DIRECT HEADPHONE DRIVER WITH ADJUSTABLE GAIN

DESCRIPTION

The UTC ALDR6138 is a pop-free stereo headphone amplifier

with the integrated charge pump generating the negative supply rail

which allows the removal of the output DC-blocking capacitors. The

UTC ALDR6138 provides a clean, pop-free ground-biased audio

signal. The UTC ALDR6138 is capable of driving 25mW into a

32-Ω load with 3.3-V supply voltage. The device has differential

inputs and uses external resistors for flexible gain setting. Gain can

be configured individually for each channel. The device can also be

configured as a second-order low-pass filter and is ideal for

interfacing with PWM audio sources.

The UTC ALDR6138 has built-in active-mute control for

pop-free audio on/off control. The UTC ALDR6138 has an external

under-voltage detector that mutes the output when monitored

voltage drop below set value.

Using the UTC ALDR6138 in audio products can reduce

component count considerably compared to traditional headphone

amplifiers.

FEATURES

* Low THD+N<0.01% at 10mW Into 32Ω

* Stereo Direct Headphone Amplifier driver 40 mW Into 32Ω With 3.3-V Supply

* Integrated charge pump Generates Negative Supply Rail

* High SNR, >90dB

* Ground-Referenced Outputs Eliminate DC-Blocking Capacitors

* Differential Input and Single-Ended Output

* Adjustable Gain by External Gain-Setting Resistors

* Pop-Free Under-Voltage Protection

* Configurable as a Second-Order Low-Pass Filter Ideal for PWM Audio Sources

* Short-Circuit Protection

* Click- and Pop-Reduction Circuitry

* Active Mute Control for Pop-Free Audio On/Off Control