ics84330c Integrated Device Technology, ics84330c Datasheet - Page 14

• Manufacturer Part Number: ics84330c
• Description: 700mhz, Low Jitter, Crystal-to-3.3v Differential Lvpecl Frequency Synthesizer
• Manufacturer: Integrated Device Technology

3. Calculations and Equations.
The purpose of this section is to derive the power dissipated into the load.
LVPECL output driver circuit and termination are shown in Figure 7.
Figure 7. LVPECL Driver Circuit and Termination
T
of 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 -0.9V)/50Ω] * 0.9V = 19.8mW
Pd_L = [(V
[(2V -1.7V)/50Ω] * 1.7V = 10.2mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 30mW
IDT™ / ICS™ LVPECL FREQUENCY SYNTHESIZER
o calculate worst case power dissipation into the load, use the following equations which assume a 50Ω load, and a termination voltage
ICS84330C
700MHZ, LOW JITTER, CRYSTAL-TO-3.3V DIFFERENTIAL LVPECL FREQUENCY SYNTHESIZER
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
= V
) = 1.7V
) = 0.9V
V
= V
-2V))/R
-2V))/R
Q1
CC
OL_MAX
OH_MAX
L
L
] * (V
] * (V
= V
= V
CC_MAX
CC_MAX
CC_MAX
CC_MAX
RL
50Ω
V
-V
-1.7V
-V
CC
-0.9V
OL_MAX
OH_MAX
-
2V
V
OUT
) = [(2V -(V
) = [(2V -(V
15
CC_MAX
CC_MAX
-V
-V
OL_MAX
OH_MAX
))/R
))/R
L]
L
* (V
] * (V
ICS84330CV REV. C JANUARY 28, 2009
CC_MAX
CC_MAX
-V
-V
OL_MAX
OH_MAX
) =
) =