VSC7960RO 查看數據表（PDF） - Vitesse Semiconductor

零件编号

产品描述 (功能)

生产厂家

VSC7960RO

3.125Gb/s CML Limiting Amplifier with LOS Detect and Laser Driver with Automatic Power Control

Vitesse Semiconductor 

VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC7960

3.125Gb/s CML Limiting Amplifier with LOS Detect

and Laser Driver with Automatic Power Control

Select Resistor for MODSET

To ensure some minimum extinction ratio over temperature and lifetime, assume an optimal extinction ratio

of 20 (13dB) at 25°C. The modulation current may be calculated from the following equation:

IMOD = Pp-p / η= 2 * PAVE * (re-1) / (re+1) / η = 2 * 6mA * (20-1) / (20 + 1) / 0.4 = 27.1mA

The graph of IMODSET vs. RMODSET in Typical Operating Characteristics shows the resistor for MODSET

should be 8.5kΩ.

Select Resistor for BIASMAX

The maximum threshold current at +85°C and end-of-life must be determined. A graph of a typical laser’s

Ith versus TC reveals a maximum threshold current of 30mA at 85°C. Therefore, the maximum bias can be

approximated by:

IBIASMAX = ITH-MAX + IMOD / 2 = 30mA + 27.1mA / 2 = 43.6mA

The graph of IBIASMAX vs. RBIASMAX in Typical Operating Characteristics shows the resistor for BIASMAX

should be 5kΩ.

Wire Bonding

For best performance gold ball-bonding techniques are recommended. Wedge bonding is not recom-

mended. For best performance and to minimize inductance keep wire bond lengths short.

PCB Layout Guidelines

Use high frequency PCB layout techniques with solid ground planes to minimize crosstalk and EMI. Keep

high speed traces as short as possible for signal integrity. The output traces to the laser diode must be short to

minimize inductance. Short output traces will provide best performance.

G52359-0, Rev 2.1

5/01/01

© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

Internet: www.vitesse.com

Page 19

Share Link: