Cirrus Logic CS5345 - Manual (Page 25)

DS658F4 25
CS5345
which could result in recording a DC level, possibly yielding clicks when switching between devices in a mul-
tichannel system.
The high-pass filter continuously subtracts a measure of the DC offset from the output of the decimation
filter. If the HPFFreeze bit (See
“High-Pass Filter Freeze (Bit 1)” on page 33. ) is set during normal operation,
the current value of the DC offset for the each channel is frozen and this DC offset will continue to be sub-
tracted from the conversion result. This feature makes it possible to perform a system DC offset calibration
by:
1. Running the CS5345 with the high-pass filter enabled until the filter settles. See the Digital Filter Char-
acteristics section for filter settling time.
2. Disabling the high-pass filter and freezing the stored DC offset.
A system calibration performed in this way will eliminate offsets anywhere in the signal path between the
calibration point and the CS5345.