HEADPHONE AMPLIFIER
ACM3232
designed to allow the removal of the output dc-blocking capacitors for reduced external component and cost. The device is designed for single-supply electronics where size and cost are critical design parameters. Direct Drive true ground technology of ACM3232 is capable of driving 2 Vrms into a 10 kΩ load with 3.3V supply voltage. The device has differential inputs and uses external gain setting resistors to support a gain range of ±1 V/V to ±10 V/V, and gain can be configured individually for each channel. Line outputs have integrated ±8 kV IEC ESD protection, requiring just a simple resistor-capacitor ESD protection circuit. The ACM3232 has built-in active-mute control for pop-free audio on/off control. The ACM3232 has an external undervoltage detector that mutes the output when the power supply is removed, to avoid pop when device is shutdown. Using the ACM3232 in audio products can reduce component count considerably compared to traditional methods of generating a 2Vrms output. The ACM3232 does not require a power supply greater than 3.3 V to generate its 5.6 Vpp output, nor does it require a split-rail power supply. The ACM3232 integrates its own charge pump to generate a negative supply rail that provides a clean, pop-free groundbiased2Vrms output. The ACM3232 is available in a 14-pin TSSOP.
