The LM4675 is a single supply, high efficiency, 2.65W, mono, Class D audio amplifier. A
spread spectrum, filterless PWM architecture reduces EMI and eliminates the output filter, reducing
external component count, board area consumption, system cost, and simplifying design.
The LM4675 is designed to meet the demands of mobile phones and other portable
communication devices. Operating on a single 5V supply, it is capable of driving a 4Ω speaker load
at a continuous average output of 2.2W with less than 1% THD+N. Its flexible power supply
requirements allow operation from 2.4V to 5.5V. The wide band spread spectrum architecture of the
LM4675 reduces EMI-radiated emissions due to the modulator frequency.
The LM4675 has high efficiency with speaker loads compared to a typical Class AB
amplifier. With a 3.6V supply driving an 8Ω speaker, the IC's efficiency for a 100mW power level is
80%, reaching 89% at 400mW output power.
The LM4675 features a low-power consumption shutdown mode. Shutdown may be enabled by
driving the Shutdown pin to a logic low (GND).
The gain of the LM4675 is externally configurable which allows independent gain control
from multiple sources by summing the signals. Output short circuit and thermal overload protection
prevent the device from damage during fault conditions.