Patent application number | Description | Published |
20080265860 | Low voltage bandgap reference source - A bandgap voltage reference circuit is described. By providing first and second bipolar devices that are operable with different current densities a base emitter voltage difference is created. This voltage difference is increased by coupling first and second cascode circuits to the first and second bipolars, the cascode circuits also being scaled relative to one another. | 10-30-2008 |
20090027030 | Low noise bandgap voltage reference - 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. | 01-29-2009 |
20090027031 | Low noise bandgap voltage reference - 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. | 01-29-2009 |
20090160537 | Bandgap voltage reference circuit - 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 ΔVbe 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. | 06-25-2009 |
20090160538 | Low voltage current and voltage generator - 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. | 06-25-2009 |
20090243708 | BANDGAP VOLTAGE REFERENCE CIRCUIT - 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 r | 10-01-2009 |
20090243711 | BIAS CURRENT GENERATOR - 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 r | 10-01-2009 |
20090243713 | REFERENCE VOLTAGE CIRCUIT - 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. The feedback load element is such that at a second predetermined temperature the voltage at the output of the amplifier is substantially equal to the voltage at the output of the amplifier at the first temperature. | 10-01-2009 |
20100001711 | REFERENCE CIRCUIT AND METHOD FOR PROVIDING A REFERENCE - 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. | 01-07-2010 |