Datasheet

ADSP-21477/ADSP-21478/ADSP-21479
Rev. C | Page 23 of 76 | July 2013
Total Power Dissipation
The information in this section should be augmented with
Estimating Power for ADSP-214xx SHARC Processors (EE-348).
Total power dissipation has two components:
1. Internal power consumption is additionally comprised of
two components:
• Static current due to leakage. Table 14 shows the static
current consumption (I
DD_INT_STATIC
) as a function of
junction temperature (T
J
) and core voltage (V
DD_INT
).
• Dynamic current (I
DD_INT_DYNAMIC
), due to transistor
switching characteristics and activity level of the pro-
cessor. The activity level is reflected by the Activity
Scaling Factor (ASF), which represents the activity
level of the application code running on the processor
core and having various levels of peripheral and exter-
nal port activity (Table 13). Dynamic current
consumption is calculated by selecting the ASF that
corresponds most closely with the user application
and then multiplying that with the dynamic current
consumption (Table 15).
2. External power consumption is due to the switching activ-
ity of the external pins.
Table 13. Activity Scaling Factors (ASF)
1
Activity Scaling Factor (ASF)
Idle 0.31
Low 0.53
Medium Low 0.62
Medium High 0.78
Peak-Typical (50:50)
2
0.85
Peak-Typical (60:40)
2
0.93
Peak-Typical (70:30)
2
1.00
High Typical 1.18
High 1.28
Peak 1.34
1
See Estimating Power for ADSP-214xx SHARC Processors (EE-348) for more
information on the explanation of the power vectors specific to the ASF table.
2
Ratio of continuous instruction loop (core) to SDRAM control code reads and
writes.
Table 14. Static Current—I
DD_INT_STATIC
(mA)
1
T
J
(°C)
Voltage (V
DD_INT
)
1.05 V 1.10 V 1.15 V 1.20 V 1.25 V 1.30 V 1.35 V
–45 < 0.1 < 0.1 0.4 0.8 1.3 2.1 3.3
–35 < 0.1 < 0.1 0.4 0.7 1.1 1.7 2.9
–25 < 0.1 0.2 0.4 0.8 1.2 1.7 2.9
–15 < 0.1 0.4 0.6 1.0 1.4 1.9 3.2
–50.20.60.91.31.82.33.7
+50.50.91.31.82.33.04.4
+15 0.8 1.4 1.8 2.3 3.0 3.7 5.1
+25 1.3 1.9 2.5 3.1 3.9 4.7 6.2
+35 2.0 2.8 3.4 4.2 5.1 6.0 8.0
+45 3.0 3.9 4.7 5.7 6.7 7.8 10.1
+55 4.3 5.4 6.3 7.6 8.8 10.3 12.9
+65 6.0 7.3 8.6 10.1 11.7 13.5 16.4
+75 8.3 9.9 11.5 13.3 15.3 17.4 21.2
+85 11.2 13.2 15.3 17.5 19.9 22.6 27.1
+95 15.2 17.6 20.1 22.9 26.1 29.4 34.6
+100 17.4 20.2 22.9 25.9 29.4 33.0 39.2
+105 20.0 23.0 26.1 29.5 33.4 N/A N/A
+115 26.3 30.0 33.9 38.2 42.9 N/A N/A
+125 34.4 38.9 43.6 48.8 54.8 N/A N/A
1
Valid temperature and voltage ranges are model-specific. See Operating Conditions on Page 21.