LDO design procedure help

[rvidya]

Hi all...

I'm trying to design an LDO with both NMOS and PMOS pass elements. Can anyone please suggest any link/ book which talks about the design procedure of the same? How to decide the gain of the error amplifier, pass transistor width etc.? Also for NMOS pass element, we'll need to use charge pump right?

Thanks..!!!

 

[ZekeR]

Yes, if you use an NMOS you will need to use a charge pump. Assuming you have already built the circuitry overhead to power an NMOS, why would you desire to add a PMOS in addition? It seems unnecessary.

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Yes, if you use an NMOS you will need to use a charge pump. Assuming you have already built the circuitry overhead to power an NMOS, why would you desire to add a PMOS in addition? It seems unnecessary.

 

[rvidya]

Sorry...I didnt mean to use NMOS and PMOS together...I need to design an LDO with PMOS as pass transistor and another LDO with NMOS as pass transistor...

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Sorry...I didnt mean to use NMOS and PMOS together...I need to design an LDO with PMOS as pass transistor and another LDO with NMOS as pass transistor...

 

[ducvilla]

Hi rvidya,

I have already designed LDO, and as far as i know, the tutorial: Low drop-out(LDO) linear regulators: design considerations and trends for high power supply rejection (PSR), the author is: Edgar Sanchez - TMU is very helpful.

Another useful document is the book: "Analog IC Design with Low Dropout Regulators (LDOs)" author: Rincon Mora.
https://users.ece.gatech.edu/rincon-mora//publicat/books/ana-ldo/

Hope this help!

 

[rvidya]

Thanks a lot for the help..I jus got a copy of the book suggested...

 

[butchi]

Hi rvidya,

You can visit course ELEN 607, here the LDO project of this course, it's very detail:

B.R,