Integrated

Circuit

Systems, Inc.

ICS852911I

852911AVI

www.icst.com/products/hiperclocks.html

REV. A MAY 23, 2005

11

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 5.

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

DDO_MAX

- V

OH_MAX

)

Pd_L = (V

OL_MAX

/R

L

) * (V

DDO_MAX

- V

OL_MAX

)

Pd_H = (1.4V/50

Ω) * (3.6V - 1.4V) = 61.6mW

Pd_L = (0.4V/50

Ω) * (3.6V - 0.4V) = 25.6mW

Total Power Dissipation per output pair = Pd_H + Pd_L = 87.2mW

V

DDO

V

OUT

RL

50Ω

Q1