MAX9791 Datasheet, PDF (1/30 Pages) Maxim Integrated Products – Windows Vista-Compliant Class D Speaker Amplifiers with DirectDrive Headphone Amplifiers

19-4217; Rev 0; 11/08
Windows Vista-Compliant Class D Speaker
Amplifiers with DirectDrive Headphone Amplifiers
General Description
The MAX9791 combines a stereo 2W Class D power
amplifier, a stereo 180mW DirectDrive^® headphone
amplifier, and a 120mA low-dropout (LDO) linear regu-
lator in a single device. The MAX9792 combines a
mono 3W Class D power amplifier, a stereo 180mW
DirectDrive headphone amplifier, and a 120mA LDO
linear regulator in a single device.
The MAX9791/MAX9792 feature Maxim’s patented**
DirectDrive headphone amplifier architecture that pro-
duces a ground-referenced output from a single supply,
eliminating the need for large DC-blocking capacitors,
saving cost, board space, and component height. High
107dB DC PSRR and low 0.006% THD+N ensure clean,
low-distortion amplification of the audio signal.
The ground sense feature senses and corrects for the
voltage difference between the output jack ground and
device signal ground. This feature minimizes head-
phone amplifier crosstalk by sensing the impedance in
the ground return trace and correcting for it at the out-
put jack. This feature also minimizes ground-loop noise
when the output socket is used as a line out connection
to other grounded equipment (for example, a PC con-
nected to a home hi-fi system).
The MAX9791/MAX9792 feature low RF susceptibility,
allowing the amplifiers to successfully operate in close
proximity to wireless applications. The MAX9791/
MAX9792 Class D amplifiers feature Maxim’s patented^†
spread-spectrum modulation and patented^†† active
emissions limiting circuitry. Industry-leading click-and-
pop suppression eliminates audible transients during
power-up and shutdown cycles.
The MAX9791/MAX9792 wake-on-beep feature wakes
up the speaker and headphone amplifiers when a qual-
ified beep signal is detected at the BEEP input.
For maximum flexibility, separate speaker and head-
phone amplifier control inputs provide independent
shutdown of the speaker and headphone amplifiers.
Additionally the LDO can be enabled independently of
the audio amplifiers.
The MAX9791/MAX9792 feature thermal-overload and
output short-circuit protection. The devices are avail-
able in 28-pin TQFN packages and are specified over
the -40°C to +85°C extended temperature range.
Applications
Features
♦ Windows Vista® Premium Compliant
♦ Low EMI Filterless Class D Speaker Amplifiers
Pass EN55022B Emissions Limit with 30cm of
Speaker Cable
♦ 180mW DirectDrive Headphone Amplifier
♦ Excellent RF Immunity
♦ Integrated 120mA LDO
♦ Eliminates Headphone Ground Loop Noise
♦ Wake-on-Beep Function
♦ Click-and-Pop Suppression
♦ Short-Circuit and Thermal-Overload Protection
♦ Thermally Efficient, Space-Saving Package
28-Pin TQFN-EP (4mm x 4mm x 0.75mm)
Ordering Information
PART
STEREO/
MONO
LDO
OUTPUT
PIN-PACKAGE
MAX9791AETI+
Stereo
4.75V 28 TQFN-EP*
MAX9791BETI+
Stereo
3.3V 28 TQFN-EP*
MAX9792AETI+
Mono
4.75V 28 TQFN-EP*
Note: All devices are specified over the -40°C to +85°C
extended temperature range.
+Denotes a lead-free/RoHS-compliant package.
*EP = Exposed pad.
Simplified Block Diagrams
SPEAKER SUPPLY HEADPHONE SUPPLY
4.5V TO 5.5V
2.7V TO 5.5V
MAX9791A
MAX9791B
CLASS D
AMP
CLASS D
AMP
Notebook Computers
Tablet PCs
Portable Multimedia Players
Windows Vista is a registered trademark of Microsoft Corp.
**U.S. Patent #7,061,327.
†_{U.S. Patent #6,847,257.}
††_{U.S. Patent #7,190,225.}
4.5V TO 5.5V
SPKR_EN
HP_EN
LDO_EN
BEEP
LDO
3.3V OR 4.75V
Simplified Block Diagrams continued at end of data sheet.
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
________________________________________________________________ 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.