What this headphone amp does on your board
The MAX9721CEBC-T is a Class AB headphone amplifier from the DirectDrive series, delivering 25mW per channel into a 16Ω load — enough to drive earbuds or small headphones from a low-voltage rail. It runs on a 0.9V to 1.8V supply, so it fits battery-powered gear where the core rail sits at 1.2V or 1.5V. The mono output handles a stereo headphone signal internally.
Package and temperature fit for field swaps
Housed in a 12-UCSP measuring 2.02x1.54mm — that is a tiny BGA-style package with no leads. Swapping it on site means hot air and a steady hand; not a socketed part you pop in from a field kit. Rated for -40°C to +85°C ambient, so it handles outdoor telecom or industrial sensor heads without a heater.
Lifecycle and compliance reality
Note the RoHS status: non-compliant. If your assembly line is RoHS-exempt or you hold a stock of tin-lead solder, this part works. For lead-free reflow, look at the lead-free variant in the same family.