A current reference circuit, comprises a main resistor, comprising: a first force contact terminal at a first end of the main resistor and coupled to a first metal-oxide-semiconductor (MOS) component; a second force contact terminal at a second end of the main resistor and coupled to a second MOS component; a first sense contact terminal coupled to one bipolar junction transistor (BJT); and a second sense contact terminal opposite the first sense contact by a length of the main resistor and coupled to another bipolar junction transistor, wherein the first and second sense contact terminals exchange a current reference independently of the first and second force contact terminals.

A current reference circuit, comprises a main resistor, comprising: a first force contact terminal at a first end of the main resistor and coupled to a first metal-oxide-semiconductor (MOS) component; a second force contact terminal at a second end of the main resistor and coupled to a second MOS component; a first sense contact terminal coupled to one bipolar junction transistor (BJT); and a second sense contact terminal opposite the first sense contact by a length of the main resistor and coupled to another bipolar junction transistor, wherein the first and second sense contact terminals exchange a current reference independently of the first and second force contact terminals.

A method and circuit for trimming a bandgap reference are described. The bandgap reference circuit comprises a first diode which is arranged in series with a first resistor between a reference point and a reference potential V.sub.SS. The circuit also comprises a second diode which is arranged in series with a second resistor and a third resistor between the reference point and the reference potential V.sub.SS. In addition, the bandgap reference circuit comprises a trimming network, wherein a bandgap reference voltage V.sub.BG CORE is provided at a midpoint between the trimming network and the current source. The circuit also comprises an operational amplifier. The method (700) comprises measuring a first diode voltage across a replica element of the first diode; determining a first resistance of a replica element of the first resistor; and setting a resistance of the trimming network using the first diode voltage and the first resistance.

Circuits, systems, and methods to automatically switch modes to provide constant reference voltages are discussed herein. For example, a bandgap reference system may include a first bandgap reference circuit configured to provide a first bandgap reference voltage, a low dropout regulator coupled to the first bandgap reference circuit, a temperature circuit coupled to the low dropout regulator, and a second bandgap reference circuit coupled to the low dropout regulator and the temperature circuit. The second bandgap reference circuit may be configured to configure one or more impedance elements based at least in part on a temperature signal and provide a second bandgap reference voltage based on one or more currents that pass through the one or more impedance elements.

A band gap reference voltage generating circuit includes a reference voltage generating circuit, a current generating circuit, a current divider circuit, and a first connection path switching circuit. The reference voltage generating circuit forms a reference voltage on first and second current input terminals thereof. First and second input terminals of the current generating circuit are connected to the first and second current input terminals, respectively. The current generating circuit generates a first current to bias the reference voltage generating circuit. The current divider circuit includes a current input terminal, a first current output terminal, and a second current output terminal. The first connection path switching circuit switches connection paths between the first input terminal and the second input terminal of the current generating circuit, and the first current input terminal and the second current input terminal of the current divider circuit.

A voltage reference circuit is disclosed comprising: a supply terminal; a ground terminal; a first current source and a Zener diode connected in series between the supply and ground terminals and having a first node therebetween and configured to supply a Zener voltage at the first node; an output node configured to provide a voltage reference; and a CTAT, circuit connected between the first node and the output node; wherein the CTAT circuit comprises: two bipolar transistors, having their respective emitters connected at a second node, and configured to, in operation, have equal collector-emitter currents, the base of the first bipolar transistor being connected to the first node, the base of the second bipolar transistor being connected to a centre node of a first voltage divider; and wherein the first voltage divider is connected between the emitter of the second bipolar transistor and the output node.

A bandgap reference voltage generating circuit includes a first current generator generating a first complementary-to-absolute temperature (CTAT) current and a first proportional-to-absolute temperature (PTAT) current, a second current generator generating a second CTAT current and a second PTAT current, and an output circuit outputting a reference voltage based on a difference between a first voltage based on the first CTAT current and the first PTAT current and a second voltage based on the second CTAT current and the second PTAT current, wherein the first CTAT current is cancelled by the second CTAT current.

The present disclosure provides a circuit for generating a complimentary to absolute temperature (CTAT) voltage reference. The primary contributor to the voltage reference is first bipolar junction transistor, which is configured in diode mode, to produce the CTAT voltage. Such references include a non-linear component. A pair of bipolar junction transistors are coupled to the first bipolar junction transistor, and are configured to generate a delta base-emitter voltage. By coupling one of the pair to a proportional to absolute temperature current source, and the other to a current course which is substantially independent of absolute temperature, a further non-linear component is introduced, which is complimentary to the non-linear component introduced by the first bipolar junction transistor. The pair of bipolar transistors share a common emitter area size. As such, the non-linear component of the first bipolar junction transistor is compensated by the delta base-emitter arrangement, resulting in a more linear output.

The present disclosure provides a circuit for generating a complimentary to absolute temperature (CTAT) voltage reference. The primary contributor to the voltage reference is first bipolar junction transistor, which is configured in diode mode, to produce the CTAT voltage. Such references include a non-linear component. A pair of bipolar junction transistors are coupled to the first bipolar junction transistor, and are configured to generate a delta base-emitter voltage. By coupling one of the pair to a proportional to absolute temperature current source, and the other to a current course which is substantially independent of absolute temperature, a further non-linear component is introduced, which is complimentary to the non-linear component introduced by the first bipolar junction transistor. The pair of bipolar transistors share a common emitter area size. As such, the non-linear component of the first bipolar junction transistor is compensated by the delta base-emitter arrangement, resulting in a more linear output.

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.