Presentation on theme: "1 Static CMOS Circuits. Ankur Agarwal 2 Static CMOS Circuits In Static CMOS circuits with n inputs, 2n transistors are needed. nMOS block is a dual of."— Presentation transcript:
1 Static CMOS Circuits
Ankur Agarwal 2 Static CMOS Circuits In Static CMOS circuits with n inputs, 2n transistors are needed. nMOS block is a dual of the pMOS block. What ever is in series in nMOS, appears in parallel in pMOS and vice versa. CMOS gates consume power only during the transition of inputs.
Ankur Agarwal 3 Static complementary gate structure Pull-up and pull-down networks pull-up network Pull-down network V DD V SS out inputs
Ankur Agarwal 4 Pull-up/pull-down network design Pull-up and pull-down networks are duals. To design one gate, first design one network, then compute dual to get other network.
Ankur Agarwal 13 AOI/OAI gates AOI = and/or/invert; OAI = or/and/invert. Implement larger functions. Pull-up and pull-down networks are compact: smaller area, higher speed than NAND/NOR network equivalents.
Ankur Agarwal 14 AOI example and or invert
Ankur Agarwal 15 Problems A A B C C B D D Y
Ankur Agarwal 16 Problems Design a CMOS circuit to implement the logic Y = A'B' + B'C + C'A Make a 2 input CMOS XOR gate to implement Y = A B. CMOS XOR and XNOR gates are similar. Just one of the input pairs (A and A' are reversed).
Ankur Agarwal 18 Stick diagrams A stick diagram is a cartoon of a layout. Does show all components/vias (except possibly tub ties), relative placement. Does not show exact placement, transistor sizes, wire lengths, wire widths, tub boundaries.