Low current OpAMP/Regulator design

Status
Not open for further replies.
P

PatrickLee

Newbie level 4
Joined
Sep 2, 2005
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,344
depletion mos voltage reference

Is anyone has experience on designing bandgap reference or op-amp with operating current around 1uA or below?

What are the limitations involved and what should be observe ?
 

opamp regulator

the noise and setting time
 

Startup time is the main issue. Then lot of nodes become really high impedance and gets coupled to power/ground noise. This makes BG outputs to completely die. So need to take care of couplings. Then area is bigger for low power bandgap due to large resistors required for this.
 

With the BG structure described in Allen and Holberg, the resistor are in the range of over 5 MOhm in order to get a BG reference with lower than 1 uA current.
Is this approach feasible ?
Is there any ways to subsitute the high value resistor with smaller area ?
 

The best method is depletion mos voltage reference.
 

What is meant by "delpetion mos voltage reference"?

Substitue the resistor with delpetion MOS ?
 

with 1uA, you can bias your transistors in weak inversion to get high gm/I and low voltage offset. but the speed is low which is normally the limitation
 

low power opamp or current mirror you have to bias the mos in weak region than strong region.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…