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 bandgap current reference circuit includes a bandgap core circuit and an error amplifier. The bandgap core circuit is configured to generate a zero temperature coefficient bandgap current. The bandgap core circuit includes a bipolar transistor. The bipolar transistor is configured to pass a current that is proportional to absolute temperature (PTAT current). The error amplifier is coupled to the bandgap core circuit and includes a bipolar differential input pair. The bipolar differential input pair is configured to ensure that the PTAT current is flowing in the bipolar transistor.

A bandgap current reference circuit includes a bandgap core circuit and an error amplifier. The bandgap core circuit is configured to generate a zero temperature coefficient bandgap current. The bandgap core circuit includes a bipolar transistor. The bipolar transistor is configured to pass a current that is proportional to absolute temperature (PTAT current). The error amplifier is coupled to the bandgap core circuit and includes a bipolar differential input pair. The bipolar differential input pair is configured to ensure that the PTAT current is flowing in the bipolar transistor.

Circuits, systems, and methods to switch modes based on temperature and to provide reference voltages are discussed herein. For example, a bandgap reference circuit may include one or more impedance elements and one or more switches coupled to the one or more impedance elements. The one or more switches may be controllable based on a temperature signal. The bandgap reference circuit may be configured to provide a bandgap reference voltage that is associated with less than a particular amount of voltage variation.

A bandgap reference circuit generates a PTAT voltage and a CTAT voltage having a different temperature characteristic from the PTAT voltage and generates a reference voltage based on the PTAT voltage, the CTAT voltage, and a compensation voltage. The bandgap reference circuit generates a CTAT current having a different temperature characteristic from the PTAT voltage based on the CTAT voltage and determines the compensation voltage based on the CTAT current.

A bandgap current reference circuit includes a bandgap core circuit and an error amplifier. The bandgap core circuit is configured to generate a zero temperature coefficient bandgap current. The bandgap core circuit includes a bipolar transistor. The bipolar transistor is configured to pass a current that is proportional to absolute temperature (PTAT current). The error amplifier is coupled to the bandgap core circuit and includes a bipolar differential input pair. The bipolar differential input pair is configured to ensure that the PTAT current is flowing in the bipolar transistor.

A bandgap current reference circuit includes a bandgap core circuit and an error amplifier. The bandgap core circuit is configured to generate a zero temperature coefficient bandgap current. The bandgap core circuit includes a bipolar transistor. The bipolar transistor is configured to pass a current that is proportional to absolute temperature (PTAT current). The error amplifier is coupled to the bandgap core circuit and includes a bipolar differential input pair. The bipolar differential input pair is configured to ensure that the PTAT current is flowing in the bipolar transistor.

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.

According to an embodiment, an arithmetic device includes a comparator, M cross switches, and M coefficient circuits. The comparator compares a first voltage generated at a first comparison terminal and a second voltage generated at a second comparison terminal. The M cross switches are provided corresponding to the M input signals. The M coefficient circuits are provided corresponding to the M coefficients, and each includes a first constant current source and a second constant current source. Each of the M cross switches performs switching between a straight state and a reverse state. In each of the M coefficient circuits, the first constant current source is connected between a positive output terminal of the corresponding coefficient circuit and a reference potential, and the second constant current source is connected between a negative output terminal of the corresponding coefficient circuit and the reference potential.

Various embodiments include an apparatus for limiting voltage for a DC voltage network, wherein overvoltages resulting from switching operations occur between a first supply potential level and a second supply potential level of the DC voltage network. The apparatus comprises at least two limiter cells connected in series between the first supply potential level and the second supply potential level. Each limiter cell comprises a controllable switching element, a discharge resistor, and a capacitor, across all of which a voltage applied between the first supply potential level and the second supply potential level is dropped. During operation of the apparatus, based at least in part on the voltage dropped across the respective capacitor of a particular limiter cell, the controllable switching element of the limiter cell is switched on or off.