The MAX9789/MAX9790 combine a stereo, 2W Class AB
speaker power amplifier with a stereo 100mW
DirectDrive? headphone amplifier in a single device. The
MAX9789/MAX9790 are designed for use with the
Microsoft Windows Vista? operating system and are fully
compliant with Microsoft’s Windows Vista specifications.
The headphone amplifier features Maxim’s patented?
DirectDrive architecture that produces a ground-referenced
output from a single supply to eliminate the need
for large DC-blocking capacitors, as well as save cost,
board space, and component height. A high +90dB
PSRR and low 0.002% THD+N ensures clean, low-distortion
amplification of the audio signal.
Separate speaker and headphone amplifier control
inputs provide independent shutdown of the speaker
and headphone amplifiers, allowing speaker and headphone
amplifiers to be active simultaneously, if
required. The industry-leading click-and-pop suppression
circuitry reduces audible transients during startup
and shutdown cycles.
The MAX9789 features an internal LDO that can be used
as a clean power supply for a CODEC or other circuits.
The LDO output voltage is set internally at 4.75V or can
be adjusted between 1.21V and 4.75V using a simple
resistive divider. The LDO is protected against thermal
overloads and short circuits while providing 120mA of
continuous output current and can be enabled independently
of the audio amplifiers.
By disabling the speaker and headphone amplifiers, and
the LDO (for MAX9789), the MAX9789/MAX9790 enter
low-power shutdown mode and draw only 0.3μA.
The MAX9789/MAX9790 operate from a single 4.5V to
5.5V supply and feature thermal-overload and output
short-circuit protection. Devices are specified over the
-40°C to +85°C extended temperature range.