方泰FT2128P两种防破音D类PC音响功放可替代NS4158

GENERAL DESCRIPTION
The ft2128 is a high-efficiency, high-performance,
Class-D audio power amplifier with dual modes of
automatic level control (ALC). It operates from
3.0V to 5.5V supply. When powered with 5V
supply voltage, it is capable of delivering a
continuous average output of 3.4W into 3Ω load
or 2.8W into 4Ω load with 4% THD+N.
The ft2128 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 the
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 power amplifier, the ft2128
features high efficiency up to 90%, which make
the device ideal for use in battery-powered
portable devices. It also features minimized
click-and-pop noise during turn-on and turn-off
transitions.
APPLICATIONS
? Portable navigation devices
? Multimedia internet devices
? Portable or Blue-tooth speakers
FEATURES
? Filterless Class-D operation
? Automatic level control to eliminate output
clipping
? Dual ALC modes of operation
? High efficiency up to 90%
? Constant output power at 5V supply (ALC-1)
3.2W (3Ω load, 1% THD+N)
2.6W (4Ω load, 1% THD+N)
1.4W (8Ω load, 1% THD+N)
? Constant output power at 5V supply (ALC-2)
3.4W (3Ω load, 4% THD+N)
2.8W (4Ω load, 4% THD+N)
1.5W (8Ω load, 4% THD+N)
? ALC Range: 12dB
? Low quiescent current: 3mA @ VDD=3.6V
? Analog or digital scheme to set ALC operating
mode
? Short-circuit & thermal overload protection
? Available in SOP-8L & MSOP-8L packages
APPLICATION CIRCUIT
470nF
470nF
VREF
Generator
CTRL
optional