8P391208 Datasheet, PDF (25/41 Pages) Integrated Device Technology – Low Additive Jitter 2:8 Buffer with Universal Differential Outputs

8P391208 Datasheet
Power Consumption Calculation
Determining total power consumption involves several steps:
1. Determine the power consumption using maximum current values for core voltage from Table 6, Table 7, Table 8 and Table 9, Page 7 for
the appropriate case of how many banks or outputs are enabled.
2. Determine the nominal power consumption of each enabled output path.
a. This consists of a base amount of power that is independent of operating frequency, as shown in Table 25 through Table 36 (depending
on the chosen output protocol).
b. Then there is a variable amount of power that is related to the output frequency. This can be determined by multiplying the output
frequency by the FQ_Factor shown in Table 25 through Table 36.
3. All of the above totals are then summed.
Thermal Considerations
Once the total power consumption has been determined, it is necessary to calculate the maximum operating junction temperature for the
device under the environmental conditions it will operate in. Thermal conduction paths, air flow rate and ambient air temperature are factors
that can affect this. The thermal conduction path refers to whether heat is to be conducted away via a heat-sink, via airflow or via conduction
into the PCB through the device pads (including the ePAD). Thermal conduction data is provided for typical scenarios in Table 42, Page 36.
Please contact IDT for assistance in calculating results under other scenarios.
Table 24: _JA vs. Air Flow Table for a 32-lead 5mm x 5mm VFQFN
_JA vs. Air Flow
Meters per Second
0
Multi-Layer PCB, JEDEC Standard Test Boards
35.23°C/W
1
31.6°C/W
2
30.0°C/W
©2016 Integrated Device Technology
25
September 1, 2016