Macronix International Co., Ltd.

Hsien-Hung Wu

Chun-Hsiung Hung

Han-Sung Chen

Yi-Ching Liu

Hsin-Yi Ho

Shin-Jang Shen

Chia-Ching Li

Tzung-Shen Chen

A thermally compensated circuit includes a first adjustable circuit, like an adjustable current source, to produce a first adjustable signal, such a reference current. The circuit includes a second adjustable circuit to produce a second adjustable signal, such as a reference voltage. Circuitry responsive to the first and second adjustable signals produces an output, such as a clock signal. A tunable circuit in the first adjustable circuit and a tunable first element of the second adjustable circuit set an operating characteristic, such as a clock period, of the output to a target level at a first temperature. A tunable second element of the second adjustable circuit sets the operating characteristic of the output signal at the target level at a second temperature. Tuning of the second tunable element at the second temperature does not substantially change the operating characteristic of the output signal at the first temperature.

Thermally compensated circuits

A reference voltage circuit includes a first circuit including a first PN junction device and a first resistor connected in series between a power supply node and a first node, and a second resistor connected between the first node and an intermediate node, and a third resistor connected between the intermediate node and a reference voltage output node, and a second circuit including a second PN junction device connected between the power supply node and a second node and a fourth resistor connected between the second node and the intermediate node. A feedback current causes voltage across the first resistor to offset changes in voltage across the first PN junction device. A correction current is applied to boost and or sink current in the voltage reference generator to extend the operating temperature range.

Reference voltage generator with extended operating temperature range

A relaxation oscillator includes an adjustable reference circuit generator to produce a reference current which is applied to a charging circuit. The charging circuit is configured to charge a capacitive node as a function of the reference current and a capacitance of an adjustable capacitor that is operably coupled to the capacitive node. A comparator having inputs operatively coupled to a reference voltage node and to the capacitive node, generates a comparator output. A control circuit alternatively enables the charging circuit to charge the capacitive node and to discharge the capacitive node in response to changes in the comparator output. Also, the control circuit outputs and oscillator output signal have an oscillator period as a function of the adjustable capacitance and the adjustable reference current.

Tuning method for current mode relaxation oscillator

A circuit generates a clock signal with a tunable clock period. The circuit comprises capacitors, first tuning circuitry and second tuning circuitry. The first tuning circuitry is configured to adjust the clock period with a first period tuning step based on a first parameter and the second tuning circuit is configured to adjust the clock period with a second period tuning step based on a second parameter. The first period tuning step is different than the second period tuning step.

Clock period tuning method for RC clock circuits

An oscillator produces an oscillator output signal usable as a clock signal, otherwise as a frequency reference on an integrated circuit. The oscillator includes an RC network with a voltage-controlled element, such as a voltage-controlled resistor, voltage-controlled capacitor or a combination including a voltage-controlled resistor and voltage-controlled capacitor. Also, a tunable element having an adjustable resistance determined by a first static parameter is included in the RC network. The oscillator also includes a feedback circuit which can include a frequency-to-voltage converter. The feedback circuit generates a control signal for the voltage-controlled element. The feedback circuit includes a feedback reference circuit having a reference output determined by a second static parameter, and a loop amplifier responsive to the reference output and the oscillator output signal.

Feedback compensated oscillator

A method and a circuit for generating a clock signal from a clock integrated circuit are introduced herein. A compensation voltage is generated according to a temperature coefficient of a resistor and a clock period of a clock circuit, where the compensation voltage is resistor-corner independent. The clock period of the clock circuit is determined by the resistor and at least one capacitor of the clock circuit. The temperature dependence of the clock period of the clock circuit is reduced according to the compensation voltage.

Method and circuit for temperature dependence reduction of a RC clock circuit

A regulator comprises an amplifier, a bias circuit, and a current trimming circuit. The bias circuit is coupled to the amplifier and supplies a first bias current to the amplifier in a first mode of a system including the regulator. The current trimming circuit is coupled to the bias circuit to adjust the first bias current.

Low drop out regulator and current trimming device

A voltage regulator, alternatively operating in an active mode in response to an enabled mode indication signal, and operating in a standby mode in response to the disabled mode indication signal, is provided. The voltage regulator comprises a regulation unit and a feedback circuit. The regulation unit drives an output node with an output signal. The feedback circuit comprises a first resistance unit, connected between the output node and the feedback node, and a second resistance unit. The second resistance unit is connected between the feedback node and a ground reference voltage, and the resistance thereof is scaled down when a mode indication signal is enabled, so as to achieve a level dip event on a feedback signal, and accordingly driving the regulation unit enhancing its drivability of the output signal.

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Hsinchu, Taiwan

Hsien-Hung Wu