Novel charge pump circuit in chip for motor drivers

Abstract

The invention discloses a novel charge pump circuit in a chip for motor drivers, which comprises at least a pair of PMOS (p-channel metal oxide semiconductor) switch tubes, at least a pair of NMOS (N-channel metal oxide semiconductor) switch tubes, a feedback control unit, an OSC oscillator, and driver units, wherein the number of the driver units is same as the number of the MOS switch tubes; and the PMOS switch tubes and the NMOS switch tubes constitute a set of H-bridge topological structure, the PMOS switch tubes and the NMOS switch tubes are respectively connected with the corresponding driver units thereof, at least a PMOS switch tube is connected with the feedback control unit, and the feedback control unit is connected with the OSC oscillator. Through using the characteristics of output voltages of charge pumps, the charge pump circuit disclosed by the invention can ensure the capacity of driving grid electrodes of H-bridge high-end NMOS power tubes in direct-current/stepping motor drivers, so that a situation that the current for driving a direct-current/stepping motor keeps constant is ensured, therefore, small electromagnetic interference is ensured, and the on-resistance of each H-bridge high-end NMOS power tube can be reduced, so that the stable current of the motor is satisfied, and the operating efficiency of the driver is ensured.

Description

technical field [0001] The invention relates to a charge pump, in particular to a charge pump circuit in a novel DC / stepping motor driver chip. Background technique [0002] A charge pump, also known as a switched-capacitor voltage converter, is a DC-DC converter that uses so-called "fast" or "pumping" capacitors (rather than inductors or transformers) to store energy. High or low, can also be used to create negative pressure. By using the charge pump, it can generate a voltage higher than the input voltage, so it is very suitable for the H-bridge power drive circuit, and can be used as the driving voltage of the H-bridge high-end power tube. Although it increases the complexity of the system, it can provide multiple power outputs and improve the overall efficiency of the system, so it is widely used in electrical and electronic products. [0003] The switching transistor inside the charge pump circuit controls the charging and discharging of the flying capacitor in a cert...

AI Technical Summary

Problems solved by technology

Therefore, the required voltage factor is variable, and the existing fixed topology charge pump is difficult to meet this requirement

[0007] 2. Compared with other DC-DC converters, the charge pump has higher energy utilization efficiency, generally up to 80%, but if the voltage factor is small, the difference between the output voltage and the input voltage is relatively small, which will lead to The efficiency of some charge pumps is greatly reduced, and most of the energy will be consumed by the switch tube and bias circuit of the charge pump, and unnecessary heat energy will be generated to affect the normal operation of the chip.

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