New answers tagged cmos
4
It is generally a good idea to include a gate resistor to avoid ringing. Ringing (parasitic oscillation) is caused by the gate capacitance in series with the connecting wire's inductance and can cause the transistor to dissipate excessive power because it doesn't turn on quickly enough and hence the current through drain/source in combination with the ...
2
You do not need a base resistor. Not only do MOSFETs not have bases (they have gates), but the gate is (very) high impedance. Except when the MOSFET is changing states, the gate current is essentially zero.
It is common practice to place a resistor (the value isn't terribly critical -- anything between \$ 1k\Omega \$ and \$1M\Omega\$ will do) from the gate ...
1
Compatibility could refer to any of a number to different and varying issues but mostly refers to fab poisoning. In general the techniques and equipment used will be similar, only sometimes is a certain piece of equipment not available.
CMOS compatible refers more to the potential to "poison" the fab. Meaning that you have introduced a material into the ...
3
Power on reset circuits are used to trigger the point that a microprocessor can start executing its code without the need to worry about whether the voltage supplies are within their prescribed limits for successful operation.
The basic principle is based on charging a capacitor. The capacitor charges at a rate intentionally slower than what the power ...
2
Rarely does a chip startup need to be overly precise as the design will likely be simulated/designed for a range of temperatures, Voltages and process corners. What is more likely is the need for certain ranges in dV/dt voltage ramps to ensure the proper sequencing of states during the initial start up phase, but typically there are brown out detectors and ...
1
In order to design the circuit you consider two conditions. The first condition is the DC analysis. This is where you are mainly interested in setting the gate voltage so that the drain voltage is roughly at midpoint on the supply. In your example, midpoint is somewhere close to 6V because you have a 12V supply.
Why is it 6V? When you have 6V DC on the ...
1
This is called small signal analysis and is predicated upon an assumption that your small signal doesn't disturb the operating point too much so that the assumptions still hold.
What is key is that that you use the bias points to determine the \$g_m\$ (which will depends upon \$I_{DS}\$ which depends upon \$V_{gs}\$ etc.).
-1
MAX3232 exactly for your purpose. uses charge pump caps to get higher voltage
0
cdwilson, how thin can you go? Most board shops dont allow trace widths < 5 mils. Unless you're routing very long traces (>12"), I wouldnt worry about making the space between traces whatever the pcb shop says is their minimum. Thats gonna as tight as you'll be able to pack in the traces. However if you decide to go with the min trace width and min ...
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