MAX9726 Datasheet, PDF (1/26 Pages) Maxim Integrated Products – DirectDrive, Headphone Amplifier with BassMax, I2C, Volume and Gain Control

19-0627; Rev 0; 9/06
DirectDrive, Headphone Amplifier with
BassMax, I²C, Volume and Gain Control
General Description
The MAX9726 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 MAX9726 operates from a sin-
gle 2.7V to 5.5V power supply and includes features that
reduce external component count, system cost, board
space, and offer improved audio reproduction. High
85dB PSRR makes the MAX9726 ideal for direct connec-
tion to a battery-powered supply and eliminates the need
for a dedicated LDO. The MAX9726 features Maxim’s
industry-leading click-and-pop suppression circuitry,
which reduces/eliminates audible transients during
power-up and power-down.
The headphone amplifier uses Maxim’s patented^†
DirectDrive architecture that produces a ground-refer-
enced output from a single supply, eliminating the need
for large DC-blocking capacitors. The headphone ampli-
fiers deliver 105mW into a 32Ω load and feature low
0.02% THD+N.
The BassMax feature boosts the bass response of the
amplifier, improving audio reproduction when using inex-
pensive headphones. The integrated volume control fea-
tures 64 discrete volume levels, eliminating the need for
an external potentiometer. External resistors set the
MAX9726’s overall gain allowing for custom gain settings.
BassMax and the volume control are enabled through the
I²C/SMBus^™-compatible interface. Shutdown can be con-
trolled through the hardware or software interface.
The MAX9726 consumes only 5.5mA of supply current,
provides short-circuit and thermal-overload protection,
and is specified over the -40°C to +85°C extended tem-
perature range. The MAX9726 is available in a tiny
(2mm x 2.5mm x 0.62mm) 20-bump chip-scale pack-
age (UCSP™) and a 20-pin TQFN package (4mm x
4mm x 0.75mm).
Cell Phones
MP3/PMP Players
Flat-Panel TVs
†_{U.S. Patent # 7,061,327}
Applications
Automotive Rear-Seat
Entertainment (RSE)
Portable CD/DVD/MD
Players
SMBus is a trademark of Intel Corp.
UCSP is a trademark of Maxim Integrated Products, Inc.
Features
♦ 105mW DirectDrive Headphone Amplifier
Eliminates Bulky DC-Blocking Capacitors
♦ 2.7V to 5.5V Single-Supply Operation
♦ Integrated 64-Level Volume Control
♦ High 85dB PSRR at 1kHz
♦ Software-Enabled Bass Boost (BassMax)
♦ Industry-Leading Click-and-Pop Suppression
♦ ±7.5kV HBM ESD-Protected Headphone Outputs
♦ Short-Circuit and Thermal-Overload Protection
♦ Low-Power Shutdown Mode (8µA)
♦ Low 0.02% THD+N
♦ I²C/SMBus-Compatible Interface
♦ Available in Space-Saving, Thermally Efficient
Packages
20-Bump UCSP (2mm x 2.5mm x 0.62mm)
20-Pin TQFN (4mm x 4mm x 0.75mm)
Ordering Information
PART
PIN-PACKAGE
SLAVE
ADDRESS
PKG
CODE
MAX9726AEBP+T* 20 UCSP-20
1001100 B20-1
MAX9726AETP+ 20 TQFN-EP** 1001100 T2044-3
MAX9726BEBP+T* 20 UCSP-20
1001101 B20-1
MAX9726BETP+ 20 TQFN-EP** 1001101 T2044-3
Note: All devices specified over the -40°C to +85°C operating
range.
+Denotes lead-free package.
*Future product—contact factory for availability.
**EP = Exposed pad.
Simplified Block Diagram
2.7V TO 5.5V SUPPLY
SCL
I²C
SDA _INTERFACE
FBL
INL
Σ
VOLUME
CONTROL
Σ
INR
FBR
MAX9726
BML ^BassMax
OUTL
OUTR
BMR
BassMax
Pin Configurations appear 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.