General Description
The MAX9701 stereo Class D audio power amplifier pro-
vides Class AB amplifier audio performance with the
benefits of Class D efficiency, eliminating the need for a
heatsink while extending battery life. The MAX9701
delivers up to 1.3W per channel into an 8
Ω load while
offering 87% efficiency. Maxim’s next-generation, low-
EMI modulation scheme allows the amplifier to operate
without an external LC filter while still meeting FCC EMI
emission levels.
The MAX9701 offers two modulation schemes: a fixed-fre-
quency (FFM) mode, and a spread-spectrum (SSM)
mode that reduces EMI-radiated emissions. The
MAX9701 oscillator can be synchronized to an external
clock through the SYNC input, allowing synchronization of
multiple Maxim Class D amplifiers. The sync output
(SYNC_OUT) can be used for a master-slave application
where more channels are required. The MAX9701 fea-
tures a fully differential architecture, a full bridge-tied load
(BTL) output, and comprehensive click-and-pop suppres-
sion. The device features internally set gains of 0dB, 6dB,
12dB, and 18dB selected through two gain-select inputs,
further reducing external component count.
The MAX9701 features high 80dB PSRR, less than 0.1%
THD+N, and SNR in excess of 88dB. Short-circuit and
thermal-overload protection prevent the device from
being damaged during a fault condition. The MAX9701 is
available in 24-pin thin QFN-EP (4mm x 4mm x 0.8mm)
and 20-bump UCSP (2mm x 2.5mm x 0.6mm) pack-
ages. The MAX9701 is specified over the extended
-40°C to +85°C temperature range.
Applications
Cellular Phones
Notebooks
Handheld Gaming Consoles
Docking Stations
MP3 Players
Features
Spread-Spectrum Modulation Lowers Radiated
Emissions
Single-Supply Operation (2.5V to 5.5V)
1.3W Stereo Output (8Ω, VDD = 5V, THD+N = 1%)
No LC Output Filter Required
87% Efficiency (RL = 8Ω, POUT = 1000mW)
Less Than 0.1% THD+N
High 80dB PSRR
Fully Differential Inputs
Integrated Click-and-Pop Suppression
Typical Low Quiescent Current (9mA)
Typical Low-Power Shutdown Mode (0.1A)
Short-Circuit and Thermal-Overload Protection
Available in Thermally Efficient, Space-Saving
Packages
24-Pin Thin QFN-EP (4mm x 4mm x 0.8mm)
20-Bump UCSP (2mm x 2.5mm x 0.6mm)
MAX9701
1.3W, Filterless, Stereo Class D Audio
Power Amplifier
________________________________________________________________
Maxim Integrated Products
1
MAX9701
GAIN2
GAIN1
VDD
GAIN
RIGHT
MODULATOR
AND H-BRIDGE
SYNC
OSCILLATOR
LEFT
MODULATOR
AND H-BRIDGE
INR+
INR-
INL+
INL-
SYNC_OUT
Block Diagram
Ordering Information
19-3457; Rev 3; 3/09
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.
PART
TEMP RANGE
PIN-PACKAGE
MAX9701EBP+TG45
-40°C to +85°C
20 UCSP
MAX9701ETG+
-40°C to +85°C
24 TQFN-EP*
Pin Configurations appear at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
+
Denotes lead(Pb)-free/RoHS-compliant package.
*
EP = Exposed pad.