LM4675

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
Supply Voltage (Note 1) ............. .6.0V
Storage Temperature........ −65°C to +150°C
Voltage at Any Input Pin . V_DD + 0.3V V GND - 0.3V
Power Dissipation (Note 3)..... . Internally Limited
ESD Susceptibility, all other pins (Note 4) .. ...2.0kV
ESD Susceptibility (Note 5)........... .. 200V
Junction Temperature (T_JMAX) ...........150°C
Thermal Resistance
_JA (micro SMD)................. 220°C/W
_JA (LLP) .....................73°C/W
Soldering Information
See AN-1112 "microSMD Wafers Level Chip Scale Package."

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 4 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 8 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.