ICS85356 데이터 시트보기 (PDF) - Integrated Circuit Systems

부품명

상세내역

일치하는 목록

ICS85356

2:1, DIFFERENTIAL-TO-3.3V DUAL LVPECL / ECL CLOCK MULTIPLEXER

Integrated Circuit Systems 

Integrated

Circuit

Systems, Inc.

ICS85356I

2:1, DIFFERENTIAL-TO-3.3V

DUAL LVPECL / ECL CLOCK MULTIPLEXER

3. Calculations and Equations.

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

LVPECL output driver circuit and termination are shown in Figure 4.

VCC

Q1

VOUT

RL = 50

VCC - 2V

Figure 4. LVPECL Driver Circuit and Termination

To calculate worst case power dissipation into the load, use the following equations which assume a 50Ω load, and a termination voltage

of V - 2V.

CC

• For logic high, V = V

=V

– 1.0V

OUT

OH_MAX

CC_MAX

(V

- V ) = 1.0V

CC_MAX OH_MAX

• For logic low, V = V = V – 1.7V

OUT

OL_MAX

CC_MAX

(V

- V ) = 1.7V

CC_MAX OL_MAX

Pd_H is power dissipation when the output drives high.

Pd_L is the power dissipation when the output drives low.

Pd_H = [(V

– (V - 2V))/R ] * (V - V ) = [(2V - (V

- V ))/R ] * (V - V ) =

OH_MAX

CC_MAX

L

CC_MAX OH_MAX

CC_MAX

OH_MAX

L

CC_MAX OH_MAX

[(2V - 1V)/50Ω] * 1V = 20.0mW

Pd_L = [(V – (V - 2V))/R ] * (V

- V ) = [(2V - (V

- V ))/R ] * (V - V ) =

OL_MAX

CC_MAX

L

CC_MAX OL_MAX

CC_MAX

OL_MAX

L

CC_MAX OL_MAX

[(2V - 1.7V)/50Ω] * 1.7V = 10.2mW

Total Power Dissipation per output pair = Pd_H + Pd_L = 30.2mW

85356AMI

www.icst.com/products/hiperclocks.html

9

REV. A OCTOBER 7, 2004

Share Link: