ics85354a Integrated Device Technology, ics85354a Datasheet - Page 15

• Manufacturer Part Number: ics85354a
• Description: Differential-to-lvpecl/ecl Multiplexer
• 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 5.
T
termination 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 - 0.935V)/50 ] * 0.935V = 19.92mW
Pd_L = [(V
[(2V - 1.67V)/50 ] * 1.67V = 11.02mW
Total Power Dissipation per output pair = Pd_H + Pd_L = 30.92mW
85354AK-01
o calculate worst case power dissipation into the load, use the following equations which assume a 50
•
•
For logic high, V
(V
For logic low, V
(V
OL_MAX
OH_MAX
CC_MAX
CC_MAX
– (V
– (V
- V
- V
OL_MAX
OH_MAX
CC_MAX
DD_MAX
CC
OUT
OUT
) = 1.67V
) = 0.935
- 2V.
- 2V))/R
- 2V))/R
= V
= V
OL_MAX
OH_MAX
L
L
] * (V
] * (V
= V
F
= V
IGURE
CC_MAX
CC_MAX
CC_MAX
CC_MAX
PRELIMINARY
5. LVPECL D
- V
– 1.67V
- V
– 0.935V
OL_MAX
OH_MAX
) = [(2V - (V
) = [(2V - (V
Q1
RIVER
VCC
D
15
IFFERENTIAL
CC_MAX
C
CC_MAX
IRCUIT AND
- V
- V
OL_MAX
OH_MAX
T
RL
50
ERMINATION
)) /R
)) /R
-
VCC - 2V
TO
L
] * (V
L
VOUT
] * (V
-LVPECL/ECL M
CC_MAX
CC_MAX
- V
- V
OL_MAX
OH_MAX
ICS85354-01
) =
) =
D
load, and a
REV. A JANUARY 16, 2008
UAL
ULTIPLEXER
2:1/1:2