Abstract: A proportional to absolute temperature (PTAT) circuit is provided. By judiciously combining circuit elements into two or more cell it is possible to effectively dump bias current into impedance resistive element of a first cell from other cells of the circuit. As a result the circuit as a whole can operate with smaller resistive elements and therefore occupy less area when implemented in silicon. It is also possible to reduce the supply current that is required for providing specific output currents or voltages.

Abstract: Circuits and method for providing voltage reference circuits that include low drift over time and lower operating voltages are provided. Generally, it is desirable that a reference circuit provide an accurate and precise reference over time. The voltage reference circuits described can provide for good long term stability, operation at lower voltages than prior designs, consistent output voltage with reduced variability due to process changes and mismatches, low noise in the reference voltage, and other advantages.

Abstract: A proportional to absolute temperature, PTAT, circuit is provided. By judiciously combining circuit elements it is possible to generate a voltage at an output node of the circuit that is temperature dependent. Such a PTAT circuit can be used as a temperature sensor or can be combined with other temperature dependent circuits to provide a voltage reference.

Abstract: A system provides for a voltage reference having a small temperature coefficient spread. The voltage reference includes a PTAT voltage trimming circuit that accurately trims the CTAT voltage component of the bandgap type voltage reference. The voltage trimming circuit includes two bipolar transistors that are biased by biasing currents to create a specific base-emitter voltage difference at an output. The bias currents can be digitally trimmed by a current digital-to-analog (“DAC”) converter. This may result in the ability to trim the voltage reference at a single temperature, without the need to trim at two or more temperatures.

Abstract: A system and method are provided for a more accurate bandgap voltage reference wherein the first and second order errors are corrected simultaneously. By using the components included in the correction of the first order error, the second order errors are corrected, advantageously providing less process variability.

Abstract: A system provides for a voltage reference having a small temperature coefficient spread. The voltage reference includes a PTAT voltage trimming circuit that accurately trims the CTAT voltage component of the bandgap type voltage reference. The voltage trimming circuit includes two bipolar transistors that are biased by biasing currents to create a specific base-emitter voltage difference at an output. The bias currents can be digitally trimmed by a current digital-to-analog (“DAC”) converter. This may result in the ability to trim the voltage reference at a single temperature, without the need to trim at two or more temperatures.

Abstract: A system and method are provided for a PTAT cell with no resistors which can operate at low power, has less sensitivity to process variation, occupies less silicon area, and has low noise. Further, a system and method are provided to scale up the reference voltage and current through a cascade of unit cells. Still further, a system and method are provided for PTAT component to be fine-tuned, advantageously providing less process variability and less temperature sensitivity.

Abstract: A system and method are provided for a PTAT cell with no resistors which can operate at low power, has less sensitivity to process variation, occupies less silicon area, and has low noise. Further, a system and method are provided to scale up the reference voltage and current through a cascade of unit cells. Still further, a system and method are provided for PTAT component to be fine-tuned, advantageously providing less process variability and less temperature sensitivity.

Abstract: A system and method are provided for a PTAT cell with no resistors which can operate at low power, has less sensitivity to process variation, occupies less silicon area, and has low noise. Further, a system and method are provided to scale up the reference voltage and current through a cascade of unit cells. Still further, a system and method are provided for PTAT component to be fine-tuned, advantageously providing less process variability and less temperature sensitivity.

Abstract: A reference circuit configured to provide a reference value. The circuit includes a first circuit unit which is configured to provide a first electrical representation that varies linearly with temperature and has a crossover point where its polarity relative to zero changes from a negative value to a positive value. A second circuit unit is configured to provide a second electrical representation that varies linearly with temperature. The first and second circuit units are operable for facilitating combining the first and second electrical representations such that the combination has a value corresponding to the value of the second electrical representation at a reference temperature.

Abstract: A bias current generator for generating bias current is described. The generator comprises an amplifier having an inverting input, a non-inverting input and an output. A first bipolar transistor is associated with one of the inverting and non-inverting inputs of the amplifier. A load MOS device is associated with the other one of the inverting and non-inverting inputs of the amplifier. The load MOS device is driven by the amplifier to operate in the triode region with a corresponding drain-source resistance ron. The first bipolar transistor and the load MOS device are arranged such that a voltage derived from the first bipolar transistor is developed across the drain-source resistance ron of the load MOS device thereby generating a bias current.

Abstract: A bandgap voltage reference circuit which provides a bandgap reference voltage without requiring a resistor. The circuit comprises an amplifier having an inverting input, a non-inverting input and an output. First and second bipolar transistors are provided which operate at different current densities each coupled to a corresponding one of the inverting and non-inverting inputs of the amplifier. A load MOS transistor of a first aspect ratio is driven by the amplifier to operate in the triode region with a corresponding drain-source resistance ron. The load MOS device is operably coupled to the second bipolar transistor such that a base-emitter difference (?Vbe) resulting from the collector current density difference between the first and second bipolar transistors is developed across the drain-source resistance ron, of the load MOS device. A cascoded MOS device of a second aspect ratio is operably coupled to the load MOS device and is driven by the amplifier to operate in the triode region.

Abstract: A system and method are provided for a PTAT cell with no resistors which can operate at low power, has less sensitivity to process variation, occupies less silicon area, and has low noise. Further, a system and method are provided to scale up the reference voltage and current through a cascade of unit cells. Still further, a system and method are provided for PTAT component to be fine-tuned, advantageously providing less process variability and less temperature sensitivity.

Abstract: A reference voltage circuit which is less dependent on semiconductor process variations compared to bandgap based reference voltage circuits. The circuit comprises a first amplifier having an inverting input, a non-inverting input and an output. A current biasing circuit provides first and second PTAT currents, and a CTAT current. The CTAT current is equal in value to the second PTAT at a first predetermined temperature and opposite in polarity. A first load element is coupled to the non-inverting input of the first amplifier and arranged for receiving the first PTAT current such that a PTAT voltage is developed across the first load element. A feedback load element is coupled between the inverting input and the output of the amplifier for receiving the summation of the CTAT current and the second PTAT current.

Abstract: A system and method are provided for a more accurate bandgap voltage reference wherein the first and second order errors are corrected simultaneously. By using the components included in the correction of the first order error, the second order errors are corrected, advantageously providing less process variability.

Abstract: A low noise voltage reference circuit is described. The reference circuit utilizes a bandgap reference component and may include at least one of a current shunt or filter to reduce high and low noise contributions to the output. Further modifications may include a curvature correction component.

Abstract: A reference circuit configured to provide a reference value. The circuit includes a first circuit unit which is configured to provide a first electrical representation that varies linearly with temperature and has a crossover point where its polarity relative to zero changes from a negative value to a positive value. A second circuit unit is configured to provide a second electrical representation that varies linearly with temperature. The first and second circuit units are operable for facilitating combining the first and second electrical representations such that the combination has a value corresponding to the value of the second electrical representation at a reference temperature.

Abstract: A bandgap reference circuit which is operable in low supply conditions is described. Such a circuit includes a second amplifier and a resistor at the output of a bandgap reference cell to create a constant current summing node at which PTAT and CTAT currents are summed. In modifications to the circuit it is possible to also provide a voltage reference node corresponding to the signal provided at the summing node. A further modification enables generation of a second voltage reference whose value is related to the base emitter voltage Vbe of a bipolar transistor. Further modifications provided for the generation of curvature correction within the circuit by biasing each of the first and second bipolar transistors Q1 and Q2 with currents of different forms.

Abstract: A bandgap voltage reference circuit that can be implemented with low noise characteristics is described. To achieve such low noise, a bandgap reference circuit is provided that includes an amplifier coupled at its inputs to first and second transistors respectively, the transistors being arranged to generate a voltage representative of the base emitter voltage differences between each of the first and second transistors across a sensing resistor. The circuit additionally provides an additional current to the sensing resistor to reduce the noise contribution into the amplifier from the first transistor. Such a circuit may be corrected for second order temperature effects by inclusion of a temperature dependent current source.

Abstract: A bandgap voltage reference circuit with an inherent curvature correction which comprises an amplifier having an inverting terminal, a non-inverting terminal and an output terminal is described. A first and second bipolar transistor operable at different current densities are provided each of the transistors being coupled to a corresponding one of the inverting and non-inverting terminals of the amplifier such that a ?Vbe is reflected across a first load element. A current biasing circuit is provided which includes a semiconductor device coupled to each of the first and second bipolar transistors and is configured for applying a non-linear bias current to the first and second bipolar transistors for biasing thereof.