ICS84330CI データシートの表示（PDF） - Integrated Device Technology

部品番号

コンポーネント説明

メーカー

ICS84330CI

720MHz, Low Jitter, Crystal-to-LVPECL Frequency Synthesizer

Integrated Device Technology 

ICS84330CI Data Sheet

720MHZ, CRYSTAL-TO-LVPECL FREQUENCY SYNTHESIZER

Termination for 3.3V LVPECL Outputs

The clock layout topology shown below is a typical termination for

LVPECL outputs. The two different layouts mentioned are

recommended only as guidelines.

The differential outputs are low impedance follower outputs that

generate ECL/LVPECL compatible outputs. Therefore, terminating

resistors (DC current path to ground) or current sources must be

used for functionality. These outputs are designed to drive 50

transmission lines. Matched impedance techniques should be used

to maximize operating frequency and minimize signal distortion.

Figures 5A and 5B show two different layouts which are

recommended only as guidelines. Other suitable clock layouts may

exist and it would be recommended that the board designers

simulate to guarantee compatibility across all printed circuit and clock

component process variations.

3.3V

Zo = 50Ω

3.3V

+

LVPECL

Zo = 50Ω

R1

50Ω

RTT =

1

((VOH + VOL) / (VCC – 2)) – 2

* Zo

_

Input

R2

50Ω

VCC - 2V

RTT

Figure 5A. 3.3V LVPECL Output Termination

3.3V

LVPECL

3.3V

R3

R4

125Ω

125Ω

3.3V

Zo = 50Ω

+

Zo = 50Ω

R1

84Ω

_

R2

84Ω

Input

Figure 5B. 3.3V LVPECL Output Termination

ICS84330CVI REVISION A JANUARY 7, 2011

10

©2011 Integrated Device Technology, Inc.

Share Link: