Qualcomm Incorporated

Xuhao Huang

Xiaohong Quan

Xu Zhang

Ankit Srivastava

Wenjing Yin

Sungmin Ock

Philip Michael Clovis

Deepti Vijayalakshmi Sriramagiri

Raghu Sankuratri

Zhengzheng Wu

Seyfollah Seyfollahi Bazarjani

Martin Saint-Laurent

Marzio Pedrali-Noy

Michael Drop

Sushma Chilukuri

Chao Song

Xufeng Chen

Edwin Jose

Yi-Hung Tseng

Shitong Zhao

Yuhe Wang

Deepti Sriramagiri

A level-shifter is provided with a first transistor and a second transistor. The first transistor functions to discharge an internal node responsive to an assertion of an inverted input signal to a first power supply voltage. A second transistor functions to discharge an inverted level-shifter output signal responsive to an assertion of an input signal to the first power supply voltage. An inverter inverts the inverted level-shifter output signal to form a level-shifter output signal that is asserted to a second power supply voltage responsive to the assertion of the input signal.

Enhanced rising and falling transitions for level shifting low-voltage input signals

An aspect relates to an apparatus, including: a ring oscillator coupled between a first node and a first voltage rail; a control circuit coupled to the first node; a delay line coupled between a second node and the first voltage rail; and a voltage regulator including an input coupled to the first node and an output coupled to the second node.

Delay line with process-voltage-temperature robustness, linearity, and leakage current compensation

A method of generating precise and PVT-stable time delay or frequency using CMOS circuits is disclosed. In some implementations, the method includes providing a reference voltage using a resistive module at a positive input terminal of an operational amplifier, coupling gates of a pair of p-type metal oxide semiconductor (pMOS) transistors and a compensation capacitor to an output terminal of the operational amplifier to generate a first bias signal, and coupling a pair of n-type metal oxide semiconductor (nMOS) transistors to a negative terminal of the operational amplifier to generate a second bias signal at the negative terminal, wherein the pair of nMOS transistors is substantially the same as a pair of nMOS transistors in the CMOS delay circuit.

Method of generating precise and PVT-stable time delay or frequency using CMOS circuits

A process-invariant RC circuit is formed by patterning a metal layer using the same mask pattern to form a metal layer resistor and a metal layer capacitor. The same mask pattern results in the metal layer resistor and the metal layer capacitor each having a plurality of longitudinally-extending fingers having the same width and separation.

Process-invariant resistor and capacitor pair

A bias current circuit is provided with a bias circuit that generates a bias voltage to control the resistance of an active resistor transistor. The bias circuit is configured to generate the bias voltage to be greater than one-half of a power supply voltage for the current bias circuit and to have a negative temperature dependency to reduce the temperature sensitivity of the bias current circuit.

Low-power temperature-insensitive current bias circuit

A voltage droop reduction circuit generally including a loop coupled to an output of a voltage regulator is provided. The loop includes a first current amplifier. The voltage droop reduction circuit may also include a first capacitor coupled between the output of the voltage regulator and an input of the first current amplifier.

Voltage droop mitigation circuit for power supply network

A hybrid pulse-width control circuit is provided that includes a ramp voltage generator for generating a ramp voltage signal. A clock pulse generator asserts an output clock signal responsive to the ramp voltage signal equaling a reference voltage.

Hybrid pulse-width control circuit with process and offset calibration

A switched-capacitor voltage divider is provided that functions to divide an input voltage only while a low-duty-cycle clock pulse signal is asserted. All the switches in the switched-capacitor voltage divider are idle during an off time for the low-duty-cycle clock pulse signal.

Low-power low-duty-cycle switched-capacitor voltage divider

An apparatus for sharing a serial communication port between a plurality of communication channels is described. The apparatus comprises a transceiver that manages communications over the serial communication port. The apparatus also includes a multiplexer coupled to the transceiver, wherein the multiplexer multiplexes the plurality of communication channels. The apparatus also includes identification information circuitry coupled to the multiplexer, wherein the identification information circuitry adds identification information to data from the plurality of communication channels that enables the plurality of communication channels to share the serial communication port. The serial communications port and the multiplexer permit communication between integrated circuits that meet at least one latency metric for the plurality of communication channels when the plurality of communication channels are active.

Systems and methods for sharing a serial communication port between a plurality of communication channels

A memory controller is provided that drives data and a corresponding first data strobe to a plurality of endpoints. Each endpoint is configured to register the received data from the memory controller responsive to the first data strobe and then to re-register the received data responsive to a second data strobe. A clock synchronization circuit functions to keep the received first data strobe at one of the endpoints sufficiently synchronous with the second data strobe.

Distributed clock synchronization

A method for data synchronization is provided according to certain embodiments. The method comprises receiving data, a data clock signal, and a clean clock signal, sampling the data using the data clock signal, synchronizing the sampled data with the clean clock signal, and outputting the synchronized sampled data. The method also comprises tracking a phase drift between the data clock signal and the clean clock signal, and pulling in the output of the synchronized sampled data by one clock cycle of the clean clock signal if the tracked phase drift reaches a first value in a first direction.

Low latency synchronization scheme for mesochronous DDR system

A clock synchronization circuit includes a multi-phase clock generator to generate a plurality of delayed clocks, each delayed clock having a unique delay with regard to a source clock. The clock synchronization circuit further includes a selection circuit that selects one of the delayed clocks according to a phase error to form a local clock driven into a local clock path and received at the clock synchronization circuit as a received local clock. The selection circuit determines the phase error by comparing the received local clock to a reference clock.

Clock synchronization

In one embodiment, a memory interface comprises a cleanup phase-locked loop (PLL) configured to receive a reference clock signal, and to generate a clean clock signal based on the reference clock signal. The memory interface also comprises a synchronization circuit configured to receive data, a data clock signal, and the clean clock signal, wherein the synchronization circuit is further configured to sample the data using the data clock signal, and to synchronize the sampled data with the clean clock signal.

A high voltage tolerant differential receiver circuit includes a voltage divider ladder that is operative to divide in half differential input signals that are greater than threshold voltages of the voltage divider ladder. A pass gate circuit is operative to receive differential input signals that are below the threshold voltage of the voltage divider ladder. Outputs from the voltage divider ladder and the pass gate circuit are provided to separate comparators. Output from the comparators are combined to generate a signal in the voltage domain of receiver circuitry.

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San Diego, CA, United States of America

Xuhao Huang