| abstract |
A ring oscillator for detecting characteristic deterioration of a MOSFET is desired to be highly sensitive to NBTI deterioration or PBTI deterioration. A semiconductor device includes a ring oscillator and a delay detection circuit that detects a delay of a gate circuit based on an oscillation frequency of the ring oscillator. The ring oscillator has an input terminal for inputting an oscillation control signal, an output terminal for outputting an oscillation signal, a first input terminal connected to the input terminal, and a second input terminal connected to a terminal different from the input terminal An oscillation control gate circuit, a NAND circuit, and a NOR circuit. The NAND circuit and the NOR circuit are alternately connected in cascade, a plurality of inputs of the NAND circuit are connected, a plurality of inputs of the NOR circuit are connected, and a driving force of the NAND circuit and a driving force of the NOR circuit Is different. [Selection] Figure 4 |