CY28412OC SPECTRALINEAR [SpectraLinear Inc], CY28412OC Datasheet - Page 7

• Manufacturer Part Number: CY28412OC
• Manufacturer: SPECTRALINEAR [SpectraLinear Inc]

Rev 1.0, November 20, 2006
Byte 6: Control Register 6
Byte 7: Vendor ID
Crystal Recommendations
The CY28412 requires a Parallel Resonance Crystal.
Substituting a series resonance crystal will cause the
CY28412 to operate at the wrong frequency and violate the
ppm specification. For most applications there is a 300-ppm
frequency shift between series and parallel crystals due to
incorrect loading.
Table 5. Crystal Recommendations
14.31818 MHz
Frequency
Bit
Bit
1
7
6
5
4
3
2
0
7
6
5
4
3
2
1
0
(Fund)
Externally
Externally
Externally
selected
selected
selected
@Pup
@Pup
0
0
1
1
1
0
0
1
0
1
0
0
0
Cut
AT
Revision Code Bit 3
Revision Code Bit 2
Revision Code Bit 1
Revision Code Bit 0
Vendor ID Bit 3
Vendor ID Bit 2
Vendor ID Bit 1
Vendor ID Bit 0
Loading Load Cap
Parallel
PCIF, SRC, PCI
RESERVED
CPUT/C
CPUT/C
CPUT/C
Name
Name
REF1
REF0
20 pF
0.1 mW
(max.)
RESERVED, Set = 0
Test Clock Mode Entry Control
1 = Hi-Z mode, 0 = Normal operation
REF1 Output Drive Strength
0 = Low, 1 = High
REF0 Output Drive Strength
0 = Low, 1 = High
SW PCI_STP# Function
0=SW PCI_STP assert, 1= SW PCI_STP deassert
When this bit is set to 0, all STOPPABLE PCI, PCIF and SRC outputs will
be stopped in a synchronous manner with no short pulses.
When this bit is set to 1, all STOPPED PCI, PCIF and SRC outputs will
resume in a synchronous manner with no short pulses.
FS_C. Reflects the value of the FS_C pin sampled on power up
0 = FS_C was low during VTT_PWRGD# assertion
FS_B. Reflects the value of the FS_B pin sampled on power up
0 = FS_B was low during VTT_PWRGD# assertion
FS_A. Reflects the value of the FS_A pin sampled on power up
0 = FS_A was low during VTT_PWRGD# assertion
Revision Code Bit 3
Revision Code Bit 2
Revision Code Bit 1
Revision Code Bit 0
Vendor ID Bit 3
Vendor ID Bit 2
Vendor ID Bit 1
Vendor ID Bit 0
Drive
Shunt Cap
Crystal Loading
Crystal loading plays a critical role in achieving low ppm perfor-
mance. To realize low ppm performance, the total capacitance
the crystal will see must be considered to calculate the appro-
priate capacitive loading (CL).
The following diagram shows a typical crystal configuration
using the two trim capacitors. An important clarification for the
following discussion is that the trim capacitors are in series
with the crystal not parallel. It’s a common misconception that
load capacitors are in parallel with the crystal and should be
approximately equal to the load capacitance of the crystal.
This is not true.
(max.)
5 pF
Motional
0.016 pF
(max.)
Description
Description
Tolerance
50 ppm
(max.)
Stability
50 ppm
(max.)
CY28412
Page 7 of 16
(max.)
Aging
5 ppm