Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


This design is for??

Views: 2266

#48670

This design is for?? | 27 March, 2007

Hi, sorry but i am new in this. This is a Freescale SRB ZigBee node schematic design.

1)Can anyone help me identify what is the use of the 10K ohm resistor (R115) used? Seems that there is some advantages and disadvantages of using it. The source is a connector from USB_power and feed to 2 diodes before going to a voltage regulator.

[IMG]http://aycu09.webshots.com/image/13128/2004194465209364812_rs.jpg[/IMG]

2)Why is two capacitor (C116 & C117) used in this case instead of one? Is this an 'extra safe' design?

[IMG]http://aycu03.webshots.com/image/12482/2000441053167699547_rs.jpg[/IMG]

Where can i find more information about such designing tips used?

Thanks!

reply »

Tom

#48928

This design is for?? | 8 April, 2007

1. Resistor is used to provide ground return for diodes. Diodes have a capacitance and with them floating a charge can build up.

2. They each perform different functions. The 100N is used for HF filtering. The 1uf is used for LF filtering and current boosting when needed.

Design Tips? You may have to find some books

reply »

SMT Spare Parts and Feeders

ICT Total SMT line Provider