Stmicroelectronics Pvt. Ltd.

Ranjeet Kumar Gupta

Paras Garg

Abhishek Katiyar

A high voltage tolerant input buffer capable of operating across wide range of power supply, including low power supply voltages, dynamically controls the gate voltage of an NMOS pass transistor by sensing the incoming high voltage signal at the pad and dynamically controlling the gate bias voltage of NMOS pass transistor.

High voltage tolerant input buffer

Output buffers which operate at high speeds require delicate handling of the noise on the supply lines. This necessitates control be exercised over current slew rate not only on the rising edge of current but also on the falling edge of the current. A circuit provides control over the current slew rate on the falling edge in high speed output driver charging/discharging heavy load without affecting the speed of the driver (which otherwise would have created supply/ground bounce due to parasitics present in the bonding wires, package pins and on-chip metal interconnects in the I/O ring). The control circuit further suppresses the supply/ground noise by a very significant level while incurring small penalty in terms of silicon area and power dissipation. This circuit includes a CMOS circuit that is cross-coupled input connected to the output buffer input signals with a dummy capacitance coupled to the CMOS circuit output.

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Raebareli, India

Ranjeet Kumar Gupta