General-purpose temperature compensating current master-bias circuit

A temperature compensating bias current generator to create a master biasing current having unique temperature characteristics, said bias current generator comprising:

• a temperature converter to provide a thermal signal indicating a magnitude of temperature;
• a current function generator in communication with the temperature converter to multiply the thermal signal by a bias function having the unique temperature characteristics to create the master biasing current;
• a plurality of mirrored current sources in communication with the current function generator to produce a plurality of bias currents mirrored from said master biasing current;
• and
• a bandgap referenced signal source that generates and communicates a plurality of reference signals to the current function generator, wherein the plurality of reference signals are compared to the thermal signal, said reference signals chosen to determine the bias function.

A temperature compensating bias current generator to create a master biasing current having unique temperature characteristics, said bias current generator comprising:

• a temperature converter to provide a thermal signal indicating a magnitude of temperature, said temperature converter comprising:
• a temperature independent current source to provide a first current that does not fluctuate with a change in temperature,
• a proportional-to-absolute-temperature current source to provide a second current that varies with temperature, and
• a current difference circuit associated with the temperature independent current source and the proportional-to-absolute-temperature current source to receive the first and second currents and from the first and second currents generate the thermal signal that is indicative of a difference between the first and second currents;
• a current function generator in communication with the temperature converter to multiply the thermal signal by a bias function having the unique temperature characteristics to create the master biasing current, said current function generator comprising:
• a current multiplier in communication with the temperature converter to receive the thermal signal, compare the thermal signal with the reference signals to determine a contributing currents indicated by the reference signals to be added to form the master biasing current;
• a plurality of mirrored current sources in communication with the current function generator to produce a plurality of bias currents mirrored from said master biasing current;
• and
• a bandgap referenced signal source that generates and communicates a plurality of reference signals to the current function generator, wherein the plurality of reference signals are compared to the thermal signal, said reference signals chosen to determine the bias function.

A method for generation of a temperature compensating bias current comprising the steps of:

• determining a piecewise function substantially describing a required bias current with respect to temperature;
• determining a plurality of reference signals, each reference signal describing an amount of a contributing current of a plurality of contributing currents, which, when summed together, generate the bias current;
• creating a thermal signal, the magnitude of said thermal signal indicating a temperature;
• comparing each of the reference signals to the thermal signal;
• identifying which of the contributing currents and which portions of said contributing currents are be included to generate the bias current;
• and
• summing identified contributing currents and the portions of the contributing currents to form the bias current.