US Patent 11342915 Cold spare tolerant radiation hardened generic level shifter circuit

A level shifting circuit, the circuit comprising a VL input; an I/O VL; a VCC input; an I/O VCC; a first pull-up resistor disposed between the VL input and I/O VL; a second pull-up resistor disposed between the VCC input and I/O VCC; a first pull-up assist circuit comprising a first pull-up assist p-channel MOSFET having a source/body, drain, and gate, the source/body and drain being connected to VL and I/O VL; a second pull-up assist circuit comprising a second pull-up assist p-channel MOSFET having a source/body, drain, and gate, the source/body and drain being connected to VCC and I/O VCC, respectively; a pass-gate n-channel MOSFET in operative communication with I/O VL, I/O VCC, and VL, the pass-gate being configured to reduce the voltage level of a signal driven from I/O VCC to the voltage level of I/O VL; and a one-shot circuit configured to detect a I/O VL or I/O VCC transition from a low state to a high state, to produce a pulse in response thereto, and to communicate that pulse to the gates of the first and second pull-up assist p-channel MOSFETs, wherein the second pull-up resistor is configured to increase the voltage level of a signal driven from I/O VL to the voltage level of I/O VCC.