general description
the ft2925 is a highly efficient 6w boosted class-g
stereo audio power amplifier with automatic level
control (alc) and battery tracking agc. it integrates
dual filterless class-d audio amplifiers with anadaptive
class-g boost regulator and operates with a wide
range of supply voltages from 3v to 5.5v. when
operating with 3.6v supply voltage, it can deliver intoa
pair of 4Ω speakers at a maximum output power of 6w
per channel with 10% thd+n, or 4.8w per channel
with 1% thd+n.
in ft2925, the power supply rail of the audioamplifier’s
output stages is internally boosted by a synchronous
pwm switching regulator with two integrated power
switches. the boost regulator employs current mode
pwm control with proprietary multi-level class-g
operation to regulate the boosted voltage in response
to the level of audio inputs.
the ft2925 features alc function to constantly monitor
audio outputs against the supply voltage applied to the
audio amplifier’s output stage, thus safeguarding
against output clipping distortion, excessive power
dissipation, and speaker over-load. once an over-level
condition is detected in either channel, the alc lowers
the voltage gain of both audio amplifiers proportionally
to eliminate output clipping. in alc mode, with 3.6v
supply voltage, the ft2925 can deliver 4.5w per channel
into a pair of 4Ω speakers with 0.3% thd+n.
in conjunction with alc, the battery tracking agc
lowers the voltage gain of the audio amplifiers to limit
the maximum audio outputs as the battery supply
voltage drops below a prescribed value, preventing the
collapse of battery voltage.
features
wide supply voltage range from 3v to 5.5v
filterless class-d audio amplifier integrated with a
multi-level class-g synchronous boost regulator
automatic level control
battery tracking agc
soft drive mode for emi reduction
maximum output power in non-alc mode
(vbat=3.6v, alc=high, 10% thd+n)
6.0w/ch (4Ω load)
3.4w/ch (8Ω load)
alc output power in alc mode
(vbat=3.6v, alc=low, 0.3% thd+n)
4.5w/ch (4Ω load)
2.6w/ch (8Ω load)
wide alc dynamic range: 12db
maximum voltage gain: 30db
high efficiency up to 76%
volume fade-in and fade-out
under-voltage lockout protection
auto-recovering over-current & short-circuit
protection
thermal over-load protection
available in tssop-28l package
applications
blue tooth speakers
performance audio speakers
consumer electronics