Qualcomm Incorporated

Kevin Jia-Nong Wang

Shyam Sivakumar

Debesh Bhatta

Luis Chen

Jeffrey Mark Hinrichs

Chao Song

Patrick Isakanian

Andrew Weil

Karthik Nagarajan

John Abcarius

Christian Venerus

Shitong Zhao

Ercem Yesil

A system includes a driver including a pull-up p-type field effect transistor (PFET). The system also includes a negative boost circuit. The negative boost circuit includes a first drive circuit configured to receive a first supply voltage, a second drive circuit configured to receive a second supply voltage different from the first supply voltage, a switch coupled between an output of the second drive circuit and a gate of the pull-up PFET, and a capacitor having a first terminal and a second terminal, wherein the first terminal is coupled to the gate of the pull-up PFET and the second terminal is coupled to an output of the first drive circuit. The system also includes a pre-drive circuit configured to drive an input of the first drive circuit and an input of the second drive circuit based on an input signal.

Voltage boosted transmitter without a negative rail

Certain aspects of the present disclosure provide methods and apparatus for minimizing, or at least reducing, a bias noise contribution to phase noise in an oscillator circuit. One example oscillator circuit generally includes an oscillator configured to generate an oscillating signal, an adjustable bias circuit coupled to a bias input of the oscillator and configured to provide a bias signal to the oscillator, and a control circuit having an input coupled to an output of the oscillator and having an output coupled to a control input of the adjustable bias circuit. The control circuit is configured to control the adjustable bias circuit to adjust the bias signal with a control signal, to determine an impact of the adjusted bias signal on a parameter of the oscillating signal, and to determine a setting for the control signal based on the impact on the parameter of the oscillating signal.

Phase noise reduction by controlling biasing for adjustable oscillators with cross-coupled transistors

An apparatus, including: a buffer configured to receive an input differential signal and generate an output signal based on the input differential signal, wherein the buffer includes a first buffer stage including: a first field effect transistor (FET); a second FET coupled in series with the first FET between a first voltage rail and a second voltage rail; a third FET; a fourth FET coupled in series with the third FET between the first voltage rail and the second voltage rail, wherein the first and third FETs include gates coupled together, and wherein the second and fourth FETs include gates configured to receive positive and negative components of the input differential signal; and a first capacitor coupled between a drain of the second FET and the gates of the first and third FETs.

Buffer for voltage controlled oscillator (VCO) or other applications

An oscillator including a switched capacitor configured to generate a sawtooth or ramp voltage in response to a switched capacitor drive signal; a low pass filter (LPF) configured to filter the sawtooth or ramp voltage to generate a filtered voltage; a reference voltage generator configured to generate a reference voltage; an integrator configured to integrate a difference between the sawtooth or ramp voltage and the reference voltage to generate a frequency control signal; a voltage controlled oscillator (VCO) configured to generate a first clock based on the frequency control signal; a frequency divider configured to frequency divide the first clock to generate a second clock; and a switched capacitor driver configured to generate the switched capacitor drive signal in response to the second clock. The oscillator may also include a switched capacitor sampler to sample the sawtooth or ramp voltage, wherein the filtered voltage is based on the sampled voltage.

Resistor-capacitor oscillator (RCO) with digital calibration and quantizaton noise reduction

Certain aspects of the present disclosure provide apparatus and techniques for digital-to-analog conversion. One example apparatus generally includes a first digital-to-analog converter (DAC) having an input coupled to a digital input node of the apparatus, a second DAC, a digital processor coupled between the digital input node and an input of the second DAC, and a combiner coupled to the first DAC and the second DAC.

Partitioned digital-to-analog converter system

An apparatus is disclosed that implements frequency synthesis with accelerated locking. In an example aspect, the apparatus includes an oscillating signal source, a modulus compensator, and a frequency generator. The oscillating signal source is configured to provide a reference signal having a reference frequency. The modulus compensator is coupled to the oscillating signal source and is configured to receive the reference signal. The modulus compensator is configured to produce a compensated modulus value based on the reference frequency, a fixed oscillator frequency of a fixed-frequency oscillator signal, and a modulus value. The frequency generator is coupled to the oscillating signal source and the modulus compensator and is configured to receive the compensated modulus value. The frequency generator is configured to generate an output signal having an output frequency that is based on the reference frequency and the compensated modulus value.

Frequency synthesis with accelerated locking

A sub-threshold MOSFET temperature sensor is provided in which a sub-threshold leakage current through a sub-threshold transistor having its source connected to its gate is mirrored through a diode-connected transistor to produce an output voltage. Feedback maintains a drain voltage for the sub-threshold transistor to equal the output voltage.

Sub-threshold-based semiconductor temperature sensor

An apparatus is disclosed for relocking of a locked loop. In an example aspect, the apparatus includes a locked loop, and the locked loop includes a loop and a locked-loop controller that is coupled to the loop. The loop is configured to run responsive to a run signal. The loop includes a memory state component and signal characteristic adjustment circuitry coupled to the memory state component. The signal characteristic adjustment circuitry is configured to produce an output signal having a characteristic that is based on the memory state component. The locked-loop controller is configured to receive an external power mode signal (EPMS). The locked-loop controller is also configured to generate the run signal to have an enable value at a first time when the EPMS is indicative of an external normal mode and at a second time when the EPMS is indicative of an external standby mode.

Systems and methods of relocking for locked loops

A capacitor may include a first set of conductive fingers interdigitated with a second set of conductive fingers at an interconnect layer in a preferred direction of the interconnect layer. The capacitor may also include the first set of conductive fingers interdigitated with the second set of conductive fingers at a next interconnect layer in the preferred direction of the next interconnect layer. The capacitor may further include a first set of through finger vias electrically coupling the first set of conductive fingers of the interconnect layer to the first set of conductive fingers of the next interconnect layer.

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Poway, CA, United States of America

Kevin Jia-Nong Wang