Voltage level translator circuit

A method of limiting the voltages of input signals, and of generating output signals with voltages less than or equal to a desired voltage limit, comprising the steps of:

• generating a reference signal and a lower rail signal, the reference signal being at a voltage equal to the sum of the lower rail voltage and the desired voltage limit;
• applying an input signal to an input of a digital device having a second upper rail voltage and a second lower rail voltage terminal;
• generating a difference signal by subtracting the output of the digital device from the reference signal;
• applying a second upper rail voltage signal to the second upper rail voltage terminal of the digital device and applying the lower rail signal to the second lower rail voltage terminal of the digital device, said second upper rail voltage signal having a voltage equal to the difference signal.

A voltage level translator circuit, for limiting an input signal to a desired voltage limit, comprising:

• a digital device receiving an input signal and providing a plurality of output signals, said digital device having an upper rail voltage terminal and a lower rail voltage terminal;
• a reference signal generator, generating a reference signal equal to a desired voltage limit;
• a differential amplifier having a first and second input, receiving the reference signal and receiving an output of the digital device, and generating a difference signal;
• means for applying the difference signal to the upper rail voltage terminal of the digital device.

A voltage level translator circuit, for limiting an input signal to a desired voltage limit, comprising:

• a digital device receiving an input signal and providing a plurality of output signals, said digital device having an upper rail voltage terminal and a lower rail voltage terminal;
• a reference signal generator, generating a reference signal equal to a desired voltage limit;
• a differential amplifier, having a first and second input, said differential amplifier generating a difference signal;
• means for connecting the reference signal to the first input of the differential amplifier;
• means for connecting an output of the digital device to the second input of the differential amplifier;
• and
• means for applying the difference signal to the upper rail voltage terminal of the digital device.