Self-Calibrating Buffer Amplifier and Resistor Trimming Network in Voice Coil Motor Driver

A buffer amplifier and self-calibration technology, which is applied in the direction of improving the amplifier to reduce the harmful effects of internal resistance, can solve the problems of reducing the service time of the battery-powered system, affecting the accuracy of the output current, increasing the power consumption of the driver, and reducing the input of the amplifier. Effects of offsetting, reducing chip cost, and prolonging system usage time

Active Publication Date: 2015-12-09
GIANTEC SEMICON LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to process changes, the amplifier itself has an input offset voltage, which will introduce a DC output offset current, affecting the accuracy of the output current.
At the same time, the amplifier offset voltage will introduce DC current at zero code
VCM drivers operate in zero-code state in most cases, so the amplifier input offset voltage will increase the power consumption of the driver, thereby reducing the operating time of the battery-powered system

Method used

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  • Self-Calibrating Buffer Amplifier and Resistor Trimming Network in Voice Coil Motor Driver
  • Self-Calibrating Buffer Amplifier and Resistor Trimming Network in Voice Coil Motor Driver
  • Self-Calibrating Buffer Amplifier and Resistor Trimming Network in Voice Coil Motor Driver

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Embodiment Construction

[0045] based on the following Figure 2 to Figure 7 , specifically explain the preferred embodiment of the present invention.

[0046] Such as image 3 As shown, the present invention provides a high gain self-calibrating buffer amplifier comprising a pre-amplification stage and a folded amplifier stage in circuit connection.

[0047] The pre-amplification stage includes a current source I0, input pair transistors MP0 and MP1, and a resistor trimming network.

[0048] The current source I0 is connected to the sources of the input pair transistors MP0 and MP1, the gate of MP0 is connected to the input terminal INM, and the gate of MP1 is connected to the input terminal INP, such as Figure 4 As shown, the input terminal IN of the resistor trimming network is connected to the drains of the input pair transistors MP0 and MP1, the output terminal OUT of the resistor trimming network is grounded to VSS, and the Vreg terminal of the resistor trimming network is connected to the po...

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Abstract

The invention relates to a self-calibration buffer amplifier in a voice coil motor driver and a resistor trimming network, which are applied to a voice coil motor lens driver system. The self-calibration buffer amplifier and a self-calibration Class AB buffer amplifier ensure precision of a chip system; direct current power consumption is eliminated or greatly reduced; good system functions are achieved; the chip cost is saved; and with the adoption of the optimized resistor trimming network, the network disorder and network area are reduced, so that the purposes of improving performances of the network and lowering the chip cost are achieved.

Description

technical field [0001] The invention relates to a self-calibration buffer amplifier and a resistance trimming network in a voice coil motor driver, which belongs to the field of integrated circuit design and is applied to large-scale integrated circuits, especially to chip systems for high-precision output current. Background technique [0002] Voice coil motors (VoiceCoilMotor) are widely used in electronic products. In recent years, it has been widely used in smart phones and tablet computers. [0003] Such as figure 1 As shown, the position of the camera lens is driven by the voice coil motor, and the distance of the lens position is proportional to the output current of the voice coil motor driver. When the power of the voice coil motor driver is turned on, the power-on reset device establishes the initial state and bias current / voltage of the driver chip, and sends the chip start signal to the image signal processing main chip through the I2C serial interface (not sho...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): H03F1/08
Inventor张洪杨清
OwnerGIANTEC SEMICON LTD