ICS8422002I-01

FEMTOCLOCKS™ CRYSTAL-TO-LVHSTL FREQUENCY SYNTHESIZER

PRELIMINARY

IDT™ / ICS™ LVHSTL FREQUENCY SYNTHESIZER

12

ICS8422002AGI-01 REV. C NOVEMBER 1, 2007

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 5.

Figure 5. LVHSTL 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.

Pd_H = (1.0V/50

Ω) * (2V - 1.0V) = 20mW

Pd_L = (0.4V/50

Ω) * (2V - 0.4V) = 12.8mW

Total Power Dissipation per output pair = Pd_H + Pd_L = 32.8mW

V

OUT

V

DDO

Q1

RL

50

Ω