Abstract: The invention provides a bandgap voltage reference circuit that is adapted to provide a ?Vbe of sufficiently large value that no amplification is required, and therefore any offset contribution is not gained. Using a stacked arrangement of three pairs of transistors, the invention reduces the requirement for multiple resistors within a circuit and can therefore minimise errors due to resistor matching and value. Internally provided circuitry for reducing voltage curvature is provided with the result that a circuit having low offset sensitivity and curvature correction is provided.

Abstract: A bandgap voltage reference is described which has reduced sensitivity to noise and amplifier offset. By configuring the circuitry such that the base width of the component transistors is not varied on application of a bias, it is possible to obviate the Early effect.

Abstract: A voltage reference circuit is provided which includes PTAT and CTAT generating components. The CTAT components are provided in a feedback configuration about an operational amplifier and are combined with PTAT generating components which are coupled to the inputs of the amplifier. The combination of the CTAT and PTAT components is effected in a manner which provides for a temperature curvature correction of the output voltage of the circuit.

Abstract: A voltage bandgap reference voltage circuit is provided. The circuit includes an amplifier having a first and second transistor coupled to the inputs of the amplifier. The circuit is adapted to operate with lower headroom by effecting a subtraction of a voltage substantially equivalent to Delta Vbe of the first and second transistors from the voltage applied to the common input of the amplifier.

Abstract: The present invention provides a method and apparatus for compensating for temperature effects in the operation of semiconductor processes circuitry, such as reference circuits. The method operates on the realisation that the second order effects such as “curvature” in the reference voltage variation over a temperature range is removed. The reference voltage variation over a temperature range can be represented as a straight line. This method provides for the trimming of the absolute voltage by scaling the reference voltage at a first temperature to the desired value by a temperature independent voltage. Then, at a second temperature, the output voltage slope is corrected by adding or subtracting a voltage which is always zero at the first temperature.

Abstract: The invention describes a bandgap reference circuit that may be configured to provide a reference current or voltage as an output thereof. The output may be provided in the form of a constant source, or one including PTAT or CTAT dependencies. The circuit utilises a single amplifier whose output is coupled to a current control block which is then used to drive a dual feedback loop of the amplifier. Inputs to the amplifier are directly coupled to reference nodes in a manner which establishes a PTAT voltage across a resistor at an input of the amplifier.

Abstract: The present invention provides an improved reference source. The reference source has reduced sensitivity to the input offset voltage of the amplifier components in the reference circuit. This is achieved by subtracting two currents at the reference output node such that the combined offset sensitivity is less than the corresponding offset sensitivity for only one current.

Abstract: A bandgap voltage reference circuit (1) comprises a bandgap cell (7) comprising first and second transistor stacks (8,9) of first transistors (Q1,Q2) and second transistors (Q3,Q4), respectively, arranged for developing a correcting PTAT voltage (&Dgr;Vbe) across a primary resistor (R1) proportional to the difference in the base-emitter voltages of the first and second transistor stacks (8,9). A first current mirror circuit (10) provides PTAT currents (12 to 15) to the emitters of the first and second transistors (Q1 to Q4), and an operational amplifier (A1) maintains the voltage on the emitter of the first transistor (Q2) of the first transistor stack (8) at the same level as the resistor (R1) and sinks a PTAT current from the first current mirror circuit (10) from which the other PTAT currents are mirrored.

Abstract: A voltage bandgap reference voltage circuit is provided. The circuit includes an amplifier having a first and second transistor coupled to the inputs of the amplifier. The circuit is adapted to operate with lower headroom by effecting a subtraction of a voltage substantially equivalent to Delta Vbe of the first and second transistors from the voltage applied to the common input of the amplifier.

Abstract: A voltage reference circuit is provided which includes PTAT and CTAT generating components. The CTAT components are provided in a feedback configuration about an operational amplifier and are combined with PTAT generating components which are coupled to the inputs of the amplifier. The combination of the CTAT and PTAT components is effected in a manner which provides for a temperature curvature correction of the output voltage of the circuit.