2 results about "Current controlled oscillator" patented technology

A process monitoring technique for transistor-based devices is described. The technique utilizes an oscillator-based sensor and operates in two phases: calibration and measurement. During calibration, the oscillator is supplied with a calibration current, and the resulting frequency is measured. A correction factor is calculated by dividing the measured frequency by the calibration current. In the measurement phase, the oscillator is supplied with current from the device under test, such as a memory cell or other transistor-based structure. The frequency produced is measured and divided by the correction factor to determine the current from the device. This approach yields a current value independent of parasitic resistances and capacitances in the oscillator. The technique enables accurate process variation monitoring with little modification to existing circuit structures and is applicable to various transistor-based devices, including SRAM cells, logic circuits, and analog circuits.

A system comprises an oscillator circuit that includes first and second tuning banks and a current-controlled oscillator. The first tuning bank is connected to a voltage node and receives the tuning signal, generates a voltage drop at the voltage node that corresponds to the tuning signal, and allows the flow of a first current therethrough that varies with the voltage drop. The second tuning bank is connected to the voltage node and receives an oscillator input signal and regulates a second current that flows therethrough in response to a voltage difference between the voltage drop and the oscillator input signal. The current-controlled oscillator receives a third current that is a sum of the first and second currents and fine-tunes an oscillator output signal based on the third current to track a frequency of a reference input signal.