aryajur
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pass transistor layout
I have attached 2 Layout configurations below. The red rectangle is the pass transistor and the blue rectangles are the Pads that contact the transistor source and drain fingers. The Dark Green area marks the top metal connected to the IN pads and the light green area marks the top metal connected to the OUT pads.
So which configuration of the top metal will be better? In config 1 the IN connected metal is thickest on the left side where it connects to the IN pads, but in config 2 it is thickest on the opposite side. Config 2 seems better if we think that since the metal is covering the pads so we have a wide metal in the pad area of the transistor and also wide metal on the side where the PAD is not there thus a more even width distribution of the top metal. In config 1 we have a thick metal in the pad area but a thin metal width on the area where the pads are not present.
I have attached 2 Layout configurations below. The red rectangle is the pass transistor and the blue rectangles are the Pads that contact the transistor source and drain fingers. The Dark Green area marks the top metal connected to the IN pads and the light green area marks the top metal connected to the OUT pads.
So which configuration of the top metal will be better? In config 1 the IN connected metal is thickest on the left side where it connects to the IN pads, but in config 2 it is thickest on the opposite side. Config 2 seems better if we think that since the metal is covering the pads so we have a wide metal in the pad area of the transistor and also wide metal on the side where the PAD is not there thus a more even width distribution of the top metal. In config 1 we have a thick metal in the pad area but a thin metal width on the area where the pads are not present.