Bandgap reference designs with stacked diodes, integrated current source and integrated sub-bandgap reference

A bandgap reference circuit, comprising:

• a first leg including two series-connected diodes;
• a second leg including a resistor connected in series with a plurality of diode branches that are connected in parallel with one another, each said diode branch including two series-connected diodes;
• an amplifier having a pair of inputs and an output, the input respectively coupled to said first and second legs;
• and
• a current source structure having a control input coupled to said amplifier output and having first and second current source outputs respectively coupled to said first and second legs.

A bandgap reference circuit, comprising:

• a first leg having a first diode structure;
• a second leg having a second diode structure in series with a resistor, said second diode structure having a larger diode area than said first diode structure;
• an amplifier having a pair of inputs and an output, the inputs respectively coupled to said first and second legs;
• and
• a current source structure having a control input coupled to said amplifier output and having first and second current source outputs respectively coupled to said first and second legs;
• wherein said first current source output provides a first amount of current to said first leg and said second current source output provides a second amount of current to said second leg, said first amount of current at least approximately twice as large as said second amount of current;
• and
• wherein said amplifier includes first and second N-channel transistors respectively connected to said amplifier inputs, each of said N-channel transistors produced using a triple well CMOS process, and each of said N-channel transistors having a bulk thereof connected to a source thereof.

A bandgap reference circuit, comprising:

• a first leg having a first diode structure;
• a second leg having a second diode structure in series with a resistor, the second diode structure having a larger diode area than the first diode structure;
• an amplifier having a pair of inputs and an output, the inputs respectively coupled to the first and second legs;
• and
• a current source structure having a control input coupled to the amplifier output and having first and second current source outputs respectively coupled to the first and second legs;
• wherein the amplifier includes first and second N-channel transistors respectively connected to the amplifier inputs, each of the N-channel transistors produced using a triple well CMOS process, each of the N-channel transistors having a bulk thereof connected to a source thereof.