Qualcomm Incorporated

Abheek Gupta

Vaishnav Srinivas

Vivek Mohan

Vijay Shankar

An interface input has an input circuit adapted to receive input signal levels higher than a maximum signal level that a host circuitry's electronic components can reliably handle. The input circuit shifts the level of the input signal to a desired signal level. A keeper circuit is coupled to the input circuit and maintains trigger levels of the shifted signals consistent with the input signal level.

High signal level compliant input/output circuits

A signal driver for an interface circuit has a first stage level shifter to accept input signals and output signals at a first signal level. The signal driver also has a second stage level shifter coupled to the first stage level shifter to output signals at a second signal level. Electronic components of the first and second stage level shifter have reliability limits less than the second signal level. The first and second stage configurations of the first stage level shifter and the second stage level shifter prevents exposing the electronic components to terminal to terminal signal levels higher than the reliability limits when processing signals for output at the second signal level.

A level shifter has at least one of either a pull up or a pull down circuit. The circuit is made of electronic components with reliability limits less than a maximum signal level output by the level shifter. The level shifter also has a timing circuit coupled to at least on of either the pull up or pull down circuit. The timing circuit controls a time of application of an input signal to at least one of either the pull up or pull down circuit preventing a terminal to terminal signal level experienced by the electronic components exceeding the reliability limits.

A level detector has an input circuit adapted to accept signals of multiple signal levels for detecting a specific level. The signal levels include a first signal level and a larger second signal level. Electronic components of the input circuit have reliability levels less than the second signal level. A latch circuit is coupled to the input circuit for latching a signal consistent with a detected level of an accepted signal.

A signal interface circuit has a signal path for communicatively coupling host circuitry to peripheral circuitry of multiple peripherals. Communication signals in the signal path are of a peripheral signal level. The signal path has electronic components adapted for use in communicating signals between the host circuitry and the peripheral circuitry. The electronic components in the signal path have reliability limits less than the peripheral signal level. The configuration of the electronic components in the signal path allow communication of signals at the peripheral signal level.

Methods and apparatuses are presented for voltage tolerant floating N-well circuits. An apparatus for mitigating leakage currents caused by input voltages is presented which includes a first transistor having a source coupled to a positive voltage supply, and a drain coupled to a floating node. The apparatus may further include a controllable pull-down path coupled to a negative voltage supply and the first transistor, wherein the controllable pull-down path is configured to turn on the first transistor and pull-up the floating node during a first state. The apparatus may further include a second transistor having a source coupled to a gate of the first transistor, and drain coupled to the floating node, wherein the second transistor is configured to place the floating node at a floating potential during a second state.

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San Francisco, CA, United States of America

Abheek Gupta