CN202905114U

CN202905114U - LED display drive circuit

Info

Publication number: CN202905114U
Application number: CN2012204850923U
Authority: CN
Inventors: 蔡峻
Original assignee: ZHONGSHAN JINGWEI ELECTRONIC TECHNOLOGY Co Ltd
Current assignee: ZHONGSHAN JINGWEI ELECTRONIC TECHNOLOGY Co Ltd
Priority date: 2012-09-21
Filing date: 2012-09-21
Publication date: 2013-04-24
Anticipated expiration: 2022-09-21

Abstract

The utility model discloses a LED display drive circuit comprising a drive chip provided with N drive ports and a LED array, two LEDs are connected in parallel between two random drive ports of the N drive ports of the drive chip, an anode of any LED of the two LEDs connected in parallel is connected with a cathode of the other LED, and all the LEDs in the LED array are arranged in an N*(N-1) matrix form. Compared with conventional drive (N/2)*(N/2), utilization rate is greatly improved; even compared with most advanced combination arrangement mode=N*(N-1)/2 in the prior art, 100% improvement is made; so PCB wiring and pad are reduced, LED driving hardware members are reduced, and printed circuit board fabricating difficulty and system cost can be effectively reduced.

Description

A kind of LED display driver circuit

Technical field

The utility model relates to a kind of display driver circuit, especially a kind of LED display driver circuit.

Background technology

Fig. 1 is a kind of connected mode of a kind of common cathode of common LED digitron, by being lighted by control respectively or extinguishing 8 LED, can form digital " 0 " to " 9 ", partial character and radix point.

Fig. 2 is that LED drives the synoptic diagram that chip is connected with display tube.Can see that each digitron of 8 sections needs the driving port of a common cathode.N of conventional ADS driving chip drives port only can drive (N/2) * (N/2) LEDs, again such as the present most effective technology of disclosed driving chip, i.e. a kind of invention of LED display driver circuit, employing be the arrangement mode that makes up in the mathematics Be N drive port can driving N * (N-1)/2 LED, there is very large utilization factor to promote than conventional ADS driving, but also do not reach best utilization factor effect, therefore when connecing a plurality of LED display, often need more to drive chip and drive, so just mean the increase of hardware cost, printed circuit board area, pad, cabling be corresponding increase also, thereby has increased printed circuit board (PCB) fabric swatch difficulty and system cost.

The utility model content

The technical problems to be solved in the utility model provides a kind of the highest LED display driver circuit of port utilization ratio that drives.

For solving the problems of the technologies described above, the technical solution adopted in the utility model is: a kind of LED display driver circuit, comprise and have N driving chip and led array that drives port, two LEDs in parallel between any two in the N of described driving chip the driving port, anode any one among the LED of described two parallel connections all links to each other with another negative electrode, all LED arrange with the matrix form of N* (N-1) and form in the described led array, wherein N is columns, N-1 is line number, and the connected mode of LED is the row common anode utmost point or row common cathode in the described led array.

Further, described driving port voltage is greater than the LED conduction voltage drop and less than the LED conduction voltage drop of twice.

Further, described driving port is separately controllable ternary output and drives port.

Further, the working method of described ternary output driving port is the dynamic scan operation.

The beneficial effects of the utility model: all be parallel with positive and negative two LEDs between any two in the N of described driving chip the driving port, described led array is how much arrangements

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, driving LED quantity

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=N*(N-1), there is great utilization factor to promote than conventional ADS driving (N/2) * (N/2), with state-of-the-art combination arrangement mode in the prior art

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=N*(N-1)/2 compare 100% lifting is also arranged, can effectively reduce printed circuit board (PCB) fabric swatch difficulty and system cost, wherein A and C are respectively the mathematic sign of " arrangement " and " combination ".

Description of drawings

Below in conjunction with accompanying drawing embodiment of the present utility model is described further.

Fig. 1 is a kind of connected mode of a kind of common cathode of LED digitron;

Fig. 2 is that LED drives the synoptic diagram that chip is connected with display tube;

Fig. 3 is the LED display driver circuit schematic diagram of an embodiment;

Fig. 4 is the three-state driver model;

Fig. 5 is three-state driver driving LED schematic diagram.

Embodiment

Figure 3 shows that a kind of LED display driver circuit schematic diagram of present embodiment, comprise and have N driving chip 1 and led array 2 that drives port D1 ~ DN, two LEDs in parallel between any two in N the driving port of driving chip 1, anode any one among the LED of two parallel connections all links to each other with another negative electrode, all LED arrange with the matrix form of N* (N-1) and form in the led array 2, wherein N is columns, N-1 is line number, and N is the positive integer more than or equal to 2, and the connected mode of LED is the row common anode utmost point or row common cathode in the described led array.Described driving port voltage can guarantee to be unlikely to connect two relevant LEDs of conducting greater than the LED conduction voltage drop and less than the LED conduction voltage drop of twice when a certain tie point breaks down.

Present embodiment is the LED display driver circuit of N=16, and among other embodiment, N can get appropriate value according to the driving force of D mouth, obtains different LED display driver circuits.According to calculating, have N driving chip 1 that drives port and can connect altogether N* (N-1) LEDs.There is great utilization factor to promote with respect to conventional ADS driving (N/2) * (N/2), with state-of-the-art driving combination arrangement mode in the prior art

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=N*(N-1)/2 compare 100% lifting is also arranged, therefore reduced PCB layout and pad, reduce LED and driven hardware element, can effectively reduce printed circuit board (PCB) fabric swatch difficulty and system cost.

The LED display driver circuit of present embodiment adopts separately controllable ternary output to drive port.Figure 4 shows that the three-state driver model, there is an automatic transfer switch three-state driver inside, and when switching over arrived the NC contact, D exported high-impedance state; When switching over arrives VDD, D output 1(high level); When switching over arrives GND, D output 0(low level).

Figure 5 shows that three-state driver driving LED principle, Q1 internal drive switch switches to VDD, and Q2 internal drive switch switches to GND, at this moment, Q1 output 1(high level), Q2 output 0(low level), being added in the voltage forward of LED, the LED forward conduction is luminous.When needs are lighted some LED lamps, just allow its forward conduction, namely the LED anode adds high level voltage, and negative electrode adds low level voltage, the LED forward conduction.Extinguish if wish LED, the driving port that allows corresponding LED connect is high level simultaneously or is that low level or arbitrary end are high-impedance state simultaneously.

The driver that LED drives chip is not quiescent operation, but adopts dynamic scan mode to carry out work, and all LED lamps all are that to organize be that unit lights in turn or extinguishes.The LED that the LED display driver circuit of present embodiment has reduced application system drives chip 1 quantity, drives port with still less LED and drives more light-emitting diode display spare.Drive lead-in wire and LED driving port number owing to reduced, so that whole system has more pcb board space to realize other greater functionality or make design be more prone to the layout cabling when design, enhance product performance, alleviate maintenance and maintenance difficulties.

The above only is preferential embodiment of the present utility model, and the utility model is not limited to above-mentioned embodiment, as long as realize that with basic identical means the technical scheme of the utility model purpose all belongs within the protection domain of the present utility model.

Claims

1. LED display driver circuit, comprise and have N driving chip (1) and led array (2) that drives port, it is characterized in that, two LEDs in parallel between any two in N the driving port of described driving chip (1), anode any one among the LED of described two parallel connections all links to each other with another negative electrode, all LED arrange with the matrix form of N* (N-1) and form in the described led array (2), wherein N is columns, N-1 is line number, and the connected mode of LED is the row common anode utmost point or row common cathode in the described led array.

2. a kind of LED display driver circuit according to claim 1 is characterized in that, described driving port voltage is greater than the LED conduction voltage drop and less than the LED conduction voltage drop of twice.

3. a kind of LED display driver circuit according to claim 1 is characterized in that, described driving port is separately controllable ternary output and drives port.