H03K4/502

Precision oscillators that use imprecise components

Trimming components within an oscillator comprising: a trim-capable current source, wherein the trim-capable current source comprises a trimmable resistor and a trimmable current component, a comparator comprising a first input terminal that couples to the trim-capable current source and the second input terminal that couples to a reference voltage source, a switch coupled to the first input terminal and the trim-capable current source, and a trim-capable capacitor coupled to the switch, wherein the switch is coupled between the trim-capable capacitor and the trim-capable current source.

Tunable oscillator with temperature and power voltage compensation function
11283404 · 2022-03-22 · ·

A tunable oscillator includes a current bias circuit configured to generate a reference bias current, a variable voltage bias circuit configured to receive the reference bias current and generate a bias voltage varied based on a voltage control signal, an oscillation signal generator circuit configured to generate an oscillation signal based on the reference bias current and a switching control signal, and a switching control circuit configured to generate the switching control signal based on the bias voltage and the oscillation signal. A frequency of the oscillation signal is varied based on a magnitude of the bias voltage.

COMBINING VOLTAGE RAMPS TO CREATE LINEAR VOLTAGE RAMP
20210167763 · 2021-06-03 · ·

An improved ramp generator enables a very high degree of linearity in an output voltage ramp signal. Output ramps of the output voltage ramp signal are alternatingly produced from two preliminary ramp signals during alternating time periods. Preliminary ramps are produced at different preliminary ramp nodes that are alternatingly connected to an output node. The preliminary ramps continuously ramp during and in some cases beyond, e.g., before and/or after, the time periods. In some embodiments, switches alternatingly connect two capacitors to at least one current source, a reset voltage source, and the output node to alternatingly produce the preliminary ramps.

Oscillator circuit resistant to noise and jitter
11025233 · 2021-06-01 · ·

An oscillator circuit includes a bias circuit, a signal generation circuit, and a control circuit. The bias circuit is configured to generate a reference voltage based on a reference current and a bias resistor. The signal generation circuit is configured to generate a bias current based on the reference current, perform charging and discharging of a capacitor using the bias current, and generate an oscillation signal based on the charging and the discharging of the capacitor. The control circuit is configured to generate a control signal having a constant discharging time, based on the reference voltage and the oscillation signal, controlling the charging and the discharging of the capacitor.

Oscillator circuit resistant to noise and jitter
11025233 · 2021-06-01 · ·

An oscillator circuit includes a bias circuit, a signal generation circuit, and a control circuit. The bias circuit is configured to generate a reference voltage based on a reference current and a bias resistor. The signal generation circuit is configured to generate a bias current based on the reference current, perform charging and discharging of a capacitor using the bias current, and generate an oscillation signal based on the charging and the discharging of the capacitor. The control circuit is configured to generate a control signal having a constant discharging time, based on the reference voltage and the oscillation signal, controlling the charging and the discharging of the capacitor.

Current-controlled oscillator

A current-controlled oscillator receives an input current. Ramp voltage generating circuitry generates first and second ramp voltages in response to the input current. Selecting circuitry selects one of the first and second ramp voltages depending on their relative values. Switching circuitry receives a selected ramp voltage, generates a signal based on the selected ramp voltage relative to a reference voltage, and outputs a clock signal. In one embodiment, a comparator receives the reference voltage, one of the first and second ramp voltages, and outputs a comparison signal. Logic circuitry controls the ramp voltage generating circuitry to output one of the ramp voltages during one half of a clock cycle and to output the other ramp voltage during another half cycle of the clock signal based on the comparison signal and logic states of the logic circuitry.

Current-controlled oscillator

A current-controlled oscillator receives an input current. Ramp voltage generating circuitry generates first and second ramp voltages in response to the input current. Selecting circuitry selects one of the first and second ramp voltages depending on their relative values. Switching circuitry receives a selected ramp voltage, generates a signal based on the selected ramp voltage relative to a reference voltage, and outputs a clock signal. In one embodiment, a comparator receives the reference voltage, one of the first and second ramp voltages, and outputs a comparison signal. Logic circuitry controls the ramp voltage generating circuitry to output one of the ramp voltages during one half of a clock cycle and to output the other ramp voltage during another half cycle of the clock signal based on the comparison signal and logic states of the logic circuitry.

Temperature- and voltage-independent oscillator circuit
10972050 · 2021-04-06 · ·

A temperature- and voltage-independent oscillator circuit including a bias circuit configured to generate a reference voltage based on a reference current and a bias resistor; a signal generator circuit configured to generate a bias current based on the reference current, and generate an oscillation signal by repeatedly charging a capacitor using the bias current, and discharging the charged capacitor; and a control circuit configured to control the charging of the capacitor and the discharging of the charged capacitor based on the reference voltage and a voltage of the oscillation signal, wherein a period of the oscillation signal is determined by a resistance value of the bias resistor and a capacitance value of the capacitor.

Temperature- and voltage-independent oscillator circuit
10972050 · 2021-04-06 · ·

A temperature- and voltage-independent oscillator circuit including a bias circuit configured to generate a reference voltage based on a reference current and a bias resistor; a signal generator circuit configured to generate a bias current based on the reference current, and generate an oscillation signal by repeatedly charging a capacitor using the bias current, and discharging the charged capacitor; and a control circuit configured to control the charging of the capacitor and the discharging of the charged capacitor based on the reference voltage and a voltage of the oscillation signal, wherein a period of the oscillation signal is determined by a resistance value of the bias resistor and a capacitance value of the capacitor.

Ramp signal generation device and CMOS image sensor including the same
10931268 · 2021-02-23 · ·

A ramp signal generation device includes a sampling circuit suitable for sampling a ramp current and storing a voltage corresponding to the sampled ramp current; a current maintaining circuit suitable for maintaining the ramp current; a current transferring circuit suitable for transferring a current corresponding to the voltage stored on the sampling circuit; and a current-to-voltage converter suitable for converting and generating a ramp voltage corresponding to the current transferred from the current transferring circuit.