19-2862; Rev 2; 3/07
750mW Audio Amplifiers with Headphone Amp,
Microphone Preamp, and Input Mux
The MAX9765/MAX9766/MAX9767 family combines
speaker, headphone, and microphone amplifiers, all in
a small thin QFN package. The MAX9765 is targeted at
stereo speaker playback applications and includes a
stereo bridge-tied load (BTL) speaker amp, stereo
headphone amp, single-ended output mic amp, input
MUX, and I2C control. The MAX9766 is targeted at
mono speaker playback applications and includes a
mono BTL speaker amp, stereo headphone amp, differ-
ential output mic amp, input MUX, and I2C control. The
MAX9767 is targeted at applications that do not require
a headphone amp and includes a stereo BTL speaker
amp, differential output mic amp, and parallel control.
These devices operate from a single 2.7V to 5.5V supply.
A high 95dB PSRR allows these devices to operate from
noisy supplies without additional power conditioning. An
ultra-low 0.003% THD+N ensures clean, low distortion
amplification of the audio signal. Click-and-pop suppres-
sion eliminates audible transients on power and shut-
In speaker mode, the amplifiers can deliver up to
750mW of continuous average power into a 4Ω load. In
headphone mode, the amplifier can deliver up to 65mW
of continuous average power into a 16Ω load. The gain
of the amplifiers is externally set, allowing maximum
flexibility in optimizing output levels for a given load.
The MAX9765/MAX9766 also feature a 2:1 input multi-
plexer, allowing multiple audio sources to be selected.
The various functions are controlled by either an I2C-
compatible (MAX9765/MAX9766) or simple parallel
control interface (MAX9767).
All devices include two low-noise microphone pre-
amps, a differential amp for internal microphones, and
a single-ended amplifier for additional external micro-
phones. A microphone bias output is provided, reduc-
ing external component count.
The MAX9765/MAX9766/MAX9767 are available in a
thermally efficient 32-pin thin QFN package (5mm ✕
5mm ✕ 0.8mm). All devices have short-circuit and
thermal-overload protection (OVP) and are specified
over the extended -40°C to +85°C temperature range.
PDA Audio Systems
♦ 750mW BTL Stereo Speaker Amplifier
♦ 65mW Stereo Headphone Amplifier
♦ 2.7V to 5.5V Single-Supply Operation
♦ Click-and-Pop Suppression
♦ Low 0.003% THD+N
♦ Low Quiescent Current: 13mA
♦ Low-Power Shutdown Mode: 5µA
♦ MUTE Function
♦ Headphone Sense Input
♦ Stereo 2:1 Input Multiplexer
♦ Optional 2-Wire, I2C-Compatible, or Parallel
♦ Small 32-Pin Thin QFN (5mm ✕ 5mm ✕ 0.8mm)
-40oC to +85oC
-40oC to +85oC
MAX9767ETJ -40oC to +85oC 32 TQFN-EP* T3255-4
*EP = Exposed paddle.
Pin Configurations and Functional Diagrams appear at end of data
________________________________________________________________ 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.