National Semiconductor Introduces Audio Power Amplifier with Integrated Fault Detection for Automotive Instrument Cluster Applications

The LM48100Q Boomer® audio power amplifier is AEC-Q100 Grade 2 qualified for operation between -40 degrees C and 105 degrees C. The mono 1.3W amplifier includes several features not available in competitive devices to ensure that the speaker and amplifier always operate:
* Open drain FAULT output indicates when a fault has occurred
* Comprehensive output short circuit and thermal overload protection prevents damage during a fault condition

The LM48100Q offers dual audio inputs that can be mixed and multiplexed to the device output, with each path having its own independent 32 step volume control. With its low quiescent current of 6 mA at 5V, this audio power amplifier is a member of National’s growing PowerWise® family of energy-efficient products.

Key Technical Features – LM48100 Audio Power Amplifier

The LM48100Q is a single-supply, mono bridge-tied load amplifier with I2C-compatible volume control. The device includes a comprehensive output fault detection system that senses the load conditions, protecting the device during short circuit events, as well as detecting open circuit conditions. Operating from a single 5V supply, the LM48100Q delivers 1.3W of continuous output power to an 8-Ohm load with less than 1 percent total harmonic distortion plus noise (THD+N).

The LM48100Q’s flexible power supply requirements allow operation from 3V to 5.5V. The amplifier’s high power supply rejection ratio (PSRR) of 74dB at 1 kHz allows the device to operate in noisy environments without additional power supply conditioning. A low power shutdown mode reduces supply current consumption to 0.01 uA. The amplifier’s advanced “pop-and-click” circuitry eliminates noise that typically occurs during turn-on and turn-off transitions and during shutdown.