ICS8533AG-11 ICST [Integrated Circuit Systems], ICS8533AG-11 Datasheet - Page 12

• Manufacturer Part Number: ICS8533AG-11
• Description: LOW SKEW, 1-TO-4, CRYSTAL OSCILLATOR/ DIFFERENTIAL-TO-3.3V LVPECL FANOUT BUFFER
• 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 8.
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
REV. D JULY 16, 2001
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
F
L
L
] * (V
IGURE
] * (V
= V
= V
CC_MAX
CC_MAX
CC_MAX
CC_MAX
13 - LVPECL D
- V
– 1.7V
- V
OH_MAX
OL_MAX
– 1.0V
OL_MAX
OH_MAX
= 1.765V
= 2.465V
)
)
D
IFFERENTIAL
V
RIVER
Q1
CC
12
C
L
IRCUIT AND
OW
S
-
TO
KEW
RL
V
T
50
-3.3V LVPECL F
CC
ERMINATION
- 2V
, 1-
V
OUT
TO
-4, C
RYSTAL
ICS8533-11
ANOUT
O
SCILLATOR
B
UFFER
/