A54SX16-1CG256 ACTEL [Actel Corporation], A54SX16-1CG256 Datasheet - Page 19

• Manufacturer Part Number: A54SX16-1CG256
• Description: SX Family FPGAs RadTolerant and HiRel
• Manufacturer: ACTEL [Actel Corporation]

Power Dissipation
where:
Accurate values for N and M are difficult to determine
because they depend on the design and on the system I/O.
The power can be divided into two components: static
and active.
Static Power Component
Power consumption due to standby current is typically a
small component of the total power consumption.
Standby power is shown below for military, worst-case
conditions (70°C).
Table 1-9 •
I
outputs are changing.
I
I
V
N is the number of outputs driving TTL loads to V
M is the number of outputs driving TTL loads to V
Equivalent Capacitance (pF)
Modules
Input Buffers
Output Buffers
Routed Array Clock Buffer Loads
Dedicated Clock Buffer Loads
Fixed Capacitance (pF)
routed_Clk1
routed_Clk2
Fixed Clock Loads
Clock Loads on Dedicated Array Clock
CC
CC
OL
OL
P = (I
I
standby is the current flowing when no inputs or
active is the current flowing due to CMOS switching.
, I
OH
, V
OH
I
20 mA
CC
* (V
OH
CC
are TTL sink/source currents.
standby + I
are TTL level output voltages.
CCA
Equivalent Capacitance Values
– V
OH
) * M
CC
V
3.6 V
active) * V
CC
CCA
+ I
Power
72 mW
OL
* V
OL
* N +
OL
OH
EQ 1-2
C
C
C
C
C
.
EQCD
EQCR
EQM
.
EQO
s
r
r
EQI
1
2
1
v2.1
Active Power Component
Power dissipation in CMOS devices is usually dominated
by
component is frequency-dependent, a function of the
logic and the external I/O. Active power dissipation
results from charging the internal chip capacitances of
the interconnects, unprogrammed antifuses, module
inputs, and module outputs, plus external capacitance
due to PCB traces and load device inputs. An additional
component of the active power dissipation is the totem
pole current in CMOS transistor pairs. The net effect can
be associated with an equivalent capacitance that can be
combined with frequency and voltage to represent
active power dissipation.
Equivalent Capacitance
The power dissipated by a CMOS circuit can be expressed
by
where:
Equivalent capacitance is calculated by measuring
I
circuit component of interest. Measurements have been
made over a range of frequencies at a fixed value of
V
so that the results may be used over a wide range of
operating conditions. Equivalent capacitance values are
shown in
CC
C
V
F
CCA
EQ
CCA
RT54SX16
active at a specified frequency and voltage for each
EQ
Power (µW) = C
the
. Equivalent capacitance is frequency-independent
10.0
0.25
120
120
528
7.0
2.0
0.4
1-3:
= Equivalent capacitance in pF
= Power supply in volts (V)
= Switching frequency in MHz
Table
active
1-9.
A54SX16
SX Family FPGAs RadTolerant and HiRel
EQ
(dynamic)
0.15
528
3.9
1.0
5.0
0.2
60
60
* V
CCA
2
* F
RT54SX32
power
1,080
10.0
0.34
210
210
7.0
2.0
0.6
dissipation.
A54SX32
1,080
0.23
107
107
5.0
3.9
1.0
0.3
EQ 1-3
This
1-15