ICS8523CGI REVISION E NOVEMBER 15, 2012

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©2012 Integrated Device Technology, Inc.

ICS8523I Data Sheet

LOW SKEW, 1-TO-4, DIFFERENTIAL-TO-HSTL FANOUT BUFFER

3. Calculations and Equations.

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

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

Figure 6. HSTL Driver Circuit and Termination

To calculate worst case power dissipation into the load, use the following equations which assume a 50 load.

Pd_H is power dissipation when the output drives high.

Pd_L is the power dissipation when the output drives low.

Pd_H = (VOH_MAX /RL) * (VDDO_MAX - VOH_MAX)

Pd_L = (VOL_MAX /RL) * (VDDO_MAX - VOL_MAX)

Pd_H = (0.9V/50

) * (2V - 0.9V) = 19.8mW

Pd_L = (0.4V/50

) * (2V - 0.4V) = 12.8mW

Total Power Dissipation per output pair = Pd_H + Pd_L = 32.6mW

V

OUT

V

DDO

Q1

RL

50

Ω