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Electronics => Beginners => Topic started by: kumar on August 28, 2014, 06:55:27 am

Title: Help required in field strength calculation.
Post by: kumar on August 28, 2014, 06:55:27 am

I have a signal generator which generates fast rise time pulses and I wish to couple them to IC pin using a E-field probe. Given below are the specs;

1) Voltage at the tip of the probe: 250V DC
2) Distance bet. IC and probe: 1cm.
3) Rise time of the signal: 1nS

What will be the field strength in terms of V/m ( will it be 25000?) and 88dBm ?

Can any of the experts please comment ?

Title: Re: Help required in field strength calculation.
Post by: T3sl4co1l on August 28, 2014, 12:19:47 pm

If the probe is large and planar, and the circuit is large and planar and grounded, the field should be around that, yes.  If you require knowing that it is 25 000 +/- 0.5 V/m, you'll have to do an awful lot more work.

What kind of a test is this?  MIL something?!  EMC is done up to 20 V/m or so.  You're practically doing ESD.  Except over an internal connection.

Tim

Title: Re: Help required in field strength calculation.
Post by: kumar on August 30, 2014, 07:31:28 am

Thanks for your reply.

I am using a DIY pin probe to troubleshoot the EFT/ESD issues in a microcontroller pcb. How much voltage you think is sufficient to locate them? Can you please specify separate values for EFT and ESD troubleshooting? I have made provision to reduce the voltage, so I will test the pcb as per your suggestion.