Freescale Semiconductor,inc.

Artery Technology Company

Nxp Usa, Inc.

Faraday Technology Corporation

Zhengxiang Wang

Liang Zhang

Chao Li

Wei-Chih Chen

Jie Jin

Jianzhou Wu

Yizhong Zhang

Feng Xu

Baotian Hao

Jian Zhou

Weitie Wang

Yang Wang

Yan Huang

Chao Liang

Hao Zhi

Chiao-Wen Lo

Hung-Yu Lin

Wenlong Zhang

Gui Feng Zhou

Jiangwei Liu

Haitao Wang

Wei-Tai Tsai

Chen-Chun Huang

A resistor-capacitor (RC) oscillator with shared circuit architecture includes a current mirror circuit, a comparator circuit, a bias voltage generator, and a clock buffer. The current mirror circuit utilizes a plurality of transistors to perform current control, to adjust a second current on a second current path according to a first current on a first current path. The comparator circuit includes a first transistor, a second transistor, a resistor, and a capacitor, wherein a comparison result signal generated by the comparator circuit corresponds to a voltage of the capacitor. The bias voltage generator generates a bias voltage as a comparator reference voltage between the first transistor and the resistor. The clock buffer buffers the comparison result signal to generate an output signal. The bias voltage generator at least shares the resistor with the comparator circuit, and the RC oscillator may achieve targets of low cost and high performance.

Resistor-capacitor oscillator with shared circuit architecture

An analog-to-digital converter (ADC) device equipped with a conversion suspension function and an associated operation method thereof are provided. The ADC device includes: an interleaved clock controller, arranged to generate a first clock signal and a second clock signal according to a master clock signal; and a multi-ADC circuit, coupled to the interleaved clock controller, arranged to perform analog-to-digital conversion. The multi-ADC circuit includes a first ADC and a second ADC, wherein the first ADC performs sampling and conversion operations according to the first clock signal, and the second ADC performs sampling and conversion operations according to the second clock signal. Based on the timing control of the first clock signal and the second clock signal, when any ADC of the first ADC and the second ADC is performing a sampling operation, the other ADC of the first ADC and the second ADC suspends conversion.

Analog-to-digital converter device equipped with conversion suspension function, and operation method thereof

A voltage divider circuit regarding a battery voltage and an associated electronic device equipped with the voltage divider circuit are provided. The voltage divider circuit may include a first level shifter circuit, a second level shifter circuit and a controlled voltage divider. The first level shifter circuit selectively performs a first level shifting operation on an original enable signal according to respective voltage levels of multiple control signals to generate a first enable signal. The second level shifter circuit selectively performs a second level shifting operation on the first enable signal according to a voltage level of the first enable signal to generate a second enable signal. The controlled voltage divider selectively performs a voltage dividing operation on the battery voltage according to a voltage level of the second enable signal to generate a divided voltage of the battery voltage to be an output of the voltage divider circuit.

Voltage divider circuit regarding battery voltage, and associated electronic device equipped with voltage divider circuit

The present invention discloses a hysteresis comparator comprising an input stage, a hysteresis current generating circuit and an output stage. In the operation of the hysteresis comparator, the input stage is configured to receive a pair of differential input signals to generate at least one differential current signal; the hysteresis current generating circuit is configured to generate at least one hysteresis current to adjust the differential current signal to generate an adjusted differential current signal, wherein the hysteresis current generating circuit includes a common mode voltage detecting circuit for detecting a common mode voltage of the differential input signal for generating the hysteresis current; and the output stage is configured to generate an output signal according to the adjusted differential current signal.

Hysteresis comparator

A delay circuit and an electronic system equipped with the delay circuit are provided. The delay circuit includes an input terminal, an output terminal, a bias current generator and a delay generator. The bias current generator is coupled between a first reference voltage and a second reference voltage, and is configured to generate a bias current. The delay generator is coupled between the first reference voltage and the second reference voltage, and is configured to generate a delay of the delay signal relative to the input signal according to the bias current. The bias current generator includes a current mirror, a current module and a transistor. The delay generator includes a first current mirror sub-circuit, a second current mirror sub-circuit, a transistor, a capacitor, a switch circuit and a Schmitt inverter, wherein the output terminal is coupled to the Schmitt inverter to output the delay signal.

Delay circuit and electronic system equipped with delay circuit

A power-on reset circuit arranged to generate a reset signal according to a power supply voltage includes: a power supply voltage detector, a holding circuit, a reference voltage generator and a reset determination circuit. The power supply voltage detector is controllable by the reset signal, and arranged to detect a level of the power supply voltage to generate a detection signal. The holding circuit is arranged to output an enablement signal according to the detection signal, wherein the holding circuit selectively maintains a level of the enablement signal according to a level of the detection signal. The reference voltage generator is controllable by the enablement signal to selectively output a reference voltage. The reset determination circuit is arranged to output the reset signal according to the power supply voltage and the reference voltage.

Power-on reset circuit and related reset method

A relaxation oscillator for generating a low temperature coefficient (LTC) clock signal includes a reference voltage generator and an oscillator. The reference voltage generator generates an LTC current and a bandgap reference voltage. The reference voltage generator includes positive temperature coefficient (PTC) resistors to compensate for the effects of temperature variations. The oscillator receives the LTC current and the bandgap reference voltage, and generates a clock signal. In another embodiment, the reference voltage generator generates a charge current that varies with temperature. The oscillator receives the charge current and generates first and second output signals. Set and reset comparators include PTC resistors that determine the gains of the set and reset comparators. The PTC resistors compensate for variation in the first and second output signals due to the temperature variations by varying the gains of the set and reset comparators.

Low temperature coefficient clock signal generator

A voltage regulator generates an output voltage that is a designed voltage level below the supply voltage. A reference voltage generator generates a reference voltage between ground and supply voltages. A voltage divider generates a feedback voltage between the supply and output voltages. An amplifier generates an amplifier output voltage based on a difference between the reference and feedback voltages. A buffer buffers the amplifier output voltage. A pass transistor receives the buffered voltage at its control node to sink an average load current appearing at the output node. A capacitor is connected between the supply and output voltages to provide a peak load current. A load-current-detecting transistor receives the buffered voltage at its control node to sense the load current. A compensation transistor compensates for leakage current. An internal load converts the sensed load current into a voltage control signal applied to the compensation transistor.

Supply-side voltage regulator

A voltage supply for providing a clamped voltage to a circuit element to be protected against electrical overstress (EOS) has a reference voltage module and a voltage clamp module. The reference voltage module has a first field-effect transistor (FET) whose source and drain are connected in series between a programmable reference current source and a first resistor across a power supply. The gate of the first FET is connected to its drain to provide a reference voltage defined by the reference current flowing in the first resistor. The voltage clamp module has a second FET whose gate receives the reference voltage and whose source is connected to provide to the protected circuit element the clamped voltage whose variation is limited by the reference voltage.

Voltage clamping circuit

A relaxation oscillator system has a relaxation oscillator and a frequency control (FC) unit. The oscillator includes first and second oscillator sub-circuits and a latch. The first and second oscillator sub-circuits receive from the FC unit, respectively, first and second control signals for controlling corresponding outputs provided to the latch by the first and second oscillator sub-circuits. The latch outputs a variable frequency feedback signal provided to the FC unit. The FC unit receives a frequency control signal for controlling the frequency of an oscillator output signal and generates the first and second control inputs based on the frequency control signal and the feedback signal so that changes to the oscillator frequency are implemented by each oscillator sub-circuit while that sub-circuit is in an idle state to avoid glitches in the oscillator output signal.

Variable frequency relaxation oscillator

A relaxation oscillator shares charging current and comparator biasing current between just two current sources, thereby relaxing requirements on total supply current. The resulting reduction in power consumption has no adverse effect on the speed and accuracy of the oscillator. A switching arrangement directs charging and biasing currents between the two current sources and two charging capacitors and their associated comparators.

Relaxation oscillator

An AC-inverting amplifier for a waveform conversion circuit includes a first MOS transistor of a first conductivity type having a gate that receives an input signal, a drain that provides an inverted amplified output signal, and a source coupled to a first power supply voltage. A current source provides a first bias current and a second bias current in proportion to the first bias current. The second bias current is coupled to the drain of the first MOS transistor to bias the first MOS transistor. The first bias current has a magnitude that is determined by a DC voltage applied at the gate of the first MOS transistor.

Waveform conversion circuit with reduced jitter

A relaxation oscillator has a comparator that includes first through third bias current transistors coupled to a first supply rail. First and second input transistors form a pair of parallel coupled transistors connected to the first bias current transistor. A first current mirror control transistor connects the first input transistor to a second supply rail. A first current mirror output transistor is coupled to the first current mirror control transistor, and connects the second bias current transistor to the second supply rail. A second current mirror control transistor connects the second input transistor to the second supply rail. A second current mirror output transistor is coupled to the second current mirror control transistor, and connects the third bias current transistor to the second supply rail. A transition time reduction transistor, coupled across the third bias current transistor, is coupled to the second bias current transistor, and provides a comparator output.

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Suzhou, China

Zhengxiang Wang