Datasheet

TPA6141A2
SLOS634A –MARCH 2009–REVISED AUGUST 2009.................................................................................................................................................... www.ti.com
POWER SUPPLY AND HPVDD DECOUPLING CAPACITORS AND CONNECTIONS
The TPA6141A2 DirectPath headphone amplifier requires adequate power supply decoupling to ensure that
output noise and total harmonic distortion (THD) remain low. Use good low equivalent-series-resistance (ESR)
ceramic capacitors (X5R material or better is required for best performance). Place a 2.2 μF capacitor within
5 mm of the AVDD pin. Reducing the distance between the decoupling capacitor and AVDD minimizes parasitic
inductance and resistance, improving TPA6141A2 supply rejection performance. Use 0402 or smaller size
capacitors if possible. Ensure that the ground connection of each of the capacitors has a minimum length return
path to the device. Failure to properly decouple the TPA6141A2 may degrade audio or EMC performance.
For additional supply rejection, connect an additional 10 μF or higher value capacitor between AVDD and
ground. This will help filter lower frequency power supply noise. The high power supply rejection ratio (PSRR) of
the TPA6141A2 makes the 10 μF capacitor unnecessary in most applications.
Connect a 2.2 μF capacitor between HPVDD and ground. This ensures the amplifier internal bias supply remains
stable and maximizes headphone amplifier performance.
DO NOT connect HPVDD directly to AVDD or an external supply voltage. The
voltage at HPVDD is generated internally. Connecting HPVDD to an external
voltage can damage the device.
LAYOUT RECOMMENDATIONS
GND CONNECTIONS
The SGND pin is an input reference and must be connected to the headphone ground connector pin. This
ensures no turn-on pop and minimizes output offset voltage. Do not connect more than ±0.3 V to SGND.
AGND is a power ground. Connect supply decoupling capacitors for AVDD, HPVDD, and HPVSS to AGND.
BOARD LAYOUT
In making the pad size for the WCSP balls, it is recommended that the layout use non-solder-mask defined
(NSMD) land. With this method, the solder mask opening is made larger than the desired land area, and the
opening size is defined by the copper pad width. Figure 29 and Table 1 shows the appropriate diameters for a
WCSP layout.
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