Providing power, clock, and control signals as a single combined signal across an isolation barrier in an ADC

An isolated analog-to-digital converter system comprising:

• an analog-to-digital converter subsystem including an analog-to-digital converter for converting an analog signal to a digital data stream;
• a microcontroller subsystem for providing power, clock and control signals as a single combined signal for an analog-to-digital converter, the single combined signal comprising a pulse train having a nominal frequency and having control signal pulse width modulated thereon;
• and
• an isolation subsystem for electrically isolating the analog-to-digital converter subsystem from the microcontroller subsystem, the isolation subsystem comprising:
• a first transformer, coupled to the microcontroller subsystem, for receiving the single combined signal as a differential input signal, and
• a voltage divider, coupled to one leg of the first transformer for receiving the differential input signal and outputting the pulse width modulated clock and control signals to the analog-to-digital converter subsystem at a reduced amplitude.

A method for isolating an analog-to-digital converter comprising the steps of:

• in an analog-to-digital converter subsystem including an analog-to-digital converter, converting an analog signal to a digital data stream,
• in a microcontroller subsystem, providing power, clock signals, and control signals as a single combined signal for the analog-to-digital converter, the single combined signal comprising a pulse train having a nominal frequency and having control signal pulse width modulated thereon, and
• in an isolation subsystem, electrically isolating the analog-to-digital converter subsystem from the microcontroller subsystem, said step of electrically isolating further comprising the steps of:
• in a first transformer, coupled to the microcontroller subsystem, receiving the single combined signal as a differential input signal, and
• in a rectifier, coupled to the first transformer, rectifying the differential input signal to produce at least one power supply voltage for the analog-to-digital converter subsystem.

A method for isolating an analog-to-digital converter comprising the steps of:

• an analog-to-digital converter subsystem including an analog-to-digital converter for converting an analog signal to a digital data stream,
• a microcontroller subsystem for providing power, clock and control signals as a single combined signal for an analog-to-digital converter, the single combined signal comprising a pulse train having a nominal frequency and having control signal pulse width modulated thereon, and
• an isolation subsystem for electrically isolating the analog-to-digital converter subsystem from the microcontroller subsystem, said step of electrically isolating further comprising the steps of:
• in a first transformer, coupled to the microcontroller subsystem, receiving the single combined signal as a differential input signal, and
• in a voltage divider, coupled to one leg of the first transformer, receiving the differential input signal and outputting the pulse width modulated clock and control signals to the analog-to-digital converter subsystem at a reduced amplitude.