Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
The switching threshold, Vm, is defined as the point where Vin = Vout. Switching threshold can be set by the ratio of relative driving strengths of the PMOS and NMOS transistors.
To move Vm upwards, a larger value of ratio is required, which means making the PMOS wider. Increasing the strength of the NMOS, on the other hand, moves the switching threshold closer to GND.
Why is switching threshold important???
The effect of changing the Wp/Wn ratio is to shift the transient region of the VTC. Increasing the width of the PMOS or the NMOS moves VM towards VDD or GND
respectively. This property can be very useful, as asymmetrical transfer characteristics are actually desirable in some designs.
The attached image shows one advantage of understanding Vm.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
