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azure_sky

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Could you let me know this type of circuit ?
Mar 28^th, 2013, 12:08am

I am reading some book but dosen't know a circuit.

1) What type of this Internal supply voltage regulator is ?
2) What is pros and cons for this circuit
� compared with simple 1-stage regulator which is usually used ?
3) What materials can I read for that ?

If you let me know that, it will be very helpful for me.

Thank you for reading this.
Have a nice day.

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loose-electron Senior Fellow Offline Best Design Tool = Capable Designers Posts: 1638 San Diego California	Re: Could you let me know this type of circuit ? Reply #1 - Apr 24^th, 2013, 8:48pm quick look -- its an OTA setup in unity gain feedback mode, without gain-phase compensation capacitor.
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azure_sky

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Re: Could you let me know this type of circuit ?
Reply #2 - Apr 24^th, 2013, 9:50pm

Thanks a lot.
Anyway, I knew this type is OTA like last week.
But I still don't know whether this type of voltage regulator is widely used.
Have you ever seen this at voltage regulator ?
Another question is if OTA diff. source is not controlled by current source,
what problem would happen ?
I saw some OTA diff. doesn't have current source.

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boe Community Fellow Offline Posts: 615	Re: Could you let me know this type of circuit ? Reply #3 - Apr 25^th, 2013, 9:13am Azure_sky, Quote: Another question is if OTA diff. source is not controlled by current source, what problem would happen ? I saw some OTA diff. doesn't have current source. In this case you usually want a circuit that is sufficiently close to a current source in the region of interest. - B O E
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loose-electron Senior Fellow Offline Best Design Tool = Capable Designers Posts: 1638 San Diego California	Re: Could you let me know this type of circuit ? Reply #4 - Apr 26^th, 2013, 10:22am LDO regulators can be configured in this manner. Again, there is no stability compensation shown.
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azure_sky New Member Offline Posts: 6	Re: Could you let me know this type of circuit ? Reply #5 - Apr 26^th, 2013, 7:11pm Even though the above circuit doesn't have the stability capacitor, the actual circuit have the stability capacitor and leakage source. The leakage source is connected to the output load. The leakage source is better than the stability capacitor according to the simulation. Is it true ?
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Horror Vacui

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Re: Could you let me know this type of circuit ?
Reply #6 - May 2^nd, 2013, 5:15am

azure_sky wrote on Apr 26^th, 2013, 7:11pm:

Even though the above circuit doesn't have the stability capacitor,
the actual circuit have the stability capacitor and leakage source.
The leakage source is connected to the output load.
The leakage source is better than the stability capacitor
according to the simulation.
Is it true ?

What do you mean by leakage source? This term sounds strange to me.
The picture is just showing the architecture of the amp. it might be possible that you need a cap, and also in the real life the output would be cascoded for higher gain. The pictures in the books are not showing the final circuit, they just show the circuit's structure and everything which is not necessary to understand the circuits operation is left out for the sake simplicity and better understanding of the fundamentals.

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azure_sky

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Re: Could you let me know this type of circuit ?
Reply #7 - May 2^nd, 2013, 8:18am

The circuit which I mentioned as leakage source is the static current load.
I have the circuit similar to the above circuit.
It had the compensation capacitor and the static current load,
but doesn't have the cascode for the higher gain.
So I wonder whether the cicuit is a good circuit and
the necessity for changing this circuit to another type of circuit.

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loose-electron

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Re: Could you let me know this type of circuit ?
Reply #8 - May 2^nd, 2013, 11:46am

azure_sky wrote on May 2^nd, 2013, 8:18am:

The circuit which I mentioned as leakage source is the static current load.
I have the circuit similar to the above circuit.
It had the compensation capacitor and the static current load,
but doesn't have the cascode for the higher gain.
So I wonder whether the cicuit is a good circuit and
the necessity for changing this circuit to another type of circuit.

The question is vague, what are you trying to do?

Answer that and then can determine if good or bad

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Contract IC-PCB-System Design - Analog, Mixed Signal, RF & Medical

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azure_sky New Member Offline Posts: 6	Re: Could you let me know this type of circuit ? Reply #9 - May 2^nd, 2013, 5:44pm As I mentioned at the above main article, I'd like to change this type regulator to the simple diff. amp type regulator if the latter is better than the former. So I wonder which one I select.
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