Constant-current LED drive control circuit suitable for outdoor instrument

Abstract

The invention discloses a constant-current LED drive control circuit suitable for an outdoor instrument in the technical field of integrated circuits. The constant-current LED drive control circuit comprises a power-on reset module; a control module connected to the power-on reset module; a constant current control module connected to the control module; a cathode driving module connected to the constant current control module and the control module; and an anode driving module connected to the control module. All components are integrated into a single-chip IC, the cost is low, the PCB designdifficulty is simplified, a control interface is simplified after single-chip integration, the IO resources of main control equipment are saved, the program development difficulty of the whole machine is reduced, the constant-current output of an SEG port is achieved, the LED brightness is not affected by external conditions, a high-quality display effect is achieved, a shadow elimination modulecapable of being automatically closed is designed at a COM port, and the power consumption is reduced.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to a constant current LED drive control circuit suitable for outdoor instruments. Background technique [0002] LED is a common light-emitting device, which is widely used in lighting, indicator lights, displays and so on. Generally, LED display devices used indoors use logic circuits such as 74HC138, 74HC164, and 74HC273 as controls, and conventional small-drive buffer chips such as 74HC245 are used in the drive stage. However, when using LEDs in outdoor instrumentation equipment, due to factors such as high light intensity in the outdoor environment, it is necessary to use a large current drive to make the LEDs in a high-brightness state to ensure a clear display effect. The chip cannot meet the drive current requirement. [0003] The existing device uses discrete devices to form the control logic, uses small driving devices such as 74HC138 to control the power trans...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a constant current LED drive control circuit suitable for outdoor instruments, to solve the problem that the existing device proposed in the above background technology has many discrete devices, high cost, complex PCB circuit, many interfaces, and occupies the main control unit. There are many resources, which is not conducive to the development of the whole machine program. The output current of COM / SEG cannot be actively controlled. The brightness of the driving LED is affected by the number of LEDs that are lit at the same time and the power supply voltage. The display effect is poor. There is always a problem of current consumption and high energy consumption when outputting an effective high-level signal

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