# M54128 Earth Leakage Current Detector

Discussion in 'Electronics Homework Help' started by kevindd992002, Nov 24, 2010.

1. ### kevindd992002

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Nov 24, 2010
Can anyone please help me on what function does the M54128 Earth Leakage Current Detector do? I don't quite understand what it does based on the datasheet: http://pdf1.alldatasheet.com/datasheet-pdf/view/992/MITSUBISHI/M54128FP.html provided by Renesas/Mitsubishi.

I'm in the process of doing an Analysis and Simulation job in my company but I'm new to this. I have the circuit of the whole chip but am having a hard time analyzing it.

Any help would be much appreciated. Thanks.

2. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
Perhaps you need to assist us by telling us what you don't understand.

The first paragraph of the datasheet told me all I needed to know, but I guess you need to know more.

"The M54128 is a semiconductor integrated circuit designed for
high-speed type earth leakage breakers. This lC includes leakage
and abnormal voltage detecting functions"

3. ### kevindd992002

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Nov 24, 2010
Hmm. Well, I have the whole chip circuit with me (transistor level) and my task is to analyze how it works. I'm having a hard time though because it is my first time to analyze a whole chip circuit. I also have Cadence to simulate it.

Would it be possible for you guys to help me analyze each block of this IC?

What does earth-leakage exactly mean? Is this unwanted current that flows to ground?

4. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
I don't mean to sound obtuse, but are you a reenigne?

It sounds really odd that you've been employed to do this and you don't even know the function of the chip.

Have you tried this.

5. ### kevindd992002

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Nov 24, 2010
Yes, I am an Engineer. I was employed a year ago to do what a Fresh Graduate Engineer can do. I just finished my Advance Training with the company and they gave me a hard task right away which requires good analysis skills.

Anyway, I understand your concern. Thanks anyway.

6. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
(That was "reverse engineer" )

I guess if it's a test, we should move this to the homework help section.

If you read the FAQ you'll see that we won't give you answers, but we'll provide assistance.

So what do you understand, and what parts are you stuck on?

Earth leakage IS essentially what you describe, but that is not how it's typically measured -- it is measured indirectly.

7. ### kevindd992002

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Nov 24, 2010
Oh ok. Well, I started as a Reverse Engineer in the company Reverese Engineering the circuits of other competitor companies.

Well, actually I'm stuck on how to analyze the circuit that I have. Is it possible to send you, through PM, the circuit in PDF form?

8. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
There may be others far better able to help you. Can you post it publicly?

9. ### kevindd992002

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Nov 24, 2010
I don't think I can, that's the problem

10. ### kevindd992002

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Nov 24, 2010
Thanks for the info. Now I understand the function of the chip in a general sense. But I need to go in-depth looking into Transistor Level and to the expected input and output graphs presented in the datasheet.

Can you guys help me in analyzing how it works by explaining the graphs presented in page 6 of the datasheet of this chip?

11. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
They're just a series of sample inputs and the outputs you would expect.

Looking at them, the inputs are not trivial, and presumably there is a sample circuit in the datasheet somewhere that shows how one might connect this thing up (in any case you have one you can't show us)

Examine the circuit, and determine how various signals get to the input pins, and then compare the signals you would expect to get (under normal and fault conditions) to the ones in the datasheet. Under the conditions shown in the diagram, and described in the text, the outputs will change as specified. These will presumably be connected to something which will act to isolate the load.

Unless you can be more specific about what you don't understand, I can't help you short of spending hours doing the research that I suspect you are supposed to be doing. And I certainly don't feel like doing that for free or where you understand most of it anyway.

12. ### kevindd992002

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Nov 24, 2010
If I pay you for helping me, how much would the fee be?

13. ### kevindd992002

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Nov 24, 2010
bump! 10char.