OVERVIEW
The SM6453AB is a stereo headphone amplifier IC with built-in electronic volume controlled by 3-wire serial data. Two switchable input systems are supported. It features bass boost function, automatic gain control (AGC) function, power-down function, and beep sound input/output function, making it ideal for use in portable electronic products.

FEATURES
■ 2 stereo system inputs, selectable 1 output system
■ Headphone amplifier function
    • +12dB to -68dB output voltage gain range (GCNT)
    • +12dB headphone amplifier gain (GHPA)
■ Attenuation function
    • 1.0dB step width, 81 steps, 0 to –80dB range (GEVR)
■ Mute function
■ Bass boost function (2 boost characteristics controlled by external RC network)
■ Auto gain control function (AGC)
■ Beep sound input/output circuit
■ 26mW+26mW maximum output power (1kHz, THD + N = 10%, 16Ω load, 2.0V supply voltage)
■ Power-down function
■ 1.8 to 3.6V operating supply voltage range
■ Low current consumption (2.3mA total, 2.4V supply voltage)
■ Silicon-gate CMOS process
■ 32-pin QFN package