MAX9742ETX+ Maxim Integrated Products, MAX9742ETX+ Datasheet

IC AMP AUDIO PWR 20.5W D 36TQFN

MAX9742ETX+

Manufacturer Part Number
MAX9742ETX+
Description
IC AMP AUDIO PWR 20.5W D 36TQFN
Manufacturer
Maxim Integrated Products
Type
Class Dr
Datasheet

Specifications of MAX9742ETX+

Output Type
2-Channel (Stereo)
Max Output Power X Channels @ Load
20.5W x 2 @ 8 Ohm
Voltage - Supply
20 V ~ 40 V, ±10 V ~ 20 V
Features
Depop, Differential Inputs, Mute, Short-Circuit and Thermal Protection, Shutdown
Mounting Type
Surface Mount
Package / Case
36-TQFN Exposed Pad
Product
Class-D
Output Power
16 W
Thd Plus Noise
0.08 %
Supply Current
15 mA
Maximum Power Dissipation
2.86 W
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Audio Load Resistance
4 Ohms
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX9742 stereo Class D audio power amplifier
delivers up to 2 x 16W into 4Ω loads. The MAX9742
features high-power efficiency (92% with 8Ω loads),
eliminating the need for a bulky heatsink and conserv-
ing power. The MAX9742 operates from a 20V to 40V
single supply or a ±10V to ±20V dual supply. Features
include fully differential inputs, comprehensive click-
and-pop suppression, low-power shutdown mode, and
an externally adjustable gain. Short-circuit and thermal-
overload protection prevent the device from being
damaged during a fault condition.
The MAX9742 is available in a thermally efficient 36-pin
TQFN (6mm x 6mm x 0.8mm) package and is specified
over the -40°C to +85°C extended temperature range.
19-0731; Rev 0; 1/07
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.
Simplified Block Diagrams continued at end of data sheet.
SINGLE-SUPPLY CONFIGURATION
CRT TVs
Flat-Panel Display TVs
Audio Docking Stations
Multimedia Monitors
RIGHT NEGATIVE
RIGHT POSITIVE
LEFT NEGATIVE
LEFT POSITIVE
Class D Amplifier with Differential Inputs
AUDIO INPUT
AUDIO INPUT
AUDIO INPUT
AUDIO INPUT
________________________________________________________________ Maxim Integrated Products
General Description
C
C
C
C
IN
IN
IN
IN
V
R
R
R
R
2
DD
IN1
IN2
IN2
IN1
R
R
F2
F2
Applications
C
C
Single-/Dual-Supply, Stereo 16W,
FBL
FBR
INL-
INL+
MID
INR+
INR-
C
C
FBR
FBL
FBR
FBL
20V TO 40V
o 2 x 16W Output Power (R
o High Efficiency: Up to 92% with R
o Mute and Shutdown Modes
o Differential Inputs Suppress Common-Mode Noise
o Adjustable Gain
o Integrated Click-and-Pop Suppression
o Low 0.06% THD+N at 3.5W, R
o Output Short-Circuit and Thermal Protection
o Available in Space-Saving, 6mm x 6mm, 36-Pin
+ Denotes lead-free package.
* EP = Exposed paddle.
Pin Configuration located at end of data sheet.
R
V
V
MAX9742ETX+
F1
DD
SS
R
F1
TQFN Package
SHDN
MODULATOR AND
MODULATOR AND
CONTROL LOGIC/
PART
OFF
HALF-BRIDGE
HALF-BRIDGE
SEQUENCING
POWER-UP
CLASS D
CLASS D
ON
MAX9742
SFT
C
Simplified Block Diagrams
SFT
OUTR
OUTL
-40°C to +85°C
TEMP RANGE
Ordering Information
L
L
F
F
C
C
L
F
F
= 4Ω, THD+N = 10%)
PIN-PACKAGE
36 TQFN-EP*
L
C
C
OUT
OUT
= 8Ω
C
C
R
R
ZBL
ZBL
ZBL
ZBL
L
= 8Ω
Features
T3666-3
CODE
PKG
1

Related parts for MAX9742ETX+

MAX9742ETX+ Summary of contents

Page 1

... Differential Inputs Suppress Common-Mode Noise o Adjustable Gain o Integrated Click-and-Pop Suppression o Low 0.06% THD+N at 3.5W Output Short-Circuit and Thermal Protection o Available in Space-Saving, 6mm x 6mm, 36-Pin TQFN Package PART Applications MAX9742ETX+ + Denotes lead-free package Exposed paddle. Pin Configuration located at end of data sheet FBL 20V TO 40V ...

Page 2

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs ABSOLUTE MAXIMUM RATINGS NSENSE ..............................................-0.3V to +45V DD SS MID, LGND REGM, REGP, OUTR, DD OUTL to V .......................................................-0.3V to +45V SS MID, LGND, LV ...

Page 3

Class D Amplifier with Differential Inputs ELECTRICAL CHARACTERISTICS—Single-Supply, Single-Ended Output (continued 24V LGND = 0V SUB 10kΩ 0.47µ 1000µF, C SFT OUT R = 121kΩ ...

Page 4

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs ELECTRICAL CHARACTERISTICS—Dual Supplies (continued 15V -15V, V SHDN DD SS SUB 150pF 10pF 0.1µF, C FB_2 BOOT 68kΩ ∞, ...

Page 5

Class D Amplifier with Differential Inputs ELECTRICAL CHARACTERISTICS—Single-Supply, BTL Configuration (V = 24V LGND = 0V SUB 10kΩ 0.47µ 1000µF, C SFT OUT = 121kΩ 562kΩ, R ...

Page 6

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs (24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to 22kHz +25°C, unless otherwise noted. See Figure 1 for test circuits, see ...

Page 7

Class D Amplifier with Differential Inputs (24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to 22kHz +25°C, unless otherwise noted. See Figure 1 for test circuits, see Typical Application Circuits/Functional ...

Page 8

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs (24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to 22kHz +25°C, unless otherwise noted. See Figure 1 for test circuits, see ...

Page 9

Class D Amplifier with Differential Inputs (24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to 22kHz +25°C, unless otherwise noted. See Figure 1 for test circuits, see Typical Application Circuits/Functional ...

Page 10

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs (24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to 22kHz +25°C, unless otherwise noted. See Figure 1 for test circuits, see ...

Page 11

Class D Amplifier with Differential Inputs (24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to 22kHz +25°C, unless otherwise noted. See Figure 1 for test circuits, see Typical Application Circuits/Functional ...

Page 12

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs PIN NAME 1, 6, 18, N.C. No Connection. Not internally connected. 27, 28 OUTL Left Speaker Output 4 SUB Device Substrate. Connect SUB BOOTL Left-Channel ...

Page 13

Class D Amplifier with Differential Inputs PIN NAME 24 BOOTR Right-Channel Bootstrap Capacitor. Connect a 0.1µF capacitor between BOOTR and OUTR. 25, 26 OUTR Right Speaker Output 29, 30, Positive Power-Supply Input. Bypass 34, 35 the Supply ...

Page 14

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs efficiency of a linear amplifier is 78%; however, that effi- ciency is only exhibited at peak output powers. Under normal operating levels (typical music reproduction lev- els), efficiency falls below 30%, ...

Page 15

Class D Amplifier with Differential Inputs INTERNAL TRIANGLE WAVE OSCILLATOR INPUT SIGNAL V OUT_ NOTE: FOR CLARITY, SIGNAL PERIODS ARE NOT SHOWN TO ACTUAL SCALE. Figure 3a. MAX9742 Output with an Applied Input Signal V OUT_ AVERAGE VALUE OF V ...

Page 16

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs The MAX9742 features a low-power shutdown mode that reduces quiescent current consumption to less than 0.5mA in single-supply mode and less than 1µA in dual-supply mode. Drive SHDN low to place ...

Page 17

Class D Amplifier with Differential Inputs to-peak output voltage that causes 10% THD+N for a given load OUT_P P − OUT_10% where P is the output power that causes 10% OUT_10% THD+ ...

Page 18

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs Summing Configuration (Audio Mixer) Figure 6 shows the MAX9742 configured as a summing amplifier, which allows multiple audio sources to be lin- early mixed together. Using this configuration, the out- put ...

Page 19

Class D Amplifier with Differential Inputs Since each half-bridge output stage is only capable of driving loads as small as 4Ω and each half-bridge sees half of the differential load resistance when configured for BTL, only use the BTL configuration ...

Page 20

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs To guarantee stability and minimize distortion, select the external feedback resistor ( that the following conditions are met: FB_ 21 and R × ≥ F_ FB_ ...

Page 21

Class D Amplifier with Differential Inputs Using the transfer functions and the equation for f following expressions for L and × π × × SPKR ...

Page 22

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs To maximize the performance of the differential output filter and minimize EMI radiation, keep the ground con- nections of the C capacitors close together on the F PCB and place the ...

Page 23

Class D Amplifier with Differential Inputs Bootstrap Diode (D To provide sufficient gate drive voltage to the high-side transistor of the half-bridge output stage, an external diode (D ) and capacitor (C BOOT BOOT the internal bootstrapping circuitry (see Figure ...

Page 24

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs Multiple-Pole MID Network vs. Single-Pole VMID Network for Increased PSRR Performance (Single-Supply Operation) A multiple-pole MID network improves PSRR perfor- mance over a single-pole network. Since the input amplifiers of the ...

Page 25

Class D Amplifier with Differential Inputs speaker loads during mode transitions. After C charged the MAX9742 concludes the soft- MID start sequence by precharging Once the soft-start sequence is complete, the IN MAX9742 ...

Page 26

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs C VDD OFF I AVG ON C VSS CASE 1: I FLOWING INTO HALF-BRIDGE CAUSING VOLTAGE ACROSS C AVG I = AVERAGE (CONTINUOUS) OUTPUT CURRENT DURING ONE SWITCHING CYCLE. AVG I ...

Page 27

Class D Amplifier with Differential Inputs Worst-case supply pumping occurs at high output pow- ers with low-frequency signals and small load resis- tances. Since the period is longer for low-frequency signals, the continuous output current has more time to pump ...

Page 28

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs T-Network for Low THD Performance at Low Output Powers (Optional) If low THD+N performance is needed at low-output pow- ers, replace the feedback resistor (R with the T-network shown in Figure ...

Page 29

Class D Amplifier with Differential Inputs Supply Bypassing/Layout To maximize output power and minimize distortion, proper layout and supply bypassing is essential. To prevent ground-loop-induced noise and minimize noise due to parasitic ground inductance, use separate ground planes for input-signal ...

Page 30

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs These copper paths must be as wide as possible. Each of these paths contributes to the overall thermal capa- bilities of the system. The copper polygon to which the exposed paddle ...

Page 31

Class D Amplifier with Differential Inputs IN1 LEFT NEGATIVE AUDIO INPUT IN2 LEFT POSITIVE AUDIO INPUT R C FBL FBR IN2 RIGHT POSITIVE AUDIO INPUT C R ...

Page 32

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs 32 ______________________________________________________________________________________ Typical Application Circuits/Functional Diagrams ...

Page 33

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs Typical Application Circuits/Functional Diagrams (continued) ______________________________________________________________________________________ 33 ...

Page 34

Single-/Dual-Supply, Stereo 16W, Class D Amplifier with Differential Inputs Typical Application Circuits/Functional Diagrams (continued) 34 ______________________________________________________________________________________ ...

Page 35

Class D Amplifier with Differential Inputs (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information www.maxim-ic.com/packages.) ______________________________________________________________________________________ Single-/Dual-Supply, Stereo 16W, Package Information 35 ...

Page 36

... 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. 36 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2007 Maxim Integrated Products Package Information (continued registered trademark of Maxim Integrated Products, Inc ...

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