Low noise bandgap voltage reference
AssigneeAnalog Devices, Inc.
InventorStefan Marinca
Life of this patent
Estimating the term…
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.
Claims26
A bandgap voltage reference circuit configured to provide a voltage reference at an output thereof, the circuit including an amplifier coupled to first and second transistors respectively, the amplifier having inverting and non-inverting inputs, the transistors being configured to generate a voltage indicative of a base-emitter voltage difference between each of the first and second transistors across a sensing resistor, wherein the base of the first transistor is coupled to the non-inverting input of the amplifier and the collector of the first transistor is coupled to the inverting input of the amplifier, the second transistor in a diode-configuration, and the circuit provides an additional current to the sensing resistor from a diode-connected third transistor, to reduce the contribution of noise from the first transistor into the amplifier.
A curvature corrected bandgap voltage reference configured to provide a second order corrected voltage reference at an output thereof, the circuit including an amplifier coupled to first and second transistors respectively, the amplifier having inverting and non-inverting inputs, the transistors being configured to generate a voltage indicative of a base-emitter voltage difference between each of the first and second transistors across a sensing resistor, wherein the base of first transistor is coupled to the non-inverting input of the amplifier and the collector of the first transistor is coupled to the inverting input of the amplifier, the second transistor is in a diode configuration, and the circuit provides an additional current from a third, diode-connected transistor to the sensing resistor to reduce the contribution of noise from the first transistor into the amplifier, the circuit additionally including a temperature-dependent current source providing a current to the first transistor to reduce second-order temperature effects from the voltage reference.
Dependencies are inferred from the claim text.