USB2660 Standard Microsystems Corp., USB2660 Datasheet - Page 56

• Manufacturer Part Number: USB2660
• Description: Ultra Fast Usb 2.0 Hub And Multi-format Flash Media Controller With Dual Sd Interfaces
• Manufacturer: Standard Microsystems Corp.

Chapter 9 AC Specifications
Revision 1.0 (06-09-09)
9.1
C
C
C
C
C
C
C
SYMBOL
0
L
B
S
XTAL
1
2
Parallel Resonant, Fundamental Mode, 24 MHz ± 350 ppm.
Note 9.1
Note 9.2
Oscillator/Crystal
Crystal shunt capacitance
Crystal load capacitance
Total board or trace
capacitance
Stray capacitance
XTAL pin input capacitance
Load capacitors installed on
OEM board
C
and should be set to ‘0’ for use in the calculation of the capacitance formulas in Figure 9.2,
"Capacitance Formulas". However, the OEM PCB itself may present a parasitic
capacitance between XTAL1 and XTAL2. For an accurate calculation of C
the parasitic capacitance between traces XTAL1 and XTAL2 into account.
Each of these capacitance values is typically approximately 18 pF.
0
DESCRIPTION
is usually included (subtracted by the crystal manufacturer) in the specification for C
Ultra Fast USB 2.0 Hub and Multi-Format Flash Media Controller with Dual SD Interfaces
Figure 9.1 Typical Crystal Circuit
Figure 9.2 Capacitance Formulas
Table 9.1 Crystal Circuit Legend
C
C
1
2
= 2 x (C
= 2 x (C
DATASHEET
Crystal manufacturer’s specification (See
OEM board design
SMSC IC and OEM board design
SMSC IC
Calculated values based on Figure 9.2,
"Capacitance Formulas" (See
56
L
L
– C
– C
0
0
) – C
) – C
IN ACCORDANCE WITH
S1
S2
Note
9.2)
SMSC USB2660/USB2660i
Note
9.1)
1
and C
Datasheet
2,
take
L