ICS1531 datasheet(59/76 Pages) ICST

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Chapter 8

Layout and Power Considerations

ICS1531 Rev N 12/1/99

December, 1999

ICS1531 Data Sheet - Preliminary

8.1.2

Specific Guidelines for Printed Circuit Board Layout

8.1.2.1

Digital Inputs

The ICS1531 digital inputs are designed to work with either 3.3-V and 5-V signals. No extra components

are required.

8.1.2.2

Analog Inputs

To reduce noise, minimize traces for the ICS1531 analog red, green, and blue input pins by placing the

ICS1531 as close as possible to the board’s input connector. Input connectors can include any of the

following:

• 15-pin D connector

• BNC connector

• Digital Visual Interface connector (from the Digital Display Working Group)

• ‘P&D’, the ‘Plug and Display’ connector (from VESA)

8.1.2.3

External Loop Filter

The ICS1531 has software that allows for the selection of components for an internal loop filter for the pixel

clock PLL. (The internal loop filter has the advantage of not requiring any extra components.)

The ICS1531 also allows for the selection of components for an external loop filter for the pixel clock PLL.

If the external loop-filter option is used, do the following:

Place loop filter components as close as possible to the EXTFIL and XFILRET pins.

For loop filter components, typical values are as follows:

a. 6.8K

Ω for the series resistor

b. 3300 pF RF-type capacitor for the series capacitor

c. 33 pF for the shunt capacitor

ICS1531 Datasheet(PDF) 59 Page - Integrated Circuit Systems