1 static cmos circuits. ankur agarwal 2 static cmos circuits in static cmos circuits with n inputs,...
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2Ankur Agarwal
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.
3Ankur Agarwal
Static complementary gate structure
Pull-up and pull-down networks
pull-upnetwork
Pull-downnetwork
VDD
VSS
outinputs
4Ankur Agarwal
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.
5Ankur Agarwal
Static CMOS Circuits
Static CMOS Logic Structure Logic Gates – Inverter, NAND and NOR Complex Structures AOI/OAI Structures Stick Diagrams Layouts
9Ankur Agarwal
Static CMOS Circuits
Static CMOS Logic Structure Logic Gates – Inverter, NAND and NOR Complex Structures AOI/OAI Structures Stick Diagrams Layouts
12Ankur Agarwal
Static CMOS Circuits
Static CMOS Logic Structure Logic Gates – Inverter, NAND and NOR Complex Structures AOI/OAI Structures Stick Diagrams Layouts
13Ankur Agarwal
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.
16Ankur Agarwal
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).
17Ankur Agarwal
Static CMOS Circuits
Static CMOS Logic Structure Logic Gates – Inverter, NAND and NOR Complex Structures AOI/OAI Structures Stick Diagrams Layouts
18Ankur Agarwal
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.
22Ankur Agarwal
Static CMOS Circuits
Static CMOS Logic Structure Logic Gates – Inverter, NAND and NOR Complex Structures AOI/OAI Structures Stick Diagrams Layouts