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Layout and Grounding Guidelines for TLV320AIC1x
TLV320AIC12, TLV320AIC13
TLV320AIC14, TLV320AIC15
TLV320AIC12K, TLV320AIC14K
SLWS115E – OCTOBER 2001 – REVISED JANUARY 2007
TLV320AIC1x has an in-built analog antialias filter, which provides rejection to external noise at high frequencies
that may couple into the device. Digital filters with high out-of-band attenuation also reject the external noise. If
the differential inputs are used for the ADC channel, then the noise in the common-mode signal is also rejected
by the high CMRR of TLV320AIC1x. Using external common-mode for microphone inputs also helps rejecting
the external noise. However to extract the best performance from TLV320AIC1x, care must be taken in board
design and layout to avoid coupling of external noise into the device.
TLV320AIC1x supports clock frequencies as high as 100 MHz. To avoid coupling of fast switching digital signals
to analog signals, the digital and analog sections should be separated on the board. In TLV320AIC1x the digital
and analog pins are kept separated to aid such a board layout. A separate analog ground plane should be used
for the analog section of the board. The analog and digital ground planes should be shorted at only one place as
close to TLV320AIC1x as possible. No digital trace should run under TLV320AIC1x to avoid coupling of external
digital noise into the device. It is suggested to have the analog ground plane running below the TLV320AIC1x.
The power-supplies should be decoupled close to the supply pins, preferably, with a 0.1 µF-ceramic capacitor
and a 10-µF tantalum capacitor following. The ground pin should be connected to the ground plane as close as
possible to the TLV320AIC1x, so as to minimize any inductance in the path. Since the MCLK is expected to be a
high frequency signal, it is advisable to shield it with digital ground. For best performance of ADC in differential
input mode, the differential signals should be routed close to each other in similar fashion, so that the noise
coupling on both the signals is same and can be rejected by the device.
Extra care has to be taken for the speaker driver outputs, as any trace resistance can cause a reduction in the
maximum swing that can be seen at the speaker.
For devices in the RHB package, connect the device thermal pad to DRVSS.
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