Abstract: A mixed-voltage I/O buffer comprises an input circuit, an output circuit, an I/O pad, a pre-driver circuit coupled to the output circuit, two added coupled N-type transistors, and a dynamical gate-controlled circuit coupled to each gate of the two N-type transistors and the pre-driver circuit; one of the N-type transistors is coupled to the input circuit and the output circuit; the other N-type transistor and the dynamic gate-controlled circuit are together coupled to the I/O pad. Thereby, a mixed-voltage I/O buffer which receives 2×VDD-tolerant input signals and overcomes the hot-carrier degradation is realized.

Abstract: A mixed-voltage I/O buffer comprises an input circuit, an output circuit, an I/O pad, a pre-driver circuit coupled to the output circuit, two added coupled N-type transistors, and a dynamical gate-controlled circuit coupled to each gate of the two N-type transistors and the pre-driver circuit; one of the N-type transistors is coupled to the input circuit and the output circuit; the other N-type transistor and the dynamic gate-controlled circuit are together coupled to the I/O pad. Thereby, a mixed-voltage I/O buffer which receives 2×VDD-tolerant input signals and overcomes the hot-carrier degradation is realized.

Abstract: A circuit configured for providing hot-carrier effect protection, the circuit comprising a first transistor including a first terminal and a second terminal, the first terminal being coupled to a conductive pad, a switch device including a terminal coupled to the conductive pad, and a control circuit configured for keeping the switch at an off state during a receiving mode at which a signal of a first voltage level or a reference level is received at the conductive pad, keeping the switch at the off state during a transmitting mode from which a signal of a second voltage level or the reference level is transmitted at the conductive pad, and keeping the switch at an on state during a transition from the receiving mode when receiving a signal of the first voltage level to the transmitting mode when transmitting a signal having the reference voltage level, wherein during the transition a voltage across the first terminal and the second terminal of the first transistor is maintained at a level below approximately