SP506CF datasheet(19/30 Pages) SIPEX

19 / 30 page

SP505/6/7APN/03

SP505, SP506, SP507 Application Note

Another alternative is using conductive-EMI

enhanced connectors that have ferrite cores around

the pins. AMP and other connector manufacturers

also offer specially built conductive-EMI filtered

connectors. The AMPLIMITE™ Subminiature D-Sub

connectors have a DB-15 through DB-37 connectors

as well as high density connectors that have a

distributed element filter using lossy ferrite core or

a capacitive filter assembled around each pin. These

connectors have right-angle, vertical, or stacked

versions that all have the same PCB footprint as the

regular non-filtered connectors.

Various filter types are available with these connectors.

Once the serial protocol is defined and the operating

frequency known, a filter type can be chosen using

its 3dB point, which can be used as the maximum

frequency. The filter will begin filtering above this

3dB point. One should be careful when using the

capacitive filters as they will affect the overall AC

performance of the driver, specifically driver rise/

fall time. Details of the AMPLIMITE™ filtered

connectors can be found in AMP's home page

(http://connect.amp.com.), which includes insertion

loss (dB) versus frequency.

Figure 31. Common-Mode Choke Circuit with Drivers

AMPLIMITE™ is a trademark of AMP Inc.

TxD

TXCE

SP506CF Datasheet(PDF) 19 Page - Sipex Corporation