High Speed Circuits

Question 1

What is high-speed technique #1?

Answer 1

Choose the diffusion node with the smallest area as the output node, to reduce capacitance of output signal.

Question 2

What is high-speed technique #2?

Answer 2

Use metal conductors for long and heavily loaded lines, to reduce parasitic wiring resistance.

Question 3

What is high-speed technique #3?

Answer 3

Use upper metal layers for long connections and/or high frequency signals such as clock lines. Thicker layers (less resistance) and further away (less capacitance).

Question 4

What is high-speed technique #4?

Answer 4

Use recommended widths of power / ground rails, to minimize IR drop.

Question 5

What is high-speed technique #5?

Answer 5

Wide metals for clock lines, since they’re heavily loaded and high speed

Question 6

What is high-speed technique #6?

Answer 6

Shield clock lines and other high-frequency lines to confine noise emission, thereby avoiding “crosstalk”

Question 7

What is high-speed technique #7?

Answer 7

Use a “balanced clock-tree” routing scheme to reduce both clock delay and clock skew.

Question 8

What is high-speed technique #8?

Answer 8

Plenty of contacts on source and drains. Plenty of contacts and vias.

Question 9

What is high-speed technique #9?

Answer 9

Use guard rings and butting taps.

Question 10

What is high-speed technique #10?

Answer 10

Input order for transistors in series: the latest signal should be closest to the output node.