Document
TPA6135A2
www.ti.com .................................................................................................................................................. SLOS623A – FEBRUARY 2009 – REVISED APRIL 2009
DIRECTPATH™ Stereo Headphone Amplifier With Differential Input and HI-Z Mode
FEATURES
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•23 Patented DirectPath™ Technology Eliminates Need for DC-Blocking Capacitors – Outputs Biased at 0 V – Excellent Low Frequency Fidelity
• Active Click and Pop Suppression • HI-Z Output Mode • 2.1 mA Typical Supply Current • Fully Differential or Single-Ended Inputs
– Built-In Resistors Reduces Component Count
– Improves System Noise Performance • Constant Maximum Output Power from 2.3 V
to 5.5 V Supply – Simplifies Design to Prevent Acoustic
Shock • Improved RF Noise Immunity • MicrosoftTM Windows VistaTM Compliant • High Power Supply Noise Rejection
– 100 dB PSRR at 217 Hz – 90 dB PSRR at 10 kHz • Wide Power Supply Range: 2.3 V to 5.5 V • Gain Settings: 0 dB and 6 dB • Short-Circuit and Thermal-Overload Protection • ±8 kV HBM ESD Protected Outputs • Small Package Available – 16-Pin, 3 mm × 3 mm Thin QFN
APPLICATIONS
• Smart Phones / Cellular Phones • Notebook Computers • CD / MP3 Players • Portable Gaming
DESCRIPTION
The TPA6135A2 (sometimes referred to as TPA6135) is a DirectPath™ stereo headphone amplifier that eliminates the need for external dc-blocking output capacitors. Differential stereo inputs and built-in resistors set the device gain, further reducing external component count. Gain is selectable at 0 dB or 6 dB. The amplifier drives 25 mW into 16 Ω speakers from a single 2.3 V supply. The TPA6135A2 (TPA6135) provides a constant maximum output power independent of the supply voltage, thus facilitating the design for prevention of acoustic shock.
The TPA6135A2 (TPA6135) features HI-Z mode which can set the outputs to a high impedance configuration. The fully differential inputs reduce system noise pickup between the audio source and the headphone amplifier. The high power supply noise rejection performance and differential architecture provide increased RF noise immunity. For single-ended input signals, connect INL+ and INR+ to ground.
The device has built-in pop suppression circuitry to completely eliminate disturbing pop noise during turn-on and turn-off. The amplifier outputs have short-circuit and thermal-overload protection along with ±8 kV HBM ESD protection, simplifying end equipment compliance to the IEC 61000-4-2 ESD standard.
The TPA6135A2 (TPA6135) operates from a single 2.3 V to 5.5 V supply with 2.1 mA of typical supply current. Shutdown mode reduces supply current to less than 1 µA.
OUTR+
OUTRCODEC
OUTL+
OUTL-
ENABLE GAIN
HI-Z MODE VBAT
INR+
INR-
OUTR
TPA6135A2
INL+
OUTL
INL-
EN
GAIN
HI-Z VDD
HPVDD CPP
SGND PGND
HPVSS CPN
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