Self-excited charge pump circuit

Abstract

The invention relates to a self-excited charge pump circuit which comprises a switching unit and a control unit, wherein the switching unit is respectively connected with nodes in a boosting unit and used for controlling the boosting unit to charge and discharge, and the control unit is used for controlling the switching unit to carry out a corresponding switching-on / off operation according to feedback voltage of an output terminal. A clock driver required for a common charge pump circuit is omitted, loop compensation is not required, and the number of external elements can be reduced to the minimum; EMI noise of a specific frequency component generated during working of an external clock driver is reduced while the circuit design is optimized; and electromagnetic interference is restrained, the self-excited charge pump circuit is enabled to be widely used in medical equipment extremely sensitive to noise, and the shortcomings in the prior art are overcome.

Description

technical field [0001] The invention relates to a charge pump circuit, in particular to a self-excited charge pump circuit applied to medical equipment. Background technique [0002] A charge pump circuit is a circuit that converts an input potential into a positive high potential or a negative low potential. Due to system requirements or the need to improve the performance of integrated circuits, there will still be high-voltage circuits or high-voltage devices inside the integrated circuit chip, so the charge pump circuit is used as the power supply circuit in the integrated circuit, that is, the charge pump circuit is used to boost the input voltage to provide a predetermined voltage circuit use. At present, the general charge pump circuit is composed of transistors, capacitors, clock drivers and so on. However, the traditional charge pump circuit needs to use a complex external clock to drive the switch transistor circuit, and the external clock circuit not only increa...

AI Technical Summary

Problems solved by technology

However, the traditional charge pump circuit needs to use a complex external clock to drive the switch transistor circuit, and the external clock circuit not only increases the complexity of the circuit, but also the charge pump circuit will generate EMI noise with a certain frequency component when the high frequency operating clock, if This frequency component falls below the frequency band that will be suppressed in the environment in which the IC will be used, causing electronic interference problems in operation

This is especially difficult to suppress in medical imaging systems that are extremely sensitive to interfering noise

In addition, in the switching circuit, the driving circuit of the power-side transistor and the ground-side transistor does not have a circuit setting for delay processing, and it is easy for the power-side transistor and the ground-side transistor to be turned on at the same time, resulting in circuit damage.

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