8S89834AKILF IDT [Integrated Device Technology], 8S89834AKILF Datasheet - Page 13

• Manufacturer Part Number: 8S89834AKILF
• Description: Low Skew, 2-to-4 LVCMOS/LVTTL-to-LVPECL/ECL Clock Multiplexer
• Manufacturer: IDT [Integrated Device Technology]

ICS8S89834I Data Sheet
3. Calculations and Equations.
The purpose of this section is to calculate the power dissipation for the LVPECL output pairs.
LVPECL output driver circuit and termination are shown in Figure 5.
Figure 5. 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 – 0.80V)/50Ω] * 0.80V = 19.20mW
Pd_L = [(V
[(2V – 1.60V)/50Ω] * 1.60V = 12.80mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 32mW
ICS8S89834AKI REVISION A FEBRUARY 4, 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
CC_MAX
OH_MAX
OL_MAX
CC_MAX
OUT
OUT
Q1
= V
= V
) = 1.60V
) = 0.80V
V
– 2V))/R
– 2V))/R
CC
OL_MAX
OH_MAX
L
L
= V
] * (V
] * (V
= V
CC_MAX
CC_MAX
CC_MAX
CC_MAX
RL
50Ω
V
– 1.60V
CC
V
– 0.80V
– V
– V
OUT
- 2V
OL_MAX
OH_MAX
) = [(2V – (V
) = [(2V – (V
13
LOW SKEW, 2-TO-4 LVCMOS/LVTTL-TO-LVPECL/ECL CLOCK MULTIPLEXER
CC_MAX
CC_MAX
– V
– V
OL_MAX
OH_MAX
))/R
))/R
L
L
] * (V
] * (V
CO_MAX
©2010 Integrated Device Technology, Inc.
CC_MAX
– V
– V
OL_MAX
OH_MAX
) =
) =