方泰FT2708双通道带防破音D类功放，渐进渐出功能，MUTE功能

GENERAL DESCRIPTION
The ft2708 is a high efficiency, low EMI, filterless
stereo Class-D audio power amplifier with automatic
level control (ALC). It operates from 3.0V to 5.5V
supply. When powered with 5V supply voltage, the
ft2708 is capable of delivering 3.2W into a pair of 4Ω
speakers or 1.8W into a pair of 8Ω speakers, with
THD+D less than 10%.
The ft2708 features ALC on the audio output **s,
which detects the output clipping caused by the
over-level input ** and automatically adjusts the
voltage gain of the amplifier to eliminate the clipping
while maintaining a maximally-allowed dynamic
range of the audio output **s. The ALC also
eliminates the output clipping due to low battery
supply voltage.
As a Class-D audio amplifier, the ft2708 features
88% efficiency and 75dB PSRR at 1kHz, which
make the device ideal for use in portable electronic
devices. Furthermore, the ft2708 incorporates
shutdown mode to minimize the power consumption
and comprehensive protection features against
various operating faults for a safe and reliable
operation.
FEATURES
? Wide supply voltage range from 3.0V to 5.5V
? Automatic level control to eliminate output clipping
? Output power in ALC Mode 1
1.3W/Ch (VDD=5.0V, 8Ω load, 0.8% THD+N)
2.4W/Ch (VDD=5.0V, 4Ω load, 0.8% THD+N)
? Output power in ALC Mode 2
1.5W/Ch (VDD=5.0V, 8Ω load, 4% THD+N)
2.8W/Ch (VDD=5.0V, 4Ω load, 4% THD+N)
? Maximum Output power
1.8W/Ch (VDD=5.0V, 8Ω load, 10% THD+N)
3.2W/Ch (VDD=5.0V, 4Ω load, 10% THD+N)
? Low THD+N: 0.06% (typical) @ 1kHz
(VDD=5.0V, RL=4Ω, PO=1.5W)
? Wide ALC dynamic range up to 12dB
? Voltage gain: 24dB
? High efficiency up to 88%
? Mute function
? Volume fade-in/out
? Auto-recovering over-current or short-circuit
protection
? Thermal shutdown
? Available in TSSOP-16L & QFN4x4-16L package
APPLICATIONS
? Smart Phones
? Multimedia Internet Devices
? Portable