TWI425875B - Driving circuit of light emitting diodes - Google Patents

Description

Light-emitting diode driving circuit

The present invention relates to a driving circuit for a light emitting diode, and more particularly to a driving circuit capable of directly switching a function mode or adjusting a parameter by using a data input pin and a timing signal.

Light Emitting Diode (LED) is small, power-saving and durable, and as the process matures, the price drops. Recently, products using light-emitting diodes as light sources are becoming more and more popular. In addition, the light-emitting diode has a low operating voltage (only 1.5-3V), can actively emit light and has a certain brightness, and the brightness can be adjusted by voltage or current, and has the characteristics of impact resistance, vibration resistance and long life (100,000 hours). Light-emitting diodes are widely used in a variety of terminal equipment, from automotive headlights, traffic lights, text displays, billboards and large-screen video displays, to general and architectural lighting and LCD backlighting.

In the conventional technology, the driving device of the light emitting diode is configured to elastically change operation settings, such as latch signal control, gray scale setting, global brightness control (Global Brightness Control), and single point color adjustment (Dot Correction). ), enable signal control (Enable) or image update frequency setting. The drive unit will have multiple sets of control signal pins to allow the user to make adjustments based on different system usage. 1 is a driving device according to the conventional technology, the driving device includes a plurality of driving units 110-114, each of which is coupled to an operating voltage VDD, a timing signal CKI, and control signals CTR ₁ to CTR _N , wherein The drive units 110-114 are connected in series to each other to transmit a data input signal DIN. The control signals CTR ₁ to CTR _N are mainly used to control the functional modes of the drive units 110 to 114.

However, since the driving units 110 to 114 require a plurality of control signals CTR ₁ to CTR _N to implement their function mode setting, the packaging of the driving units 110 to 114 may be complicated, and a large number of pins and control lines may cause the control unit. The burden and complexity of printed circuit boards. In addition, the wire required for long-distance serial connection will also greatly increase the system manufacturing cost, and all kinds of restrictions are severely popularized by the system.

In the conventional technology, although the automatic latching technology can be used to latch the data, the automatic latching technique can only reduce the pin of the external latching control signal and cannot be applied to other control signals. The driving units 110-114 still need other control signals to adjust the functional modes of the driving units 110-114.

The invention provides a driving circuit for a light-emitting diode, which uses a waveform of a data input signal and a timing signal to switch a functional mode of the dynamic circuit, so that the driving circuit can reduce the number of pins of the control signal, thereby simplifying the complexity of the system.

The invention provides a driving circuit for a light-emitting diode. The driving circuit comprises a plurality of functional modes, and can switch the functional mode of the driving circuit according to a combination of a timing signal and a waveform of a data input signal, wherein the data input signal comprises a complex array of light. In the diode driving data, the driving circuit comprises a control unit, a setting unit and a light emitting diode driving unit. The control unit receives the timing signal and the data input signal, and outputs a mode signal according to the combination of the timing signal and the waveform of the data input signal. The setting unit is coupled to the control unit, and selects one of the function modes according to the mode signal, and extracts and transmits the data input signal according to the selected function mode. The LED driving unit is coupled to the control unit and the setting unit, and drives the plurality of LEDs according to the selected function mode.

Wherein, when the timing signal generates a uniform energy waveform, the control unit defines a detection period according to the enable waveform, and maintains the pulse characteristic generated during the detection period according to the data input signal or the data input signal is maintained during the detection period. Outputting a mode signal with a consistent length of time to select the functional modes One of the formulas. The waveform combination of the enable waveform and the data input signal is also used to control all connected drive units to immediately detect the state change of the input signal, so that each series connected drive unit can synchronously switch the function mode. In addition, the control unit may also output the latch signal and the enable signal according to the waveform of the timing signal and the data input signal.

In an embodiment of the invention, the enable waveform is a positive pulse, and a pulse width of the positive pulse is greater than a minimum pulse width of the data input signal. In addition, the enable waveform can also be a combination of a positive pulse and a negative pulse, and the pulse width of the positive pulse or the negative pulse is greater than a minimum pulse width of the data input signal.

In an embodiment of the invention, the setting unit includes a data transfer unit and a signal processing unit. The data transfer unit is configured to sample the data input signal and sequentially store the captured data input signal. The signal processing unit is coupled to the data transfer unit for storing the data input signal captured by the data transfer unit and outputting a drive enable signal to the LED driver unit according to the stored data input signal. The setting unit further includes a data input signal processing circuit, a timing processing unit and a multiplexer, wherein the data input signal processing circuit and the timing processing unit can directly output the in-phase or inverted data input signal and the timing signal to the next-stage driving circuit. , so that all serially connected drive circuits can switch between operating modes simultaneously.

From another point of view, the present invention provides another driving circuit for a light-emitting diode, the driving circuit includes a plurality of functional modes, and can determine a functional mode of the driving circuit according to a first input signal and a second input signal. The first input signal and the second input signal are encoded by a timing signal and a data input signal, wherein the data input signal comprises a complex array of LED driving data. The driving circuit comprises a decoding unit, a control unit, a setting unit, a light emitting diode driving unit and an encoding unit.

The decoding unit receives the first input signal and the second input signal, and decodes the first input signal and the second input signal to output the timing signal and the data input signal. The control unit is coupled to the decoding unit, receives the timing signal and the data input signal, and outputs a mode signal according to the combination of the timing signal and the waveform of the data input signal. The setting unit selects a corresponding function mode according to the mode signal, and extracts and transmits the data input signal according to the selected function mode. The LED driving unit is coupled to the control unit and the setting unit, and drives the plurality of LEDs according to the functional mode of the driving circuit. The coding unit is coupled to the setting unit for encoding the data input signal and the timing signal to generate a first output signal and a second output signal.

Wherein, when the timing signal generates a uniform energy waveform, the control unit defines a detection period according to the enable waveform, and maintains the pulse characteristic generated during the detection period according to the data input signal or the data input signal is maintained during the detection period. A mode signal of a consistent length can output a mode signal to select one of the functional modes.

Based on the above, the driving circuit of the present invention can reduce the required control signal pins, and can only set the operation mode of the driving circuit by using the data input signal and the timing signal, including the related operation mode setting such as gray scale setting and driving mode setting. The invention can simplify the layout of the printed circuit board of the driving device of the light-emitting diode display while simplifying the packaging complexity of the driving device. This at the same time reduces the cost of design and manufacture of the drive.

The above described features and advantages of the present invention will be more apparent from the following description.

110~114‧‧‧ drive unit

200, 400, 500, 600‧‧‧ drive circuits

210‧‧‧Control unit

220‧‧‧Lighting diode unit

222‧‧‧Lighting diode drive circuit

224‧‧‧Drive signal setting circuit

230‧‧‧Setting unit

232‧‧‧Signal Processing Unit

234‧‧‧Data Transfer Unit

236‧‧‧Time Processing Unit

410‧‧‧Decoding unit

420‧‧‧ coding unit

510‧‧‧Detection protection unit

532‧‧‧Data operation circuit

534‧‧‧Data storage circuit

535‧‧‧Data input signal processing circuit

536‧‧‧Multiplexer

631‧‧‧ counter

632~639‧‧‧ Comparator

672‧‧‧Digital analog conversion circuit

674‧‧‧reference voltage generation circuit

676‧‧‧Voltage current conversion circuit

CTR ₁ ~CTR _N ‧‧‧ control signal

CKI‧‧‧ timing signal

CKO‧‧‧ clock output signal

DIN‧‧‧ data input signal

DO‧‧‧ data output signal

DT‧‧‧Detection period

D+‧‧‧ first input signal

D-‧‧‧ second input signal

DOUT+‧‧‧ first output signal

DOUT-‧‧‧second output signal

EW‧‧‧ control signal

EN‧‧‧Enable signal

LAT‧‧‧ latch signal

P1~P4‧‧‧pulse

SEL‧‧‧Selection signal

VDD‧‧‧ working voltage

Fig. 1 shows a driving device according to a conventional art.

2 is a diagram showing a driving circuit according to a first embodiment of the present invention.

3 is a schematic diagram showing the waveform combination of the timing signal CKI and the data input signal DIN according to the first embodiment of the present invention.

4 is a diagram of a driving circuit in accordance with a second embodiment of the present invention.

Fig. 5A is a diagram showing a driving circuit in accordance with a third embodiment of the present invention.

Figure 5B is a diagram of a driving circuit in accordance with a third embodiment of the present invention.

Figure 6 is a diagram showing a driving circuit in accordance with a third embodiment of the present invention.

First embodiment

FIG. 2 is a diagram of a driving circuit according to a first embodiment of the present invention. The driving circuit 200 includes a control unit 210, a light emitting diode unit 220, and a setting unit 230. The control unit 210 is coupled to the LED driving unit 220 and the setting unit 230 , and the setting unit 230 is coupled to the LED driving unit 220 .

The driving circuit 200 includes a plurality of functional modes, and the functional mode can be switched by a combination of the timing signal CKI and the waveform of the data input signal DIN. The control unit 210 receives the timing signal CKI and the data input signal DIN, and detects a waveform change of the timing signal CKI. When the timing signal CKI generates an enable waveform (for example, a positive pulse or a negative pulse with a large pulse width), the control unit 210 defines a detection period according to the enable waveform, and then detects the data input signal DIN during the detection period. The pulse characteristics determine the functional mode of the drive circuit 200. The control unit 210 outputs the mode signal MS to the setting unit 230 and the LED driving unit 220 according to the waveform of the timing signal CKI and the data input signal DIN, and then the setting unit 230 and the LED driving unit 220 follow the mode signal. The MS adjusts its operating mode to correspond to the parameters set. It should be noted that the above enabling waveform can be set according to requirements, and the embodiment is not limited.

The function mode of the driving circuit 200 includes the setting of the number of gray scales and the lighting time control of the LEDs System, single point tone adjustment (Dot Correction), drive output signal size control, enable signal control, image update reference frequency setting (Grayscale Clock), drive signal reverse setting, drive status detection, display component status detection , drive sleep setting, drive temperature detection or drive leakage current detection or operation sleep setting. In other words, the so-called functional mode can be regarded as the operating mode of the driving circuit 200 or the corresponding circuit parameter value.

The data input signal DIN includes the driving data of the light-emitting diode, and the display data (the driving data of the light-emitting diode) is transmitted in accordance with the timing of the timing signal CKI. If the driving circuit 200 is used to drive a display device composed of a light-emitting diode, the driving data is, for example, grayscale data or graphic data. The setting unit 230 samples the data input signal DIN according to the timing signal CKI and temporarily stores the captured data input signal, and the setting unit 230 also transmits the captured data input signal. Generally, the setting unit 230 includes a plurality of registers and latches (not shown) for temporarily storing the captured data input signal DIN, and the latch is used for storing the buffers. data. The LED driving unit 220 outputs a driving signal according to the driving data stored by the setting unit 230 to drive a plurality of LEDs or display devices.

In other words, in this embodiment, the data switching signal DIN and the timing signal CKI for transmitting the display data are used to transmit the mode switching instruction, so that the driving circuit 200 can receive the instruction for switching the working mode via the same pin without using an additional Pins to transmit control signals. At the same time, the driving circuit 200 can also determine the circuit parameters to be set by combining the waveforms of the data input signal DIN and the timing signal CKI. In other words, the drive circuit 200 transmits the mode setting signal or the associated parameter setting signal by replacing the pins responsible for parameter setting or mode switching with the two pins of the transmission data input signal DIN and the timing signal CKI.

Next, the waveform combination of the timing signal CKI and the data input signal DIN is further described. Referring to FIG. 3, FIG. 3 is a waveform of the timing signal CKI and the data input signal DIN according to the first embodiment of the present invention. Combination diagram. Referring to FIG. 3(a) and FIG. 3(b), in the case that the waveform EW is a positive pulse, when the timing signal CKI generates the enable waveform EW having a large pulse width, the corresponding detection period DT is The pulse width of the waveform EW. The pulse characteristics of the data input signal DIN during the detection period, such as the number of pulses, the combination of pulses, the number of rising edges or the number of falling edges, can be used to indicate the functional mode. In Fig. 3(a), the number of pulses generated by the data input signal DIN during the detection period DT is three, that is, the pulses P1 to P3, and in Fig. 3(b), the data input signal DIN is detected. The number of pulses generated in the period DT is four, that is, the pulses P1 to P4. Thus, Figures 3(a) and 3(b) can be used to represent two functional modes, respectively.

FIG. 3(c) is a waveform combination of another data input signal DIN and a timing signal CKI, wherein the enable waveform EW includes a positive pulse and a negative pulse (the pulse widths of the positive pulse and the negative pulse may be the same or different), resulting in The period of the waveform EW corresponds to the detection period DT. The data input signal DIN generates two pulses P1, P2 during the active period of the positive pulse and two pulses P3, P4 during the active period of the negative pulse. Since the waveform of FIG. 3(c) is different from that of FIGS. 3(a) and 3(b), it can be used to indicate another functional mode. By analogy, a combination of a plurality of signal waveforms can be preset in the driving circuit 200 to correspond to different functional modes, and then the waveform of the received data input signal DIN and the timing signal CKI is used to determine the required parameter value or related to the system side. The screen displays the set values (such as resolution, grayscale, brightness, etc.).

The waveform combination of the data input signal DIN and the timing signal CKI further includes the pulse width, the duty ratio, the number of edges or the number of edges generated by the data input signal DIN during the effective pulse period of the timing signal CKI (ie, the control signal EW) The combination of the order of arrangement and the number of pulses thereof, etc., is not limited in this embodiment. In addition, the system can also determine the corresponding functional mode by maintaining the enable level (logic high level or logic low level) in the detection period DT by the data input signal DIN.

In other words, the system side does not need to additionally output a control signal to the driving circuit 200 of the LED, The parameter setting value is directly transmitted through the data input signal DIN of the transmission drive data to directly set the drive circuit 200. The drive circuit 200 also does not require additional pins for setting control signals to transmit control signals, thereby simplifying the layout of the printed circuit board and its circuit design complexity.

In addition, it is worth noting that the setting unit 230 can be used to transmit the data input signal DIN and the timing signal CKI, like a scratchpad, and then output the data output signal DO and the clock output signal CKO. Since the display device composed of the light-emitting diodes usually has a large number of light-emitting diodes, the driving circuits (wafers) are arranged in series to simultaneously drive the plurality of light-emitting diodes. The driving circuit of the pre-stage transmits the data input signal DIN to the driving circuit of the next stage, so the data output signal DO of the pre-stage and the timing signal CKO can be regarded as the data input signal DIN and the timing signal CKI of the subsequent-stage driving circuit. It should be noted that the driving circuit 200 of the present invention can directly output the data input signal DIN and the timing signal CKI to the driving circuit of the next stage, so that all the serially connected driving circuits can synchronously detect the data input signal DIN immediately, so that each The drive circuit can be switched to the same mode synchronously to facilitate proper control of the serially connected drive circuit. The control unit 210 can also output a control signal to the driving circuit of the next stage to notify the next stage driving circuit to detect the data input signal DIN to adjust its operating mode.

In addition, in the embodiment, the driving circuit can invert the data input signal DIN and the timing signal CKI according to the design requirement, so the data output signal DO and the clock output signal CKO can be the data input signal DIN and the timing signal. Inverted signal of CKI. Thereby, the attenuation problem of the timing signal CKI and the data input signal DIN during transmission can be effectively reduced. After the timing signal CKI and the data input signal DIN are transmitted through the driving circuit of several stages, the pulse width of the timing signal CKI and its waveform are still maintained.

Second embodiment

Please refer to FIG. 4. FIG. 4 is a diagram of a driving circuit according to a second embodiment of the present invention. The driving circuit 400 includes a control unit 210, a light emitting diode unit 220, a setting unit 230, a decoding unit 410, and a code list. Yuan 420. The control unit 210 is coupled to the LED driving unit 220 and the setting unit 230 , and the setting unit 230 is coupled to the LED driving unit 220 . The decoding unit 410 is coupled between the output end of the driving circuit 400 and the control unit 210 and the setting unit 230. The encoding unit 420 is coupled between the output end of the driving circuit 400 and the setting unit 230. The main difference between FIG. 4 and FIG. 2 is the decoding unit 410 and the encoding unit 420.

The decoding unit 410 receives the first input signal D+ and the second input signal D- encoded by the data input signal DIN and the timing signal CKI, and decodes the data input signal DIN and the timing signal CKI to the control unit 210 and the setting unit. 230. The data output signal DO and the timing signal CKO output by the setting unit 230 are encoded by the encoding unit 420, and then output the first output signal DOUT+ and the second output signal DOUT- to the drive circuit of the next stage. It should be noted that the signal form of the first input signal D+ and the second input signal D- may be a differential signal, which includes clock output information. The first output signal DOUT+ and the second output signal DOUT- may also be differential signals.

In this embodiment, the operation modes of the control unit 210, the LED unit 220, and the setting unit 230 are as described in the above embodiment of FIG. 2, and are not described herein. The main difference between FIG. 4 and FIG. 2 is that the driving circuit 400 can receive the signal encoded by the timing signal CKI and the data input signal DIN, and can encode the data output signal DO and the timing signal CKO before outputting.

Third embodiment

Next, the internal structure of the driving circuit will be further described. Referring to FIG. 5A, FIG. 5A is a driving circuit diagram according to a third embodiment of the present invention. The driving circuit 500 includes a control unit 210, a light emitting diode moving unit 220, a setting unit 230, and a detecting side protection unit 510. The setting unit 230 further includes a signal processing unit 232, a data transfer unit 234, and a timing processing unit 236. The LED driving unit 220 further includes a light emitting diode driving circuit 222 and a driving signal setting circuit 220. The control unit 210 is coupled to the detection and protection unit 510, the setting unit 230, and the LED driving unit 220. The signal processing unit 232 is coupled to the data The transfer unit 234 is between the light emitting diode driving unit 220. The driving signal setting circuit 220 is coupled to the LED driving circuit 22 .

The control unit 210 outputs a mode signal MS to the detection protection unit 410, the setting unit 230 and the LED driving unit 220 according to the waveform of the data input signal DIN and the timing signal CKI. The driving circuit 500 switches to the corresponding function mode or adjusts the corresponding setting parameter according to the mode signal MS. It should be noted that the control unit 210 may also output the latch signal LAT and the enable signal EN to the signal processing unit 234 according to the data input signal DIN and the waveform of the timing signal CKI for data latching and generating the driving enable signal to the light. Diode drive circuit 222.

The data transfer unit 234 can be used to extract and transfer the data input signal DIN to output the data output signal DO. The data transfer unit 234 is, for example, a shift register. The timing processing unit 236 receives the timing signal CKI and then outputs a timing output signal CKO that is in phase or inverted with the timing signal CKI according to design requirements. Regarding the waveform combination of the data input signal DIN and the timing signal CKI and the corresponding operation mode, please refer to FIG. 3, which will not be described here. In addition, it is worth noting that the data transfer unit 234 can also output a data output signal DO that is inverted from the data input signal DIN to avoid signal attenuation or distortion.

The signal processing unit 220 is configured to store (or latch) the data input signal DIN captured by the data transfer unit 234, and generate a drive enable signal to the LED driving unit 220 according to the captured data input signal DIN. To drive the light-emitting diode. The drive signal setting circuit 224 is for adjusting the drive current, the drive voltage, or the effective drive period output from the LED driver circuit 222.

It should be noted that the data output signal DO output by the data transfer unit 234 may be in phase or inverted with the data input signal DIN. The timing output signal CKO output by the timing processing unit 236 can also be in phase or inverted with the timing signal CKI. The adjustment of the above signal phase can be determined according to design requirements, and the embodiment is not limited.

The detection protection unit 510 is mainly used to detect the internal state of the driving circuit, such as temperature, voltage, The state of the current, whether the circuit is disabled, and the state of the light-emitting diode, such as short circuit, damage, degree of aging, and the like. The detection and protection unit 510 can add a detection component and a protection function required in a general circuit for circuit state monitoring and immediate adjustment. The detection protection unit 510 can adjust the working mode according to the mode signal MS output by the control unit 210 to detect different circuit parameters and environmental state values. In addition, when the detection result needs to be output, the detection protection unit 510 can output the detection result to the data transfer unit 234 and output it via the data transfer unit 234.

In addition, the circuit configuration of the setting unit 230 of the present invention is not limited to the above-described structure of FIG. 5A. Please refer to FIG. 5B, which is a driving circuit diagram according to a third embodiment of the present invention. The main difference between FIG. 5B and FIG. 5A is the data input signal processing circuit 535, the multiplexer 536, and the signal processing unit 232. The signal processing unit 232 includes a data operation circuit 532 and a data storage circuit 534.

The input ends of the multiplexer 536 are respectively coupled to the output of the data transfer unit 234 and the data input signal processing circuit 535. The output of the multiplexer 536 is coupled to the data output end of the drive circuit 500, and is output according to the control unit 210. The selection signal SEL selects the output of the data transfer unit 234 or the data input signal processing circuit 535 to generate a data output signal DO.

The data input signal processing circuit 535 can output the positive phase or the inverted data input signal DIN according to the setting. When the inverted data input signal DIN is output, the attenuation problem of the data input signal DIN during transmission can be effectively reduced. After the data input signal DIN is transmitted through the drive circuit of several stages, the pulse width of the data input signal DIN and its waveform are still maintained. The timing processing unit 236 is configured to transmit the timing signal CKI, and output a timing signal CKI according to the setting of the positive phase or the inverted phase to generate the timing output signal CKO. Similarly, when the inverted timing signal CKI is output, the attenuation problem of the timing signal CKI at the time of transmission can be effectively reduced. After the timing signal CKI is transmitted through the driving circuit of several stages, the pulse width of the timing signal CKI and its waveform are still maintained.

Since the variation of the process causes the drive circuit to have a difference between the rising edge time and the falling edge time when transmitting the signal, the signal can be effectively inverted to eliminate the difference between the rising edge time and the falling edge time by inverting the signal and then transmitting the signal. Problems such as signal attenuation or distortion. Furthermore, since the data input signal processing circuit 535 and the timing processing unit 236 of the embodiment can directly output the received data input signal DIN and the timing signal CKI, the data input signal DIN does not need to be sequentially transmitted via the shift register. It can be output to the drive circuit of the next stage. Therefore, all the serially connected driving circuits can simultaneously receive the data input signal DIN and the timing signal CKI to synchronize the setting and switching of the operation mode.

The data storage circuit 534 is coupled between the data operation circuit 532 and the data transfer unit 234, and latches the data temporarily stored in the data transfer unit 234 according to the latch signal LAT output by the control unit 210, and then transfers the data to the data operation circuit. 532 performs the operation. The data operation circuit 532 outputs a drive enable signal to the LED driver circuit 222 according to the extracted data input signal DIN to output a corresponding drive signal. The data operation circuit 532 may be composed of a gate or a digital comparator, but the present invention is not limited thereto.

Next, the internal circuit configuration of the data operation circuit 532 and the drive signal setting circuit 224 will be further described. Please refer to FIG. 6. FIG. 6 is a diagram of a driving circuit according to a third embodiment of the present invention. The main difference between the drive circuit 600 and the drive circuit 500 of FIG. 5B described above is the data operation circuit 532 and the drive signal setting circuit 224. Referring to FIG. 6, the data operation circuit 532 includes a counter 631 and a plurality of comparators 632-639 (eg, digital comparators). The comparators 632-639 are used to compare the output of the counter 631 with the latched data storage circuit 534. The data is then used to determine whether the LED driver unit 220 outputs a drive signal.

The data operation circuit 532 performs image data calculation by the counter 631 and the plurality of comparators 632-639, and the function thereof can be regarded as a pulse width modulation unit for adjusting the LED driving circuit. 222 received pulse width adjustment signal. Also has the ability to emit light Whether or not the diode driving circuit 222 outputs a driving signal. The LED driving circuit 222 adjusts the voltage and current of the driving signal according to the operating period of the received pulse width adjustment signal. In addition, the data operation circuit 532 can also be composed of a plurality of gates (not shown). The inputs of the gates are respectively coupled to the data storage circuit 534 and the uniform energy signal, and the outputs of the gates are coupled to the light emitting diodes. The polar body drive circuit 222.

The drive signal setting circuit 224 includes a digital analog conversion circuit 672, a reference voltage generation circuit 674, and a voltage current conversion circuit 676. The reference voltage generating circuit 674 is coupled to the voltage-current converting circuit 676, and the digital analog converting circuit 672 is coupled to the voltage-current converting circuit 676. The digital analog conversion circuit 672 converts the command data stored in the data storage circuit 534 (ie, the partial data included in the data input signal DIN) into an analog signal (eg, voltage) for output to the voltage current conversion circuit 676, and the voltage current conversion circuit. 676 adjusts the driving signal of the LED driving circuit 222 according to the command data and the output of the reference voltage generating circuit 674. For details of the operation of the remaining circuits of FIG. 6 and FIG. 5B, please refer to the description of the embodiment of FIG. 5 above, which will not be described here.

The invention integrates the command data of the mode switching into the data input signal DIN and the timing signal CKI, so that the data input signal DIN and the timing signal CKI can be used not only to transmit image data, but also to set the function mode of the driving circuit. Thereby, the invention can achieve the effect of reducing the number of package pins of the driving circuit and simplifying the circuit layout design. In addition, in the package, if the driving circuit includes M driving units (M is a positive integer), the driving circuit only needs M+5 pins to have a heat dissipation patch package, thereby achieving a dispersion effect, thereby reducing the package. cost.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

DIN‧‧‧ data input signal

CKI‧‧‧ timing signal

P1~P4‧‧‧pulse

EW‧‧‧ control signal

DT‧‧‧Detection period

Claims (35)

A driving circuit for a light emitting diode, the driving circuit comprising a plurality of functional modes, and receiving a timing signal and a data input signal to drive at least one light emitting diode, wherein the data input signal comprises at least one LED driving The driving circuit includes: a control unit, receiving the timing signal and the data input signal, and outputting a mode signal according to the timing signal and the waveform of the data input signal; a setting unit coupled to the control unit, The setting unit selects one of the function modes according to the mode signal, and extracts and transmits the data input signal according to one of the selected function modes; and a light emitting diode driving unit coupled to the control unit And the setting unit, and driving at least one light emitting diode according to one of the selected functional modes; wherein, when the timing signal generates a uniform energy waveform, the control unit defines a detection period according to the enabling waveform, And according to the data input signal, the pulse characteristic generated during the detection period or the data input signal is in the detect The length of time can maintain a consistent level of the mode signal output period to select one of the plurality of functional modes. The driving circuit of claim 1, wherein the enabling waveform is a positive pulse, and the pulse width of the positive pulse is greater than a minimum pulse width of the data input signal. The driving circuit of claim 1, wherein the enabling waveform is a combination of a positive pulse and a negative pulse, and a pulse width of the positive pulse or the negative pulse is greater than a minimum pulse width of the data input signal . The driving circuit of claim 1, wherein the pulse characteristic of the data input signal comprises the number of effective pulses or the duty ratio or the number of rising edges or the number of falling edges, and the enabling level of the data input signal Is logic high or logic low. The driving circuit of claim 1, wherein the setting unit comprises: a data transfer unit for sampling the data input signal and sequentially storing the captured data input signal; and a signal processing The unit is coupled to the data transfer unit for storing the data input signal captured by the data transfer unit and outputting a drive enable signal to the light emitting diode drive unit according to the stored data input signal. The driving circuit of claim 5, wherein the setting unit further comprises: a data input signal processing circuit, receiving the data input signal and outputting the data input signal in phase or inversion; and a multiplexer, A first input end of the multiplexer is coupled to the output of the data transfer unit, and a second input end of the multiplexer is coupled to an output of the data input signal processing circuit, and an output end of the multiplexer It is coupled to a data output end. The driving circuit of claim 5, wherein the setting unit further comprises: a timing processing unit that receives the timing signal and outputs one of the output timing signals in phase with or in phase. The driving circuit of claim 5, wherein the data transfer unit is a shift register. The driving circuit of claim 1, wherein the control unit further outputs a latch signal to the setting unit according to the timing signal and the waveform of the data input signal to latch the data input signal captured. . The driving circuit of claim 1, wherein the control unit further outputs a matching energy signal to the setting unit according to the timing signal and the waveform of the data input signal to enable the LED driving unit. The driving circuit of claim 1, wherein the functional modes include grayscale number setting, display component lighting time control, display component overall brightness control, single-point color gradation adjustment, and driving output signal size control, Can signal control, image update reference frequency setting, drive output signal reverse setting, drive status detection, display component status detection, drive power saving setting or operating mode setting. The driving circuit of claim 5, wherein the signal processing unit comprises: a data storage circuit for storing the data input signal captured by the data transfer unit; and a data operation circuit for outputting The drive enables the signal. The driving circuit of claim 12, wherein the data operation circuit comprises: a counter; and a plurality of comparators coupled to the counter and the data storage circuit for comparing the stored data input signals And outputting the counter to generate the driving enable signal to the LED driving unit. The driving circuit of claim 12, wherein the data operation circuit comprises: a plurality of gates, wherein the inputs of the gates are respectively coupled to the data storage circuit and the uniform energy signal, and the output of the gates The second LED driving unit is coupled to the LED. The driving circuit of claim 1, further comprising: a detecting and protecting unit for detecting a state of the light emitting diode and the driving circuit and outputting a detecting signal. The driving circuit of claim 1, wherein the LED is driven The unit further includes: a light emitting diode driving circuit; and a driving signal setting circuit coupled to the light emitting diode driving circuit for adjusting a driving signal output by the LED driving circuit. The driving circuit of claim 16, wherein the driving signal setting circuit comprises: a reference voltage generating circuit; and a digital analog converting circuit coupled to the setting unit to receive one of the data input signals And a voltage-current conversion circuit coupled to the reference voltage generating circuit and the digital analog conversion circuit for adjusting a driving signal output by the LED driving unit. A driving circuit for a light emitting diode, the driving circuit comprising a plurality of functional modes, and determining a functional mode of the driving circuit according to a first input signal and a second input signal, wherein the first input signal and the second input The signal system is encoded by a timing signal and a data input signal, wherein the data input signal comprises a complex array of LED driving data, the driving circuit comprises: a decoding unit, receiving the first input signal and the second input Transmitting, and decoding the first input signal and the second input signal to output the timing signal and the data input signal; a control unit coupled to the decoding unit, receiving the timing signal and the data input signal, and according to the The timing signal is combined with the waveform of the data input signal to output a mode signal; a setting unit is coupled to the decoding unit and the control unit, and the setting unit selects one of the function modes according to the mode signal, and according to the selected One of the functional modes captures and transmits the data input signal; and a light emitting diode driving unit coupled To the control unit and the setting unit, and the driving circuit in accordance with The function mode drives a plurality of light emitting diodes; and a coding unit coupled to the setting unit for encoding the data input signal and the timing signal to generate a first output signal and a second output signal; When the timing signal generates a uniform energy waveform, the control unit defines a detection period according to the enable waveform, and according to the pulse characteristic generated by the data input signal during the detection period or the data input signal during the detection period The mode length is output to maintain the consistent level of time to select one of the functional modes. The driving circuit of claim 18, wherein the enabling waveform is a positive pulse, and the pulse width of the positive pulse is greater than a minimum pulse width of the data input signal. The driving circuit of claim 18, wherein the enabling waveform is a combination of a positive pulse and a negative pulse, and a pulse width of the positive pulse or the negative pulse is greater than a minimum pulse width of the data input signal . The driving circuit of claim 18, wherein the pulse characteristic of the data input signal comprises the number of effective pulses or the duty ratio or the number of rising edges or the number of falling edges, and the enabling level of the data input signal Is logic high or logic low. The driving circuit of claim 18, wherein the setting unit comprises: a data transfer unit configured to perform data sampling on the data input signal and sequentially store the captured data input signal; and a signal The processing unit is coupled to the data transfer unit for storing the data input signal captured by the data transfer unit and outputting a drive enable signal to the light emitting diode drive unit according to the stored data input signal. The driving circuit of claim 22, wherein the setting unit further comprises: a data input signal processing circuit, receiving the data input signal and outputting the data input signal in phase or inversion; and a multiplexer, A first input end of the multiplexer is coupled to the output of the data transfer unit, and a second input end of the multiplexer is coupled to an output of the data input signal processing circuit, and an output end of the multiplexer It is coupled to a data output end. The driving circuit of claim 22, wherein the setting unit further comprises: a timing processing unit that receives the timing signal and outputs one of the output timing signals in phase or inversion thereof. The driving circuit of claim 22, wherein the data transfer unit is a shift register. The driving circuit of claim 18, wherein the control unit further outputs a latch signal to the setting unit according to the timing signal and the waveform of the data input signal to latch the data input signal captured. . The driving circuit of claim 18, wherein the control unit further outputs a matching energy signal to the setting unit according to the timing signal and the waveform of the data input signal to enable the LED driving unit. The driving circuit of claim 18, wherein the functional modes include gray scale number setting, display element lighting time control, display element overall brightness control, single point color gradation adjustment, driving output signal size control, Can signal control, image update reference frequency setting, drive output signal reverse setting, drive status detection, display component status detection, drive power saving setting or operating mode setting. The driving circuit of claim 18, wherein the first input signal and the second input signal are a differential signal. The driving circuit of claim 22, wherein the signal processing unit comprises: a data storage circuit for storing the data input signal captured by the data transfer unit; and a data operation circuit for outputting The drive enables the signal. The driving circuit of claim 30, wherein the data operation circuit comprises: a counter; and a plurality of comparators coupled to the counter and the data storage circuit for comparing the stored data input signals And outputting the counter to generate the driving enable signal to the LED driving unit. The driving circuit of claim 30, wherein the data operation circuit comprises: a plurality of gates, wherein the inputs of the gates are respectively coupled to the data storage circuit and the uniform energy signal, and the output of the gates The second LED driving unit is coupled to the LED. The driving circuit of claim 18, further comprising: a detecting and protecting unit for detecting a state of the light emitting diode and the driving circuit and outputting a detecting signal. The driving circuit of claim 18, wherein the LED driving unit further comprises: a light emitting diode driving circuit; and a driving signal setting circuit coupled to the LED driving circuit, Used to adjust the light emitting diode The drive signal output by the drive circuit. The driving circuit of claim 34, wherein the driving signal setting circuit comprises: a reference voltage generating circuit; and a digital analog converting circuit coupled to the setting unit to receive one of the data input signals And a voltage-current conversion circuit coupled to the reference voltage generating circuit and the digital analog conversion circuit for adjusting a driving signal output by the LED driving unit.