MAX9742ETX+ Maxim Integrated Products, MAX9742ETX+ Datasheet - Page 13

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

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

Figure 1. Test Circuits for Single-Ended and BTL Configurations
31, 32, 33
29, 30,
NOTE: SINGLE-ENDED CONFIGURATION IS AC-COUPLED IN SINGLE-SUPPLY MODE.
25, 26
34, 35
PIN
EP
24
MAX9742
MAX9742
OUTL
OUTR
OUTL
OUTR
BOOTR
NAME
OUTR
V
V
EP
Class D Amplifier with Differential Inputs
DD
SS
______________________________________________________________________________________
______________________________________________________________________________________
SINGLE-ENDED CONFIGURATION
L
L
L
L
F
F
F
F
BTL CONFIGURATION
C
C
C
C
F
F
F
F
Right-Channel Bootstrap Capacitor. Connect a 0.1µF capacitor between BOOTR and OUTR.
Right Speaker Output
Positive Power-Supply Input. Bypass V
the Supply Pumping Effects section.
Negative Power-Supply Input. For dual-supply operation, connect to negative power-supply voltage
and bypass V
connect to LGND.
Exposed Paddle. EP is internally connected to device substrate. Connect EP to V
section of copper to maximize power dissipation.
R
L
R
R
L
L
Test Circuits
SS
+
-
+
-
+
-
AUX-0025
AUX-0025
Single-/Dual-Supply, Stereo 16W,
FILTER
FILTER
to LGND with a 0.1µF plus additional bulk capacitance. For single-supply operation,
+
-
+
-
+
-
ANALYZER
ANALYZER
AUDIO
AUDIO
DD
to LGND with a 0.1µF plus additional bulk capacitance. See
The MAX9742 is a two-channel, single-ended Class D
stereo amplifier capable of providing 16W of output
power on each channel into 4Ω loads in single- or dual-
supply operation. The amplifier can also provide 32W
of output power in a mono bridge-tied-load (BTL) con-
figuration. The device offers Class AB audio perfor-
mance with Class D efficiency.
The differential input architecture reduces common-
mode noise pickup. The device can also be configured
for single-ended input signals.
The connection of external feedback components
allows custom gain settings.
Class D amplifiers are switch-mode devices capable of
significantly higher power efficiencies in comparison to
linear amplifiers. The output stage of the MAX9742 con-
sists of a half-bridge speaker driver (see Figure 2). The
high 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 current-
steering switches by switching the output between V
and V
power loss associated with the Class D output stage is
mostly due to the I
and quiescent current overhead. The theoretical best
FUNCTION
SS
(ground for single-supply operation). Any
Pin Description (continued)
Class D Operation and Efficiency
2
R loss of the MOSFET on-resistance
Detailed Description
SS
through a large
DD
13
13