DirectDrive stereo headphone amp — what it delivers
The MAX97220DETE+T is a Class AB stereo headphone amplifier from Maxim Integrated's DirectDrive® series. It delivers 125 mW per channel into a 32-ohm load, enough to drive most consumer and pro-audio headphones to comfortable listening levels. The DirectDrive architecture generates a regulated negative supply on-chip, so the output is biased around ground — no large DC-blocking capacitors between the amp and the headphone jack. That saves board space and eliminates the turn-on thump those capacitors cause. Supply range runs from 2.5 V to 5.5 V. The part is rated over -40°C to 85°C. Package is a 16-TQFN (3x3 mm) with an exposed pad for thermal relief.
Depop, shutdown, and differential inputs
Built-in depop circuitry ramps the output bias smoothly at startup, so the listener hears no click or pop when the amplifier enables. A shutdown pin lets the system cut supply current to near zero when audio is not needed — useful for battery-powered designs that need to stretch standby time. Differential inputs reject common-mode noise picked up on the audio signal traces from the codec or DAC.