Data Sheet
June 1999
ORCA
Series 3C and 3T FPGAs
Package Thermal Characteristics
(continued)
FPGA Maximum Junction Temperature
Once the power dissipated by the FPGA has been determined (see the Estimating Power Dissipation section), the
maximum junction temperature of the FPGA can be found. This is needed to determine if speed derating of the
device from the 85 °C junction temperature used in all of the delay tables is needed. Using the maximum ambient
temperature, T
Amax
, and the power dissipated by the device, Q (expressed in °C), the maximum junction tempera-
ture is approximated by:
T
Jmax =
T
Amax
+ (Q •
Θ
JA
)
ORCA
Series FPGAs.
Table 76. Plastic Package Thermal Characteristics for the
ORCA
Series
1
Package
208-Pin SQFP
1
208-Pin SQFP2
1
240-Pin SQFP
1
240-Pin SQFP2
1
256-Pin PBGA
1, 2
256-Pin PBGA
1, 3
352-Pin PBGA
1, 2
352-Pin PBGA
1, 3
432-Pin EBGA
1
600-Pin EBGA
1
0 fpm
26.5
12.8
25.5
13.0
22.5
26.0
19.0
25.5
11.0
11.0
Θ
JA
(°C/W)
200 fpm
23.0
10.3
22.5
10.0
19.0
22.0
16.0
22.0
8.5
8.5
500 fpm
21.0
9.1
21.0
9.0
17.5
20.5
15.0
20.5
7.5
7.5
T
A
= 70 °C max
T
J
= 125 °C max
@ 0 fpm (W)
2.1
4.3
2.2
4.2
2.4
2.1
2.9
2.1
5.0
5.5
1. Mounted on 4-layer JEDEC standard test board with two power/ground planes.
2. With thermal balls connected to board ground plane.
3. Without thermal balls connected to board ground plane.
Lucent Technologies Inc.
195
AGERE [ AGERE SYSTEMS ]
