ORCAD 555 Not Connected Pin

Thread Starter

iskberkan

Joined Oct 15, 2019
3
I want to leave pins 5 and 7 empty in my 555 timer circuit. But ORCAD gives the error.

ERROR(ORNET-1017): Unconnected pin, no FLOAT property or FLOAT = e X1 pin 'CONTROL'
ERROR(ORNET-1017): Unconnected pin, no FLOAT property or FLOAT = e X1 pin 'DISCHARGE'

I tried to mark it as not connected

What should I do?
 

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Thread Starter

iskberkan

Joined Oct 15, 2019
3
Welcome to AAC!

Put a capacitor on the control pin and a resistor to ground on the discharge pin.
I just want to use them as not connected I dont want to put something to them

And I can use 1N4001 but I don't have that diode on my library. Can I find its library file?
 

Analog Ground

Joined Apr 24, 2019
169
I see the error is from the PSpice netlister. Place a really, really large resistor to ground on each pin. Like 10 gigaohms. PSice probably wants something there. WIth the "no Connect" symbol, the circuit will pass schematic ERC but PSpice sometimes needs different stuff. Then, take them out if you need a real circuit.
 
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crutschow

Joined Mar 14, 2008
23,502
Really large resistors to ground, as AG suggested will have no effect on circuit operation but should eliminate the "Unconnected pin" error.
To make them less intrusive on the schematic you should be able to label the pins with a node label, and then put the resistors way off to the side with the same label to make he connections.

Edit: The Discharge pin the is just an open collector so can be connected to ground. You don't need the resistor for that.
 
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