8S89831AKILFT IDT, 8S89831AKILFT Datasheet - Page 16

• Manufacturer Part Number: 8S89831AKILFT
• Description: Clock Drivers & Distribution 1
• Manufacturer: IDT

Specifications of 8S89831AKILFT

• Rohs: yes
• Part # Aliases: ICS8S89831AKILFT

ICS8S89831I Data Sheet
3. Calculations and Equations.
The purpose of this section is to calculate the power dissipation for the LVPECL output pairs.
The LVPECL output driver circuit and termination are shown in Figure 8.
Figure 8. LVPECL Driver Circuit and Termination
T
V
Pd_H is power dissipation when the output drives high.
Pd_L is the power dissipation when the output drives low.
Pd_H = [(V
[(2V – 0.85V)/50Ω] * 0.85V = 19.55mW
Pd_L = [(V
[(2V – 1.575V)/50Ω] * 1.575V = 13.39mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 32.94mW
ICS8S89831AKI REVISION A APRIL 26, 2010
o calculate worst case power dissipation into the load, use the following equations which assume a 50Ω load, and a termination voltage of
CC
•
•
– 2V.
For logic high, V
(V
For logic low, V
(V
OL_MAX
OH_MAX
CC_MAX
CC_MAX
– (V
– (V
– V
– V
OH_MAX
OL_MAX
CC_MAX
CC_MAX
OUT
OUT
= V
V
= V
) = 1.575V
) = 0.85V
Q1
CC
– 2V))/R
– 2V))/R
OL_MAX
OH_MAX
L
= V
L
] * (V
] * (V
= V
CC_MAX
CC_MAX
CC_MAX
CC_MAX
RL
50Ω
V
– 1.575V
CC
– 0.85V
– V
– V
-
2V
V
OUT
OL_MAX
OH_MAX
) = [(2V – (V
) = [(2V – (V
16
CC_MAX
CC_MAX
– V
– V
OL_MAX
DIFFERENTIAL LVPECL-TO-LVPECL/ECL FANOUT BUFFER
OH_MAX
))/R
))/R
L]
L
* (V
] * (V
CC_MAX
©2010 Integrated Device Technology, Inc.
CC_MAX
– V
– V
OL_MAX
OH_MAX
) =
) =