1 Features

1• Ultra Low-Power, High-Performance DirectPath™

Class-G Headphone Amplifier

– Ground-Centered Output Eliminates DC-

Blocking Capacitors

– 30 mW/Ch into 32 Ω / Ch at 1% THD+N variable–

–42 dB to +6 dB Volume Control

– 2.0 μV Output Noise at –42 dB Gain

– 91-dB PSRR

– Ground Loop Rejection for Reducing Crosstalk

• Fully Differential Mic Preamplifier With Variable

Gain and 3.4-μV Low Noise

– Integrated AC-Coupling Capacitor

– Ground Loop Rejection for Reducing

Headphone to Mic Crosstalk DC•

Choice of Two Mic Bias Voltages: 2.0 V and 2.6 V

– 92-dB PSRR

– Integrated Programmable Mic Bias Resistor

• Advanced Accessory Insertion, Removal, and

Type Detection

• Passive Multi-button Support Using 10-Bit SAR

ADC

– Implements Proprietary Scheme to Reduce

Error Caused by Audio Playback Signal in

Presence of Finite Resistance on Headset

Ground Return Path

• Integrated Level-4 IEC ESD Protection on Jack

Connected Pins (on EVM)

• Ultra Low-Power Chip Shutdown Mode

• I2C Interface

• Short-Circuit Protection

• 0.4-mm Pitch 25-Ball WCSP

2 Applications

• Smart Phones and Wireless Handsets

• Portable Tablets

• Notebook PCs and Docking Stations

3 Description

The TPA6166A2 single-chip headset interface IC

simplifies the challenges of detecting what kind of

device an end user has plugged into the headphone

jack while delivering excellent audio quality. The

device enables smaller end products by integrating a

high-performance, low-power DirectPath variable–

attenuation class-G stereo headphone amplifier,

variable-gain microphone preamplifier with bias with

advanced accessory detection circuitry, all in a tiny

5-mm × 5-mm terminal, 0.4-mm pitch WCSP

package.

The class-G headphone amplifier maximizes battery

life by adjusting the supply voltage of the headphone

amplifier based on audio signal level. With 8-μV output noise at 0-dB gain and PSRR of 91 dB, the

headphone amplifier provides excellent audio

performance. DirectPath eliminates the need for DC•

blocking capacitors. The microphone preamplifier has

two programmable gains of 12 dB and 24 dB, and 3.4 μV input referred noise.

The microphone bias voltage has two programmable settings of 2 V and 2.6 V. The bias output drives up

to 1.2 mA of current, has a low output noise of 2 μV,

and 92-dB PSRR, providing excellent rejection of

power supply noise in wireless handsets.

The advanced accessory detection algorithm

automatically detects six supported accessories and

enables or disables internal components.