A power supply particularly suitable for high-speed optical data transmission employs readily available components to achieve desired voltage tolerances. More specifically, a voltage signal supplied to a load is converted into a digital signal and provided to a processor that derives a digital correction signal from the digital signal. The digital correction signal is then converted to an analog correction signal and is used by a feedback control circuit in the power supply to regulate the output voltage.
1. A power supply comprising:
a DC-to-DC converter including an output for connection to a load, a means for deriving a signal representative of the voltage at the output, and a control circuit for controlling the voltage at the output in dependence upon the derived signal;
means for connecting the output to the load;
means for deriving a digital representation of the voltage at the load;
a processor for deriving a digital correction signal from the digital representation;
means for converting the digital correction signal to an analog correction signal; and
means for combining the analog correction signal with the derived signal, wherein the means for deriving a digital representation and the means for converting the digital correction signal each have a resolution of at least 2 12 steps.
2. A power supply comprising:
a DC-to-DC converter including an output for connection to a load, a means for deriving a signal representative of the voltage at the output, and a control circuit for controlling the voltage at the output in dependence upon the derived signal;
means for connecting the output to the load;
means, for deriving a digital representation of the voltage at the load;
a processor for deriving a digital correction signal from the digital representation;
means for converting the digital correction signal to an analog correction signal; and
means for combining the analog correction signal with the derived signal,
wherein the means for connecting and the means for combining comprise resistive elements and wherein tolerances of the resistive elements and resolution of the means for deriving a digital representation and the means for converting the digital correction signal are selected such that the voltage supplied to the load has a tolerance equal to or better than approximately ±2%.