ICS8521 ICST [Integrated Circuit Systems], ICS8521 Datasheet - Page 10

• Manufacturer Part Number: ICS8521
• Description: LOW SKEW, 1-TO-9 DIFFERENTIAL-TO-LVHSTL FANOUT BUFFER
• Manufacturer: ICST [Integrated Circuit Systems]

8521BY
3. Calculations and Equations.
The purpose of this section is to derive the power dissipated into the load.
LVHSTL output driver circuit and termination are shown in Figure 10.
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 = (1.2V/50 ) * (2V - 1.2V) = 19.2mW
Pd_L = (0.4V/50 ) * (2V - 0.4V) = 12.8mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 32mW
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
For logic low, V
OL_MAX
OH_MAX
DD
- 2V.
/R
/R
L
L
) * (V
) * (V
DD_MAX
OUT
DD_MAX
OUT
= V
= V
- V
- V
OL_MAX
OH_MAX
OL_MAX
OH_MAX
F
IGURE
= V
= V
)
)
DD_MAX
DD_MAX
10 - LVHSTL D
www.icst.com/products/hiperclocks.html
– 0.4V
– 1.2V
RIVER
V
Q1
DD
10
D
C
IRCUIT AND
IFFERENTIAL
T
RL
50
ERMINATION
V
-
TO
OUT
-LVHSTL F
L
OW
ANOUT
S
ICS8521
KEW
REV. B JULY 31, 2001
, 1-
B
UFFER
TO
-9