Nxp B.v.

Steffen Rode

Andreas Johannes Köllmann

Ulrich Moehlmann

Joachim Utzig

Joerg Syré

Ralf Gero Pilaski

A control system for a digitally controlled oscillator with temperature compensation including a loop detector providing an error value, filter circuitry providing a lower resolution digital value to the DCO to generate an output oscillation signal at a frequency within a lower resolution range, tracking circuitry holding a tracking digital value at a tracking offset from center of a tracking range while the lower resolution digital value is being determined, and then regulating the frequency within a higher resolution range by adjusting the tracking digital value, temperature compensation circuitry performing temperature compensation steps to maintain the tracking digital value between first and second thresholds within the predetermined tracking range, and a controller configured to set the first and second thresholds within a narrow range around the tracking offset during a standard operating mode, and to adjust one or both thresholds within a wide range during a critical operating mode.

System and method of controlling frequency of a digitally controlled oscillator with temperature compensation

A low-pass filter comprising: a filter input terminal; a filter output terminal; a filter FET configured to provide a resistance between the filter input terminal and the filter output terminal; a filter capacitor connected between the filter output terminal and a reference terminal; a bias FET configured to provide a bias voltage to the filter FET; a buffer connected between the filter input terminal and the bias FET, the buffer configured to source a bias current for the bias FET; and an offset voltage source configured to contribute to the bias voltage provided to the filter FET.

Low-pass filter

Level-shifting devices and methods allow signals to be passed between input/output (I/O) ports. One such device comprises a first output driver that drives a first I/O port in response to a first control signal. A second output driver drives a second I/O port in response to a second control signal. A first comparator circuit, responsive to a first reference voltage and a voltage at the first I/O port, generates the second control signal. A limiter circuit limits driving of the second I/O port, by the second driver, to a limiting voltage that responsive to a the second I/O port over a first range of signaling voltages, and constrained to a set value over a second range. A voltage reference generating circuit generates a second reference voltage. A second comparator circuit generates the first control signal in response to the second reference voltage and the second I/O port.

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Lüneburg, Germany

Steffen Rode