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19-0701; Rev 1; 11/07
KIT ATION EVALU BLE AVAILA
2.4W, Single-Supply, Class G Power Amplifier
General Description
The MAX9730 features a mono Class G power amplifier with an integrated inverting charge-pump power supply. The charge pump can supply up to 500mA of peak output current over a 2.7VDC to 5.5VDC supply voltage range, guaranteeing up to 2.4W output power into an 8 load. The 2.4W output power allows for transient audio content to remain unclipped as the battery rail collapses over time. The MAX9730 maximizes battery life by offering highperformance efficiency. Maxim's proprietary output stage provides efficiency levels greater than Class AB devices without the EMI penalties commonly associated with Class D amplifiers. High efficiency allows the MAX9730 to be packaged in a UCSPTM package without derating the output power handling capability. The device utilizes fully differential inputs and outputs, comprehensive click-and-pop suppression, shutdown control, and soft-start circuitry. The MAX9730 is fully specified over the -40C to +85C extended temperature range and is available in ultra-small, lead-free, 20-bump UCSP (2mm x 2.5mm) and 28-pin TQFN (4mm x 4mm) packages. o 2.7V to 5.5V Operation o Integrated Charge-Pump Power Supply o 63% Efficiency (VCC = 5V, POUT = 1W) o 2.4W Output Power into 8 at VCC = 3.3V o Up to 2.4W Instantaneous Output Power into 8 o Clickless/Popless Operation o Small Thermally Efficient Packages 2mm x 2.5mm 20-Bump UCSP 4mm x 4mm 28-Pin TQFN
Features
MAX9730
Ordering Information
PART MAX9730EBP+T* MAX9730ETI TEMP RANGE PINPACKAGE PKG CODE B20-7 T2844-1
-40C to +85C 20 UCSP-20 -40C to +85C 28 TQFN-EP**
Applications
MP3 Players Personal Media Players Handheld Gaming Consoles Cell Phones Smartphones Notebook Computers
+Denotes lead-free package. T = Tape and reel. *Future product--contact factory for availability. **EP = Exposed pad.
Typical Application Circuit/Functional Diagram and Pin Configurations appear at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc.
Simplified Block Diagram
2.7V TO 5.5V
VCC FB+
CPVDD
MAX9730
CIN RIN+ RFB+ IN+ INCIN RINRFBFBGND CHARGE PUMP CPGND + CLASS G OUTPUT STAGE OUT+ OUT-
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
2.4W, Single-Supply, Class G Power Amplifier MAX9730
ABSOLUTE MAXIMUM RATINGS
(Voltages with respect to GND.) VCC, CPVDD .............................................................-0.3V to +6V PVSS, SVSS ...............................................................-6V to +0.3V CPGND..................................................................-0.3V to +0.3V OUT+, OUT-...................................(SVSS - 0.3V) to (VCC + 0.3V) IN+, IN-, FB+, FB- ......................................-0.3V to (VCC + 0.3V) C1N..........................................(PVSS - 0.3V) to (CPGND + 0.3V) C1P.......................................(CPGND - 0.3V) to (CPVDD + 0.3V) FS, SHDN ...................................................-0.3V to (VCC + 0.3V) Continuous Current Into/Out of OUT+, OUT-, VCC, GND, SVSS .....................................800mA CPVDD, CPGND, C1P, C1N, PVSS .................................800mA Any Other Pin ..................................................................20mA Continuous Power Dissipation (TA = +70C) 20-Bump UCSP (derate 10.3mW/C above +70C) .....827mW 28-Pin TQFN (derate 20.8mW/C above +70C) ........1667mW Operating Temperature Range ...........................-40C to +85C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) ................................+300C Bump Temperature (soldering) Reflow............................+235C
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
(VCC = CPVDD = SHDN = 3.6V, GND = CPGND = 0V, RIN+ = RIN- = 10k, RFB+ = RFB- = 10k, RFS = 100k, C1 = 4.7F, C2 = 10F; speaker load resistors (RL) are terminated between OUT+ and OUT-, unless otherwise stated; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Notes 1, 2)
PARAMETER GENERAL Supply Voltage Range Quiescent Current Chip Power Dissipation Shutdown Current Turn-On Time Input DC Bias Voltage Charge-Pump Oscillator Frequency (Slow Mode) Maximum Capacitive Load SHDN Input Threshold (Note 3) SHDN Input Leakage Current SPEAKER AMPLIFIER Output Offset Voltage Common-Mode Rejection Ratio Click-and-Pop Level VOS CMRR VCP TA = +25C TMIN TA TMAX fIN = 1kHz (Note 4) Peak voltage into/out of shutdown A-weighted, 32 samples per second (Notes 5, 6) 68 -52 3 15 20 mV dB dBV VCC ICC PDISS ISHDN tON VBIAS fOSC CL VIH VIL 1.4 0.4 1 VOUT = 2.8VRMS, f = 1kHz, RL = 8 SHDN = GND Time from shutdown or power-on to full operation IN_ inputs ILOAD = 0mA (slow mode) ILOAD > 100mA (normal mode) 1.1 55 230 Inferred from PSRR test 2.7 8 0.9 0.3 50 1.24 83 330 200 1.4 110 430 pF V A 5 5.5 12 V mA W A ms V kHz SYMBOL CONDITIONS MIN TYP MAX UNITS
2
_______________________________________________________________________________________
2.4W, Single-Supply, Class G Power Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(VCC = CPVDD = SHDN = 3.6V, GND = CPGND = 0V, RIN+ = RIN- = 10k, RFB+ = RFB- = 10k, RFS = 100k, C1 = 4.7F, C2 = 10F; speaker load resistors (RL) are terminated between OUT+ and OUT-, unless otherwise stated; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Notes 1, 2)
PARAMETER Voltage Gain SYMBOL AV (Notes 4, 7) VCC = 5V Continuous Output Power POUT THD+N = 1%, f = 1kHz, RL = 8 VCC = 4.2V VCC = 3.6V VCC = 3.0V VCC = 5V f = 1kHz, 1% THD+N, ZL = 1F + 10 Output Voltage VOUT f = 10kHz, 1% THD+N, ZL = 1F + 10, no load VCC = 2.7V to 5.5V Power-Supply Rejection Ratio (Note 4) f = 217Hz, 200mVP-P ripple PSRR f = 1kHz, 200mVP-P ripple f = 20kHz, 200mVP-P ripple Total Harmonic Distortion Plus Noise Signal-to-Noise Ratio Dynamic Range THD+N SNR DR RL = 8, VOUT = 1kHz / 400mW RL = 8, VOUT = 1kHz / 1W VOUT = 0.5W, inputs to GND by C1N, A-weighted (Note 9) 22Hz to 22kHz A-weighted VCC = 4.2V VCC = 3.6V VCC = 3.0V VCC = 5V VCC = 4.2V VCC = 3.6V VCC = 3.0V 63 CONDITIONS MIN 11.5 TYP 12 2.4 1.67 1.25 0.8 7.1 5.9 5.1 4.2 6.5 5.4 4.7 3.8 77 77 77 58 0.007 0.12 95 96 99 % dB dB dB W VRMS MAX 12.5 UNITS dB
MAX9730
Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8:
Note 9:
All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design. Testing performed with resistive and inductive loads to simulate an actual speaker load. For dynamic speakers, RL = 8, 68H. Designed for 1.8V logic. RIN_ and RFB_ have 0.5% tolerance. Amplifier inputs AC-coupled to GND. Testing performed at room temperature with 8 resistive load in series with 68H inductive load connected across BTL output for speaker amplifier. Mode transitions are controlled by SHDN. VCP is the peak output transient expressed in dBV. Voltage gain is defined as: [VOUT+ - VOUT-] / [VIN+ - VIN-]. Mode A tone burst tested at full amplitude for one cycle and half amplitude for nine cycles. Mode B tone burst tested at full amplitude for three cycles and half amplitude for seven cycles. Full amplitude is defined as 1% THD+N at full battery (VCC = 4.2V). Electrical Characteristics table targets must be met at THD+N = 1% for one cycle (Mode A) and THD+N < 5% for three cycles (Mode B). Dynamic range is calculated by measuring the RMS voltage difference between a -60dBFS output signal and the noise floor, then adding 60dB. Full scale is defined as the output signal needed to achieve 1% THD+N.
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3
2.4W, Single-Supply, Class G Power Amplifier MAX9730
Typical Operating Characteristics
(VCC = CPVDD = SHDN = 3.6V, GND = CPGND = 0V, RIN+ = RIN- = 10k, RFB+ = RFB- = 10k, RFS = 100k, C1 = 4.7F, C2 = 10F, RL = 8; speaker load resistors (RL) are terminated between OUT+ and OUT-, unless otherwise stated; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Notes 1, 2)
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY
VCC = 3V 1 THD+N (%)
MAX9730 toc01
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY
MAX9730 toc02
TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY
VCC = 5V 1 THD+N (%) POUT = 2.08W
MAX9730 toc03
10
10 VCC = 3.6V 1 THD+N (%) POUT = 0.93W
10
POUT = 0.69W
0.1
0.1 POUT = 0.37W 0.01
0.1
0.01
POUT = 0.33W
0.01
POUT = 0.83W
0.001 0.01 0.1 1 FREQUENCY (kHz) 10 100
0.001 0.01 0.1 1 FREQUENCY (kHz) 10 100
0.001 0.01 0.1 1 FREQUENCY (kHz) 10 100
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER
MAX9730 toc04
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER
VCC = 3.6V fIN = 10kHz 1 fIN = 1kHz THD+N (%) THD+N (%) 0.1 0.1
MAX9730 toc05
TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER
VCC = 5V fIN = 10kHz 1 fIN = 1kHz
MAX9730 toc06
10 VCC = 3V 1 fIN = 1kHz THD+N (%) 0.1 fIN = 10kHz
10
10
0.01 fIN = 20Hz 0.001 0 0.5 1.0 1.5 OUTPUT POWER (W)
0.01
fIN = 20Hz
0.01 fIN = 20Hz 0.001
0.001 0 0.5 1.0 OUTPUT POWER (W) 1.5 2.0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
OUTPUT POWER (W)
POWER-SUPPLY REJECTION RATIO vs. FREQUENCY
MAX9730 toc07
POWER EFFICIENCY vs. OUTPUT POWER
MAX9730 toc08
POWER EFFICIENCY vs. OUTPUT POWER
MAX9730 toc09
0 -10 -20 -30 PSRR (dB) -40 -50 -60 -70 -80 -90 0.01 0.1 1 FREQUENCY (kHz) 10 VRIPPLE = 200mVP-P
70 60 50 EFFICIENCY (%) 40 30 20 10 0 VCC = 3V fIN = 1kHz 0 0.5 1.0
70 60 50 EFFICIENCY (%) 40 30 20 10 0 VCC = 3.6V fIN = 1kHz 0 0.5 1.0
100
1.5
1.5
OUTPUT POWER (W)
OUTPUT POWER (W)
4
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2.4W, Single-Supply, Class G Power Amplifier
Typical Operating Characteristics (continued)
(VCC = CPVDD = SHDN = 3.6V, GND = CPGND = 0V, RIN+ = RIN- = 10k, RFB+ = RFB- = 10k, RFS = 100k, C1 = 4.7F, C2 = 10F, RL = 8; speaker load resistors (RL) are terminated between OUT+ and OUT-, unless otherwise stated; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Notes 1, 2)
POWER EFFICIENCY vs. OUTPUT POWER
MAX9730 toc10
MAX9730
STARTUP WAVEFORM
MAX9730 toc11
SHUTDOWN WAVEFORM
MAX9730 toc12
70 60 50 EFFICIENCY (%) 40 30 20 10 0 0 1 2 3 VCC = 5V fIN = 1kHz
SHDN 5V/div
SHDN 5V/div
OUT+ - OUT500mV/div
OUT+ - OUT500mV/div
10ms/div
10ms/div
OUTPUT POWER (W)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX9730 toc13
SHUTDOWN CURRENT vs. SUPPLY VOLTAGE
0.9 SHUTDOWN CURRENT (A) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1
MAX9730 toc14
12 10 SUPPLY CURRENT (mA) 8 6 4 2 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
1.0
0 6.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V)
OUTPUT POWER vs. SUPPLY VOLTAGE
MAX9730 toc15
OUTPUT POWER vs. LOAD RESISTANCE
fIN = 1kHz POUT AT 1% THD+N
MAX9730 toc16
4.0 3.5 OUTPUT POWER (W) 3.0 2.5 2.0 1.5 1.0 0.5 fIN = 1kHz 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 1% THD+N 10% THD+N
3.0 2.5 OUTPUT POWER (W) 2.0 1.5 1.0 0.5 VCC = 3.6V 0 VCC = 5V
6.0
0
20
40
60
80
100
SUPPLY VOLTAGE (V)
LOAD RESISTANCE ()
_______________________________________________________________________________________
5
2.4W, Single-Supply, Class G Power Amplifier MAX9730
Typical Operating Characteristics (continued)
(VCC = CPVDD = SHDN = 3.6V, GND = CPGND = 0V, RIN+ = RIN- = 10k, RFB+ = RFB- = 10k, RFS = 100k, C1 = 4.7F, C2 = 10F, RL = 8; speaker load resistors (RL) are terminated between OUT+ and OUT-, unless otherwise stated; TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Notes 1, 2)
CLASS G OUTPUT WAVEFORM
MAX9730 toc17
FREQUENCY RESPONSE
18 POUT = 1W
MAX9730 toc18
20
OUT+ 5V/div GAIN (dB) 1% THD+N 200s/div
16 14 12 10 8 6 4 2 0 10 100 1k FREQUENCY (Hz) 10k
OUT5V/div
OUT+ - OUT10V/div
100k
Pin Description
PIN TQFN 1 2, 5, 6, 8, 11, 17, 19, 23, 25, 28 3 4 7 9 10 12 13 14, 22 15, 21 16 18 20 24 26 27 EP UCSP B2 -- A2 A3 A4 A5 B5 B4 C5 D1, D5 C2, C4 D4 D3 D2 C1 B1 A1 -- NAME SHDN N.C. C1P CPVDD FBININ+ FB+ FS VCC SVSS OUTGND OUT+ PVSS C1N CPGND EP Shutdown No Connection. No internal connection. Charge-Pump Flying Capacitor, Positive Terminal. Connect a 4.7F capacitor between C1P and C1N. Charge-Pump Positive Supply Negative Amplifier Feedback Negative Amplifier Input Positive Amplifier Input Positive Amplifier Feedback Charge-Pump Frequency Set. Connect a 100k resistor from FS to GND to set the charge-pump switching frequency. Supply Voltage. Bypass with a 10F capacitor to GND. Amplifier Negative Power Supply. Connect to PVSS. Negative Amplifier Output Ground Positive Amplifier Output Charge-Pump Output. Connect a 10F capacitor between PVSS and CPGND. Charge-Pump Flying Capacitor, Negative Terminal. Connect a 4.7F capacitor between C1N and C1P. Charge-Pump Ground. Connect to GND. Exposed Pad. Connect the TQFN EP to GND. FUNCTION
6
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2.4W, Single-Supply, Class G Power Amplifier
Detailed Description
The MAX9730 Class G power amplifier with inverting charge pump is the latest in linear amplifier technology. The Class G output stage offers the performance of a Class AB amplifier while increasing efficiency to extend battery life. The integrated inverting charge pump generates a negative supply capable of delivering up to 500mA. The Class G output stage and the inverting charge pump allow the MAX9730 to deliver an output power that is up to four times greater than a traditional single-supply linear amplifier. This allows the MAX9730 to maintain 0.8W into an 8 load as the battery rail collapses. ply range. In this range, the operation of the device is identical to a traditional single-supply Class AB amplifier where: ILOAD = IN1 As the output signal increases, so a wider supply is needed, the device begins its transition to the higher supply range (VCC to SVSS) for the large signals. To ensure a seamless transition between the low and high supply ranges, both of the lower transistors are on so that: ILOAD = IN1 + IN2 As the output signal continues to increase, the transition to the high supply is complete. The device then operates in the higher supply range, where the operation of the device is identical to a traditional dual-supply Class AB amplifier where: ILOAD = IN2 During operation, the output common-mode voltage of the MAX9730 adjusts dynamically as the device transitions between supply ranges.
MAX9730
Class G Operation and Efficiency
The MAX9730 Class G amplifier is a linear amplifier that operates within a low (VCC to GND) and high (VCC to SVSS) supply range. Figure 1 illustrates the transition from the low to high supply range. For small signals, the device operates within the lower (VCC to GND) sup-
BTL CLASS G SUPPLY TRANSITION VCC VCC VCC
IP ON P RL ON P
IP RL ON P
IP RL
IN1
N1
ON
IN1
N1
ON
N1
OFF
N2
OFF
IN2
N2
ON
IN2
N2
ON
SVSS LOW SUPPLY RANGE OPERATION IP = IN1
SVSS SUPPLY TRANSITION IP = IN1 + IN2
SVSS HIGH SUPPLY RANGE OPERATION IP = IN2
Figure 1. Class G Supply Transition
_______________________________________________________________________________________ 7
2.4W, Single-Supply, Class G Power Amplifier MAX9730
Utilizing a Class G output stage with an inverting charge pump allows the MAX9730 to realize a 2.4W output power with a 5V supply. 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 MAX9730 still exhibits 50% efficiency under the same conditions.
Click-and-Pop Suppression
The MAX9730 Class G amplifier features Maxim's comprehensive, industry-leading click-and-pop suppression. During startup, the click-and-pop suppression circuitry eliminates any audible transient sources internal to the device.
Applications Information
Differential Input Amplifier
The MAX9730 features a differential input configuration, making the device compatible with many CODECs, and offering improved noise immunity over a single-ended input amplifier. In devices such as PCs, noisy digital signals can be picked up by the amplifier's input traces. The signals appear at the amplifiers' inputs as common-mode noise. A differential input amplifier amplifies the difference of the two inputs, and signals common to both inputs are canceled out. When configured for differential inputs, the voltage gain of the MAX9730 is set by: RFB _ A V = 20 log4 x (dB) RIN _ where AV is the desired voltage gain in dB. RIN+ should be equal to RIN- and RFB+ should be equal to RFB-. The Class G output stage has a fixed gain of 4V/V (12dB). Any gain or attenuation set by the external input stage resistors will add to or subtract from this fixed gain. See Figure 3.
Inverting Charge Pump
The MAX9730 features an integrated charge pump with an inverted supply rail that can supply greater than 700mA over the positive 2.7V to 5.5V supply range. In the case of the MAX9730, the charge pump generates the negative supply rail (PVSS) needed to create the higher supply range, which allows the output of the device to operate over a greater dynamic range as the battery supply collapses over time.
Shutdown Mode
The MAX9730 has a shutdown mode that reduces power consumption and extends battery life. Driving SHDN low places the MAX9730 in a low-power (0.3A) shutdown mode. Connect SHDN to V CC for normal operation.
MAX9730 EFFICIENCY vs. CLASS AB
MAX9730 fig02
100 90 80 EFFICIENCY (%) 70 60 50 40 30 20 10 0 0 0.5 1.0 OUTPUT POWER (W) 1.5 TRADITIONAL CLASS AB MAX9730
FB+
MAX9730
RFB+ CINRIN+ IN+ INCINRINRFB+ CLASS G OUTPUT STAGE
FB2.0
Figure 2. MAX9730 Efficiency vs. Class AB Efficiency vs. Class D Efficiency
Figure 3. Gain Setting
8
_______________________________________________________________________________________
2.4W, Single-Supply, Class G Power Amplifier
In differential input configurations, the common-mode rejection ratio (CMRR) is primarily limited by the external resistor and capacitor matching. Ideally, to achieve the highest possible CMRR, the following external components should be selected where: RFB + RFB - = RIN+ RIN- and CIN+ = CIN- to provide sufficient current drive. Increasing the value of C1 improves load regulation and reduces the chargepump output resistance to an extent. Above 1F, the onresistance of the switches and the ESR of C1 and C2 dominate. A 4.7F capacitor is recommended.
MAX9730
Hold Capacitor (C2) The output capacitor value and ESR directly affect the ripple at PVSS. Increasing C2 reduces output ripple. Likewise, decreasing the ESR of C2 reduces both ripple and output resistance. A 10F capacitor is recommended. Charge-Pump Frequency Set Resistor (RFS) The charge pump operates in two modes. When the charge pump is loaded below 100mA, it operates in a slow mode where the oscillation frequency is reduced to 1/4 of its normal operating frequency. Once loaded, the charge-pump oscillation frequency returns to normal operation. In applications where the design may be sensitive to the operating charge-pump oscillation frequency, the value of the external resistor RFS can be changed to adjust the charge-pump oscillation frequency (see Figure 4).
Component Selection
Input-Coupling Capacitor The AC-coupling capacitors (CIN_) and input resistors (RIN_) form highpass filters that remove any DC bias from an input signal (see the Typical Application Circuit/Functional Diagram). CIN_ blocks DC voltages from the amplifier. The -3dB point of the highpass filter, assuming zero source impedance due to the input signal source, is given by:
f-3dB = 1 (Hz) 2 x RIN _ x CIN _
CHARGE-PUMP OSCILLATION FREQUENCY (kHz)
Choose CIN so that f-3dB is well below the lowest frequency of interest. Setting f-3dB too high affects the amplifier's low frequency response. Use capacitors with low-voltage coefficient dielectrics. Aluminum electrolytic, tantalum, or film dielectric capacitors are good choices for AC-coupling capacitors. Capacitors with high-voltage coefficients, such as ceramics (non-C0G dielectrics), can result in increased distortion at low frequencies.
CHARGE-PUMP OSCILLATION FREQUENCY vs. RFS
ILOAD > 100mA 550 500 450 400 350 300 250 200 50 75 100 RFS (k) 125 150
MAX9730 fig04
600
Charge-Pump Capacitor Selection Use capacitors with an ESR less than 50m 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. Flying Capacitor (C1) The value of the flying capacitor (C1) affects the load regulation and output resistance of the charge pump. A C1 value that is too small degrades the device's ability
Figure 4. Charge-Pump Oscillation Frequency vs. RFS
_______________________________________________________________________________________
9
2.4W, Single-Supply, Class G Power Amplifier MAX9730
Thermal Considerations
Class G 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 and include consideration of many parameters. This section examines Class G amplifiers using general examples to illustrate good design practices. The copper polygon to which the exposed pad is attached should have multiple vias to the opposite side of the PCB, where they connect to GND. Make this polygon as large as possible within the system's constraints.
UCSP Applications Information
For the latest application details on UCSP construction, dimensions, tape carrier information, PCB techniques, bump-pad layout, and recommended reflow temperature profile, as well as the latest information on reliability testing results, go to the Maxim website at www.maximic.com/ucsp for the application note, UCSP--A WaferLevel Chip-Scale Package.
TQFN Considerations The exposed pad is the primary route of keeping heat away from the IC. With a bottom-side exposed pad, the PCB and its copper become the primary heatsink for the Class G amplifier. Solder the exposed pad to a large copper polygon that is connected to the ground plane.
Typical Application Circuit/Functional Diagram
VDD
0.1F 14, 22 (D1, D5) 4 (A3) VCC CPVDD
*
1 (B2) SHDN 12 (B4) FB+
MAX9730
CIN 1F RIN10k RFB+ 10k 10 (B5) IN+ 9 (A5) INCIN 1F RIN10k RFB10k 7 (A4) FBGND 18 (D3) CPGND C1N 26 (B1) CHARGE PUMP C1P PVSS FS 13 (C5) RFS 100k + CLASS G OUTPUT STAGE OUT+ 20 (D2) OUT- 16 (D4)
SVSS 15, 21 (C2, C4) C2 10F
27 (A1)
3 (A2) 24 (C1)
( ) UCSP PACKAGE
C1 4.7F
DEVICE SHOWN WITH AV = 12dB *SYSTEM-LEVEL REQUIREMENT TYPICALLY 10F
10
______________________________________________________________________________________
2.4W, Single-Supply, Class G Power Amplifier
Pin Configurations
TOP VIEW
CPGND PVSS N.C. C1N N.C. N.C. VCC
MAX9730
TOP VIEW (BUMP SIDE DOWN) MAX9730
1 2 3 4 5
28
27
26
25
24
23
+
SHDN N.C. C1P CPVDD N.C. N.C. FB-
22
1 2 3 4 5 6 7 EP* 10 11 12 13 14
21 20 19
SVSS OUT+ N.C. GND N.C. OUTSVSS
A CPGND B C1N C PVSS D VCC OUT+ GND OUTVCC SVSS SVSS FS SHDN FB+ IN+ C1P CPVDD FBIN-
MAX9730
18 17 16 15
8
N.C.
9
IN-
IN+
N.C.
FB+
FS
VCC
UCSP
THIN QFN
*EXPOSED PAD.
Chip Information
PROCESS: BiCMOS
______________________________________________________________________________________
11
2.4W, Single-Supply, Class G Power Amplifier MAX9730
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.) 24L QFN THIN.EPS 12 ______________________________________________________________________________________
2.4W, Single-Supply, Class G Power 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.)
MAX9730
______________________________________________________________________________________
13
2.4W, Single-Supply, Class G Power Amplifier MAX9730
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.)
5x4 UCSP.EPS
14
______________________________________________________________________________________
2.4W, Single-Supply, Class G Power Amplifier
Revision History
REVISION NUMBER 0 1 REVISION DATE 1/07 11/07 Initial release Include tape and reel note, edit Absolute Maximum Ratings, update TQFN package outline DESCRIPTION PAGES CHANGED -- 1, 2,12, 13
MAX9730
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15
(c) 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

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