Lattice Semiconductor
191
Data Sheet
November 2006
ORCA Series 3C and 3T FPGAs
Package Coplanarity
The coplanarity limits of the
ORCA Series 3 packages are as follows.
Table 77. Package Coplanarity
Package Parasitics
The electrical performance of an IC package, such as signal quality and noise sensitivity, is directly affected by the
package parasitics.
Table 78 lists eight parasitics associated with the
ORCA packages. These parasitics represent
the contributions of all components of a package, which include the bond wires, all internal package routing, and
the external leads.
Four inductances in nH are listed: LSW and LSL, the self-inductance of the lead; and LMW and LML, the mutual
inductance to the nearest neighbor lead. These parameters are important in determining ground bounce noise and
inductive crosstalk noise. Three capacitances in pF are listed: CM, the mutual capacitance of the lead to the near-
est neighbor lead; and C1 and C2, the total capacitance of the lead to all other leads (all other leads are assumed
to be grounded). These parameters are important in determining capacitive crosstalk and the capacitive loading
effect of the lead. The lead resistance value, RW, is in M
Ω.
The parasitic values in
Table 78 are for the circuit model of bond wire and package lead parasitics. If the mutual
capacitance value is not used in the designer’s model, then the value listed as mutual capacitance should be
added to each of the C1 and C2 capacitors.
Table 78. Package Parasitics
Package Type
Coplanarity Limit
(mils)
EBGA
8.0
PBGA
8.0
SQFP/SQFP2
4.0
3.15
TQFP
3.15
Package Type
LSW
LMW
RW
C1
C2
CM
LSL
LML
144-Pin TQFP
3
1
140
1
0.6
4—6
2—2.5
208-Pin SQFP
4
2
200
1
7—10
4—6
208-Pin SQFP2
4
2
200
1
6—9
4—6
240-Pin SQFP
4
2
200
1
8—12
5—8
240-Pin SQFP2
4
2
200
1
7—11
4—7
256-Pin PBGA
5
2
220
1
5—8
2—4
352-Pin PBGA
5
2
220
1.5
7—12
3—6
432-Pin EBGA
4
1.5
500
1
0.3
3—5.5
0.5—1
Select
devices
have
been
discontinued.
See
Ordering
Information
section
for
product
status.