ISPLSI8840-60LB432 LATTICE [Lattice Semiconductor], ISPLSI8840-60LB432 Datasheet - Page 18

• Manufacturer Part Number: ISPLSI8840-60LB432
• Manufacturer: LATTICE [Lattice Semiconductor]

Power consumption in the ispLSI 8840 device depends
on two primary factors: the speed at which the device is
operating and the number of product terms used. The
product terms have a fuse-selectable speed/power
tradeoff setting. Each group of four product terms has a
single speed/power tradeoff control fuse that acts on the
complete group of four. The fast “high-speed” setting
Figure 10. Typical Device Power Consumption vs fmax
I CC can be estimated for the ispLSI 8840 using the following equation:
I CC = 48.0 + (# of Turbo PTs * 0.346) + (# of Non-Turbo PTs * 0.165) + (# of Macrocells Used * fmax * AF * 0.049)
# of Turbo PTs = Number of Turbo Product Terms Used in Design
# of Non-Turbo PTs = Number of Non-Turbo Product Terms Used in Design
fmax = Maximum Operating Frequency
Note: An Activity Factor of 1.0 means all macrocell registers toggle at Fmax. An Activity Factor of 0.5 means the
average macrocell registers toggle at half of fmax.
The I CC estimate is based on typical conditions (V CC = 5.0V, room temperature) and an assumption of two GLB loads
on average exists. These values are for estimates only. Since the value of I CC is sensitive to operating conditions
and the program in the device, the actual I CC should be verified.
AF (Activity Factor) =
Power Consumption
1200
1100
1000
Average Macrocell Toggle Frequency
900
800
700
600
500
400
300
200
0
10
Fmax
20
30
Notes: Configuration of 42 20-bit counters
40
Typical current at 5V, 25 C
50
18
f
max (MHz)
operates product terms at their normal full power con-
sumption. For portions of the logic that can tolerate
longer propagation delays, selecting the slower “low-
power” setting will significantly reduce the power
dissipation for these product terms. Figure 10 shows the
relationship between power and operating speed.
60
Specifications ispLSI 8840
70
80
ispLSI 8840
90 100
Turbo
Non-Turbo
110 120
0127/8840