PI3A288 Datasheet, PDF (8/9 Pages) Pericom Semiconductor Corporation – Ultra-Low-THD Dual-SPDT Analog Switch with Negative Signal Handling Capability

PI3A288
Ultra-Low-THD Dual-SPDT (0.35Ω) Analog Switch
with Negative Signal Handling Capability
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Click and Pop Operation
The PI3A288 can pass ground referenced audio signals which allows it to be directly connected to audio drivers that
output ground referenced audio signals, eliminating the need for a DC blocking capacitor. Audio drivers that swing
around ground, however, do generate some DC offset, from a few millivolts to tens of millivolts. When switching
between audio channels or muting the audio signal, these small DC offset levels of the drivers can lead to a voltage
step across the speaker loads and create unwanted clicks and pops.
The PI3A288 has a special soft-start feature that slowly ramps the DC offset voltage from the audio driver to the
speaker load when turning on a switch channel. The ramp rate at the load is determined by the capacitor value
connected at the SSCAP pin. A soft-start capacitor value of 0.01μF provides obvious effect of eliminating pop-click
noise and is recommended.
2015-10-0009
PT0541-4 11/03/15
8