Cirrus Logic CS5364 - Manual (Page 20)

20 DS625F5
CS5364
4.3 Master Clock Source
The CS5364 requires a Master Clock that can come from one of two sources: an on-chip crystal oscillator
driver or an externally generated clock.
4.3.1 On-Chip Crystal Oscillator Driver
When using the on-board crystal oscillator driver, the XTI pin (pin 21) is the input for the Master Clock (MC-
LK) to the device. The XTO pin (pin 22) must not be used to drive anything other than the oscillator tank
circuitry. When using the on-board crystal driver, the topology shown in
Figure 7 must be used. The crystal
oscillator manufacturer supplies recommended capacitor values. A buffered copy of the XTI input is avail-
able as an output on the MCLK pin (pin 23), which is level-controlled by VLS and may be used to synchro-
nize other parts to the device.
Figure 7. Crystal Oscillator Topology
4.3.2 Externally Generated Master Clock
If an external clock is used, the XTI and XTO pins must be grounded, and the MCLK pin becomes an input
for the system master clock. The incoming MCLK should be at the logic level set by the user on the VLS
supply pin.
XTI
XTO
22
21