A physically unclonable function device includes a set of diode-connected MOS transistors having a random distribution of respective threshold voltages. A first circuit is configured to impose, on each first transistor, a fixed respective gate voltage regardless of the value of a current flowing in this first transistor. A second circuit is configured to impose, on each second transistor, a fixed respective gate voltage regardless of the value of a current flowing in this second transistor. A current mirror stage is coupled between the first circuit and the second circuit and is configured to deliver the reference current from a sum of the currents flowing in the first transistors. A comparator is configured to deliver a signal whose level depends on a comparison between a first current obtained from a reference current based on the first transistors and a second current of the second transistors.

A physically unclonable function device includes a set of diode-connected MOS transistors having a random distribution of respective threshold voltages. A first circuit is configured to impose, on each first transistor, a fixed respective gate voltage regardless of the value of a current flowing in this first transistor. A second circuit is configured to impose, on each second transistor, a fixed respective gate voltage regardless of the value of a current flowing in this second transistor. A current mirror stage is coupled between the first circuit and the second circuit and is configured to deliver the reference current from a sum of the currents flowing in the first transistors. A comparator is configured to deliver a signal whose level depends on a comparison between a first current obtained from a reference current based on the first transistors and a second current of the second transistors.

An electronic device may include a transceiver with mixer circuitry that up-converts or down-converts signals based on a voltage-controlled oscillator (VCO) signal. The transceiver circuitry may include first, second, third, and fourth VCOs. Each VCO may include a VCO core that receives a control voltage and an inductor coupled to the VCO core. Fixed linear capacitors may be coupled between the VCO cores. A switching network may be coupled between the VCOs. Control circuitry may place the VCO circuitry in one of four different operating modes and may switch between the operating modes to selectively control current direction in each of the inductors. The VCO circuitry may generate the VCO signal within a respective frequency range in each of the operating modes. The VCO circuitry may exhibit a relatively wide frequency range across all of the operating modes while introducing minimal phase noise to the system.

A method for multiphase frequency to voltage conversion includes generating for each cycle of an oscillating input, one of a plurality of non-overlapping clocks. A respective voltage in proportion to an input frequency of the oscillating input, is generated in response to each of the non-overlapping clocks, with a respective one of a plurality of frequency to voltage converters. Each of the respective voltages is summated to generate a voltage sum proportional to the input frequency.

A physically unclonable function device includes a set of diode-connected MOS transistors having a random distribution of respective threshold voltages. A first circuit is configured to impose, on each first transistor, a fixed respective gate voltage regardless of the value of a current flowing in this first transistor. A second circuit is configured to impose, on each second transistor, a fixed respective gate voltage regardless of the value of a current flowing in this second transistor. A current mirror stage is coupled between the first circuit and the second circuit and is configured to deliver the reference current from a sum of the currents flowing in the first transistors. A comparator is configured to deliver a signal whose level depends on a comparison between a first current obtained from a reference current based on the first transistors and a second current of the second transistors.

A physically unclonable function device includes a set of diode-connected MOS transistors having a random distribution of respective threshold voltages. A first circuit is configured to impose, on each first transistor, a fixed respective gate voltage regardless of the value of a current flowing in this first transistor. A second circuit is configured to impose, on each second transistor, a fixed respective gate voltage regardless of the value of a current flowing in this second transistor. A current mirror stage is coupled between the first circuit and the second circuit and is configured to deliver the reference current from a sum of the currents flowing in the first transistors. A comparator is configured to deliver a signal whose level depends on a comparison between a first current obtained from a reference current based on the first transistors and a second current of the second transistors.

A phase locked loop (PLL) comprises: a reference oscillator to generate a reference clock having a reference frequency; a voltage controlled oscillator (VCO) to generate a VCO clock having a VCO frequency controlled in response to a control signal applied to the VCO; a first integrator to integrate the reference frequency into a first ramp slope; a second integrator to integrate the VCO frequency into a second ramp slope; and a slope comparator to generate a slope difference between the first ramp slope and the second ramp slope and that is conveyed by the control signal, such that the control signal is configured to drive the VCO frequency toward the reference frequency to minimize the slope difference and frequency lock the VCO frequency to the reference frequency.

A phase locked loop (PLL) comprises: a reference oscillator to generate a reference clock having a reference frequency; a voltage controlled oscillator (VCO) to generate a VCO clock having a VCO frequency controlled in response to a control signal applied to the VCO; a first integrator to integrate the reference frequency into a first ramp slope; a second integrator to integrate the VCO frequency into a second ramp slope; and a slope comparator to generate a slope difference between the first ramp slope and the second ramp slope and that is conveyed by the control signal, such that the control signal is configured to drive the VCO frequency toward the reference frequency to minimize the slope difference and frequency lock the VCO frequency to the reference frequency.

A method for multiphase frequency to voltage conversion includes generating for each cycle of an oscillating input, one of a plurality of non-overlapping clocks. A respective voltage in proportion to an input frequency of the oscillating input, is generated in response to each of the non-overlapping clocks, with a respective one of a plurality of frequency to voltage converters. Each of the respective voltages is summated to generate a voltage sum proportional to the input frequency.

A method for multiphase frequency to voltage conversion includes generating for each cycle of an oscillating input, one of a plurality of non-overlapping clocks. A respective voltage in proportion to an input frequency of the oscillating input, is generated in response to each of the non-overlapping clocks, with a respective one of a plurality of frequency to voltage converters. Each of the respective voltages is summated to generate a voltage sum proportional to the input frequency.