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Nmos Inverter Layout

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16 Threads found on Nmos Inverter Layout
hello, i'm new with analog design with this pack of ibm and i have a trouble that i can't solve. I'm doing a simple inverter with Mentor Graphics in this technology and in the schematic i put the subc for the nmos, but i don't have a contact for the substrate of the PMOS, and when i do the DRC, this is an error message that shows up, i prove to
Designed one layout of CMOS inverter in L'edit software. Its extract file showed three Parasitic Capacitors and the last capacitor was between the VSS and 0 (VSS = Drain of nmos). Wanted to know how to use this capacitor which is between VSS and GND??
The right one (nmos with 2 fingers, too) is the better layout: less input gate series resistance, less parasitic output capacitance, and saves real estate area.
hi, You can find the minimum width of pmos and nmos by designing a inverter whose switching point is middle of your supply voltage and Make sure the width of the Mos has atleast two contacts in the layout... it is useful for the designing.. Thanks...
Actually this error message is rather self-explaining: you need a p+ diffusion area ("Psub tap") close (<= 10.0 um) to the n+ source (and drain) areas of the nmos. Connect this Psub tap via contact and metal_1 to GND (like your nmos source, probably). See e.g. this inverter layout from a Cādence tutorial: 97294
Hello, I have circuit in CADENCE, in which I use a cmos inverter with 5 finger for pmos and 4 finger for nmos. I have another PMOS in the same design with 10 fingers. When I do the LVS, it fails because it can not relate the inverter in the layout to the inverter in the schematic. and says the instance is (...)
"Multiple Stamped Connections" means that you have multiple nets connecting to the bulk. In your case, I believe, the nmos transistor does not have a bulk connection.
Sure I cant post links yet so this is just a filler ---------- Post added at 21:27 ---------- Previous post was at 21:23 ---------- So I found this article on the internet Connecting PMOS and nmos towards the bottom it talks about a "P-substrate contact"
Hi All, If I have a inverter connected directly my pad, then how do I layout this inverter protecting from ESD and Latch Up issues ? please explain in details. consider for example W/L of PMOS = 200/0.5 amd W/L of nmos = 75/0.5. -- warm regards, krrao.
Hi, The easiest way is to open Virtuoso from Composer window. Tools-> Design Synthesis -> layout XL. Then from layout XL got to Design -> Gen from source. Lets say you have an inverter in the Schematic window. After you do Gen from source it will place 1 nmos and 1 PMOS and all i/o pins. Press shift f to get the (...)
i have designed an inverter (5 pmos, 2 nmos), and their gates connect together. but when i run calibre PEX, it says that, there are two gates not connected, floating gate, but i connect them together indeed, and LVS is OK. why? it is very strange, has anyone met this problem before? pls help me. thanks.
they won't work.... Vgs needs to have a certain positive value for the nmos to work...and if the transistor drain is connected to Vdd and its source is connected to the output, then the voltage on the source is unknown and the value of Vgs isn't necessarily the voltage needed for the correct operation of the it won't work :) same
I've seen one 1.2um project inverter nmos: w/l=1.1um/1.2um pmos: w/l=2.2um/1.2um
Hi, I am layout the output buffer whcih drive a ~10pF load cap at 80MHz. The output buffer size is for PMOS 12/0.6,m=40 and for nmos,it is 12/0.6, m=20. The max size of the W in my process is limited to Wmax=20. Anyone can see any risk for selction the multiple number is high to 40 for PMOS and 20 for nmos? Thanks in adavnce for (...)
Hi, Our ciruit used a big inveretr as buffer to drive a ~10pF load cap to CMOS level. The working frequency is 155Mbps.The size of the inveretr is for PMOS 12/0.6,m=40 and for nmos,it is 12/0.6mm=20. The process is 0.6um CMOS. We feel puzzled for how to draw it in layout. There are two main problems. One is how to place the input and output
I have a question to lay, because I don't know how full custom EDA tools recognise devices... when I design a inverter or a nmos layout, how IC cadence system recognise that my layout is a inverter or a nmos and how IC tool assign device characteristics, parassitic parameters, etc... (...)