Qualcomm Incorporated

Reza Jalilizeinali

Sreeker Dundigal

Eugene Robert Worley

Chiew-Guan Tan

Wilson Jianbo Chen

Evan Siansuri

Brian Matthew Henderson

Vivek Mohan

Alvin Leng Sun Loke

Shiqun Gu

Thomas Clark Bryan

Luverne Ray Peterson

Tin Tin Wee

Stephen Knol

Wen-Yi Chen

Krishna Chaitanya Chillara

Matthew Michael Nowak

Michael J Brunolli

Dong Wook Kim

Seyfollah Seyfollahi Bazarjani

Thomas R Toms

Mikhail Popovich

Junmou Zhang

Gregory Ameriada Uvieghara

Patrick Isakanian

Boris Andreev

Chang Ki Kwon

Gregory Lynch

Bo Yu

Stephen Thilenius

Aliasgar Presswala

Yuan-Cheng Pan

Ronnie A Lindley

Taeghyun Kang

Stephen Clifford Thilenius

Gregory A Uvieghara

Yuan-Cheng Christopher Pan

Sreeker R Dundigal

An ESD protection circuit has a driver transistor with a drain that is coupled to an I/O pad of an IC device and a source that is coupled to a first rail of a power supply in the IC device, and a diode that couples the I/O pad to the first rail and that is configured to be reverse-biased when a rated voltage is applied to the I/O pad. The rated voltage lies within a nominal operating range for voltage levels defined for the input/output pad. The ESD protection circuit has a gate pull transistor that couples a gate of the driver transistor to the I/O pad or the first rail. The gate pull transistor may be configured to present a high impedance path between the gate of the driver transistor and the I/O pad or the first rail when the rated voltage is applied to the I/O pad. The gate pull transistor may be configured to provide a low impedance path between the gate of the driver transistor and the I/O pad or the first rail when an overvoltage signal applied to the I/O pad has a magnitude that exceeds the nominal operating range of voltage levels defined for the I/O pad.

Interface circuit with robust electrostatic discharge

An output driver in an integrated circuit includes a voltage shifter. The output driver has a low voltage section configured to provide a low voltage signal responsive to an input signal and a high voltage section configured to provide a high voltage signal responsive to the input signal. A first biasing circuit is configured to provide a bias to a first transistor in the high voltage section such that the bias is modified during a transition in the output signal. A second biasing circuit is configured to turn on a second transistor in the high voltage section when the output signal is at a low voltage level. The second transistor is configured to discharge a terminal of the first transistor. The input signal switches between 0 Volts and 0.9 Volts. The output signal switches between 0 Volts and 1.2 Volts or between 0 Volts and 1.8 Volts.

Static and intermittent dynamic multi-bias core for dual pad voltage level shifter

A method of protecting a serializer/deserializer (SERDES) differential input/output (I/O) circuit includes detecting an electrostatic discharge event. The method also includes selectively disengaging a power supply terminal from a pair of I/O transistors of the SERDES differential I/O circuit in response to the detected electrostatic discharge event. The method further includes selectively disengaging a ground terminal from the pair of I/O transistors of the SERDES differential I/O circuit in response to the detected electrostatic discharge event.

Electrostatic discharge (ESD) isolated input/output (I/O) circuits

Circuits and methods for loopback testing are provided. A die incorporates a receiver (RX) to each transmitter (TX) as well as a TX to each RX. This architecture is applied to each bit so, e.g., a die that transmits or receivesdata bits during operation would havetransceivers (one for each bit). Focusing on one of the transceivers, a loopback architecture includes a TX data path and an RX data path that are coupled to each other through an external contact, such as a via at the transceiver. The die further includes a transmit clock tree feeding the TX data path and a receive clock tree feeding the RX data path. The transmit clock tree feeds the receive clock tree through a conductive clock node that is exposed on a surface of the die. Some systems further include a variable delay in the clock path.

Systems and methods for wafer-level loopback test

Circuits and methods for loopback testing are provided. A die incorporates a receiver (RX) to each transmitter (TX) as well as a TX to each RX. This architecture is applied to each bit so, e.g., a die that transmits or receives 32 data bits during operation would have 32 transceivers (one for each bit). Focusing on one of the transceivers, a loopback architecture includes a TX data path and an RX data path that are coupled to each other through an external contact, such as a via at the transceiver. The die further includes a transmit clock tree feeding the TX data path and a receive clock tree feeding the RX data path. The transmit clock tree feeds the receive clock tree through a conductive clock node that is exposed on a surface of the die. Some systems further include a variable delay in the clock path.

A latch-based power-on checker (POC) circuit for mitigating potential problems arising from an improper power-up sequence between different power domains (e.g., core and input/output (I/O)) on a system-on-chip (SoC) integrated circuit (IC). In one example, the core power domain having a first voltage (CX) should power up before the I/O power domain having a second voltage (PX), where PX&#x3e;CX. If PX ramps up before CX, the POC circuit produces a signal indicating an improper power-up sequence, which causes the I/O pads to be placed in a known state. After CX subsequently ramps up, the POC circuit returns to a passive (LOW) state. If CX should subsequently collapse while PX is still up, the POC circuit remains LOW until PX also collapses.

Latch-based power-on checker

An electronic circuit and methods of operating the electronic circuit are provided. The electronic circuit includes a pull-up transistor for pulling up an input/output (I/O) node of the output circuit to a first voltage and a first isolation transistor for coupling the pull-up transistor to the I/O node. The electronic circuit also includes a pull-down transistor for pulling down the I/O node to a second voltage and a second isolation transistor for coupling the pull-down transistor to the I/O node. In the electronic circuit, the pull-up and the pull-down transistors are transistors supporting a first drain-to-source voltage and a first gate-to-source voltage, while the first and the second isolation transistors are transistors supporting the first drain-to-source voltage and a second gate-to-source voltage greater than the first gate-to-source voltage.

Transistors configured for gate overbiasing and circuits therefrom

An input/output (I/O) driver that includes circuitry for over-voltage protection of first and second FETs coupled in series between a first rail and an output, and third and fourth FETs coupled between the output and a second rail. The circuitry is configured to generate a gate bias voltage for the second FET that transitions from high to low bias voltages state when the output voltage (V) begins transitioning from low to high logic voltages, and transitions back to the high bias voltage while Vcontinues to transition towards the high logic voltage. Further, the circuitry is configured to generate a gate bias voltage for the third FET that transitions from low to high bias voltages when Vbegins transitioning from high to low logic voltages, and transitions back to the low bias voltage while Vcontinues to transition towards the low logic voltage.

Input/output (I/O) driver implementing dynamic gate biasing of buffer transistors

A back-power prevention circuit is provided that protects a buffer transistor from back-power during a back-power condition by charging a signal lead coupled to a gate of the buffer transistor to a pad voltage and by charging a body of the buffer transistor to the pad voltage.

Output driver with back-powering prevention

A system interconnect includes a first resistor-capacitor (RC) clamp having a first RC time constant. The system interconnect also includes second RC clamps having a second RC time constant. The first and second RC clamps are arranged along the system interconnect. In addition, the first RC time constant is different from the second RC time constant.

Mixed mode RC clamps

An active diode with fast turn-on time, low capacitance, and low turn-on resistance may be manufactured without a gate and without a shallow trench isolation region between doped regions of the diode. A short conduction path in the active diode allows a fast turn-on time, and a lack of gate oxide reduces susceptibility of the active diode to extreme voltages. The active diode may be implemented in integrated circuits to prevent and reduce damage from electrostatic discharge (ESD) events. Manufacturing the active diode is accomplished by depositing a salicide block between doped regions of the diode before salicidation. After the salicide layers are formed on the doped regions, the salicide block is removed.

Active diode having no gate and no shallow trench isolation

In a particular embodiment, a method includes modifying an output impedance associated with the input receiver. In response to modifying the output impedance, the method restricts an output voltage at an output node of the input receiver. Particular embodiments of an input receiver circuit are also disclosed.

Low-power interface and method of operation

One feature pertains to a multi-chip module that comprises at least a first integrated circuit (IC) die and a second IC die. The second IC die has an input/output (I/O) node electrically coupled to the first IC die by a through substrate via. The second die's active surface also includes a fuse that is electrically coupled to the I/O node and adapted to protect the second IC die from damage caused by an electrostatic discharge (ESD). In particular, the fuse protects the second IC die from ESD that may be generated as a result of electrically coupling the first die to the second die during the manufacturing of the multi-chip module. Upon coupling the first die to the second die, the fuse may bypass the ESD current generated by the ESD to ground. After packaging of the multi-chip module is complete, the fuse may be blown open.

Electrostatic protection for stacked multi-chip integrated circuits

An input receiver for stepping down a high-voltage domain input signal into a low-voltage-domain stepped-down signal includes a waveform chopper. The waveform chopper chops the high-voltage domain input signal into a first chopped signal and a second chopped signal. A high-voltage-domain receiver combines the first chopped signal and the second chopped signal into a high-voltage-domain combined signal. A step-down device converts the high-voltage-domain combined signal into a stepped-down low-voltage-domain signal.

High-voltage input receiver using low-voltage devices

In a particular embodiment, a circuit includes a power supply, a ground, and a clamping transistor circuit coupled to the power supply and to the ground. The circuit further includes a disable clamp circuit. The disable clamp circuit is coupled to the power supply and is responsive to a second power supply input to selectively disable the clamping transistor circuit by modifying a charging current applied to a capacitor of the clamping transistor circuit. In a particular embodiment, modifying the charging current includes enabling a second charging path. Enabling the second charging path enables charging the capacitor at a higher charging rate than a charging rate associated with charging the capacitor via a first charging path.

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Oceanside, CA, United States of America

Reza Jalilizeinali