ICS853014

LOW SKEW, 1-TO-5, DIFFERENTIAL-TO-2.5V, 3.3V LVPECL/ECL FANOUT BUFFER

IDT™ / ICS™ 2.5V, 3.3V LVPECL/ECL FANOUT BUFFER

15

ICS853014BG REV. DNOVEMBER 12, 2007

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 7.

Figure 7. LVPECL Driver Circuit and Termination

•

•

Pd_H is power dissipation when the output drives high.

Pd_L is the power dissipation when the output drives low.

[(2V – 0.935V)/50

Ω] * 0.935V = 19.92mW

[(2V – 1.67V)/50

Ω] * 1.67V = 11.02mW

Total Power Dissipation per output pair = Pd_H + Pd_L = 30.94mW

V

OUT

V

CC

V

Q1

RL

50

Ω