Optical isolation amplifier with sigma-delta modulation

An optical isolation amplifier comprising:

• input pads for receiving an analog input signal;
• a sigma-delta converter coupled to the input pads for converting the analog input signal to a digital pulse stream;
• an encoder coupled to the sigma-delta converter for converting the digital pulse stream to edge-encoded digital signals;
• and
• an optical transmitter/receiver coupled to the encoder for transmitting an optical signal indicative of the digital signal over an optical channel and detecting the transmitted optical signal.

A method for sensing signals in a system comprising the steps of:

• providing an optical isolation amplifier having an input chip including a sigma-delta analog-to-digital converter optically coupled to an output chip;
• passing an analog voltage input signal into the isolation amplifier;
• converting the analog voltage signal to a plurality of digital pulses having a time-average value substantially equal to the analog voltage input signal;
• edge-encoding the digital pulses;
• and
• modulating a light emitting diode with the edge-encoded digital pulses.

An optical isolation amplifier package comprising:

• an input chip having a p-channel punch-through device coupled to a sigma-delta converter for receiving an analog signal and converting the analog signal to a digital signal;
• a light source for optically transmitting the digital signal;
• and
• an output chip optically coupled to the light source for receiving the digital signal.