Example implementations include a bandgap voltage device with a first current source operatively coupled to a bandgap input node and a bandgap output node and operable to output a first proportional-to-absolute-temperature (PTAT) current, a current mirror including a first bandgap transistor and a second bandgap transistor, and operatively coupled to the bandgap output node, and a second current source operatively coupled to the current mirror and operable to output a second PTAT current. Example implementations also include a bandgap transistor device with a first P+ layer proximate to a center of a planar surface of a transistor device, a first N+ layer at least partially surrounding the first P+ layer along the planar surface, a second P+ layer at least partially surrounding the first N+ layer along the planar surface, a second N+ layer at least partially surrounding the second P+ layer along the planar surface, and a third P+ layer at least partially surrounding the second N+ layer along the planar surface.

A bandgap reference circuit includes first through fourth bipolar junction transistors (BJTs). The base and collector of the first BJT are shorted together. The second BJT is coupled to the first BJT via a first resistor. The base of the third BJT is coupled to the base of the first BJT. The base and collector of the fourth BJT are coupled together and also are coupled to the base of the second BJT. A second resistor is coupled to the fourth emitter of the fourth BJT. A third resistor is coupled to the second resistor and to the emitter of the second BJT. An operational amplifier has a first input coupled to the first resistor and the collector of the second BJT, a second input coupled to the emitter of the third BJT and the collector of the fourth BJT, and an output coupled to the collectors of the first and third BJTs.

An integrated circuit includes an output driver circuit configured to provide a first voltage at an output terminal. The output driver circuit includes a transistor having a first current electrode coupled at a voltage supply terminal and a second current electrode coupled at the output terminal, and a resistor having a first terminal coupled at the output terminal and a second terminal coupled at a first node. An amplifier circuit is coupled to the output driver circuit and is configured to generate a proportional to absolute temperature (PTAT) current in a first circuit branch of the output driver circuit coupled at the first node. A complementary to absolute temperature (CTAT) circuit is configured to generate a CTAT current in a second circuit branch coupled at the first node.

A first current proportional to absolute temperature flows in a first current line through a first p-n junction and a second p-n junction arranged in series. A cascaded arrangement of p-n junctions is coupled to the second p-n junction and includes a further p-n junction with a current flowing therethrough that has a third order proportionality on absolute temperature. A differential circuit has a first input coupled to the further p-n junction and a second input coupled to a current mirror from the first p-n junction, with the differential circuit configured to generate a bandgap voltage with a low temperature drift from a sum of first voltage (that is PTAT) derived from the first current and a second voltage (that is PTAT.sup.3) derived from the third current.

A bandgap reference circuit includes first through fourth bipolar junction transistors (BJTs). The base and collector of the first BJT are shorted together. The second BJT is coupled to the first BJT via a first resistor. The base of the third BJT is coupled to the base of the first BJT. The base and collector of the fourth BJT are coupled together and also are coupled to the base of the second BJT. A second resistor is coupled to the fourth emitter of the fourth BJT. A third resistor is coupled to the second resistor and to the emitter of the second BJT. An operational amplifier has a first input coupled to the first resistor and the collector of the second BJT, a second input coupled to the emitter of the third BJT and the collector of the fourth BJT, and an output coupled to the collectors of the first and third BJTs.

Bandgap reference circuitry comprises a first current mirror connected to a power supply line and configured to supply a first current to a first node and a second current to a second node virtually-shorted to the first node, a first pn junction element between the first node and a ground line; a first variable resistor element between the second node and the ground line, and a second pn junction element connected in series to the first variable resistor element. The first variable resistor element has a resistance dependent on a power supply voltage supplied to the power supply line.

Bandgap reference circuitry comprises a first current mirror connected to a power supply line and configured to supply a first current to a first node and a second current to a second node virtually-shorted to the first node, a first pn junction element between the first node and a ground line; a first variable resistor element between the second node and the ground line, and a second pn junction element connected in series to the first variable resistor element. The first variable resistor element has a resistance dependent on a power supply voltage supplied to the power supply line.

A semiconductor device that can perform voltage monitoring with a small circuit area is provided. The resistive subdivision circuit RDIV performs the resistive subdivision of the input voltage Vin by means of the input ladder resistor (R1-R4), and drives the nMOS transistors MN1-MN3 by the subdivided input voltages Vi1-Vi3 each having different resistive subdivision ratios, respectively. The pMOS transistor MP0 is provided in common for the pMOS transistors MP1-MP3, and configures a current mirror circuit with each of the pMOS transistors MP1-MP3. The bias current generating circuit IBSG supplies a bias current to the pMOS transistor MP1.

A first current proportional to absolute temperature flows in a first current line through a first p-n junction and a second p-n junction arranged in series. A cascaded arrangement of p-n junctions is coupled to the second p-n junction and includes a further p-n junction with a current flowing therethrough that has a third order proportionality on absolute temperature. A differential circuit has a first input coupled to the further p-n junction and a second input coupled to a current mirror from the first p-n junction, with the differential circuit configured to generate a bandgap voltage with a low temperature drift from a sum of first voltage (that is PTAT) derived from the first current and a second voltage (that is PTAT.sup.3) derived from the third current.

An apparatus comprising: a first supply node; a second supply node; a first transistor coupled to the first supply node, the first transistor is to provide a first current which is complementary to absolute temperature (CTAT); a second transistor coupled to the first supply node, the second transistor is to provide a second current which is proportional to absolute temperature (PTAT); a resistive device coupled in series at a node with the first and second transistors, and coupled to the second supply node, wherein the node is to sum the CTAT and the PTAT currents.