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ICS85222AM-02 REV. B SEPTEMBER 12, 2007

ICS85222-02

1-TO-2, LVCMOS/LVTTL-TO-DIFFERENTIAL HSTL TRANSLATOR

3. Calculations and Equations.

The purpose of this section is to derive the power dissipated into the load.

HSTL output driver circuit and termination are shown in Figure 1.

Ω load.

Pd_H is power dissipation when the output drives high.

Pd_L is the power dissipation when the output drives low.

Pd_H = (V

OH_MAX

/R

L

) * (V

DD_MAX

- V

OH_MAX

)

Pd_L = (V

OL_MAX

/R

L

) * (V

DD_MAX

- V

OL_MAX

)

Pd_H = (1.4V/50

Ω) * (3.465V - 1.4V) = 57.8mW

Pd_L = (0.4V/50

Ω) * (3.465V - 0.4V) = 24.52mW

Total Power Dissipation per output pair = Pd_H + Pd_L = 82.3mW

V

DD

V

OUT

RL

50

Ω

Q1