Thermal Resistance
Thermal resistance values for Cyclone II devices are provided for a board
meeting JEDEC specifications and for a typical board. The values
provided are as follows:
Thermal
Resistance
■
■
■
■
θ
JA (°C/W) Still Air—Junction-to-ambient thermal resistance with
no airflow when a heat sink is not being used.
JA (°C/W) 100 ft./minute—Junction-to-ambient thermal resistance
with 100 ft./minute airflow when a heat sink is not being used.
JA (°C/W) 200 ft./minute—Junction-to-ambient thermal resistance
with 200 ft./minute airflow when a heat sink is not being used.
JA (°C/W) 400 ft./minute—Junction-to-ambient thermal resistance
with 400 ft./minute airflow when a heat sink is not being used.
θ
θ
θ
■
■
θ
θ
JC (°C/W)—Junction-to-case thermal resistance for device.
JB (°C/W)—Junction-to-board thermal resistance for specific board
being used.
Table 15–2 provides θJA (junction-to-ambient thermal resistance) values
and θJC (junction-to-case thermal resistance) values for Cyclone II devices
on a board meeting JEDEC specifications for thermal resistance
calculation. The JEDEC board specifications require two signal and two
power/ground planes and are available at www.jedec.org.
Table 15–2. Thermal Resistance of Cyclone II Devices for Board Meeting JEDEC Specifications (Part 1 of 2)
θJA (°C/W)
Still Air
θ
JA (°C/W)
θ
JA (° C/W)
θ
JA (° C/W)
θJC
Pin
Count
Device
Package
100 ft./min. 200 ft./min. 400 ft./min. (°C/W)
EP2C5
144 TQFP
31
29.3
29.2
26.1
28.3
28.8
23
27.9
27.3
23.6
26.9
26.9
20.5
17.8
14.8
21.4
17.8
14.8
13.3
14.5
12.6
25.5
22.3
21.7
24.9
21.7
18.5
16
10
5.5
8.7
9.9
5.4
7.1
5.5
4.2
4.2
5.5
4.2
3.3
5
208 PQFP
30.4
30.2
29.8
30.2
27
256 FineLine BGA
144 TQFP
EP2C8
208 PQFP
256 FineLine BGA
256 FineLine BGA
484 FineLine BGA
240 PQFP
EP2C15
EP2C20
24.2
21
20
17
13.1
17.4
16
26.6
24.2
21
24
256 FineLine BGA
484 FineLine BGA
484 FineLine BGA
484 Ultra FineLine BGA
672 FineLine BGA
20
17
13.1
11.7
12.8
11.1
EP2C35
19.4
20.6
18.6
15.4
16.6
14.6
3.1
15–2
Altera Corporation
February 2007
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
