OC-12/STM-4 AND OC-3/STM-1 CLOCK/DATA RECOVERY DEVICE 11 Rev C 2/19/15
894D115I-01 DATA SHEET
Power Considerations
This section provides information on power dissipation and junction temperature for the 894D115I-01.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the 894D115I-01 is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for V
CC
= 3.3V + 5% = 3.465V, which gives worst case results.
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
• Power (core)
MAX
= V
CC_MAX
* I
EE_MAX
= 3.465V * 80mA = 277.20mW
• Power (outputs)
MAX
= 30mW/Loaded Output pair
If all outputs are loaded, the total power is 2 * 30mW = 60mW
Total Power_
MAX
(3.3V, with all outputs switching) = 277mW + 60mW = 337mW
2. Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the device. The
maximum recommended junction temperature for HiPerClockS devices is 125°C.
Lower temperature refers to ambient temperature, maximum temperature refers to case temperature.
Table 7. Thermal Resistance
JA
for 20 Lead TSSOP, Forced Convection
3. Calculations and Equations.
The purpose of this section is to derive the power dissipated into the load.
JA
by Velocity
Meters per Second 012.5
Multi-Layer PCB, JEDEC Standard Test Boards 81.3°C/W 76.9°C/W 74.8°C/W
