ex256-ptq64pp Actel Corporation, ex256-ptq64pp Datasheet - Page 21

• Manufacturer Part Number: ex256-ptq64pp
• Description: Ex Family Fpgas
• Manufacturer: Actel Corporation

C
C
C
C
C
C
C
fm
fm
fn
fp
fq1
fq2
fs1
The eX, SX-A and RTSX-S Power Calculator can be used to
estimate the total power dissipation (static and dynamic)
of eX devices and can be found at
http://www.actel.com/products/rescenter/power/
calculators.asp.
Package Type
Thin Quad Flat Pack (TQFP)
Thin Quad Flat Pack (TQFP)
Chip Scale Package (CSP)
Chip Scale Package (CSP)
Chip Scale Package (CSP)
eqsm
eqi
eqcr
eqhv
eqhf
eqo
L
c
s
= Average R-cell switching frequency, typically
=
= Equivalent capacitance of input buffers
= Equivalent capacitance of routed array clocks
= Variable capacitance of dedicated array clock
= Fixed capacitance of dedicated array clock
= Equivalent capacitance of output buffers
=
= Average C-cell switching frequency, typically
= Average input buffer switching frequency,
= Average output buffer switching frequency,
= Frequency of routed clock A
= Frequency of routed clock B
= Frequency of dedicated array clock
modules
typically 10 pF
F/10
F/10
typically F/5
typically F/5
Maximum Power Allowed
Equivalent
Average
output
capacitance
loading
=
Max. junction temp. (°C) Max. ambient temp. (°C)
---------------------------------------------------------------------------------------------------------------------------------
Pin Count
of
100
128
180
64
49
capacitance,
sequential
θ
ja
12.0
14.0
θ
(°C/W)
jc
v4.3
–
Thermal Characteristics
The temperature variable in the Designer software refers
to
temperature. This is an important distinction because the
heat generated from dynamic power consumption is
usually hotter than the ambient temperature.
shown below, can be used to calculate junction
temperature.
Where:
θ
located in the
below.
Package Thermal Characteristics
The device junction-to-case thermal characteristic is θ
and the junction-to-ambient air characteristic is θ
thermal characteristics for θ
different air flow rates. θ
The maximum junction temperature is 150°C.
The maximum power dissipation allowed for eX devices
is a function of θ
maximum power dissipation allowed for a TQFP 100-pin
package at commercial temperature and still air is as
follows:
ja
∆T = Temperature gradient between junction
= Junction to ambient of package.
the
Still Air
42.4
33.5
72.2
54.1
57.8
Junction Temperature = ∆T + T
(silicon) and ambient = θ
junction
T
"Package Thermal Characteristics" section
a
ja
= Ambient Temperature
200 ft/min
. A sample calculation of the absolute
1.0 m/s
=
36.3
27.4
59.5
44.6
47.6
temperature,
θ
150°C 70°C
---------------------------------- -
ja
P = Power
33.5°C/W
jc
is provided for reference.
–
ja
500 ft/min
2.5 m/s
are shown with two
=
34.0
25.0
54.1
40.6
43.3
2.39W
not
ja
eX Family FPGAs
θ
ja
the
* P
a
numbers are
(1)
Units
°C/W
°C/W
°C/W
°C/W
°C/W
ambient
EQ
ja
EQ 1-1
. The
1-1,
1-17
jc
,