Abstract: A level shifter that shifts a voltage level of an input signal, where the input signal oscillates between a voltage level of a first supply voltage and ground. The level shifter includes a bias circuit, and first and second transistors. The bias circuit provides a bias voltage to the first transistor based on the first supply voltage. The second transistor is connected in series with the first transistor, and the series combination is connected between voltage supplies that provide second and third supply voltages. The second transistor receives the input signal at its gate, and a level-shifted version of the input signal is output at a node between the first and second transistors. The level-shifted signal oscillates between the voltage levels of the second and third supply voltages.

Abstract: A buffer circuit includes an inverter and a level-shifter. The inverter receives a first oscillating signal at a first voltage level and generates an inverted version of the first oscillating signal at a second voltage level. The level-shifter receives a second oscillating signal at a third voltage level, which has a phase difference from the first oscillating signal, and the inverted first oscillating signal, and generates a buffer output signal at a fourth voltage level.

Abstract: An integrated circuit with a testable power-on-reset (POR) circuit includes a voltage divider, an inverter, a level-shifter, a buffer and a flip-flop. The voltage divider receives a first supply voltage and generates a second supply voltage. The POR circuit receives the second supply voltage and generates a POR voltage signal when the second supply voltage exceeds a POR de-assertion threshold. The level-shifter receives the POR voltage signal and an inverted POR voltage signal from the inverter circuit and generates a level-shifted POR voltage signal at a voltage level of the first supply voltage. The buffer receives the level-shifted POR voltage signal and outputs a delayed level-shifted POR voltage signal. The flip-flop receives the first supply voltage as data input, the delayed level-shifted POR voltage signal as clock input, the level-shifted POR voltage signal as reset input, and outputs a voltage-monitor signal at the voltage level of the first supply voltage.

Abstract: An integrated circuit with a testable power-on-reset (POR) circuit includes a voltage divider, an inverter, a level-shifter, a buffer and a flip-flop. The voltage divider receives a first supply voltage and generates a second supply voltage. The POR circuit receives the second supply voltage and generates a POR voltage signal when the second supply voltage exceeds a POR de-assertion threshold. The level-shifter receives the POR voltage signal and an inverted POR voltage signal from the inverter circuit and generates a level-shifted POR voltage signal at a voltage level of the first supply voltage. The buffer receives the level-shifted POR voltage signal and outputs a delayed level-shifted POR voltage signal. The flip-flop receives the first supply voltage as data input, the delayed level-shifted POR voltage signal as clock input, the level-shifted POR voltage signal as reset input, and outputs a voltage-monitor signal at the voltage level of the first supply voltage.

Abstract: A duty cycle correction circuit for correcting the duty cycle of a clock signal generated by a clock generator includes a complementary buffer chain, level shifter circuits and a self-bias circuit. A clock signal with a distorted duty cycle and its complement are provided to the level shifter circuits. The level shifter circuits reduce the magnitude of voltage of the clock signal and the complement and generate level shifted signals. The level shifted signals are provided to a differential amplifier that generates a control signal indicating the magnitude of distortion in the duty cycle. The control signal is used to correct the duty cycle of the clock signal. The self-bias circuit is used to bias the differential amplifier.