General Description
The MAX9721 fixed-gain, stereo headphone amplifier is ideal for portable equipment where board space is at a premium. The MAX9721 uses a unique, patented DirectDrive architecture to produce a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height. Fixed gains of -2V/V (MAX9721A), -1.5V/V (MAX9721B), and -1V/V (MAX9721C) further reduce external component count.

Features
♦ Single Cell, 0.9V to 1.8V Single-Supply Operation
♦ Fixed Gain Eliminates External Feedback Network
    MAX9721A: -2V/V
    MAX9721B: -1.5V/V
    MAX9721C: -1V/V
♦ Ground-Referenced Outputs Eliminate DC Bias
♦ No Degradation of Low-Frequency Response Due to Output Capacitors
♦ 20mW per Channel into 32Ω
♦ Low 0.006% THD+N
♦ High PSRR (80dB at 1kHz)
♦ Integrated Click-and-Pop Suppression
♦ Low Quiescent Current (2.2mA)
♦ Low-Power Shutdown Control
♦ Short-Circuit Protection
♦ ±8kV ESD-Protected Amplifier Outputs
♦ Available in Space-Saving Packages
    12-Bump UCSP (1.54mm x 2.02mm x 0.6mm)
    12-Pin Thin QFN (4mm x 4mm x 0.8mm)

Applications
    MP3 Players
    Cellular Phones
    PDAs
    Smart Phones
    Portable Audio Equipment