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, differential
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. Patented click-and-pop
suppression eliminates audible transients on power and
shutdown cycles.
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 multiplexer,
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 preamps,
a differential amp for internal microphones, and
a single-ended amplifier for additional external microphones.
A microphone bias output is provided, reducing
external component count.
The MAX9765/MAX9766/MAX9767 are available in a
thermally efficient 32-pin thin QFN package (5mm x
5mm x 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.