
POWER SUPPLY AND HPVDD DECOUPLING CAPACITORS
LAYOUT RECOMMENDATIONS
EXPOSED PAD ON TPA6132A2RTE
GND CONNECTIONS
POWER SUPPLY CONNECTIONS
www.ti.com ........................................................................................................................................................................................... SLOS597 – DECEMBER 2008
The TPA6132A2 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
F capacitor within
5 mm of the VDD pin. Reducing the distance between the decoupling capacitor and VDD minimizes parasitic
inductance and resistance, improving TPA6132A2 supply rejection performance. Use 0402 or smaller size
capacitors if possible.
For additional supply rejection, connect an additional 10
F or higher value capacitor between VDD and ground.
This will help filter lower frequency power supply noise. The high power supply rejection ratio (PSRR) of the
TPA6132A2 makes the 10
F capacitor unnecessary in most applications.
Connect a 2.2
F capacitor between HPVDD and ground. This ensures the amplifier internal bias supply remains
stable and maximizes headphone amplifier performance.
WARNING:
DO NOT connect HPVDD directly to VDD or an external supply voltage. The
voltage at HPVDD is generated internally. Connecting HPVDD to an external
voltage can damage the device.
Solder the exposed metal pad on the TPA6132A2RTE QFN package to the landing pad on the PCB. Connect
the landing pad to ground or leave it electrically unconnected (floating). Do not connect the landing pad to VDD
or to any other power supply voltage.
If the pad is grounded, it must be connected to the same ground as the PGND pin (10). See the layout and
mechanical drawings at the end of the data sheet for proper sizing. Soldering the thermal pad is required for
mechanical reliability and enhances thermal conductivity of the package.
WARNING:
DO NOT connect the TPA6132A2RTE exposed metal pad to VDD or any other
power supply voltage.
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.
PGND is a power ground. Connect supply decoupling capacitors for VDD, HPVDD, and HPVSS to PGND.
Connect the supply voltage to the VDD pin and decouple it with an X5R or better capacitor. Connect the HPVDD
pin only to a 2.2
F, X5R or better, capacitor. Do not connect HPVDD to an external voltage supply. Place both
capacitors within 5 mm of their associated pins on the TPA6132A2. Ensure that the ground connection of each of
the capacitors has a minimum length return path to the device. Failure to properly decouple the TPA6132A2 may
degrade audio or EMC performance.
Copyright 2008, Texas Instruments Incorporated
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