Active production — what the BOM engineer needs to know
The MAX13331GEE/V+: The /V+ suffix indicates AEC-Q100 automotive qualification, which is the core differentiator from the base MAX13331GEE.
135mW into 32Ω — what the power rating means for headphone drive
The amplifier delivers 135mW per channel into a 32Ω load, which is the standard impedance for portable and automotive aftermarket headphones. At this power level, the output voltage swing is approximately 2.1V RMS — sufficient to drive most dynamic drivers to 110+ dB SPL without clipping. The Class AB output stage keeps crossover distortion below the noise floor of a typical automotive audio bus. The shutdown feature pulls the quiescent current to near-zero when the headphone output is not active, which matters for battery-backed keep-alive circuits in telematics units. Short-circuit protection on the output prevents damage if the headphone jack is plugged or unplugged while the amplifier is active — a common fault in automotive headphone jacks subjected to vibration and thermal cycling. The depop circuit suppresses the audible pop when the amplifier transitions from shutdown to active, which otherwise would produce an audible thump through the headphones.