843034-06 Datasheet, PDF (17/24 Pages) Integrated Device Technology – FemtoClock™ Multi-Rate 3.3V LVPECL Frequency Synthesizer

843034-06 DATA SHEET
POWER CONSIDERATIONS
This section provides information on power dissipation and junction temperature for the 843034-06.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the 843034-06 is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for V = 3.3V + 5% = 3.465V, which gives worst case results.
CC
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
Core and LVPECL Output Power Dissipation
• Power (core) = V * I = 3.465V * 173mA = 599.45mW
MAX
CC_MAX
EE_MAX
• Power (outputs) = 30mW/Loaded Output pair
MAX
If all outputs are loaded, the total power is 2 * 30mW = 60mW
LVCMOS Output Power Dissipation
• Output Impedance R Power Dissipation due to Loading 50Ω to V /2
OUT
CCO_REF
Output Current I = V / [2 * (50Ω + R )] = 3.465V / [2 * (50Ω + 7Ω] = 30.4mA
OUT
CCO_MAX
OUT
• Power Dissipation on the R per LVCMOS output
OUT
Power (R ) = R * (I )² = 7Ω * (30.4mA)² = 6.97mW per output
OUT
OUT
OUT
Total Power Dissipation
• Total Power
= Power (LVPECL) + Power (R )
OUT
= 599.45mW + 60mW + 6.47mW
= 665.92mW
FemtoClock™ Multi-Rate 3.3V LVPECL Frequency Synthesizer
17
REVISION B 8/17/15