ICS85322AM-T ICST [Integrated Circuit Systems], ICS85322AM-T Datasheet - Page 10

• Manufacturer Part Number: ICS85322AM-T
• Description: DUAL LVCMOS/LVTTL-TO-DIFFERENTIAL 2.5V/3.3V LVPECL TRANSLATOR
• Manufacturer: ICST [Integrated Circuit Systems]

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 6.
T
voltage 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
Pd_L = [(V
Pd_H = [(2.465V - (3.465V - 2V))/50 ] * (3.465V - 2.465V) = 20mW
Pd_L = [(1.765V - (3.465V - 2V))/50 ] * (3.465V - 1.765V) = 10.2mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 30.2mW
85322AM
o calculate worst case power dissipation into the load, use the following equations which assume a 50 load, and a termination
•
•
For logic high, V
Using V
For logic low, V
Using V
OL_MAX
OH_MAX
CC
- 2V.
– (V
CC_MAX
CC_MAX
– (V
CC_MAX
CC_MAX
= 3.465, this results in V
= 3.465, this results in V
OUT
OUT
- 2V))/R
- 2V))/R
= V
= V
OL_MAX
OH_MAX
L
F
L
] * (V
] * (V
IGURE
= V
= V
CC_MAX
CC_MAX
CC_MAX
CC_MAX
6 - LVPECL D
www.icst.com/products/hiperclocks.html
- V
– 1.7V
- V
OH_MAX
OL_MAX
– 1.0V
OL_MAX
OH_MAX
= 1.765V
= 2.465V
)
)
RIVER
V
Q1
CC
10
C
D
IRCUIT AND
LVCMOS / LVTTL- -D
2.5V / 3.3V LVPECL T
RL
T
V
50
ERMINATION
CC
- 2V
V
OUT
ICS85322
REV. A JULY 31, 2001