Phase margin is an important specification for closed loop systems and in op amps specifically. It can be difficult to understand intuitively. A recent post by Signal Processing Group provides a way to understand this specification. Please visit our website and select the “complementary” tab and then access the article on phase margin.
The product of the MOSFET transconductance ( KP/KN) and the aspect ratio ( W/L) is being labeled as the gain of the operating MOSFET. A simple calculator to do this is now available for a first order estimate on the Signal Processing Group website. Please check the “complementary” item menu in the SPG website for this and other items of interest.
In analog CMOS design the MOSFET is usually operated in saturation where the IDS – VDS curves are close to being flat. The slight slope leads to the definition of the channel length modulation parameter. A simple calculator has been released by Signal Processing Group to allow a first order calculation of this current as starting points of a design. Please visit the SPG website and look under the “calculators” menu item.
The body effect parameter comes into play for analog CMOS design when the source and substrate is not connected to the same node but have a reverse bias voltage across them. It affects the threshold voltage of the MOSFET and thereby is critical to the operation of the MOSFET. Signal Processing Group has released a simple calculator to evaluate this parameter given the substrate doping and the gate capacitance. The solution is based on a first order model and is primarily useful as a starting point for design. Please visit the Signal Processing Group website for this and other very useful information.
The surface potential in a strongly inverted MOSFET is one of the component parameters in the calculation of current in strong inversion ( or for that matter in weak inversion) of a MOSFET. It is used in the calculation of the threshold voltage. It depends strongly on the surface concentration of the MOSFET and the intrinsic concentration of the substrate ( ni). Signal Processing Group has released a simple calculator for first order calculations of this important quantity. Please visit the Signal Processing Group website and look under the ” calculators” menu item to find this calculator as well as many others.
The gm of a MOSFET in saturation ( in the strong inversion region) is an important parameter for analog CMOS design. The hand calculation value is easy to calculate using a simple calculator such as the one that Signal Processing Group has released on their website. Please visit the Signal Processing Group website and look under the “calculators” menu.
The effective gate voltage of a MOSFET in strong inversion is a critical design parameter for MOSFET analog and digital design. It provides the designer with a simple way to do hand calculations of the current and size of the device. A simple calculator has been released by Signal Processing Group that may be used to do this calculation as a starting point for more fine tuning by an advanced circuit simulator. Please visit our website and search under the “calculators” menu.
COX is a critical design parameter for CMOS design. It is the capacitance generated by the gate oxide capacitance and is a parameter that generates the transconductance gain number for the MOSFET. A calculator for this parameter was posted by the team at Signal Processing Group Inc. to facilitate the designer’s task of designing CMOS circuits. It can be found under the “calculators” menu item on the SPG website.