ICS843S1333DG REVISION A MAY 6, 2010

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©2010 Integrated Device Technology, Inc.

ICS843S1333D Data Sheet

CRYSTAL-TO-3.3V LVPECL CLOCK SYNTHESIZER

3. Calculations and Equations.

The purpose of this section is to calculate the power dissipation for the LVPECL output pair.

LVPECL output driver circuit and termination are shown in Figure 6.

Figure 6. LVPECL Driver Circuit and Termination

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Pd_H is power dissipation when the output drives high.

Pd_L is the power dissipation when the output drives low.

[(2V – 0.8V)/50

Ω] * 0.8V = 19.2mW

[(2V – 1.6V)/50

Ω] * 1.6V = 12.8mW

Total Power Dissipation per output pair = Pd_H + Pd_L = 32mW

V

OUT

V

CC

V

Q1

RL

50

Ω