A built-in self-test (BIST) methodology and apparatus provide for testing and calibration of an integrated circuit oscillator circuit topology that uses a one-pin (a single-pin) external resonator. The method employs dedicated test circuitry, also referred to herein as BIST apparatus, for the pass/fail verification of both the active and passive building blocks of the oscillator. At the same time, the methodology ensures accurate calibration and matching of the capacitors using dedicated digital circuitry and algorithms.

Modulation testing separately enables slices of an analog varactor array of an LC oscillator. For each enabled slice, a reference voltage supplying a resistor ladder is set to a plurality of different reference voltage values. Resistor ladder voltages generated for the different reference voltage values are supplied to the enabled slice and a control voltage coupled to the enabled slice is swept for each of the reference voltage values. Respective frequencies of an oscillator signal coupled to an output of the LC oscillator are measured for each enabled slice for each combination of the reference voltage values and the control voltage values. The linearity of LC oscillator gain is determined for each of the reference voltage values for each slice based on the respective frequencies and the control voltage values. Passing/failing the modulation testing is based on the linearity of the LC oscillator gain.

A method for inspecting a crystal unit, the method includes: generating a sub-vibration in a crystal blank of the crystal unit by applying an input signal to a plurality of electrodes formed on the crystal blank; obtaining frequency characteristics of impedance between the plurality of electrodes from an output signal of the plurality of electrodes; and comparing the frequency characteristics obtained with reference frequency characteristics indicating quality of the crystal unit.

Silicon test structures are described that enable separate measurement of n-channel metal-oxide semiconductor (NMOS) and p-channel metal-oxide semiconductor (PMOS) transistor delays. NMOS and PMOS specific non-inverting stages may be used to construct a multi-stage ring oscillator. Each of the non-inverting stages generates either a rising or falling primary transition that is determined by either NMOS or PMOS transistors, respectively. The opposing transition for a particular non-inverting stage is triggered by propagation of the primary transition to a subsequent non-inverting stage (producing a reset pulse). A frequency of the ring oscillator is determined by the primary transition and one transistor type (NMOS or PMOS). Specifically, the frequency is determined by the propagation delay of the primary transition through the entire ring oscillator.

A vector network analyzer for obtaining at least one wave frequency ratio with respect to a frequency-converting device under test is provided. The vector network analyzer comprises a transmitter side configured to be controlled by at least one transmitter side clock signal, a receiver side configured to be controlled by at least one receiver side clock signal, and a central clock configured to generate a central clock signal. The at least one transmitter side clock signal and the at least one receiver side clock signal are based on the central clock signal, the at least one transmitter side clock signal and the at least one receiver side clock signal are generated with a fixed phase relation to each other with the aid of a start pulse.

Method and system for temperature-dependent frequency compensation. For example, the method for temperature-dependent frequency compensation includes determining a first frequency compensation as a first function of temperature using one or more crystal oscillators, processing information associated with the first frequency compensation as the first function of temperature, and determining a second frequency compensation for a crystal oscillator as a second function of temperature based on at least information associated with the first frequency compensation as the first function of temperature. The one or more crystal oscillators do not include the crystal oscillator, and the first frequency compensation as the first function of temperature is different from the second frequency compensation as the second function of temperature.

A probe system configured to receive a radio-frequency (RF) signal from a radio-frequency (RF) antenna includes a heater and a control circuit. The heater includes a resistive heating element routed through the probe system. An operational voltage is provided to the resistive heating element to provide heating for the probe system and the resistive heating element has an element capacitance. The control circuit is configured to determine an antenna response of the resistive heating element and determine a remaining useful life of the probe system based on the antenna response over time.

A system and method for an aircraft includes a probe, first and second current sensors, and a control circuit. The probe includes a heater that includes a resistive heating element routed through the probe, wherein an operational current is provided to the resistive heating element to provide heating for the probe. The first current sensor is configured to sense a first current through the resistive heating element, and the second current sensor is configured to sense a second current through the resistive heating element. The control circuit is configured to determine a leakage current based on the first and second currents and determine a remaining useful life the probe based on the leakage current over time.

A testing system includes a testing device including a display screen. The testing device can display, via the display screen, a representation of a vehicle and oscillators of the vehicle. The testing device transmits a test request that identifies a selected oscillator of the plurality of oscillators for testing. A vehicle receives the test request. An electronic control unit of the vehicle instructs the selected oscillator to generate test signals. The testing calculates a performance metric of the test signals. The testing device determines whether the selected oscillator is properly placed, functioning at a predetermined threshold, or both. Improperly placed or improperly functioning oscillators can be adjusted or replaced.

An electronic apparatus for testing an integrated circuit (IC) that includes a ring oscillator is provided. The apparatus configures the ring oscillator to produce oscillation at a first frequency and configures the ring oscillator to produce oscillation at a second frequency. The apparatus then compares the second frequency with an integer multiple of the first frequency to determine a resistive voltage drop between a voltage applied to the IC and a local voltage at the ring oscillator. The ring oscillator has a chain of inverting elements forming a long ring and a short ring. The ring oscillator also has an oscillation selection circuit that is configured to disable the short ring so that the ring oscillator produces a fundamental oscillation based on signal propagation through the long ring and enable the short ring so that the ring oscillator produces a harmonic oscillation based on a signal propagation through the short ring and the long ring.