MAX9789A Datasheet, PDF (1/26 Pages) Maxim Integrated Products – Windows Vista-Compliant, Stereo Class AB Speaker Amplifiers and DirectDrive Headphone Amplifiers

19-0606; Rev 0; 9/06
Windows Vista-Compliant, Stereo Class AB Speaker
Amplifiers and DirectDrive Headphone Amplifiers
General Description
The MAX9789A/MAX9790A combine a stereo, 2W Class
AB speaker power amplifier with a stereo 100mW
DirectDrive™ headphone amplifier in a single device.
The MAX9789A/MAX9790A are designed for use with the
Microsoft Windows Vista™ operating system and are fully
compliant with Microsoft’s Windows Vista specifications.
The headphone amplifier features Maxim’s patented^†
DirectDrive architecture that produces a ground-refer-
enced output from a single supply to eliminate the need
for large DC-blocking capacitors, as well as save cost,
board space, and component height. A high +90dB
PSRR and low 0.002% THD+N ensures clean, low-distor-
tion amplification of the audio signal.
Separate speaker and headphone amplifier control
inputs provide independent shutdown of the speaker
and headphone amplifiers, allowing speaker and head-
phone amplifiers to be active simultaneously, if
required. The industry-leading click-and-pop suppres-
sion circuitry reduces audible transients during startup
and shutdown cycles.
The MAX9789A features an internal LDO that can be
used as a clean power supply for a CODEC or other cir-
cuits. The LDO output voltage is set internally at 4.75V or
can be adjusted between 1.21V and 4.75V using a sim-
ple resistive divider. The LDO is protected against ther-
mal overloads and short circuits while providing 120mA
of continuous output current and can be enabled inde-
pendently of the audio amplifiers.
By disabling the speaker and headphone amplifiers, and
the LDO (for MAX9789A), the MAX9789A/MAX9790A
enter low-power shutdown mode and draw only 0.3µA.
The MAX9789A/MAX9790A operate from a single 4.5V
to 5.5V supply and feature thermal-overload and out-
put short-circuit protection. Devices are specified over
the -40°C to +85°C extended temperature range.
Applications
Notebook Computers
Tablet PCs
Portable Multimedia Players
Pin Configurations appear at end of data sheet.
†_{U.S. Patent # 7,061,327}
Windows Vista is a trademark of Microsoft Corp.
Features
o Microsoft Windows Vista Compliant
o Class AB 2W Stereo BTL Speaker Amplifier
o 100mW DirectDrive Headphone Amplifier
Eliminates Costly, Bulky DC-Blocking Capacitors
o Excellent RF Immunity
o Integrated 120mA LDO (MAX9789A)
o High +90dB PSRR, Low 0.002% THD+N
o Low-Power Shutdown Mode
o Click-and-Pop Suppression
o Short-Circuit and Thermal-Overload Protection
o ±8kV ESD-Protected Headphone Driver Outputs
o Available in 32-Pin Thin QFN (5mm x 5mm x
0.8mm) Package
Ordering Information
PART
PIN-PACKAGE
INTERNAL
LDO
PKG
CODE
MAX9789AETJ+ 32 Thin QFN-EP*
Yes
T3255N-1
MAX9790AETJ+ 32 Thin QFN-EP*
No
T3255N-1
Note: All devices are specified over the -40°C to +85°C extended
temperature range.
+Denotes lead-free package.
*EP = Exposed paddle.
Simplified Block Diagrams
SPEAKER SUPPLY HEADPHONE SUPPLY
4.5V TO 5.5V
3.0V TO 5.5V
SPKR_INR
SPKR_INL
MAX9789A
HP_INR
HP_INL
SPKR_EN
HP_EN
MUTE
GAIN1
GAIN2
4.5V TO 5.5V
LDO
1.21V TO 4.75V
Simplified Block Diagrams continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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.