Core Chip Technology (nanjing) Co., Ltd.

Aucmos Technologies Usa, Inc.

Teh-Shang Lu

A ring oscillator includes: (i) one or more current sources each connected to a supply voltage source; and (ii) oscillation elements connected in series in a ring configuration each element including: (a) first and second input terminals; (b) first and second output terminals; (c) first and second inverters receiving input signals from the first and second input terminals, respectively, and providing output signals on the first and second output terminals, respectively; and (d) third and fourth inverters, each having an input terminal and an output terminal, wherein the input terminals of the third and fourth inverters are coupled to the first and second output terminals of the oscillator element, respectively, wherein the output terminals of third and fourth inverters are coupled to the second and first output terminals of the oscillator element, respectively, and wherein each of first, second, third and fourth inverters are coupled to the supply voltage source through the current sources.

Jitter-free ring oscillator

A programmable gain amplifier may include: (a) a differential amplifier having first and second input terminals and first and second output terminals, the differential amplifier providing an output signal of the programmable gain amplifier across the first and second output terminals of the differential amplifier; (b) a first set of one or more resistors coupling the first output terminal of the differential amplifier to the first input terminal of the differential amplifier; (c) a second set of one or more resistors coupling the first input terminal of the differential amplifier to a first input terminal of the programmable gain amplifier; and (d) a first set of one or more switches each connected in parallel with one or more resistors in the first or second set of resistors. The first set of switches may include two or more individually programmable switches. Each of the switches may be implemented by an input-signal independent switch disclosed herein.

Programmable gain amplifier

A proximity detector circuit that receives a single-ended sensor signal includes (a) an adaptive level control circuit maintaining the single-ended sensor signal within a predetermined voltage range relative a common mode reference signal; and (b) a programmable gain amplifier receiving the single-ended sensor signal and the common mode reference signal as a differential input signal, and providing an output signal derived from amplifying the differential input signal.

Proximity sensor

A phase-locked loop circuit includes (a) a phase frequency detector which receives the input signal of the phase-locked loop and a feedback signal that is derived from the output signal of the phase-locked loop, the phase-frequency detector providing a phase-difference signal indicating a difference in phase or frequency between the input signal and the feedback signal; (b) a voltage control oscillator which receives a voltage control signal and which provide the output signal of the phase-locked loop according to the voltage control signal; (c) first and second charge pump-filter circuits each receiving the phase difference signal and each comprising: (i) a charge pump circuit which provide a predetermined signal in accordance with the phase difference signal; and (ii) a filter circuit receiving the predetermined signal to provide a filtered signal, the filter circuit comprising one or more resistors and one or more capacitors; and (d) a summing circuit which sums the filtered signal of the first charge pump-filter circuit and the filtered signal of the second charge pump-filter circuit to provide the voltage control signal.

Low-jitter phase-locked loop circuit

A reference voltage generation circuit includes (a) a native MOS transistor coupled to between a power supply voltage source, and the output terminal of the reference voltage generation circuit; (b) an enhancement mode MOS transistor coupled between the output terminal and ground; and (c) a filter circuit that are coupled to the gate terminals of both the native MOS transistor, the enhancement mode transistor and the output terminal of the reference voltage generation circuit, in which the filter circuit has a transfer function including one or more zeroes at predetermined noise frequencies.

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Sunnyvale, CA, United States of America

Teh-Shang Lu