Image ratio constant flow source circuit driving multipath light emitting diode

Abstract

The invention provides an image ratio constant flow source circuit driving a multipath light emitting diode, belonging to the electronic technical field. The circuit structure comprises a pedestal generation circuit (11), a low-pass filter circuit (12), a V / I0 conversion circuit (13), a multipath image ratio constant flow source circuit (14) and a switch control circuit (16), wherein the image ratio constant flow source circuit (14) comprises transistors (Q10, Q11, ... Q1n), Light Emitting Diode loads (D10, D11, ... D1n), ratio resistors (R10, R11, ... R1n) and a sampling resistor (R0); the switch control circuit (16) comprises a third resistor (R3) and a fourth transistor (Q4), and completes control action by a digital signal (Di). The circuit of the invention leads illumination intensity of the multipath light emitting diode to be stable, can obtain continuous spectrum or modulated spectrum, has convenient use, low cost and electricity conservation, and is convenient for portable instrument use.

Description

technical field [0001] The invention belongs to the field of electronic technology, in particular to a mirror image ratio constant current source circuit for driving multiple light emitting diodes. Background technique [0002] As we all know, the halogen tungsten lamp is the most widely used light source on the spectrometer. Its main advantage is that its radiated spectrum can cover the entire visible to near-infrared region, and it is a continuous spectrum, which realizes continuous Scanning provides the possibility to obtain relatively high resolution. However, tungsten-halogen lamps also have many disadvantages as light sources, such as high power consumption, high heat generation, short service life, effective heat insulation and heat dissipation devices between optical components and tungsten-halogen lamps, etc., therefore, it is not suitable as a Light source use for portable instruments. [0003] Light-emitting diode (LED) is a new type of semiconductor light-emitt...

AI Technical Summary

Problems solved by technology

At present, there is no constant current source circuit that can drive multiple light-emitting diodes in current mode at the same time, the driving current of each channel can be adjusted independently, the structure is relatively simple, and the cost is relatively cheap.

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