CS5368-DQZR Cirrus Logic Inc, CS5368-DQZR Datasheet - Page 21

• Manufacturer Part Number: CS5368-DQZR
• Description: IC,A/D CONVERTER,OCTAL,24-BIT,QFP,48PIN
• Manufacturer: Cirrus Logic Inc

DS624A1
4. APPLICATIONS
4.1
4.2
Power
For convenient interfacing to external devices, there are five independent power pins for the CS5368. VD
powers the digital core. VA powers the analog core. VLS powers the Serial Audio Interface. VLC powers
the control logic. VX powers the crystal oscillator. The power pins may have any supported voltage range
of the specified voltages supplied simultaneously.
To meet full performance specifications, the CS5368 requires normal low noise board layout. The
Connection Diagram” on page 23
clean supply. VD, which powers the digital filter, may be run from the system logic supply, or it may be pow-
ered from the analog supply via a single-pole decoupling filter.
Decoupling capacitors should be placed as near to the ADC as possible, with the lower value high frequency
capacitors being placed nearest to the device leads. Clocks should be kept away from the FILT+ and VQ
pins in order to avoid unwanted coupling into the device. The FILT+ and VQ decoupling capacitors must be
positioned to minimize the electrical path to ground.
The CDB5368 evaluation board demonstrates an optimum layout for the device.
Clocking
The device supports clocking through the use of either an on-board crystal oscillator driver or an externally
supplied clock. When using the on-board crystal driver, the topology shown in
Topology"
When using the on-board crystal oscillator driver, the XTI pin is the input for the Master clock (MCLK) to the
device. The XTO pin must not be used to drive anything other than the oscillator tank circuitry. Instead, a
buffered copy of XTI is available on the MCLK pin, which is level controlled by VLS and may be used to
synchronize other parts to the device.
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 CS5368 provides on board master clock dividers that precede all other internal clocking. The available
dividers are divide by 1, 1.5, 2, 3, 4.
must be used. The crystal oscillator manufacturer supplies recommended capacitor values.
Figure 8. Crystal Oscillator Topology
shows the recommended power arrangements, with VA connected to a
XTO
XTI
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22
Figure 8. "Crystal Oscillator
CS5368
“Typical
25