General Description
The MAX9723 stereo DirectDrive
®
headphone amplifier
with BassMax and volume control is ideal for portable
audio applications where space is at a premium and per-
formance is essential. The MAX9723 operates from a sin-
gle 1.8V to 3.6V power supply and includes features that
reduce external component count, system cost, board
space, and improves audio reproduction.
The headphone amplifier uses Maxim’s DirectDrive
architecture that produces a ground-referenced output
from a single supply, eliminating the need for large DC-
blocking capacitors. The headphone amplifiers deliver
62mW into a 16Ω load, feature low 0.006% THD+N, and
high 90dB PSRR. The MAX9723 features Maxim’s indus-
try-leading click-and-pop suppression.
The BassMax feature boosts the bass response of the
amplifier, improving audio reproduction when using
inexpensive headphones. The integrated volume con-
trol features 32 discrete volume levels, eliminating the
need for an external potentiometer. BassMax and the
volume control are enabled through the I
2
C/SMBus™-
compatible interface. Shutdown is controlled through
either the hardware or software interfaces.
The MAX9723 consumes only 3.7mA of supply current
at 1.8V, provides short-circuit and thermal-overload
protection, and is fully specified over the extended
-40°C to +85°C temperature range. The MAX9723 is
available in a tiny (2mm x 2mm x 0.62mm) 16-bump
chip-scale package (UCSP™) or 16-pin thin QFN (4mm
x 4mm x 0.8mm) package.
Applications
Features
♦ 62mW, DirectDrive Headphone Amplifier
Eliminates Bulky DC-Blocking Capacitors
♦ 1.8V to 3.6V Single-Supply Operation
♦ Integrated 32-Level Volume Control
♦ High 90dB PSRR at 1kHz
♦ Low 0.006% THD+N
♦ Industry-Leading Click-and-Pop Suppression
♦ ±8kV HBM ESD-Protected Headphone Outputs
♦ Short-Circuit and Thermal-Overload Protection
♦ Low-Power Shutdown Mode (5µA)
♦ Software-Enabled Bass Boost (BassMax)
♦ I
2
C/SMBus-Compatible Interface
♦ Available in Space-Saving, Thermally Efficient
Packages:
16-Bump UCSP (2mm x 2mm x 0.62mm)
16-Pin Thin QFN (4mm x 4mm x 0.8mm)
MAX9723
Stereo DirectDrive Headphone Amplifier
with BassMax, Volume Control, and I
2
C
________________________________________________________________ Maxim Integrated Products 1
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
SMBus is a trademark of Intel Corp.
UCSP is a trademark of Maxim Integrated Products, Inc.
**Replace the ‘_’ with the one-letter code that denotes the
slave address and maximum programmable gain. See the
Selector Guide.
+Denotes a lead-free/RoHS-compliant package.
*Future product—contact factory for availability.
Pin Configurations appear at end of data sheet.
PDA Audio
Portable CD Players
Mini Disc Players
Automotive Multimedia
MP3-Enabled Cellular
Phones
MP3 Players