Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

current mirror layout floorplan

Status
Not open for further replies.

diego.fan

Member level 3
Joined
Aug 31, 2015
Messages
56
Helped
0
Reputation
0
Reaction score
0
Trophy points
6
Activity points
532
Dear all,

I am new to analog layout. Here I'd like to design current mirror for ADC. A: m=8, b: m=1 , c: m=2, and then 4,8,16,32. Total number is 72. I plan to use common centroid.
the apsect ratio for unit is nearly 2:1. So 6:12 array is ok I think. But I have no idea how to make the floorplan.
Could you please give some suggestion how to place these units?
 

dick_freebird

Advanced Member level 5
Joined
Mar 4, 2008
Messages
7,036
Helped
2,055
Reputation
4,114
Reaction score
1,903
Trophy points
1,393
Location
USA
Activity points
56,397
I would not start with trying to floorplan the current mirror
by itself. Presumably there would be switches as well. The
unit cell then might be very different in aspect.

Why is "A" so many fingers, if it is the LSB?

A 6-bit (?) DAC should be pretty forgiving of mismatch
but you want to consider the big picture too, especially
presence of "heaters" that could impose a layout gradient.

It might be a good idea to intersperse the higher order
bits as 1X unit cells, (*N) throughout the "nest" so that
any such systematic error is averaged away.
 
Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top