C

I

I

1

f =

(2

R

C )

p ´

´

(5)

I

I

C

1

C =

(2

R

f )

p ´

´

(6)

BOARD LAYOUT

TPA2016D2

The TPA2016D2 is a high-performance Class-D audio amplifier that requires adequate power supply decoupling

to ensure the efficiency is high and total harmonic distortion (THD) is low. For higher frequency transients,

spikes, or digital hash on the line, a good low equivalent-series-resistance (ESR) 1-

µF ceramic capacitor

(typically) placed as close as possible to the device PVDD (L, R) lead works best. Placing this decoupling

capacitor close to the TPA2016D2 is important for the efficiency of the Class-D amplifier, because any resistance

or inductance in the trace between the device and the capacitor can cause a loss in efficiency. For filtering

lower-frequency noise signals, a 4.7

µF or greater capacitor placed near the audio power amplifier would also

help, but it is not required in most applications because of the high PSRR of this device.

Equation 5.

The value of the input capacitor is important to consider as it directly affects the bass (low frequency)

performance of the circuit. Speakers in wireless phones cannot usually respond well to low frequencies, so the

corner frequency can be set to block low frequencies in this application. Not using input capacitors can increase

output offset. Equation 6 is used to solve for the input coupling capacitance. If the corner frequency is within the

audio band, the capacitors should have a tolerance of ±10% or better, because any mismatch in capacitance

causes an impedance mismatch at the corner frequency and below.

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 36 and Table 5 shows the appropriate diameters for a

WCSP layout. The TPA2016D2 evaluation module (EVM) layout is shown in the next section as a layout

example.

Copyright © 2008, Texas Instruments Incorporated

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Product Folder Link(s): TPA2016D2