Linear Current Driver

Abstract

The invention discloses a linear current driver. According to an embodiment, the linear current driver includes: a current source for generating a reference current; a first resistance circuit for converting the reference current into a reference voltage; a second resistance circuit for generating a feedback voltage; a driving circuit, providing a first gate voltage according to the reference voltage and the feedback voltage; an adjustment circuit providing an adjusted internal current according to the first gate voltage so that the feedback voltage follows the reference voltage; an output circuit that provides a drive current that is n times the internal current according to the first gate voltage, where n is a positive integer; a buffer circuit that provides an adjusted second gate voltage so that The drain voltage of the regulating circuit follows the drain voltage of the output circuit; the switcher circuit is connected between the second resistor circuit and the regulating circuit, and is used for regulating the voltage of the regulating circuit according to the second gate voltage. the internal current.

Description

technical field [0001] The invention relates to a linear current driver of an Optical Image Stabilization (OIS; Optical Image Stabilization) voice coil motor (VCM; Voice Coil Motor) applicable to electronic equipment such as mobile phones. Background technique [0002] Usually, the current driver of an optical image stabilization (OIS; Optical Image Stabilization) voice coil motor (VCM; Voice Coil Motor) applied to electronic devices such as mobile phones needs to ensure that the current used to drive the VCM is maintained within the range from the minimum current to the maximum current. linear characteristics. [0003] A current driver, which is one of conventional current drivers, may include a comparator, a semiconductor switching element, and two resistors. [0004] In the current driver as described above, the input voltage of the comparator becomes the same as the middle node voltage of the 2 resistors, a voltage twice higher than the middle node voltage is applied to...

AI Technical Summary

Problems solved by technology

[0005] However, for the existing current driver, the input voltage of the comparator is directly reflected to the output terminal, so the offset (offset) of an analog circuit such as a comparator is directly displayed at the output terminal, so a solution for offset is required

[0006] Moreover, in order to enable the existing current driver to provide the required drive current, it is necessary to include at least 2 resistors with relatively large capacity (for example, 1Ω) at the output end. Due to the large resistance and size of these resistors, there are technical problems. is that there are limitations in implementing small current drivers

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