URGENT: REGARDING DESIGN OF LDO

[ram_kumar_abc]

i need to design a low dropout regulator with the following specifications:
350um technology
Vdd: 2.5v
Vout: 1.8v
max load current: 10m A
load cap: 10p F
phase margin: 40 degrees atleast
PSRR: -40dB atleast

plz tell the w/l of the pass transistor from the above specifications mentioned that i need to use.
i am using a differential amplifier as the op-amp.

 

[dick_freebird]

You get that by simulation using the foundry's models.
Nobody can size it for you without that info and effort.

I recommend you work from a VDDmin, not VDDnom
input and give yourself at least a 2X load current margin
in design so that your 10mA is still well with regulation.
LDOs are difficult to stabilize when the pass transistor
is "buried" trying to swing RON to get current.

 

[ram_kumar_abc]

You get that by simulation using the foundry's models.
Nobody can size it for you without that info and effort.

I recommend you work from a VDDmin, not VDDnom
input and give yourself at least a 2X load current margin
in design so that your 10mA is still well with regulation.
LDOs are difficult to stabilize when the pass transistor
is "buried" trying to swing RON to get current.

i m using tsmcmm018 library

 

[ashish_chauhan]

i need to design a low dropout regulator with the following specifications:
350um technology
Vdd: 2.5v
Vout: 1.8v
max load current: 10m A
load cap: 10p F
phase margin: 40 degrees atleast
PSRR: -40dB atleast

plz tell the w/l of the pass transistor from the above specifications mentioned that i need to use.
i am using a differential amplifier as the op-amp.

In first snap you said it to be 0.35um... ?? now its 0.18um ... can you clear it ...

I can help you out on this design ...

 

[arghpok]

take a look at this paper:

If you need further information, msg me.

 

[nikakmal]

hi...
currently i work on layout for LDO
my problem now is to do layout for the capacitors and resistors
for ur info i'm using mentor graphics tool
i tried google but cant find any info on it.
anyone familiar with it?
help me plz....
thanks

 

[ashish_chauhan]

HI

I guess u are using IC station from mentor graphics ...

Its a really user friendly tool for layout.

every thing is controlled through graphical strokes.

for help press the right button on ur mouse and draw the shape of question mark with cursor... a sub window will open telling u about details on other strokes for cut copy paste stretch shrink rotate etc.

hope this helps