Description
The TS4621B is a class-G stereo headphone driver dedicated to high audio performance, high power efficiency and space-constrained applications. It is based on the core technology of a low power dissipation amplifier combined with a highefficiency step-down DC/DC converter for supplying this amplifier. When powered by a battery, the internal stepdown DC/DC converter generates the appropriate voltage to the amplifier depending on the amplitude of the audio signal to supply the headsets. It achieves a total 2.1 mA current consumption at 100 µW output power (10 dB crest factor). THD+N is 0.02 % maximum at 1 kHz and PSRR is 100 dB at 217 Hz, which ensures a high audio quality of the device in a wide range of environments. The traditionally bulky output coupling capacitors can be removed. A dedicated common-mode sense pin removes parasitic ground noise. The TS4621B is designed to be used with an output serial resistor. It ensures unconditional stability over a wide range of capacitive loads. The TS4621B is packaged in a tiny 16-bump flip-chip package with a pitch of 400 µm. TS4621BEIJT - flip-chip Balls are underneath Pinout (top view) AVDD SW INLC1 CMS SDA AGND C2 HPVDD VOUTL VOUTR INL+ INR+ PVSS SCL INR4 3 2 1 A B C D AVDD SW INLC1 CMS SDA AGND C2 HPVDD VOUTL VOUTR INL+ INR+ PVSS SCL INR4 3 2 1 A B C D

Features
■ Power supply range: 2.3 V to 4.8 V
■ 0.6 mA/channel quiescent current
■ 2.1 mA current consumption with 100 µW/channel (10 dB crest factor)
■ 0.006% typical THD+N at 1 kHz
■ 100 dB typical PSRR at 217 Hz
■ 100 dB of SNR A-weighted at G = 0 dB
■ Zero pop and click
■ I2C interface for volume control
■ Digital volume control range from -60 dB to +4 dB
■ Independent right and left channel shutdown control
■ Integrated high-efficiency step-down converter
■ Low software standby current: 5 µA max
■ Output-coupling capacitors removed

Applications
■ Cellular phones, smart phones
■ Mobile internet devices
■ PMP/MP3 players