Rainbow Electronics MAX9712 User Manual
General description, Applications features, Pin configurations ordering information

General Description
The MAX9712 mono class D audio power amplifier pro-
vides class AB amplifier performance with class D effi-
ciency, conserving board space, and extending battery
life. Using a class D architecture, the MAX9712 delivers
up to 500mW into an 8
Ω load while offering efficiencies
above 85%. A patented, low EMI modulation scheme
renders the traditional class D output filter unnecessary.
The MAX9712 offers two modulation schemes: a fixed-
frequency (FFM) mode, and a spread-spectrum (SSM)
mode that reduces EMI-radiated emissions due to the
modulation frequency. Furthermore, the MAX9712 oscil-
lator can be synchronized to an external clock through
the SYNC input, allowing the switching frequency to be
user defined. The SYNC input also allows multiple
MAX9712s to be cascaded and frequency locked, mini-
mizing interference due to clock intermodulation. The
device utilizes a fully differential architecture, a full-
bridged output, and comprehensive click-and-pop sup-
pression. The gain is internally set to +4V/V, further
reducing external component count.
The MAX9712 features high 72dB PSRR, a low 0.01%
THD+N, and SNR in excess of 90dB. Short-circuit and
thermal-overload protection prevent the device from
damage during a fault condition. The MAX9712 is avail-
able in 10-pin TDFN (3mm
✕
3mm
✕
0.8mm), 10-pin
µMAX, and 12-bump UCSP™ (1.5mm
✕
2mm
✕
0.6mm)
packages. The MAX9712 is specified over the extended
-40°C to +85°C temperature range.
Applications
Features
♦ Filterless Amplifier Passes FCC Radiated
Emissions Standards with 100mm of Cable
♦ Unique Spread-Spectrum Mode Offers 5dB
Emissions Improvement Over Conventional
Methods
♦ Optional External SYNC Input
♦ Simple Master-Slave Setup for Stereo Operation
♦ 85% Efficiency
♦ Up to 500mW into 8Ω
♦ Low 0.01% THD+N
♦ High PSRR (72dB at 217Hz)
♦ Integrated Click-and-Pop Suppression
♦ Low Quiescent Current (4mA)
♦ Low-Power Shutdown Mode (0.1µA)
♦ Short-Circuit and Thermal-Overload Protection
♦ Available in Thermally Efficient, Space-Saving
Packages
10-Pin TDFN (3mm
✕
3mm
✕
0.8mm)
10-Pin µMAX
12-Bump UCSP (1.5mm
✕
2mm
✕
0.6mm)
MAX9712
500mW, Low EMI, Filterless,
Class D Audio Amplifier
________________________________________________________________ Maxim Integrated Products
1
1
2
3
4
5
10
9
8
7
6
PV
DD
OUT-
OUT+
PGND
GND
IN-
IN+
V
DD
MAX9712
TDFN/
µMAX
TOP VIEW
SYNC
SHDN
Pin Configurations
Ordering Information
MAX9712
DIFFERENTIAL
AUDIO INPUT
SYNC
INPUT
V
DD
OSCILLATOR
MODULATOR
AND H-BRIDGE
Simplified Block Diagram
19-2917; Rev 0; 8/03
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.
Cellular Phones
PDAs
MP3 Players
Portable Audio
PART
TEMP RANGE
PIN/BUMP-
PACKAGE
TOP
MARK
MAX9712ETB
-40°C to +85°C
10 TDFN
AAI
MAX9712EUB
-40°C to +85°C
10 µMAX
—
MAX9712EBC-T*
-40°C to +85°C
12 UCSP-12
ABN
Pin Configurations continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
*Future product—contact factory for availability.