max9791 Maxim Integrated Products, Inc., max9791 Datasheet - Page 17

• Manufacturer Part Number: max9791
• Description: Windows Vista-compliant Class D Speaker Amplifiers With Directdrive Headphone Amplifiers
• Manufacturer: Maxim Integrated Products, Inc.

The MAX9791 combines a stereo 2W Class D power
amplifier, a stereo 175mW DirectDrive headphone
amplifier, and a 120mA LDO linear regulator in a single
device. The MAX9792 combines a mono 3W Class D
power amplifier, a stereo 175mW DirectDrive head-
phone amplifier, and a 120mA LDO linear regulator in a
single device.
The MAX9791/MAX9792 feature wake-on-beep detec-
tion, comprehensive click-and-pop suppression, low-
power shutdown mode, and excellent RF immunity.
These devices incorporate an integrated LDO that
serves as a clean power supply for CODEC or other cir-
cuits. The MAX9791/MAX9792 are Windows Vista
Premium compliant. See Table 1 for a comparison of the
Windows Vista Premium specifications and MAX9791/
MAX9792 specifications.
Amplifiers with DirectDrive Headphone Amplifiers
17, 26
18, 25
19, 24
20, 23
PIN
1, 5
10
11
12
13
14
15
16
21
22
27
28
—
2
3
4
6
7
8
9
LDO_OUT
SPKR_EN
Windows Vista-Compliant Class D Speaker
SPKR_IN
LDO_EN
CPGND
______________________________________________________________________________________
HP_INR
HP_INL
HPVDD
SENSE
CPVSS
HP_EN
NAME
PGND
AVDD
OUT+
PVDD
BEEP
COM
OUT-
GND
HPR
C1N
HPL
C1P
EP
Detailed Description
Signal Ground. Star connect to PGND.
Right-Channel Headphone Amplifier Input
Left-Channel Headphone Amplifier Input
Common-Mode Voltage Sense Input
LDO Output. Bypass with two 1µF ceramic low ESR capacitors to GND.
Positive Power Supply and LDO Input. Bypass with a 0.1µF and two 1µF capacitors to GND.
LDO Enable. Connect LDO_EN to AVDD to enable the LDO.
Right-Channel Headphone Amplifier Output
Left-Channel Headphone Amplifier Output
Headphone Ground Sense
Headphone Amplifier Negative Power Supply. Connect a 1µF capacitor between CPVSS and PGND.
Charge-Pump Flying Capacitor Negative Terminal. Connect a 1µF capacitor between C1P and C1N.
Charge-Pump Ground. Connect directly to PGND plane.
Charge-Pump Flying Capacitor Positive Terminal. Connect a 1µF capacitor between C1P and C1N.
H ead p hone Am p l i fi er P osi ti ve P ow er S up p l y. C onnect a 10µF cap aci tor b etw een H P V D D and P GN D .
Speaker Amplifier Power-Supply Input. Bypass with a 0.1µF capacitor to PGND.
Speaker Amplifier Output, Negative Phase
Speaker Amplifier Output, Positive Phase
Power Ground. Star connect to GND.
PC Beep Input. Connect to GND if beep detection function is disabled.
Active-High Headphone Amplifier Enable
Active-Low Speaker Amplifier Enable
Speaker Amplifier Input
Exposed Pad. Connect to GND.
The MAX9791/MAX9792 feature spread-spectrum mod-
ulation and active emission limiting circuitry that offers
significant improvements to switch-mode amplifier tech-
nology. These devices offer Class AB performance with
Class D efficiency in a minimal board-space solution.
The headphone amplifiers use Maxim’s patented
DirectDrive architecture to eliminate the bulky output
DC-blocking capacitors required by traditional head-
phone amplifiers. A charge pump inverts the positive
supply (HPVDD) to create a negative supply (CPVSS).
The headphone amplifiers operate from these bipolar
supplies with their outputs biased about GND. The ben-
efit of the GND bias is that the amplifier outputs no
longer have a DC component (typically V
feature eliminates the large DC-blocking capacitors
required with conventional headphone amplifiers to
FUNCTION
MAX9792 Pin Description
DD
/2). This
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