Supply voltage independent bandgap based reference generator circuit for SOI/bulk CMOS technologies

A reference generating circuit comprising:

• a load element connected between a terminal for receiving a first external power supply voltage and an output reference terminal;
• means for supplying a current through said load element, including means for receiving a second external power supply voltage and for receiving a load current control voltage, and means for supplying the current through said load element in response to the received second power supply voltage and in accordance with the received load current control voltage;
• a differential amplifier having a first branch, a second branch, and a common current branch, said first branch and said second branch connected in parallel between a terminal for receiving the second external voltage and a first end of the common current branch,
• said first branch including a first current control element connected in series with a second current control element, each having a current input, a current output and a control terminal, and each having means for controlling the current between its current input and current output according to a voltage received at its respective control terminal, the means for controlling the current between the current input and current output of the second current control element passing a predetermined current through the second current control element when its control terminal receives a voltage equal to a first bias voltage,
• said second branch including means for detecting a current passing through said second branch and for outputting, based on said detected current, the load current control voltage to the means for supplying a current through said load element, and including a third current control element and a fourth current control element, each having a current input and a current output and a control terminal, and each having means for controlling the current between its respective input and output according to a voltage received at its respective control terminal, wherein the means for controlling the current between the current input and output of the fourth current control element passes approximately said predetermined current through the fourth current control element when the voltage on its control terminal is above a first threshold voltage of the fourth current control element, and
• the common current branch includes a second bias control terminal for receiving a second bias voltage and includes a bias means for controlling a current from the first end of the common current branch to a terminal for receiving the first external voltage in accordance with the received second bias voltage, and
• wherein
• the control terminal of the first current control element is connected to the control terminal of the third current control element,
• the reference terminal of the load element is connected to the control terminal of the fourth current control element,
• whereby
• upon concurrently receiving the first predetermined bias voltage at the control terminal of the second current control element, the second predetermined bias voltage at the second bias control terminal, and a predetermined range of first and second external power supply voltages, the reference output terminal output is driven to approximately the first threshold voltage of the fourth current control element.