Prop Chip power input!! Why so many pins?

computer guy

Why is there multiple power pins on the propeller chip?
Do you have to use all of them?
On the proto board schematic there is a 1uf capacitor on one of the sets of pins, what is this for?

Thank you for your answers

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Check out my robot using the propeller robot.tmcp.com.au
If you offer cheap PCB fabrication, perl programming or any other helpful services please email me at.
anthonybmyatt@yahoo.com.au

Post Edited (computer guy) : 6/9/2007 9:51:09 AM GMT

Erik Friesen

The pins are all connected internally I think you only need to connect one but I like to have all connected just for the anyhow. The 1uf cap is a bypass and supply damper that Is absolutely essential to the proper operation of the chip as I have found out the hard way.

Paul Baker

Connect all of them together, while they are tied internally that connection has some resistance so for efficient power distribution connect them. In general connect two 0.1uF capacitors on opposite sides of the chip, the released ProtoBoard and DemoBoard have a single capacitor for space reasons, but a more robust design will have 2.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.

computer guy

Thank you both

I currently only have one and so that will have to do.
So the capacitor/s protect the chip from power spikes/drops?

My design is for a remote control adc-->prop-->xbee

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xbee-->prop-->motor controller-->motors.

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Control

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Robot

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so it shouldn't have to much load on the supply.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Check out my robot using the propeller robot.tmcp.com.au
If you offer cheap PCB fabrication, perl programming or any other helpful services please email me at.
anthonybmyatt@yahoo.com.au

Post Edited (computer guy) : 6/10/2007 12:21:42 AM GMT