
General Description
The MAX9702 combines a highly efficient Class D
speaker amplifier with a high-linearity Class AB head-
phone amplifier. This ensures maximum battery life in
speaker mode and maximum performance in head-
phone mode. The MAX9702 delivers up to 1.1W per
channel into an 8Ω load and 1.8W into a 4Ω load from a
5V power supply. Maxim’s 2nd-generation, spread-
spectrum modulation scheme renders the traditional
Class D output filter unnecessary.
The MAX9702 speaker amplifier offers two modulation
schemes: a fixed-frequency (FFM) mode and a spread-
spectrum (SSM) mode that reduces EMI-radiated emis-
sions. The MAX9702 speaker amplifier features a fully
differential architecture, full-bridged (BTL) output, and
comprehensive click-and-pop suppression. The
MAX9702 speaker amplifier features high 75dB PSRR,
low 0.07% THD+N, and SNR in excess of 97dB. Short-
circuit and thermal-overload protection prevent the
device from being damaged during a fault condition.
The headphone amplifier uses Maxim’s DirectDriveTM
architecture that produces a ground-referenced output
from a single supply, eliminating the need for large DC-
blocking capacitors, saving cost, board space, and
component height. A high 80dB PSRR and low 0.02%
THD+N ensures clean, low-distortion amplification of
the audio signal.
An I2C interface sets the speaker and headphone gain,
mono, stereo, and mute functions.
The MAX9702 is available in a 28-pin thin QFN-EP (5mm
x 5mm x 0.8mm) package. The MAX9702 is specified
over the extended -40°C to +85°C temperature range.
Applications
Cellular Phones
Notebook PCs
PDAs
Handheld Gaming Consoles
Features
Spread-Spectrum Modulation Reduces EMI
Emissions
Programmable Mono, Stereo, Mute, and Mix
Functions
1.1W Stereo Output (8Ω, VDD = 5V)
48mW Headphone Output (32Ω, VDD = 3.3V)
1.8W Stereo Output (4Ω, VDD = 5V)
94% Efficiency (RL = 8Ω, PO = 1.1W)
High 73dB PSRR (f = 217Hz)
I2C Programmable Gain Up to +21dB
Integrated Click-and-Pop Suppression
Low-Power Shutdown Mode (0.1A)
Short-Circuit and Thermal-Overload Protection
±8kV (HBM) ESD-Protected Headphone Driver
Outputs
MAX9702
1.8W, Filterless, Stereo, Class D Audio Power
Amplifier and DirectDrive Stereo Headphone Amplifier
________________________________________________________________ Maxim Integrated Products
1
PART
PIN–PACKAGE
I
2C SLAVE
ADDRESS
PKG
CODE
MAX9702ETI+
28 TQFN-EP*
1001100
T2855-6
MAX9702BETI+ 28 TQFN-EP*
1001110
T2855-6
Ordering Information
19-3608; Rev 1; 10/05
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.
Note: All devices specified for -40°C to +85°C operating tem-
perature range.
*EP = Exposed paddle.
+ Denotes lead-free package.
Pin Configurations appear at end of data sheet.
EVALUATION
KIT
AVAILABLE
Simplified Block Diagram
MAX9702
RIGHT MODULATOR
AND H-BRIDGE
INR
INM
INL
SHDN
SCL
SDA
I2
C
CONTROL
INPUT
MUX
GAIN
CONTROL
SYNC_OUT
SYNC
OSCILLATOR
∑
LEFT MODULATOR
AND H-BRIDGE