10 5 0 7 8 9 10 11
MUTE 5V/div
SHDN 5V/div
OUTPUT 50mV/div
OUTPUT 50mV/div
12
40ms/div
40ms/div
LOAD RESISTANCE ()
_______________________________________________________________________________________
7
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Typical Operating Characteristics (continued)
(PVDD = VDD = +18V, PGND = GND = 0V, CSS = 0.47F, CREG = 0.01F, C1 = 0.1F, C2 = 1F, 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 = +25C, unless otherwise stated.)
COMMON-MODE REJECTION RATIO vs. FREQUENCY
-65 -70 -75 CMRR (dB) -80 -85 -90 -95 -100 -105 -110 10 100 1k FREQUENCY (Hz) 10k 100k -100 -110 10 100 1k FREQUENCY (Hz) 10k 100k -110 -120 10 100 1k FREQUENCY (Hz) 10k 100k PSRR (dB) -60 -70 -80 -90 INPUT REFERRED
MAX9708 toc21
POWER-SUPPLY REJECTION RATIO vs. FREQUENCY
MAX9708 toc22
CROSSTALK vs. FREQUENCY
-50 -60 CROSSTALK (dB) -70 -80 -90 -100
MAX9708 toc23
-60
-30 -40 -50
-40
MAXIMUM STEADY-STATE OUTPUT POWER vs. TEMPERATURE
MAX9708 toc24
MAXIMUM STEADY-STATE OUTPUT POWER vs. TEMPERATURE
PVDD = 18V, 4 MONO MODE, 1kHz, FS1 = FS2 = 1 TH0 = TH1 = 1 TH2 = 0
MAX9708 toc25
40 OUTPUT POWER PER CHANNEL (W) 35 30 25 20 15 10 5 0 30 40 50 60 MEASURED WITH THE EV KIT (TQFN PACKAGE), JUNCTION TEMPERATURE MAINTAINED AT +110C PVDD = 18V, 8 STEREO MODE, 1kHz, FS1 = FS2 = 1 TH0 = TH1 = 1 TH2 = 0
70 60 OUTPUT POWER (W) 50 40 30 20 10 0 MEASURED WITH THE EV KIT (TQFN PACKAGE), JUNCTION TEMPERATURE MAINTAINED AT +110C 30 40 50 60
70
70
AMBIENT TEMPERATURE (C)
AMBIENT TEMPERATURE (C)
Pin Description
PIN TQFP 1, 8, 13, 16, 17, 32, 33, 41, 48, 49, 50, 55, 58, 63, 64 2, 3, 4, 45, 46, 47, 56, 57 5, 6, 7, 42, 43, 44 TQFN 1, 12, 42, 43, 44, 55, 56 2, 3, 4, 39, 40, 41, 49, 50 5, 6, 7, 36, 37, 38 NAME FUNCTION
N.C.
No Connection. Not internally connected.
PGND PVDD
Power Ground Positive Power Supply. Bypass to PGND with a 0.1F and a 47F capacitor with the smallest capacitor placed as close to pins as possible.
8
_______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
Pin Description (continued)
PIN TQFP 9 10 11 12 14 15 18 19 20 21 22, 23, 24 25, 26 27 28 29 30 31 34 35 TQFN 8 9 10 11 13 14 15 16 17 18 19, 20, 21 22, 23 24 25 26 27 28 29 30 NAME C1N C1P CPVDD FUNCTION Charge-Pump Flying Capacitor C1, Negative Terminal Charge-Pump Flying Capacitor C1, Positive Terminal Charge-Pump Power Supply. Bypass to PVDD with a 1F capacitor as close to the pin as possible.
MAX9708
SYNCOUT Open-Drain, Slew-Rate Limited Clock Output. Pullup with a 10k resistor to REG. SYNCIN FS2 FS1 INLINL+ MONO REG GND SS VDD INRINR+ G1 G2 SHDN Clock Synchronization Input. Allows for synchronization of the internal oscillator with an external clock. SYNCIN is internally pulled up to VREG with a 100k resistor. Frequency Select 2 Frequency Select 1 Left-Channel Negative Input (Stereo Mode Only) Left-Channel Positive Input (Stereo Mode Only) Mono/Stereo Mode Input. Drive logic-high for mono mode. Drive logic-low for stereo mode. Internal Regulator Output Voltage (6V). Bypass with a 0.01F capacitor to GND. Analog Ground Soft-Start. Connect a 0.47F capacitor to GND to utilize soft-start power-up sequence. Analog Power Supply. Bypass to GND with a 0.1F capacitor as close to pin as possible. Right-Channel Negative Input. In mono mode, INR- is the negative input. Right-Channel Positive Input. In mono mode, INR+ is the positive input. Gain Select Input 1 Gain Select Input 2 Active-Low Shutdown Input. Drive SHDN high for normal operation. Drive SHDN low to place the device in shutdown mode. 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 100k resistor. Thermal Flag Output, Open Drain. Pull up with a 10k resistor to REG. Temperature Flag Threshold Select Input 2 Temperature Flag Threshold Select Input 1 Temperature Flag Threshold Select Input 0 Right-Channel Negative Output Right-Channel Positive Output Left-Channel Negative Output Left-Channel Positive Output Exposed Paddle. Connect to GND with multiple vias for best heat dissipation.
36 37 38 39 40 51, 52 53, 54 59, 60 61, 62 EP
31 32 33 34 35 45, 46 47, 48 51, 52 53, 54 EP
MUTE TEMP TH2 TH1 TH0 OUTROUTR+ OUTLOUTL+ EP
_______________________________________________________________________________________
9
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Typical Application Circuits/Functional Diagrams
VDD 0.1F PVDD 47F*
VDIGITAL 15 (18) FS1 14 (15) FS2 13 (14) SYNCIN
22, 23 (25, 26) GND
25 (28) VDD
5-7, 36-38 (5-7, 42-44) PVDD
2-4, 39-41 49-50 (2-4, 45-47, 56-57) PGND SYNCOUT
VDIGITAL
10k 11 (12)
CONTROL RF
MAX9708
VBIAS PVDD OUTL+ 53, 54 (61, 62) 51, 52 (59, 60)
1F + LEFT CHANNEL 1F
17 (20) INL+
RIN
16 (19) INL-
RIN
CLASS D MODULATOR AND H-BRIDGE
OUTL-
RF RF PVDD 1F + RIGHT CHANNEL 1F 27 (30) INR+ RIN OUTR+ MUX 26 (29) INRRIN VBIAS VDIGITAL 30 (35) 31 (36) MUTE 28 (31) G2 29 (34) G1 18 (21) MONO THERMAL SENSOR SHDN RF GAIN CONTROL CHARGE PUMP CLASS D MODULATOR AND H-BRIDGE OUTR47, 48 (53, 54) 45, 46 (51, 52) C2 1F PVDD 9 (10) 8 (9) C1 0.1F
CPVDD C1P C1N REG TEMP
10 (11)
REGULATOR
19, 20, 21 (22, 23, 24) 32 (37) CREG 0.01F
TH0 35 (40) 34 (39)
TH1
TH2 33 (38)
SS 24 (27) CSS 0.47F
10k
VDIGITAL
VDIGITAL
CONFIGURATION: TQFN STEREO MODE, SSM, INTERNAL OSCILLATOR, GAIN = 22dB, THERMAL SETTING = +120C ( ) TQFP PACKAGE *ADDITIONAL BULK CAPACITANCE
Figure 1. Typical Application and Functional Diagram in Stereo Mode
10
______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
Typical Application Circuits/Functional Diagrams (continued)
VDD 0.1F PVDD 47F*
MAX9708
0.1F VDIGITAL 15 (18) FS1 14 (15) FS2 13 (14) SYNCIN RF 22, 23 (25, 26) GND 25 (28) VDD 5-7, 36-38 (5-7, 42-44) PVDD 2-4, 39-41 49-50 (2-4, 45-47, 56-57) PGND SYNCOUT 11 (12) VDIGITAL
10k
CONTROL
MAX9708
VBIAS PVDD OUTL+ 53, 54 (61, 62) 51, 52 (59, 60)
1F + AUDIO INPUT 1F
17 (20) INR+
RIN
16 (19) INR-
RIN
CLASS D MODULATOR AND H-BRIDGE PVDD RF MUX CLASS D MODULATOR AND H-BRIDGE
OUTL-
OUTR+ OUTR-
47, 48 (53, 54) 45, 46 (51, 52) C2 1F PVDD 9 (10) 8 (9) C1 0.1F
CPVDD VDIGITAL 30 (35) SHDN CHARGE PUMP 31 (36) MUTE 28 (31) G1 29 (34) G2 VDIGITAL 18 (21) MONO THERMAL SENSOR C1P GAIN CONTROL C1N REG TEMP
10 (11)
REGULATOR
19, 20, 21 (22, 23, 24) 32 (37) CREG 0.01F
TH0 35 (40) 34 (39)
TH1
TH2 33 (38)
SS 24 (27) CSS 0.47F
10k
VDIGITAL
VDIGITAL
CONFIGURATION: TQFN MONO MODE, SSM, INTERNAL OSCILLATOR, GAIN = 22dB, THERMAL SETTING = +120C ( ) TQFP PACKAGE *ADDITIONAL BULK CAPACITANCE
Figure 2. Typical Application and Functional Diagram in Mono Mode
______________________________________________________________________________________
11
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Detailed Description
The MAX9708 filterless, Class D audio power amplifier features several improvements to switch-mode amplifier technology. The MAX9708 is a two-channel, stereo amplifier with 21W output power on each channel. The amplifier can be configured to output 42W output power in mono mode. The device offers Class AB performance with Class D efficiency, while occupying minimal board space. A unique filterless modulation scheme and spread-spectrum switching mode create a compact, flexible, low-noise, efficient audio power amplifier. The differential input architecture reduces common-mode noise pickup, and can be used without input-coupling capacitors. The device can also be configured as a single-ended input amplifier. powers. Under normal operating levels (typical music reproduction levels), efficiency falls below 30%, whereas the MAX9708 still exhibits 87% efficiency under the same conditions.
Shutdown
The MAX9708 features a shutdown mode that reduces power consumption and extends battery life. Driving SHDN low places the device in low-power (0.1A) shutdown mode. Connect SHDN to digital high for normal operation.
Mute Function
The MAX9708 features a clickless/popless mute mode. When the device is muted, the outputs stop switching, muting the speaker. Mute only affects the output stage and does not shut down the device. To mute the MAX9708, drive MUTE to logic-low. Driving MUTE low during the power-up/down or shutdown/turn-on cycle optimizes click-and-pop suppression.
Mono/Stereo Configuration
The MAX9708 features a mono mode that allows the right and left channels to operate in parallel, achieving up to 42W of output power. The mono mode is enabled by applying logic-high to MONO. In this mode, an audio signal applied to the right channel (INR+/INR-) is routed to the H-bridge of both channels, while a signal applied to the left channel (INL+/INL-) is ignored. OUTL+ must be connected to OUTR+ and OUTL- must be connected to OUTR- using heavy PC board traces as close to the device as possible (see Figure 2). When the device is placed in mono mode on a PC board with outputs wired together, ensure that the MONO pin can never be driven low when the device is enabled. Driving the MONO pin low (stereo mode) while the outputs are wired together in mono mode may trigger the short circuit or thermal protection or both, and may even damage the device.
Click-and-Pop Suppression
The MAX9708 features comprehensive click-and-pop suppression that eliminates audible transients on startup and shutdown. While in shutdown, the H-bridge is pulled to GND through a 330k resistor. During startup 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 Hbridge is subsequently enabled. Following startup, a soft-start function gradually un-mutes the input amplifiers. The value of the soft-start capacitor has an impact on the click-and-pop levels as well as startup time.
Thermal Sensor
The MAX9708 features an on-chip temperature sensor that monitors the die temperature. When the junction temperature exceeds a programmed level, TEMP is pulled low. This flags the user to reduce power or shut down the device. TEMP may be connected to SS or MUTE for automatic shutdown during overheating. If TEMP is connected to MUTE, during thermal-protection mode, the audio is muted and the device is in mute mode. If TEMP is connected to SS, during thermal-protection mode, the device is shut down but the thermal sensor is still active.
Efficiency
Efficiency 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 currentsteering switches and consume negligible additional power. Any power loss associated with the Class D output 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
12
______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
TEMP returns high once the junction temperature cools below the set threshold minus the thermal hysteresis. If TEMP is connected to either MUTE or SS, the audio output resumes. The temperature threshold is set by the TH0, TH1, and TH2 inputs as shown in Table 1. An RC filter may be used to eliminate any transient at the TEMP output as shown in Figure 3.
Operating Modes
Fixed-Frequency Modulation (FFM) Mode The MAX9708 features three switching frequencies in the FFM mode (Table 3). In this mode, the frequency spectrum of the Class D output consists of the fundamental switching frequency and its associated harmonics (see the Wideband Output Spectrum graph in the Typical Operating Characteristics). Select one of the three fixed switching frequencies such that the harmonics do not fall in a sensitive band. The switching frequency can be changed at any time without affecting audio reproduction. Spread-Spectrum Modulation (SSM) Mode The MAX9708 features a unique, patented spreadspectrum (SSM) 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 = high. In SSM mode, the switching frequency varies randomly by 4% around the center frequency (200kHz). 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. SSM mode reduces EMI compared to fixed-frequency mode. This can also help to randomize visual artifacts caused by radiated or supply-borne interference in displays. Synchronous Switching Mode The MAX9708 SYNCIN input allows the Class D amplifier to switch at a frequency defined by an external clock frequency. Synchronizing the amplifier with an external clock source may confine the switching frequency to a less sensitive band. The external clock frequency range is from 600kHz to 1.2MHz and can have any duty cycle, but the minimum pulse must be greater than 100ns. SYNCOUT is an open-drain clock output for synchronizing external circuitry. Its frequency is four times the amplifier's switching frequency, and it is active in either internal or external oscillator mode.
MAX9708
Gain Selection
The MAX9708 features four pin-selectable gain settings; see Table 2.
VDIGITAL
10k 10k TEMP 0.1F TO DIGITAL INPUT
Figure 3. An RC Filter Eliminates Transient During Switching
Table 1. MAX9708 Junction Temperature Threshold Setting
JUNCTION TEMPERATURE (C) 80 90 100 110 120 129 139 150 TH2 Low Low Low Low High High High High TH1 Low Low High High Low Low High High TH0 Low High Low High Low High Low High
Table 2. MAX9708 Gain Setting
G1 Low High High Low G2 High High Low Low GAIN (dB) 22 25 29.5 36
Table 3. Switching Frequencies
FS1 0 0 1 1 FS2 0 1 0 1 SYNCOUT FREQUENCY (kHz) 200 250 160 200 4 MODULATION Fixed-Frequency Fixed-Frequency Fixed-Frequency Spread-Spectrum
______________________________________________________________________________________
13
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Linear Regulator (REG)
The supply voltage range for the MAX9708 is from 10V to 18V to achieve high-output power. An internal linear regulator reduces this voltage to 6.3V for use with small-signal and digital circuitry that does not require a high-voltage supply. Bypass a 0.01F capacitor from REG to GND.
1F INR+
MAX9708
INR1F
Applications Information
Logic Inputs
All of the digital logic inputs and output have an absolute maximum rating of +12V. If the MAX9708 is operating with a supply voltage between 10V and 12V, digital inputs can be connected to PVDD or VDD. If PVDD and VDD are greater than 12V, digital inputs and outputs must connected to a digital system supply lower than 12V.
Figure 4. Single-Ended Input Connections
Input Amplifier
Differential Input The MAX9708 features a differential input structure, making them compatible with many CODECs, and offering improved noise immunity over a single-ended input amplifier. In devices such as flat-panel displays, noisy digital signals can be picked up by the amplifier's inputs. These signals appear at the amplifiers' inputs as common-mode noise. A differential input amplifier amplifies only the difference of the two inputs, while any signal common to both inputs is attenuated. Single-Ended Input The MAX9708 can be configured as a single-ended input amplifier by capacitively coupling either input to GND and driving the other input (Figure 4).
Choose CIN so that f-3dB is well below the lowest frequency of interest. Setting f-3dB too high affects the low-frequency response of the amplifier. Use capacitors with dielectrics that have low-voltage coefficients, such as tantalum or aluminum electrolytic. Capacitors with high-voltage coefficients, such as ceramics, may result in increased distortion at low frequencies. Output Filter The MAX9708 does not require an output filter. However, output filtering can be used if a design is failing radiated emissions due to board layout or cable length, or the circuit is near EMI-sensitive devices. Refer to the MAX9708 Evaluation Kit for suggested filter topologies. The tuning and component selection of the filter should be optimized for the load. A purely resistor load (8) used for lab testing will require different components than a real, complex load-speaker load. Charge-Pump Capacitor Selection The MAX9708 has an internal charge-pump converter that produces a voltage level for internal circuitry. It requires a flying capacitor (C1) and a holding capacitor (C2). Use capacitors with an ESR less than 100m for optimum performance. Low-ESR ceramic capacitors minimize the output resistance of the charge pump. For best performance over the extended temperature range, select capacitors with an X7R dielectric. The capacitors' voltage rating must be greater than 36V.
Component Selection
Input Filter An input capacitor, CIN, in conjunction with the input impedance of the MAX9708, forms a highpass filter that removes the DC bias from an incoming signal. The ACcoupling capacitor allows the amplifier to bias the signal to an optimum DC level. Assuming zero-source impedance, the -3dB point of the highpass filter is given by: f-3dB = 1 2 RIN CIN
14
______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Sharing Input Sources
In certain systems, a single audio source can be shared by multiple devices (speaker and headphone amplifiers). When sharing inputs, it is common to mute the unused device, rather than completely shutting it down, preventing the unused device inputs from distorting the input signal. Mute the MAX9708 by driving MUTE low. Driving MUTE low turns off the Class D output stage, but does not affect the input bias levels of the MAX9708. Continuous Sine Wave vs. Music When a Class D amplifier is evaluated in the lab, often a continuous sine wave is used as the signal source. While this is convenient for measurement purposes, it represents a worst-case scenario for thermal loading on the amplifier. It is not uncommon for a Class D amplifier to enter thermal shutdown if driven near maximum output power with a continuous sine wave. The PC board must be optimized for best dissipation (see the PC Board Thermal Considerations section). Audio content, both music and voice, has a much lower RMS value relative to its peak output power. Therefore, while an audio signal may reach similar peaks as a continuous sine wave, the actual thermal impact on the Class D amplifier is highly reduced. If the thermal performance of a system is being evaluated, it is important to use actual audio signals instead of sine waves for testing. If sine waves must be used, the thermal performance will be less than the system's actual capability for real music or voice. PC Board Thermal Considerations The exposed pad is the primary route for conducting heat away from the IC. With a bottom-side exposed pad, the PC board and its copper becomes the primary heatsink for the Class D amplifier. Solder the exposed pad to a copper polygon. Add as much copper as possible from this polygon to any adjacent pin on the Class D amplifier as well as to any adjacent components, provided these connections are at the same potential. These copper paths must be as wide as possible. Each of these paths contributes to the overall thermal capabilities of the system. The copper polygon to which the exposed pad is attached should have multiple vias to the opposite side of the PC board, where they connect to another copper polygon. Make this polygon as large as possible within the system's constraints for signal routing. Additional improvements are possible if all the traces from the device are made as wide as possible. Although the IC pins are not the primary thermal path out of the package, they do provide a small amount. The total improvement would not exceed approximately 10%, but it could make the difference between acceptable performance and thermal problems.
Frequency Synchronization
The MAX9708 outputs up to 21W on each channel in stereo mode. If higher output power or a 2.1 solution is needed, two MAX9708s can be used. Each MAX9708 is synchronized by connecting SYNCOUT from the first MAX9708 to SYNCIN of the second MAX9708 (see Figure 5). Supply Bypassing/Layout Proper power-supply bypassing ensures low-distortion operation. For optimum performance, bypass PVDD to PGND with a 0.1F capacitor as close to each PVDD pin as possible. A low-impedance, high-current powersupply connection to PVDD is assumed. Additional bulk capacitance should be added as required depending on the application and power-supply characteristics. GND and PGND should be star-connected to system ground. For the TQFN package, solder the exposed paddle (EP) to the ground plane using multiple-plated through-hole vias. The exposed paddle must be soldered to the ground plane for rated power dissipation and good ground return. Use wider PC board traces to lower the parasitic resistance for the high-power output pins (OUTR+, OUTR-, OUTL+, OUTL-). Refer to the MAX9708 Evaluation Kit for layout guidance.
Thermal Considerations
Class D amplifiers provide much better efficiency and thermal performance than a comparable Class AB amplifier. However, the system's thermal performance must be considered with realistic expectations along with its many parameters.
______________________________________________________________________________________
15
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
Auxiliary Heatsinking If operating in higher ambient temperatures, it is possible to improve the thermal performance of a PC board with the addition of an external heatsink. The thermal resistance to this heatsink must be kept as low as possible to maximize its performance. With a bottom-side exposed pad, the lowest resistance thermal path is on the bottom of the PC board. The topside of the IC is not a significant thermal path for the device, and therefore is not a costeffective location for a heatsink. If an LC filter is used in the design, placing the inductor in close proximity to the IC can help draw heat away from the MAX9708. Thermal Calculations The die temperature of a Class D amplifier can be estimated with some basic calculations. For example, the die temperature is calculated for the below conditions: * TA = +40C * POUT = 16W * Efficiency () = 87% * JA = 21C/W First, the Class D amplifier's power dissipation must be calculated: PDISS = 16W POUT - POUT = - 16W = 2.4W 0.87
MAX9708
Another consideration is the load impedance across the audio frequency band. A loudspeaker is a complex electro-mechanical system with a variety of resonance. In other words, an 8 speaker usually has 8 impedance within a very narrow range. This often extends well below 8, reducing the thermal efficiency below what is expected. This lower-than-expected impedance can be further reduced when a crossover network is used in a multidriver audio system.
Systems Application Circuit
The MAX9708 can be configured into multiple amplifier systems. One concept is a 2.1 audio system (Figure 5) where a stereo audio source is split into three channels. The left- and right-channel inputs are highpass filtered to remove the bass content, and then amplified by the MAX9708 in stereo mode. Also, the left- and right-channel inputs are summed together and lowpass filtered to remove the high-frequency content, then amplified by a second MAX9708 in mono mode. The conceptual drawing of Figure 5 can be applied to either single-ended or differential systems. Figure 6 illustrates the circuitry required to implement a fully differential filtering system. By maintaining a fully differential path, the signal-to-noise ratio remains uncompromised and noise pickup is kept very low. However, keeping a fully differential signal path results in almost twice the component count, and therefore performance must be weighed against cost and size. The highpass and lowpass filters should have different cutoff frequencies to ensure an equal power response at the crossover frequency. The filters should be at -6dB amplitude at the crossover frequency, which is known as a Linkwitz-Riley alignment. In the example circuit of Figure 6, the -3dB cutoff frequency for the highpass filters is 250Hz, and the -3dB cutoff frequency for the lowpass filter is 160Hz. Both the highpass filters and the lowpass filters are at a -6dB amplitude at approximately 200Hz. If the filters were to have the same -3dB cutoff frequency, a measurement of sound pressure level (SPL) vs. frequency would have a peak at the crossover frequency. The circuit in Figure 6 uses inverting amplifiers for their ease in biasing. Note the phase labeling at the outputs has been reversed. The resistors should be 1% or better in tolerance and the capacitors 5% tolerance or better.
Then the power dissipation is used to calculate the die temperature, TC, as follows:
TC = TA + PDISS x JA = 40C + 24W x 21C / W = 90.4C
Load Impedance The on-resistance of the MOSFET output stage in Class D amplifiers affects both the efficiency and the peak-current capability. Reducing the peak current into the load reduces the I2R losses in the MOSFETs, which increases efficiency. To keep the peak currents lower, choose the highest impedance speaker that can still deliver the desired output power within the voltage swing limits of the Class D amplifier and its supply voltage. Although most loudspeakers fall either 4 or 8, there are other impedances available that can provide a more thermally efficient solution.
16
______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
Mismatch in the components can cause discrepancies between the nominal transfer function and actual performance. Also, the mismatch of the input resistors (R15, R17, R19, and R21 in Figure 6) of the summing amplifier and lowpass filter will cause some high-frequency sound to be sent to the subwoofer. The circuit in Figure 6 drives a pair of MAX9708 devices similar to the circuit in Figure 5. The inputs to the MAX9708 still require AC-coupling to prevent compromising the click-and-pop performance of the MAX9708. The left and right drivers should be at an 8 to 12 impedance, whereas the subwoofer can be 4 to 12 depending on the desired output power, the available power-supply voltage, and the sensitivity of the individual speakers in the system. The four gain settings of the MAX9708 allow gain adjustments to match the sensitivity of the speakers.
MAX9708
RIGHT AUDIO
HIGHPASS FILTER
INR+ INRMONO
OUTR+ OUTR-
8 FULLRANGE SPEAKER
MAX9708
LEFT AUDIO HIGHPASS FILTER INL+ INLSYNCOUT OUTL+ OUTL8 FULLRANGE SPEAKER
SYNCIN
LOWPASS FILTER VDIGITAL
INR+ INR-
OUTR+ OUTR-
4 OR 8 WOOFER
MAX9708
MONO INL+ INLOUTL+ OUTL-
Figure 5. Multiple Amplifiers Implement a 2.1 Audio System
______________________________________________________________________________________
17
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
R1 56.2k R2, 56.2k R3 28k C1 47nF C2 47nF 2
U1A
1
RIGHT AUDIO INPUT R7 28k
R4 28k
MAX4478
R5 56.2k C4 47nF
BIAS
3 RIGHT AUDIO OUTPUT
R6, 56.2k C3 47nF 6
U1B MAX4478
7 RIGHT AND LEFT OUTPUTS ARE AC-COUPLED TO A MAX9708 CONFIGURED AS A STEREO AMPLIFIER
R8 56.2k C5 47nF C6 47nF
BIAS
5
R9, 56.2k R10 28k 9
U1C
8
LEFT AUDIO INPUT R14 28k
R11 28k
MAX4478
R12 56.2k C8 47nF
BIAS
10 LEFT AUDIO OUTPUT
R13, 56.2k C7 47nF 13
U1D MAX4478
14
R15 26.1k
R16 13k
BIAS
12 SUBWOOFER OUTPUT IS AC-COUPLED TO A MAX9708 CONFIGURED AS A MONO AMPLIFIER
C9, 47nF R17 26.1k R18 7.5k 2
U2A
R19 26.1k
C10 47nF
1
MAX4478
R20 13k
BIAS
3 SUBWOOFER AUDIO OUTPUT
C11, 47nF R21 28k R22 7.5k 6
U2B MAX4478
7
BIAS NOTE: OP-AMP POWER PINS OMITTED FOR CLARITY. ALL RESISTORS ARE 1% OR BETTER. ALL CAPACITORS ARE 5% OR BETTER.
5
Figure 6. Fully Differential Crossover Filters
18
______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
Pin Configurations
MAX9708
TOP VIEW
PGND PGND PGND MUTE TEMP SHDN
30
PVDD
PVDD
PVDD
N.C.
TH1
TH0
TH2
42
41
40
39
38
37
36
35
34
33
32
31
29 28 G1 27 INR+ 26 INR25 VDD 24 SS 23 GND 22 GND
N.C. 43 N.C. 44 OUTR- 45 OUTR- 46 OUTR+ 47 OUTR+ 48 PGND 49 PGND 50 OUTL- 51 OUTL- 52 OUTL+ 53 OUTL+ 54 N.C. 55 N.C. 56
1 2 3 4 5 6 7 8 9 10 11 12 13 14
G2
21 REG 20 REG 19 REG 18 17 16
MAX9708
MONO INL+ INL-
15 FS1
SYNCIN
N.C.
C1P
THIN QFN
______________________________________________________________________________________
SYNCOUT
N.C.
PGND
PGND
PGND
PVDD
PVDD
PVDD
C1N
CPVDD
FS2
19
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Pin Configurations (continued)
TOP VIEW
OUTR+ OUTR+ OUTL+ OUTL+ OUTROUTROUTLOUTLPGND PGND
N.C.
N.C.
N.C.
N.C.
N.C.
64
63 62 61 60 59 58
57 56 55 54 53 52 51 50 49
N.C. PGND PGND PGND PVDD PVDD PVDD N.C. C1N
N.C.
48 N.C. 47 PGND 46 PGND 45 PGND 44 PVDD 43 PVDD 42 PVDD 41 N.C. 40 TH0 39 TH1 38 TH2 37 TEMP 36 MUTE 35 SHDN 34 G2 33 N.C.
1 2 3 4 5 6 7 8 9
MAX9708
C1P 10 CPVDD 11 SYNCOUT 12 N.C. 13 SYNCIN 14 FS2 15 N.C. 16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
INL+
N.C.
INL-
FS1
SS
GND
MONO
GND
INR-
REG
REG
REG
INR+
TQFP
N.C.
VDD
G1
Chip Information
PROCESS: BiCMOS
20
______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
56L THIN QFN.EPS
MAX9708
PACKAGE OUTLINE 56L THIN QFN, 8x8x0.8mm
21-0135
E
1
2
______________________________________________________________________________________
21
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE 56L THIN QFN, 8x8x0.8mm
21-0135
E
2
2
22
______________________________________________________________________________________
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
64L TQFP.EPS
MAX9708
PACKAGE OUTLINE, 64L TQFP, 10x10x1.4mm
21-0083
B
1
2
______________________________________________________________________________________
23
20W/40W, Filterless, Spread-Spectrum, Mono/Stereo, Class D Amplifier MAX9708
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE, 64L TQFP, 10x10x1.4mm
21-0083
B
2
2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
24 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
Freed

▲Up To Search▲

Price & Availability of MAX9708

	To Download MAX9708 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .