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The idea of a sigma-delta modulator is to allow high resolution analog to digital conversion using simple circuit components by oversampling.
A first order modulator consists of three parts:
1. Integrator
2. 1-bit Comparator
3. 1-bit Feedback DAC
The integrator samples the input at a frequency...
An integrator and LPF are the same thing.
In order to understand the link between a low pass filter and an integrator, you must understand what integration means in this context.
Integration is, in this case, the average signal level. This is in fact the DC bias level. So an lpf will in fact...
I think the problems are quiescent current and SNR. Lets take your OR gate as an example.
If one input is tied high, the other could either be high or low or anywhere in between.
Lets say that a PMOS is open and charges the output to high. If the NMOS of the floating input opens wide enough to...
The layout of a transistor is dependant upon the application.
Lets talk CMOS for a second here.
Basiclly, there is no real diff between an analog and digital transistor.
Analog transistors deal with intermidiate voltage levels (small signal), and Digital transistors only deal in two basic...
You were thinking in the right direction.
These TG devices are so simple, yet can be used for many applications.
They can be used as stand-alone switches, like what you want.
You can also create whole logic gates with them.
And their original application - they were used in ethernet drivers to...
I get what you are saying, but the problem with non-technical terms is that it`s not always clear how they link in to the technical terms.
If I see the word overstress voltage on a datasheet, I`ll ask myself "Is this distructive? Does the device break down? What type of breakdown?"
and if it...
It is usually better to use a transmission gate as a switch.
Transmission gate - Wikipedia, the free encyclopedia
Unlike PMOS only or NMOS only switches, it can pass both a low and high voltage with out degrading it. (as well as negative and positive)
The NMOS passes the positive and PMOS the...
I never heard the term overstressed used, but there are several issues with overbiasing a MOS transistor.
One problem is hot electron injection - where electrons (or holes, but less common because of smaller mobility) travel very fast near the drain side and colide and become embedded in the...
Hi,
I am trying to layout a DRAM sense amplifier.
I already have a layout, but I`m sure it`s not optimal,
since I made it without a refrence. It barely fits within the cell pitch.
Can someone please point me to a refrence design or some other such resource?
Thank you!
Edit: I`ll elaborate on...
Ok... here we go :)
A thyristor is a NPN and PNP BJTs cross-couled.
As you can see from the image, this creates a NPNP block, where the base of the NPN is the collector of the PNP and vise versa.
The problem is that when the NPN and PNP BJTs are both conducting they keep each other in...
Hi,
I am working on a DRAM project and I laid out the dram array itself and only did a schematic of the decoders, drivers, etc.
I want to take the extracted circuit, with parasitic capacitors and resistors and get it back into s-edit in order to simulate the whole thing.
I can always merge...
Guard rings are used to prevent injection of charge carriers from the substrate to active devices through latchup.
Since latch up requires two cross-coupled BJTs (i.e. creating a parasitic thyristor), the idea of the guard rings is to provide
an alternative collector or emitter for the parasitic...
Hi,
In ADC selection, there are two major considerations.
First is the frequency and bandwidth of you input signal and second is the output resolution in bits.
For example, audio sampling requires low frequency (20Hz ~ 22KHz) and high resolution (usually 16bit or more) and then you can use a...
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