Voltage reference and startup circuit having low operating current

Abstract

The invention relates to a voltage reference and a startup circuit having a low operating current, and the startup circuit for the voltage reference circuit includes first, second, and third transistors. The first transistor has a first current electrode coupled to the voltage reference circuit, a control electrode, and a second current electrode coupled to a ground terminal. The second transistorhas a first current electrode and a control electrode both coupled to a power supply voltage terminal, and a second current electrode. The third transistor has a first current electrode coupled to the second current electrode of the second transistor and to the control electrode of the first transistor, a control electrode coupled to the voltage reference circuit, and a second current electrode coupled to the ground terminal. During application of a power supply voltage, the second transistor is off, thus providing only a leakage current to the gate of the first transistor. This provides forreliable startup with very low residual current after startup is complete.

Description

technical field [0001] The present disclosure relates generally to circuits and, more particularly, to voltage reference and start-up circuits with low operating currents. Background technique [0002] In integrated circuits, voltage reference circuits are used to provide reference voltages and currents to other circuit blocks. A bandgap voltage reference circuit is a type of reference circuit that uses a silicon bandgap to provide a stable, accurate reference voltage. One type of voltage reference circuit has two stable states, an OFF state with zero current and an ON state with appropriate current to provide the required voltage. An example of this type of voltage reference circuit is in the figure 1 shown in and will be discussed later. To avoid the voltage reference circuit starting up in the off state, a start-up circuit can be used to ensure that current is flowing when the voltage reference circuit is powered. [0003] There are two types of voltage reference star...

AI Technical Summary

Problems solved by technology

However, unlike start-up circuits 13 and 15, start-up circuit 17 requires a clock signal to function, which may add complexity to the circuit design

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