Advanced Micro Devices Corporation

Rajesh Mangalore Anand

Prasant Kumar Vallur

Girish Anathahalli Singrigowda

Jagadeesh Anathahalli Singrigowda

Piyush Gupta

Aniket Bharat Waghide

Ashish Sahu

Systems and techniques for applying voltage biases to gates of driver circuitry of an integrated circuit (IC) based on a detected bus voltage, IC supply voltage, or both are used to mitigate Electrical Over-Stress (EOS) issues in components of the driver circuitry caused, for instance, by high bus voltages in serial communication systems relative to maximum operating voltages of those components. A driver bias generator selectively applies bias voltages at gates of transistors of a stacked driver structure of an IC to prevent the voltage drop across any given transistor of the stacked driver structure from exceeding a predetermined threshold associated with the maximum operating voltage range of the transistors.

Adaptive biasing circuit for serial communication interfaces

A driver circuit drives a high voltage I/O interface using stacked low voltage devices in the pull-up and pull-down portions of the driver. The transistor closest to the PAD in the pull-up portion receives a dynamically adjusted gate bias voltage adjusted based on the value of the data supplied to the output circuit and the transistor in the pull-down portion closest to the PAD receives the same dynamically adjusted gate bias voltage. The transistors closest to the power supply nodes receive gate voltages that are level shifted from the core voltage levels of the data supplied to the output circuit. The transistors in the middle of the pull-up and pull-down transistor stacks receive respective static gate voltages. The bias voltages are selected such that the gate-drain, source-drain, and gate-source voltages of the transistors in the output circuit do not exceed the voltage tolerance levels of the low voltage devices.

High voltage output circuit with low voltage devices using data dependent dynamic biasing

Driver and pre-driver circuitry operate in an integrated circuit with two supply voltages. In one form, a reference voltage generation circuit is operable to respond to varying voltage supply conditions in which a driver may be subject to over voltage effects by generating a reference voltage based the first supply voltage when the second supply voltage is not available, and based on the second supply voltage when the first supply voltage is not available. A first drive signal generation circuit drives a pull-up transistor gate based on a data signal, varying the gate voltage between the second supply voltage and the reference voltage. A second drive signal generation circuit drives a pull-down transistor gate with a signal varying between the second supply voltage minus the reference voltage, and zero volts. In one form, certain gate-source voltages in the driver are maintained to be equal.

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Bengaluru, India

Rajesh Mangalore Anand