pseudo nMOS

• Explain the detail about pseudo-nMOS gates with neat circuit diagram.

• Figure (a) shows a pseudo-nMOS inverter.
• The static load is built from a single pMOS transistor that has its gate grounded, so it is always ON.
• The beta ratio affects the shape of the transfer characteristics and the VOL of the inverter.
• Larger relative pMOS transistor size offer faster rise time, but less sharp transfer characteristics.
• Drawback: Pseudo-nMOS gates will not operate correctly if VOL >VIL of the receiving gate.

Figure shows several pseudo-nMOS logic gates.