_{The LM48511 integrates a boost converter with a high efficiency
Class D audio power amplifier to provide 3W continuous
power into an 8Ω speaker when operating from a 5V
power supply. When operating from a 3V to 4V power supply,
the LM48511 can be configured to drive 1 to 2.5W into an
8Ω load with less than 1% distortion (THD+N). The Class D
amplifier features a low noise PWM architecture that eliminates
the output filter, reducing external component count,
board area consumption, system cost, and simplifying design.
A selectable spread spectrum modulation scheme suppresses
RF emissions, further reducing the need for output filters.
The LM48511’s switching regulator is a current-mode boost
converter operating at a fixed frequency of 1MHz. Two selectable
feedback networks allow the LM48511 regulator to
dynamically switch between two different output voltages, improving
efficiency by optimizing the amplifier’s supply voltage
based on battery voltage and output power requirements^.}