Abstract: A first switch is operable to couple a start-up oscillator circuit to a first crystal pin during operation in a start-up mode and decouple the start-up oscillator circuit from the first crystal pin during operation in a normal mode, and a second switch is operable to couple the start-up oscillator circuit to a second crystal pin during operation in the start-up mode and decouple the start-up oscillator circuit from the second crystal pin during operation in the normal mode. A switched oscillator circuit is coupled to the startup oscillator during operation in the startup mode, and to the first and second crystal pins during operation in the start-up and normal modes. The switched oscillator circuit includes a sample and charge circuit which is configured to sample a direct current (DC) level of the first crystal pin and pre-charge a first coupling capacitor during operation in the startup mode.

Abstract: An integrated circuit device includes a level shifter circuit with a supply voltage rail to provide a supply voltage, a first pull-up circuit coupled between the supply voltage rail and a first node, a second pull-up circuit coupled between the supply voltage rail and a second node, a first switch including a first terminal coupled to the supply voltage rail, a second terminal coupled to the first node, and a control terminal coupled to the second node, and an inverter including an input terminal coupled to the first node, a voltage supply terminal coupled to the supply voltage, and an output terminal to provide an output voltage from the level shifter circuit.

Abstract: An integrated circuit (IC) is disclosed that includes a load circuit, and a voltage regulator circuit configured to provide a load voltage and a load current to the load circuit. The voltage regulator circuit can regulate the load voltage based on the load current.