ICS8535-31 ICST [Integrated Circuit Systems], ICS8535-31 Datasheet - Page 10

• Manufacturer Part Number: ICS8535-31
• Description: LOW SKEW, 1-TO-4, CRYSTAL OSCILLATOR/ LVCMOS-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 4.
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
[(2V - 0.9V)/50 ] * 0.9V = 19.8mW
Pd_L = [(V
[(2V - 1.7V)/50 ] * 1.7V = 10.2mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 30mW
8535AG-31
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
(V
For logic low, V
(V
OL_MAX
OH_MAX
CC_MAX
CC_MAX
CC
- 2V.
– (V
Integrated
Circuit
Systems, Inc.
– (V
- V
- V
OH_MAX
OL_MAX
CC_MAX
CC_MAX
OUT
OUT
) = 1.7V
) = 0.9V
- 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
4. LVPECL D
www.icst.com/products/hiperclocks.html
– 1.7V
- V
- V
– 0.9V
OL_MAX
OH_MAX
) = [(2V - (V
) = [(2V - (V
RIVER
V
Q1
CC
LVCMOS-
10
C
CC _MAX
CC _MAX
IRCUIT AND
L
OW
- V
- V
OL_MAX
OH_MAX
S
TO
KEW
RL
T
V
50
)) /R
ERMINATION
CC
)) /R
-3.3V LVPECL F
- 2V
V
L
, 1-
] * (V
L
OUT
] * (V
TO
CC_MAX
CC_MAX
-4, C
- V
- V
OL_MAX
OH_MAX
RYSTAL
ICS8535-31
) =
) =
ANOUT
O
REV. B APRIL 29, 2005
SCILLATOR
B
UFFER
/