USB2240I-AEZG-XX Standard Microsystems (SMSC), USB2240I-AEZG-XX Datasheet - Page 46

• Manufacturer Part Number: USB2240I-AEZG-XX
• Manufacturer: Standard Microsystems (SMSC)

Specifications of USB2240I-AEZG-XX

• Lead Free Status / RoHS Status: Compliant

Chapter 10 AC Specifications
Revision 2.0 (10-14-09)
10.1
C
C
C
C
C
C
C
SYMBOL
0
L
B
S
XTAL
1
2
Parallel Resonant, Fundamental Mode, 24 MHz ± 350 ppm.
Note 10.1 C
Note 10.2 Each of these capacitance values is typically approximately 18 pF.
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
and should be set to ‘0’ for use in the calculation of the capacitance formulas in
Figure 10.2, "Capacitance Formulas". However, the OEM PCB itself may present a
parasitic capacitance between XTAL1 and XTAL2. For an accurate calculation of C
C
C
0
2,
C
2
DESCRIPTION
1
is usually included (subtracted by the crystal manufacturer) in the specification for C
take the parasitic capacitance between traces XTAL1 and XTAL2 into account.
C
0
Figure 10.1 Typical Crystal Circuit
Figure 10.2 Capacitance Formulas
Table 10.1 Crystal Circuit Legend
Crystal
C
C
1
2
= 2 x (C
= 2 x (C
Ultra Fast USB 2.0 Multi-Format, SD/MMC, and MS Flash Media Controllers
C
DATASHEET
L
Crystal manufacturer’s specification (See
OEM board design
SMSC IC and OEM board design
SMSC IC
Calculated values based on Figure 10.2,
"Capacitance Formulas" (See
46
L
L
– C
– C
1 M
0
0
) – C
) – C
IN ACCORDANCE WITH
S1
S2
XTAL2
(C
XTAL1
(C
S1 =
S2 =
C
C
B2
B1
+ C
+ C
Note
XTAL1
XTAL2
10.2)
)
)
Note
10.1)
SMSC USB224x
Datasheet
1
and
L