TPA3221

8

21

22

IN2_M

IN1_P

IN2_P

IN1_P

IN1_M

9

+

-

+

-

IN1_M

IN2_P

IN2_M

TPA3221

1

21

22

AVDD

GND

VDD

GVDD

100nF

470uF

1µF

1µF

+5V

3R3

5V LDO

TPA3221

1

21

22

GND

GVDD

100nF

470uF

1µF

1µF

3R3

+7V”PVDD

AVDD

GND

VDD

5V LDO

15

TPA3221

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SLASEE9 – JUNE 2017

Product Folder Links: TPA3221

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Copyright © 2017, Texas Instruments Incorporated

9.3 Feature Description

9.3.1 Internal LDO

TPA3221 has a built in an optional LDO (Low DropOut voltage regulator) to supply the analog and digital circuits

as well as the gate drive for the output stages. The LDO can be used in systems where only the high voltage

power rail is available, hence no additional power supply rails need to be generated for the TPA3221 to operate.

As being a linear regulator, the LDO will add to the power losses of the device due to the (PVDD-5V) voltage

drop accross and the supply current for AVDD and GVDD given in the Electrical Characteristics table.

Figure 2. Internal LDO for Single Supply Systems

When using the internal LDO in TPA3221 the VDD terminal should be connected to a voltage source between

7V and PVDD. In a single supply system the VDD terminal should be connected directly to the PVDD terminal.

The LDO output is connected to the AVDD terminal, and can be used to supply the gate drive by supplying the

GVDD from AVDD through a RC filter for best noise performance as shown in .

Figure 3. Internal LDO Bypass for Highest Power Efficiency

For highest system power efficiency the LDO can be bypassed by connecting VDD to an external 5 V supply. In

this configuration AVDD and GVDD should be supplied by 5 V from the external power supply. GVDD should be

supplied through a RC filter for best noise performance as shown in .

9.3.1.1 Input Configuration, Gain Setting And Master / Slave Operation

TPA3221 is designed to accept either a differential or a single-ended audio input signal. To accept a wide range

of system front ends TPA3221 has selectable input gain that allows full scale output with a wide range of input

signal levels.

Best system noise performance is obtained with balanced audio interface. However, to be used in systems with

only a single ended audioinput signal available, one input terminal can be connected to AC ground, to accept

single ended audio input signals.

Figure 4. Balanced Audio Input Configuration