×

Low drift voltage reference

  • US 9,448,579 B2
  • Filed: 12/20/2013
  • Issued: 09/20/2016
  • Est. Priority Date: 12/20/2013
  • Status: Active Grant
First Claim
Patent Images

1. A voltage reference circuit comprising:

  • a zener diode, including an anode, a cathode, and a positive temperature coefficient for a voltage generated between the anode and the cathode; and

    a temperature compensation circuit, connected to the cathode of the zener diode, configured to provide a temperature stable output voltage reference by subtracting from the voltage at the cathode of the zener diode, a series of base-emitter voltage differences respectively provided by bipolar transistors having different emitter current densities, wherein the temperature compensation circuit includes a series of base-emitter voltage difference circuits to generate the series of base-emitter voltage differences, wherein a base emitter voltage difference circuit is arranged in a cell, the cell comprising;

    a plurality of bipolar transistors arranged in first, second and third arms of the cell and configured to generate a proportional to absolute temperature voltage at an output of the cell that is dependent on individual ones of the plurality of bipolar transistors, and wherein each of the first arm, second arm and third arms are coupled to a single bias current such that the bias current is divided into each of the arms and each of the arms compensates for base current variations in the other of the arms.

View all claims
  • 4 Assignments
Timeline View
Assignment View
    ×
    ×