
ICS8741004
DIFFERENTIAL-TO-LVDS/0.7V DIFFERENTIAL PCI EXPRESS JITTER ATTENUATOR
IDT / ICS PCI EXPRESS JITTER ATTENUATOR
15
ICS8741004AG REV. AMAY 29, 2008
3. Calculations and Equations.
The purpose of this section is to calculate power dissipation on the IC per HCSL output pair.
HCSL output driver circuit and termination are shown in Figure 6.
Figure 6. HCSL Driver Circuit and Termination
HCSL is a current steering output which sources a maximum of 17mA of current per output. To calculate worst case on-chip power
dissipation, use the following equations which assume a 50
load to ground.
The highest power dissipation occurs when VDD_MAX.
Power
= (VDD_MAX – VOUT) * IOUT, since VOUT = IOUT * RL
= (VDD_MAX – IOUT * RL) * IOUT
= (3.465V – 17mA * 50
) * 17mA
Total Power Dissipation per output pair = 44.5mW
VDD
VOUT
RL
50
IC
IOUT = 17mA
RREF =
475
± 1%