Apparatus for Reference Voltage Generation for I/O Interface Circuit

摘要

An apparatus includes a first input/output (I/O) interface circuit having a maximum voltage rating. The first I/O interface circuit includes a level shifter and an output stage. A reference voltage bias generator is coupled to the first I/O interface circuit, to a first supply voltage, and to a first ground potential. The reference voltage bias generator is configured to generate a plurality of reference bias signals, including a first reference voltage and a second reference voltage. When the first supply voltage is not greater than the maximum voltage rating, the first reference voltage is equal to the first supply voltage and the second reference voltage is equal to the first ground potential. When the first supply voltage is greater than the maximum voltage rating, the first reference voltage is equal to the first supply voltage times a first fraction, and the second reference voltage is equal to the first supply voltage times a second fraction.

主权项

1. An apparatus comprising:
a first input/output (I/O) interface circuit having a maximum voltage rating, the first I/O interface circuit comprising a level shifter and an output stage; and a reference voltage bias generator coupled to the first I/O interface circuit, to a first supply voltage, and to a first ground potential, wherein
the reference voltage bias generator is configured to generate a plurality of reference bias signals comprising a first reference voltage and a second reference voltage,when the supply voltage is not greater than the maximum voltage rating, the first reference voltage is equal to the supply voltage and the second reference voltage is equal to the first ground potential, andwhen the supply voltage is greater than the maximum voltage rating, the first reference voltage is equal to the supply voltage times a first fraction, and the second reference voltage is equal to the supply voltage times a second fraction.