ZHCSJZ0 June 2019 TUSB8042A
PRODUCTION DATA.
The TUSB8042A accepts a crystal input to drive an internal oscillator or an external clock source. If a clock is provided to XI instead of a crystal, XO is left open. Otherwise, if a crystal is used, the connection needs to follow the guidelines below. Since XI and XO are coupled to other leads and supplies on the PCB, it is important to keep them as short as possible and away from any switching leads. It is also recommended to minimize the capacitance between XI and XO. This can be accomplished by shielding C1 and C2 with the clean ground lines.