CN202584690U

CN202584690U - Light-emitting diode (LED) display screen constant-current drive control system

Info

Publication number: CN202584690U
Application number: CN2012202191917U
Authority: CN
Inventors: 胡家同
Original assignee: SHENZHEN MOONCELL ELECTRONICS CO Ltd
Current assignee: SHENZHEN MOONCELL ELECTRONICS CO Ltd
Priority date: 2012-05-16
Filing date: 2012-05-16
Publication date: 2012-12-05
Anticipated expiration: 2022-05-16

Abstract

The utility model discloses a light-emitting diode (LED) display screen constant-current drive control system. the LED display screen constant-current drive control system comprises cascaded LED constant-current driving chips, a clock CLK end, a data latching LE end and an output enabling OE end, wherein the number of the cascaded LED constant-current driving chips is N. Clock CLK pins of the LED constant-current driving chips are connected with one another and then connected to the clock CLK end in the end. Data latching LE pins of the LED constant-current driving chips are connected with one another and then connected to the data latching LE end in the end. Output enabling OE pins of the LED constant-current driving chips are connected with one another and then connected to the output enabling OE end in the end. Any two ends or three ends of the output enabling OE end, the data latching LE end and the clock CLK end are used as current control signal input terminals to input current control signals to the LED display screen constant-current drive control system, and output pins OUT1 to OUTM of the LED constant-current driving chips are controlled through the current control signals to output current.

Description

A kind of LED display constant-current driving control system

Technical field

The utility model relates to a kind of LED Drive Control Technique, relates in particular to a kind of constant-current LED display screen driving control system that function is set fast that has.

Background technology

Display screen is that people receive one of important media of various information.As a kind of multimedia display terminal, display screen has an important indicator, the i.e. capability of fast response of display screen.The current controling signal of traditional LED constant-current driven chip all adopts the serial transmission step by step of shift LD module and since the shift LD module be with word as handling unit, word length is long more, the processing time is also long more; Usually the current controling signal figure place transmits the delivery time that also need pass through whole word less than the data of word length all less than word length like this, has so just limited the data information transmission speed less than word length; Particularly when a plurality of LED constant-current driven chip cascade, postpone more obviously, cascade is many more; Postpone just serious more; Make data transmission efficiency descend, the capability of fast response of LED display control program also is restricted, and systemic-function is difficult for expansion.

The utility model content

In view of this, be necessary a kind of LED display constant-current driving control system to be provided to the problems referred to above.

The utility model adopts following technical scheme: a kind of LED display constant-current driving control system; The LED constant-current driven chip, clock CLK end, data latching LE end, the output enable OE end that comprise N cascade; Wherein the data of LED constant-current driven chip output DO pin links to each other with the data input DI pin of the 2nd LED constant-current driven chip; The data output DO pin of the 2nd LED constant-current driven chip links to each other with the data input DI pin of the 3rd LED constant-current driven chip, is cascaded to N LED chip for driving like this; The clock CLK pin of said N LED constant-current driven chip interconnects, and tandem is to said clock CLK end; The data latching LE pin of said N LED constant-current driven chip interconnects, and tandem is to said data latching LE end; The output enable OE pin of said N LED constant-current driven chip interconnects, and tandem is to said output enable OE end; A said N LED constant-current driven chip M separately output pin OUT1-OUTM links to each other with the led array of its each Self Control; The power vd D pin of said N LED constant-current driven chip is received on the power supply; The ground GND pin of said N LED constant-current driven chip is received power supply on the ground; Said N LED constant-current driven chip outer meeting resistance REXT pin is separately received power supply on the ground through current setting resistance separately; Any two terminals are above as the current controling signal input terminal in said output enable OE end, data latching LE end, three terminals of clock CLK end; In order to the input current control signal, control the output current of the output OUT1-OUTM pin of said N LED constant-current driven chip.

In the LED of the utility model driving control system, the state of a control data of said N LED constant-current driven chip output OUT1-OUTM pin separately are from the data input DI end input of a said LED constant-current driven chip.

In the LED of the utility model driving control system, said current controling signal comprises clock and Current Control data.

The beneficial effect of the utility model is: because the control data of output current need not just obtain after the serial through chip step by step; Therefore the word length of uncontrolled word restriction makes Current Control speed speed, chip for driving cascade many more; Effect is more obvious; Improved hardware utilization like this, made the function easy expansion of system, the response performance of LED control system also improves.

Description of drawings

Fig. 1 is LED display constant-current driving control system synoptic diagram (chip output is example with 16);

Fig. 2 is transmission OUT0-OUT15 of the prior art (chip output is example with 16) control data data time sequence figure;

Fig. 3 is a transmission current control signal sequential chart of the prior art;

Fig. 4 is the sequential chart of first kind of embodiment output current control method of the utility model;

Fig. 5 is the sequential chart of second kind of embodiment output current control method of the utility model.

Embodiment

To combine accompanying drawing and concrete embodiment that the utility model is further explained below.

Fig. 1 is LED driving control system synoptic diagram (chip output is example with 16); As can be seen from the figure; The cascade of N LED constant-current driven chip; Wherein the data output pin DO of a LED constant-current driven chip links to each other with the data input pin DI of the 2nd LED constant-current driven chip, and the data output pin DO of the 2nd LED constant-current driven chip links to each other with the data input pin DI of the 3rd LED constant-current driven chip, is cascaded to N LED chip for driving like this; The clock CLK pin of N LED constant-current driven chip interconnects, and tandem is to clock CLK end; The data latching LE pin of N LED constant-current driven chip interconnects, and tandem is to data latching LE end; The output enable OE pin of N LED constant-current driven chip interconnects, and tandem is to output enable OE end; A N LED constant-current driven chip M separately output pin OUT1-OUTM links to each other with led array; The power pins VDD of N LED constant-current driven chip receives on the power supply; The ground pin GND of N LED constant-current driven chip receives power supply on the ground; N LED constant-current driven chip outer meeting resistance pin REXT separately receives power supply on the ground through current setting resistance separately; During the input current control signal; Above with any two terminals in output enable OE end, data latching LE end, three terminals of clock CLK end as the current controling signal input terminal; In order to the input current control signal, the output current of the output pin OUT1-OUTM of N LED constant-current driven chip of control; Because current controling signal is no longer imported from data input pin DI serial, but directly bring in transmission, so current controling signal almost arrives each cascade LED chip for driving simultaneously with clock CLK end, data latching LE end, output enable OE; Fig. 2, shown in Figure 3 be prior art, can find out if the series connection of 4 chips is arranged then need 64 CLK could accomplish current settings; Adopt the utility model just much quick from data input pin DI cascade serial input like this, improved the system responses performance, made full use of hardware resource than current controling signal in the prior art shown in Figure 3.

In such scheme, the state of a control data of N LED constant-current driven chip output pin OUT1-OUTM separately are from the data input pin DI input of a LED constant-current driven chip.

In such scheme, control output current with following control method:

During the input current control signal, with in output enable OE end, data latching LE, three terminals of clock CLK end any two with upper terminal as the current controling signal input end, the output current of the output pin OUT1-OUTM of N LED constant-current driven chip of control.

In said method, can be:

Current controling signal comprises clock and Current Control data: comprise non-electric current adjustment state and two kinds of duties of electric current adjustment state during the work of LED display constant-current driving control system;

At non-electric current adjustment state,, then get into electric current adjustment state if the Current Control data are high when rising edge clock signal.After getting into electric current adjustment state, follow-up Current Control data are written into each LED constant-current driven chip in the LED display constant-current driving control system, and LED display constant-current driving control system withdraws from electric current adjustment state after accomplishing; Each LED constant-current driven chip is realized N output current regulating that drives output pin OUT1-OUTM to each LED constant-current driven chip in the LED display constant-current driving control system according to the Current Control data in the LED display constant-current driving control system.

As shown in Figure 4, with current controling signal 6bit being arranged is example, and system comprises two kinds of duties: (1) non-electric current adjustment state, (2) electric current adjustment state.

If under the non-electric current adjustment state during at the CLK rising edge LE for high (D0 is for high) then get into electric current adjustment state; After getting into electric current adjustment state; 6 follow-up bit are written into the LED constant-current driven chip, and the LED constant-current driven chip is regulated the output current of OUT1-OUTN according to these 6 bit.This method can access 64 kinds of current values at most.After electric current adjustment state is through 7 CLK, return to non-electric current adjustment state.

In said method, can also be:

Current controling signal comprises clock and level;

Comprise non-electric current adjustment state and two kinds of duties of electric current adjustment state during the work of LED display constant-current driving control system;

At non-electric current adjustment state; If when rising edge clock signal; Level is high, then gets into electric current adjustment shape, behind the entering electric current adjustment state; Each LED constant-current driven chip, is accomplished in the LED display constant-current driving control system of back each LED constant-current driven chip and is withdrawed from electric current and adjust state level width counting through clock in the LED display constant-current driving control system; Each LED constant-current driven chip is realized N output current regulating that drives output pin OUT1-OUTM to each LED constant-current driven chip in the LED display constant-current driving control system according to count value in the LED display constant-current driving control system.

As shown in Figure 5, system comprises two kinds of duties: (1) non-electric current adjustment state, (2) electric current adjustment state.

If under the non-electric current adjustment state during at the CLK rising edge LE be height then get into electric current adjustment state; After getting into electric current adjustment state; Through CLK the high level of LE is counted, the LED constant-current driven chip is regulated the output current of OUT1-OUTN according to count value.This method can access 6 kinds of current values at most.After electric current adjustment state is through 7 CLK, return to non-electric current adjustment state.

The above embodiment has only expressed several kinds of embodiments of the utility model, but can not therefore be interpreted as the restriction to the utility model claim.Should be pointed out that for the person of ordinary skill of the art under the prerequisite that does not break away from the utility model design, can also make some distortion and improvement, these all belong to the protection domain of the utility model.Therefore, the protection domain of the utility model patent should be as the criterion with accompanying claims.

Claims

1. LED display constant-current driving control system; The LED constant-current driven chip, clock CLK end, data latching LE end, the output enable OE end that comprise N cascade; It is characterized in that: wherein the data of LED constant-current driven chip output DO pin links to each other with the data input DI pin of the 2nd LED constant-current driven chip; The data output DO pin of the 2nd LED constant-current driven chip links to each other with the data input DI pin of the 3rd LED constant-current driven chip, is cascaded to N LED chip for driving like this; The clock CLK pin of said N LED constant-current driven chip interconnects, and tandem is to said clock CLK end; The data latching LE pin of said N LED constant-current driven chip interconnects, and tandem is to said data latching LE end; The output enable OE pin of said N LED constant-current driven chip interconnects, and tandem is to said output enable OE end; A said N LED constant-current driven chip M separately output pin OUT1-OUTM links to each other with the led array of its each Self Control; The power vd D pin of said N LED constant-current driven chip is received on the power supply; The ground GND pin of said N LED constant-current driven chip is received power supply on the ground; Said N LED constant-current driven chip outer meeting resistance REXT pin is separately received power supply on the ground through current setting resistance separately; Any two terminals are above as the current controling signal input terminal in said output enable OE end, data latching LE end, three terminals of clock CLK end; In order to the input current control signal, control the output current of the output OUT1-OUTM pin of said N LED constant-current driven chip.

2. LED display constant-current driving control system according to claim 1; It is characterized in that the state of a control data of said N LED constant-current driven chip output OUT1-OUTM pin separately are from the data input DI end input of a said LED constant-current driven chip.

3. LED display constant-current driving control system according to claim 1 and 2 is characterized in that said current controling signal comprises clock and Current Control data.