Breadboarding With CMOS Devices

Delta Prime

Joined Nov 15, 2019
991
Hello there
:)
All MOS devices have insulated gates that are subject to voltage breakdown
When lead-straightening or hand-soldering is required, provide ground straps for the apparatus used and be sure that soldering ties are grounded.
Do not exceed the maximum ratings specified in the data sheet.
All unused device inputs should be connected to VDD or Vss All low-impedance equipment (pulse generators, etc) should be connected to CMOS inputs only after the device is energized
 

dl324

Joined Mar 30, 2015
12,871
As a novice, you should wear a grounding strap when handling the devices. An ESD mat will provide additional safety. Manufacturers include ESD protection that's tested at a couple thousand volts. You can build up much more than that.

Discrete MOSFETs rarely have ESD protection and as little as 20V can damage devices. If you're lucky, the devices will die outright. If you're unlucky, they'll sort of work and then die prematurely.

When you're not grounded, you should avoid touching device leads. Handle them with ESD tweezers.
 

Thread Starter

radioshack5209

Joined Nov 25, 2020
68
Hello there
:)
All MOS devices have insulated gates that are subject to voltage breakdown
When lead-straightening or hand-soldering is required, provide ground straps for the apparatus used and be sure that soldering ties are grounded.
Do not exceed the maximum ratings specified in the data sheet.
All unused device inputs should be connected to VDD or Vss All low-impedance equipment (pulse generators, etc) should be connected to CMOS inputs only after the device is energized
What would you use as a ground? A metal table leg, the screw on a receptacle plate? Thanks guys.
 
Last edited:

crutschow

Joined Mar 14, 2008
27,175
An important thing is to work on an antistatic mat and connect your wriststrap to it before you touch any of the CMOS devices or circuitry.
You always want to keep you body at the same potential as the devices.
 

Delta Prime

Joined Nov 15, 2019
991
What would you use as a ground? A metal table leg, the screw on a receptacle plate?
I would only be repeating what my superiors have already mentioned. Soooo I will mix it up and make it my own.Think of ESD
(Electrostatic discharge) the same as you would walk across a carpet in your socks you come across a closed door you extend your arm and reach for the doorknob and you get a shock, it's exactly what happens if you don't use ESD protection. the anti-static mat and wrist strap actually dissipates or slows down that static shock by placing a one mega ohm resistor in series from both your wrist strap and anti-static mat to ground. I hope that makes sense to you. Electronics is about having fun and after you master the dissipation of potential difference of energy I'll show you how to make very large sparks on purpose. :)
 

Thread Starter

radioshack5209

Joined Nov 25, 2020
68
I would only be repeating what my superiors have already mentioned. Soooo I will mix it up and make it my own.Think of ESD
(Electrostatic discharge) the same as you would walk across a carpet in your socks you come across a closed door you extend your arm and reach for the doorknob and you get a shock, it's exactly what happens if you don't use ESD protection. the anti-static mat and wrist strap actually dissipates or slows down that static shock by placing a one mega ohm resistor in series from both your wrist strap and anti-static mat to ground. I hope that makes sense to you. Electronics is about having fun and after you master the dissipation of potential difference of energy I'll show you how to make very large sparks on purpose. :)
Thanks to all of you!
 

michael8

Joined Jan 11, 2015
137
The one mega ohm resistor is there mostly to protect the person. If you are directly connected to ground and you happen to touch
a live circuit (like a power line) the current flow would be high. The one mega ohm resistor limits the current flow in this case.
while allowing static charges to bleed off -- they may be higher voltage than the power line but static charges are limited by
the charge on the capacitance which is charged with the static.
 
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