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Body Effect In Cmos

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what is body effect in cmos?and how it will come and how it will reduced?
using Deep-Nwell , the body effect will be relieved
Do we have body effect in NMOS and PMOS individually ?????????????????????? If yes why and how? plz explain me
MTcmos stands for muliple threshold cmos it is mainly used in lowpower cmos to reduce the body effect in cmos
Hi can anyone tell me what is body effect in cmos? and what is meant by process in PVT conditions.. thanks in advance Check the below link for a brief description of process, voltage and temperature variations, ASIC-S
as far as i thought ,,body effects makes the threshold voltage of mosfet changes,,,so,,you must care when placing the mosfets in series that they still operate in saturation region and this depend to a great extend on the supply voltage ;as it shrinks down ,placing mosfets in series becomes more difficult check this also
hi guys, i am highly confuse that why do ground body pin of R, C & L in cmos device, but i know the reasion for actice device. but 4 passive i dont know the reasion. thanks In order to model the parasitic effect of these passive devices we need 3 terminals.... Now, the question is where do we want to connect
The body effect describes the changes in the threshold voltage by the change in VSB, the source-bulk voltage of the MOSFET. Since VSB influences the channel and hence the Threshold voltage (when it is not tied to the source), it can be thought of as a second gate, and is sometimes referred to as the "back gate"; the body (...)
The rectifier block uses a cascaded Dickson voltage multiplier circuit with multiple cascaded sections in order to convert the extremely low input voltage up to a potential suffi cient for operating cmos circuits. The bulk terminals of the PMOS transistors were tied to the gate and drain terminals (back-bias) to reduce the effective threshold vol
Hello all, In razavi's design of analog cmos integrated circuit, chapter 3, it states/shows that body effect decrease the output resistance. But I find it puzzling. I bias the NMOS source with a certain voltage, eg 0.3V. Setup 1: Base and Source are connected together to 0.3V bias. (No body effect) (...)
Hi, i have a question on the substrate connection for mixed signal circuit with p-sub lightly-dopled submicron cmos process. In my mixed block, we have seperate analog vdd/gnd and digital vdd/gnd for crosstalk reduction from digital part. I want to know the substrate connection, in my cicruit, i connected it to the analog gnd for which we beli
in real fact. all mos are 4 terminal devices. generally, there are 2 operating. (use nmos for example) 1. source and bulk(substrate or pwell) connect together. based on standard cmos process, there are not isolated P-well, so, bulk is directly connected to substrate together with source, without body effect. 2. bulk connects to lowest (...)
Yes! if Vbs>about 0.7v, you can see big current! just try it Hi butterfish, I guess you mean Vsd>~0.7V or Vbd>~0.7V, it is not Vbs>~0.7V.Here, the source and body shorted. Right? Yes, Vbs Vbd are same. as I know, in cmos tech, if the parasitic diode maybe triged, you'd better care about l
Hi, You would have to calculate the value of CLM from plots. Get the Id Vs Vds transfer characteristic for the MOS. Use the claculator function in ADE and chop the curve so that you have curve for saturation region. Extrapolate the lines to X axis and get the early volatge value. Inverse of that would give you CLM value. You can you equatio
we can not say which is beter or which is worse. In different situation, the answer is different. NMOS, the speed is better than PMOS,but PMOS can connect its bulk to its source which can avoid body effect. cmos has very small static current in digital logic circuit.
This is the circuit from the book. You can find all the images from For the circuit: It looks simple, works with very small Vgs-Vt due to resistor and the body effect of M5R. But you need to take into count the additional resistor noise. This is a simple one, hope it works for you.
Background: in layouts I have seen, usually dummy transistors are used when the source is connected to vdd or vss (PMOS or NMOS respectively). no body effect to worry about. Question: can you use dummy transistors when the PMOS source is connected to the well to remove the body effect (standard cmos (...)
hi, I read "Noise in Current-commutating cmos Mixers",in this paper, he said " it is worth noticing that no specific value of VT is needed to calculate the drain current of M1 and M2. The behavior ofthe switching pair is independent of VT and therefore to a first order is independent of the body effect and the common-mode LO voltage. This (...)
hi how these effect the performance of short channel and long channel? body effect, velocity saturation channel length modulation, hot carrier, cmos latch up effect. which effect is more prominent in short channel and why?
Hi everyone! I am reading a paper about a cmos LNA design. But I am not sure where the parameters' values of a cmos technology are from??? The process used in the paper is SMIC 0.18um RF cmos processes. The values cited are: (1) Gate oxide capacitance per unit area, Cox=9mF/(m^2); (2) body effect (...)
that is a psrr problem. look at increasing the psrr of your error amp by cascoding mirrors at the top and bottom of your diff pair. you also need to increase length way beyond 0.18u. not sure what gds would be in your process, but start at 1um and work up. I think somewhere around 2um for pmos and 5um for nmos will be a good guess but you need
One of the biggest. You could simulate your regular working analog cmos circuit is you modify each bulk. For PMOS and for NMOS make an additional series RC network. That mimic the floating body. But negleate the intercoupling. So you now that about 20-30% of the gate charge is put into substrate. Now also the sereis RC network react by controlli
you should think about the mos case (no base current). for example. a cmos voltage follower has 3v on the gate, so the source wants to rest at about 3v-Vth, maybe 2.2v or so. it's drain is connected to VDD, so it can just POUR current into the load to satisfy Vout=2.2v, therefore it is considered VERY low output impedance. only problem i
vt is a parameter of channel lenght in both pmos and nmos. this effect is called channel modulation effect considered with parameter lambda in the equation of cmos current equation. the best way to bypass this altering effect is to connect source to bulk of the mosfet. I think what you said should be (...)
Deep Nwell process is for RF purpose and needs extra mask and charge. But it offers better noise performance and the cascode device will not have body effect. Yibin.
i run hspice simulations recently, found that the threshold voltage is different for same device, i mean other than body effect, is there any other factors affect threshold voltage?
substrate are negative biased in Digital and most Analog Circuit, which meas the p-substrate is connected to VSS, and n-substrate is connected to VDD. however, this would could cause body effect when source are not connect to ground or supply.
hi the inverter acts like a weak buffer. with a reduced noise margin/ output voltage swing. H= Vdd -Vthn L= Vss + Vthp Reasono for this is body effect .. look it up in google. hth cheers rogger
Does the body effect limit the number of transistors that can be placed in series in a cmos gate at low frequencies. Please explain
Thank you.I got it. If we use PMOS instead of Nmos,How to connect the Pmos substrate ?Using floating Nwell? Any idea? As far as I known, there are at least 3 solutions: 1. Floating well, as you mentioned. 2. Dynamic substrate connection switching: At least 2 methods. Please refer to a. Pierre al, "
Here are some Questions......... Explain why & how a MOSFET works Draw Vds-Ids curve for a MOSFET. Now, show how this curve changes (a) with increasing Vgs (b) with increasing transistor width (c) considering Channel Length Modulation Explain the various MOSFET Capacitances & their significance Draw a cmos Inverter. Explain its
For two MOS transistors both of them should have source connected to well to prevent body effect. So if your substrate is p-type use PMOS, if substrate n-type use NMOS.
For the below two topology, I thought the linearity of (b) should be better than (a) for there is no body effect. However, the Specture simulation results show that (a) is better than (b). Anyone know why? Thanks
Thank you! timesmile! A:dnwpw is the model name, and you have to provide model info for spectre。 Q:i'm using chrt 0.18 rf pdk. and i can find the model of dnwpw_1p8 in the pdk models. but there is no model for dnwpw. how could this dnwpw be produced , A:The problem may be fixed by renaming that mod
I use 0.18um cmos process to design my opamp, and the telescopic structure with Nmos input transistor is used. The body of input transistor is connected to gnd, however i find that when i do corner simulation, the opamp works abnormally at some corner condition, and the problem comes from the large vth variation of the input Nmos. My common-mod
These are only three current mirrors: the linearization is achieved by using a wide M5R so its Vgs~Vth hence (neglecting body effect): the voltage across the resistor in the source of M5R is VinVCO-Vth and the branch current is (almost) linear I=(VinVCO-Vth)/R If you have problems mirroring accurately you should still be able to increase L to reduc
Substrate or body effect is discussed more detailed in paragraph 2.3 As an intuitive explanation, the subtrate acts as a second gate or backgate with it's own transconductance contribution. Because substrate and gate are both grounded AC-wise in the diode load configuration, the total transconductance and in return the source output c
So, what happens when the source/bulk of the NMOS transistor is biased positively? Will the bulk/body voltage rise, due to a current injection (majority carriers - holes) into the substrate, that will be picked up (extracted from the substrate) by the neighboring p+ contacts / guard rings? Do you want to account for that body voltage increase in
Has any body designed low noise Operational Amplifier? In which way you minimized the noise? What i mean is mainly based on cmos process.