An open-loop charge pump

A charge pump and circuit technology, used in electrical components, high-efficiency power electronic conversion, output power conversion devices, etc., can solve the problems of audio signal interference and take a long time to drop, and achieve improved sound quality and increased ripple frequency. Effect

CN108242888BActive Publication Date: 2020-04-21SHANGHAI AWINIC TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2020-04-21

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Abstract

The invention discloses an open-loop charge pump. The open-loop charge pump is provided with a peak current limiting control circuit between the control circuit and the booster circuit. The control circuit is based on the overvoltage protection signal , driving the peak current limiting control circuit, and controlling the boost circuit to be in the charging phase or the discharging phase through the peak current limiting control circuit. When the output voltage is greater than the upper threshold voltage, the boost circuit continues to be in the charging phase, stops supplying power to the output load, and supplies power to the output load through the discharge of the output capacitor; when the output voltage is less than When the threshold voltage is lower than the lower limit, the boost circuit is in the normal working mode. In this way, the music noise problem caused by the ripple frequency of the output voltage of the charge pump being in the audio frequency range can be avoided, and the sound quality is improved.
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Description

technical field

[0001] The invention relates to the technical field of integrated circuits, and more specifically relates to an open-loop charge pump. Background technique

[0002] A charge pump, also known as an inductorless DC / DC converter, is a special type of switching DC / DC converter that uses capacitors as energy storage elements. In battery-powered portable electronic devices, a boost charge pump circuit is often used as a power converter, which requires no power compared to an inductive switching DC / DC converter that uses an inductor as an energy storage element. Inductors have the advantages of small EMI (electromagnetic interference), small footprint, and low system cost. Charge pumps can generally be divided into regulated output types and unregulated output types. The voltage-regulated output charge pump circuit generally adopts a closed-loop control structure. The output voltage of the charge pump circuit is sampled through a voltage dividing resistor inside t...

Examples

Embodiment Construction

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0035] refer to figure 1 with figure 2 , figure 1 It is a schematic diagram of the circuit structure of an open-loop charge pump, figure 2 for figure 1 The voltage sequence diagram of the open-loop charge pump shown, the open-loop charge pump includes: output voltage detection circuit 14, overvoltage protection circuit 13, control circuit 12, clock circuit 16, boost circuit 11, overcurrent detection 17 and reference Circuit 15. The boost circuit 11 prov...