EX128 Datasheet, PDF (12/36 Pages) List of Unclassifed Manufacturers – eX Family FPGAs

eX Family FPGAs
Junction Temperature (T_J)
The temperature variable in the Designer Series software
refers to the junction temperature, not the ambient
temperature. This is an important distinction because the
heat generated from dynamic power consumption is usually
hotter than the ambient temperature. Equation 1, shown
below, can be used to calculate junction temperature.
Junction Temperature = ∆T + T_a
(1)
Where:
T_a = Ambient Temperature
∆T = Temperature gradient between junction (silicon) and
ambient
∆T = θ_ja * P
P = Power
θ_ja = Junction to ambient of package. θ_ja numbers are
located in the Package Thermal Characteristics section
below.
Package Thermal Characteristics
The device junction to case thermal characteristic is θ_jc,
and the junction to ambient air characteristic is θ_ja. The
thermal characteristics for θ_ja are shown with two different
air flow rates.
The maximum junction temperature is 150°C.
A sample calculation of the absolute maximum power
dissipation allowed for a TQFP 100-pin package at
commercial temperature and still air is as follows:
Maximum Power Allowed
=
-M-----a---x---.---j-u---n---c---t--i-o---n-----t-e---m-----p---.----(---^°---C---)----–-----M-----a--x---.---a---m-----b---i--e--n---t---t--e---m----p---.---(---^°---C---)-
θ _{j a} ( ° C/W)
=
1---5---30---7-°_{--.-C5---°--–-C----7/--W-0---}°_---C--
=
2.1W
Package Type
Thin Quad Flat Pack (TQFP)
Thin Quad Flat Pack (TQFP)
Chip Scale Package (CSP)
Chip Scale Package (CSP)
Chip Scale Package (CSP)
Pin Count
θ_jc
64
14
100
12
49
3
128
3
180
3
θ_ja
Still Air
51.2
37.5
71.3
54.1
57.8
θ_ja
300 ft/min
35
30
56.0
47.8
51
Units
°C/W
°C/W
°C/W
°C/W
°C/W
12
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