CN103578406B - LED screen shows constant-current drive circuit in high precision - Google Patents
LED screen shows constant-current drive circuit in high precision Download PDFInfo
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- CN103578406B CN103578406B CN201210254089.5A CN201210254089A CN103578406B CN 103578406 B CN103578406 B CN 103578406B CN 201210254089 A CN201210254089 A CN 201210254089A CN 103578406 B CN103578406 B CN 103578406B
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Abstract
The invention discloses a kind of high accuracy LED screen and show constant-current drive circuit, relate to LED screen and show drive circuit.Circuit (110), constant-current control circuit (120), electric current output driving circuit (130), 16 latch circuits (140) and 16 bit shift register circuit (150) are trimmed including electric current;Described electric current trims resistor network and amplifier (AMP0) composition that circuit (110) is made up of four resistance (R1, R2, R3, R4), four resistance (R1, R2, R3, R4) are in parallel, each resistant series one switch, switchs ground connection;The parallel connected end of four resistance connects the input of amplifier (AMP0);Parallel resistance (R0) between the input and output side of amplifier (AMP0).The present invention uses the SSOP24 of standard to encapsulate, in order to replace the general driving device used on single dual-colored LED screen at present.
Description
Technical field
The present invention relates to driving circuit structure, be specifically related to LED screen and show drive circuit.
Background technology
Single dual-colored LED display screen now, drives LED luminescence generally to use general-purpose chip
74HC595,74HC595 have 8 latches, string the function such as shift register and ternary output, every road electricity
Stream maximum output is up to 35mA, as shown in Figure 1.As LED drive circuit, there is circuit with 74HC595
Simple in construction, the advantages such as data transmission bauds is fast.But its shortcoming is obvious too, the most interchannel output
Current difference possesses constant current function more greatly and not, have impact on the display effect of LED screen and the use of LED
Life-span.Its subchannel output electric current can not adjust, and does not the most possess high voltage performance.Due to chip output current
Can not adjust, the overall brightness of LED screen will be unable to adjust, simultaneously because chip is typically single 5V
Power supply is powered, and lacks limit can be with the number of series LED in output channel the support of high pressure.
Summary of the invention
The present invention provides a kind of high accuracy LED screen to show constant-current drive circuit, it is an object of the invention to provide one
LED screen shows constant-current drive circuit in high precision, uses the SSOP24 encapsulation of standard, in order to replace at present at list
The general driving device used on dual-colored LED screen.
The present invention proposes a kind of circuit design technique and realizes the driving of high-precision LED constant current, and this technology includes
In traditional driving chip, introduce electric current trim circuit and constant-current control circuit.Electric current trims circuit and can make
Flow through the current difference of any two LED on screen and minimize, constant-current drive technology may insure that on screen
Every LEDs electric current of flowing through when opening do not become with external environment (supply voltage, temperature etc.) change
Changing, simultaneously by an outer meeting resistance, output electric current arbitrarily can also be arranged between 3mA-45mA.
For solving the problems referred to above, the present invention adopts the following technical scheme that high accuracy LED screen shows constant-current driving electricity
Road, trims circuit, constant-current control circuit, electric current output driving circuit, 16 latch circuits including electric current
With 16 bit shift register circuit;16 bit shift register circuit output ends connect 16 latch circuits,
Serial input data is converted to parallel data by 16 bit shift register circuit, is input to 16 latch electricity
Road, input signal IN1 of 16 bit shift register circuit is to show the serial input of main control chip from LED screen
Data, coordinate clock signal IN2;16 latch circuit outfans connection electric current output driving circuits, 16
Position latch circuit inputs a signal into electric current output driving circuit;Electric current output driving circuit connects constant current control
Circuit processed, constant-current control circuit connects electric current and trims circuit;
Described electric current trims resistor network and the amplifier that circuit is made up of four resistance R1, R2, R3, R4
AMP0 is constituted, and four resistance R1, R2, R3, R4 are in parallel, each resistant series one switch, switch
Ground connection;The parallel connected end of four resistance connects the input of amplifier AMP0;The input of amplifier AMP0 and
Parallel resistance R0 between outfan, it is defeated that the input in the same direction of amplifier AMP0 connects BANDGAP circuit
The first reference voltage V REF1 gone out.
Described constant-current control circuit (120) includes four amplifiers AMP1, AMP2, AMP3, AMP4;Amplify
The input in the same direction of device AMP1 accesses electric current and trims the output voltage VREF1, amplifier AMP1 of circuit (110)
Reverse input end connect resistance R5 one end, resistance R5 other end ground connection, the reverse input of amplifier AMP1
Being connected to the source electrode of semiconductor N MOS4, the outfan of amplifier AMP1 is connected to the grid of semiconductor N MOS4,
The drain electrode of semiconductor N MOS4 is connected with the drain electrode of quasiconductor PMOS1, the drain electrode of quasiconductor PMOS1 with partly lead
The grid of body PMOS2 connects, and the grid of quasiconductor PMOS1 connects the input in the same direction of amplifier AMP2,
The input in the same direction of amplifier AMP2 is connected with the grid of quasiconductor PMOS2, the source electrode of quasiconductor PMOS2 with
And drain electrode all reverse input ends with amplifier AMP2 of quasiconductor PMOS3 are connected, the grid of quasiconductor PMOS3
Pole connects the outfan of amplifier AMP2, and the source electrode of quasiconductor PMOS2 and the source electrode of quasiconductor PMOS1 all connect
Connecing DC source, the reverse input end of amplifier AMP3 connects the source electrode of quasiconductor PMOS3, amplifier
The input in the same direction of AMP3 accesses the second reference voltage V REF2, and the outfan of amplifier AMP3 connects quasiconductor
The grid of NMOS1, the drain electrode of semiconductor N MOS1 is connected with the source electrode of quasiconductor PMOS3, quasiconductor PMOS3
Source electrode connect the input in the same direction of amplifier AMP4, the reverse input end of amplifier AMP4 connects quasiconductor
The drain electrode of NMOS2, the outfan of amplifier AMP4 connects the grid of semiconductor N MOS3, semiconductor N MOS3
Source electrode connect semiconductor N MOS2 drain electrode, the source electrode of semiconductor N MOS1 and the source of semiconductor N MOS2
Extremely all ground connection, the grid of semiconductor N MOS1 is connected with the grid of semiconductor N MOS2, semiconductor N MOS3
Drain electrode outwards output electric current Iout.
The present invention is 16 high accuracy constant current driver circuit for LED chips, and its technical characterstic is as follows: 1. propose
By the way of chip internal electric current trims, reduce the difference exporting electric current between chip and chip, and design
A kind of electric current trims circuit (Fig. 2), and this circuit can carry out school to output electric current in the range of 10%
Just, the chip after being corrected by test can ensure that the output current deviation of any passage of any chip is less than
3%, it is greatly improved the luminous concordance of display screen and display effect.2. a kind of current constant control of design electricity
Road (Fig. 3), this circuit may insure that when driving passage is opened, the current constant flowing through LED is constant.3.
Design one based on technical scheme 1 and 16 passage high accuracy LED constant current driving chip of technical scheme 2
(Fig. 4) SSOP24 encapsulation this chip replacement, using standard is original with 74HC595 as representative
General-purpose chip.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of background technology scheme;
Fig. 2 is block diagram of the present invention;
Fig. 3 is that in Fig. 2, electric current trims circuit diagram;
Fig. 4 is constant-current control circuit figure in Fig. 2.
Symbol description in figure: LED screen shows constant-current drive circuit 100 in high precision, electric current trims circuit 110,
Constant-current control circuit 120,130,16 latch circuit 140,16 bit shifts of electric current output driving circuit
Register circuit 150.
Detailed description of the invention
By optimal embodiment, the present invention is described in detail below.
As in figure 2 it is shown, high accuracy LED screen shows constant-current drive circuit, trim circuit 110, perseverance including electric current
Flow control circuit 120), 130,16 latch circuit 140 and 16 bit shifts of electric current output driving circuit post
Latch circuit 150;16 bit shift register circuit 150 outfans connect 16 latch circuits 140,16
Serial input data is converted to parallel data by bit shift register circuit 150, is input to 16 latch electricity
Road (140), input signal IN1 of 16 bit shift register circuit 150 is for show main control chip from LED screen
Serial input data, coordinate clock signal IN2;Input signal IN3 of 16 latch circuits 140 and
IN4 is respectively the latching clock signal from main control chip and enable signal;16 latch circuits 140 are defeated
Go out end connection 130,16 latch circuits (140) of electric current output driving circuit to input a signal into electric current output
Drive circuit 130, electric current output driving circuit 130 is opened or closes defeated according to the signal that latch is given
Go out passage;Electric current output driving circuit 130 connects constant-current control circuit 120, and constant-current control circuit 120 is even
Connect electric current and trim circuit 110;Constant-current control circuit 120 ensures to open the constant current hold of passage, electric current
Trim circuit 110 and guarantee that between chip and chip, channel current deviation is minimized.
As it is shown on figure 3, the resistor network of four resistance R1, R2, R3, R4 compositions and amplifier AMP0
Together form electric current and trim circuit 110, four resistance R1, R2, R3, R4 are in parallel, each resistance string
Join a switch, switch ground connection;The parallel connected end of four resistance connects the reverse input end of amplifier AMP0;
Series resistance R0 between reverse input end and the outfan of amplifier AMP0, amplifier AMP0 is in the same direction
Input connects the first reference voltage V REF1 of BANDGAP circuit output.
BANDGAP electricity in the reference voltage that the input signal of this circuit produces from self, i.e. Fig. 3
Road.Output signal is as input signal VREF1 of constant-current control circuit.When chip testing, can pass through
Output current sample to chip, adjusts the ON-OFF state of switch S1-S4, thus changes VREF1
Voltage.VREF1 will react on the output electric current of chip as the input voltage of current constant control, thus real
Now output electric current is trimmed.
Described high accuracy LED screen shows constant-current drive circuit and uses the SSOP24 encapsulation of standard.
As shown in Figure 4, described constant-current control circuit 120 include four amplifier AMP1, AMP2, AMP3,
AMP4;The input in the same direction of amplifier AMP1 accesses electric current and trims the output voltage VREF1 of circuit 110,
The reverse input end of amplifier AMP1 connects resistance R5 one end, resistance R5 other end ground connection, amplifier
The reverse input end of AMP1 is connected to the source electrode of semiconductor N MOS4, and the outfan of amplifier AMP1 is connected to partly lead
The grid of body NMOS4, the drain electrode of semiconductor N MOS4 is connected with the drain electrode of quasiconductor PMOS1, quasiconductor
The drain electrode of PMOS1 is connected with the grid of quasiconductor PMOS2, and the grid of quasiconductor PMOS1 connects amplifier
The input in the same direction of AMP2, the input in the same direction of amplifier AMP2 is connected with the grid of quasiconductor PMOS2,
The drain electrode of quasiconductor PMOS2 and the source electrode of quasiconductor PMOS3 are all with the reverse input end of amplifier AMP2 even
Connecing, the grid of quasiconductor PMOS3 connects the outfan of amplifier AMP2, the source electrode of quasiconductor PMOS2 and half
The source electrode of conductor PMOS1 is all connected with DC source, and the reverse input end of amplifier AMP3 connects quasiconductor
The drain electrode of PMOS3, the input in the same direction of amplifier AMP3 accesses the second reference voltage V REF2, amplifier
The outfan of AMP3 connects the grid of semiconductor N MOS1, the drain electrode of semiconductor N MOS1 and quasiconductor PMOS3
Drain electrode connect, quasiconductor PMOS3 drain electrode connect amplifier AMP4 input in the same direction, amplifier
The reverse input end of AMP4 connects the drain electrode of semiconductor N MOS2, and the outfan of amplifier AMP4 connects partly leads
The grid of body NMOS3, the source electrode of semiconductor N MOS3 connects semiconductor N MOS2
The input signal of this circuit trims the output VREF1 of circuit from electric current.Due to amplifier AMP1's
Clamping action, voltage added on resistance R5 is VREF1, and the electric current then flowing through resistance R5 is
I=VREF1/R5.PMOS1 and PMOS2 constitutes classical current-mirror structure, due to amplifier AMP2
Clamping action, the grid leak step voltage of PMOS2 is equal to the drain-to-gate voltage of PMOS1, then flow through PMOS2
Electric current be just equal to flow through the electric current of PMOS1 and that is to say the electric current of resistance R5, this electric current flows through simultaneously
NMOS1.NMOS1 and NMOS2 constitutes again the current-mirror structure of classics, simultaneously because amplifier
The effect of AMP3 and AMP4, the drain voltage fall of NMOS1 and NMOS2 is equal to VREF2,
So flow through the ratio that the electric current of NMOS2 then depends entirely on the breadth length ratio of NMOS2 and NMOS1, if
The ratio determining the breadth length ratio of the NMOS2 breadth length ratio relative to NMOS1 is K, then flow through the electricity of NMOS2
Stream that is to say that the output electric current of passage is equal to: Iout=VREF1*K/R5.NMOS3 have employed high-pressure MOS
Tubular construction, the voltage endurance capability both having improved chip output also ensure that the constant current ability of passage simultaneously.In order to
Obtaining higher precision, R5 uses outer meeting resistance, is understood by output current formula simultaneously and changes resistance R5's
Value can also adjust the size of output electric current.
Last it is noted that obvious, above-described embodiment is only by clearly demonstrating the act that the present invention is made
Example, and not restriction to embodiment.For those of ordinary skill in the field, state upper
Can also make other changes in different forms on the basis of bright.Here without also cannot be to all of
Embodiment gives exhaustive.And the obvious change thus amplified out or variation are still in the present invention's
Among protection domain.
Claims (2)
1. high accuracy LED screen shows constant-current drive circuit, it is characterized in that, trim circuit (110), constant-current control circuit (120), electric current output driving circuit (130), 16 latch circuits (140) and 16 bit shift register circuit (150) including electric current;16 bit shift register circuit (150) outfans connect 16 latch circuits (140), serial input data is converted to parallel data by 16 bit shift register circuit (150), it is input to 16 latch circuits (140), input signal IN1 of 16 bit shift register circuit (150) is to show the serial input data of main control chip from LED screen, coordinates clock signal IN2;16 latch circuit (140) outfans connect electric current output driving circuit (130), and 16 latch circuits (140) input a signal into electric current output driving circuit (130);Electric current output driving circuit (130) connects constant-current control circuit (120), and constant-current control circuit (120) connects electric current and trims circuit (110);
Described electric current trims resistor network that circuit (110) is made up of four resistance R1, R2, R3, R4 and amplifier AMP0 is constituted, and four resistance R1, R2, R3, R4 are in parallel, each resistant series one switch, switch ground connection;The parallel connected end of four resistance connects the reverse input end of amplifier AMP0;Series resistance R0 between reverse input end and the outfan of amplifier AMP0, the input in the same direction of amplifier AMP0 connects the first reference voltage V REF1 of BANDGAP circuit output.
2. high accuracy LED screen shows constant-current drive circuit as claimed in claim 1, it is characterised in that described constant-current control circuit (120) includes four amplifiers AMP1, AMP2, AMP3, AMP4;nullThe input in the same direction of amplifier AMP1 accesses electric current and trims the output voltage VREF1 of circuit (110),The reverse input end of amplifier AMP1 connects resistance R5 one end,Resistance R5 other end ground connection,The reverse input end of amplifier AMP1 is connected to the source electrode of semiconductor N MOS4,The outfan of amplifier AMP1 is connected to the grid of semiconductor N MOS4,The drain electrode of semiconductor N MOS4 is connected with the drain electrode of quasiconductor PMOS1,The drain electrode of quasiconductor PMOS1 is connected with the grid of quasiconductor PMOS2,And the grid of quasiconductor PMOS1 connects the input in the same direction of amplifier AMP2,The input in the same direction of amplifier AMP2 is connected with the grid of quasiconductor PMOS2,The drain electrode of quasiconductor PMOS2 and the source electrode of quasiconductor PMOS3 all reverse input ends with amplifier AMP2 are connected,The grid of quasiconductor PMOS3 connects the outfan of amplifier AMP2,The source electrode of quasiconductor PMOS2 and the source electrode of quasiconductor PMOS1 are all connected with DC source,The reverse input end of amplifier AMP3 connects the drain electrode of quasiconductor PMOS3,The input in the same direction of amplifier AMP3 accesses the second reference voltage V REF2,The outfan of amplifier AMP3 connects the grid of semiconductor N MOS1,The drain electrode of semiconductor N MOS1 is connected with the drain electrode of quasiconductor PMOS3,The drain electrode of quasiconductor PMOS3 connects the input in the same direction of amplifier AMP4,The reverse input end of amplifier AMP4 connects the drain electrode of semiconductor N MOS2,The outfan of amplifier AMP4 connects the grid of semiconductor N MOS3,The source electrode of semiconductor N MOS3 connects the drain electrode of semiconductor N MOS2,The source electrode of semiconductor N MOS1 and the source grounding of semiconductor N MOS2,The grid of semiconductor N MOS1 is connected with the grid of semiconductor N MOS2,The drain electrode of semiconductor N MOS3 outwards exports electric current Iout.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
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CN2012203558656U CN202887673U (en) | 2012-07-23 | 2012-07-23 | High-precision LED screen-display constant-current drive circuit |
CN201210254089.5A CN103578406B (en) | 2012-07-23 | 2012-07-23 | LED screen shows constant-current drive circuit in high precision |
US14/417,123 US9827080B2 (en) | 2012-07-23 | 2013-04-03 | Head structure of a brush appliance |
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CN2012203558656U CN202887673U (en) | 2012-07-23 | 2012-07-23 | High-precision LED screen-display constant-current drive circuit |
CN201210254089.5A CN103578406B (en) | 2012-07-23 | 2012-07-23 | LED screen shows constant-current drive circuit in high precision |
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CN103578406A CN103578406A (en) | 2014-02-12 |
CN103578406B true CN103578406B (en) | 2016-12-21 |
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CN2012203558656U Expired - Lifetime CN202887673U (en) | 2012-07-23 | 2012-07-23 | High-precision LED screen-display constant-current drive circuit |
CN201210254089.5A Active CN103578406B (en) | 2012-07-23 | 2012-07-23 | LED screen shows constant-current drive circuit in high precision |
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Families Citing this family (8)
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CN202887673U (en) * | 2012-07-23 | 2013-04-17 | 重庆中科芯亿达电子有限公司 | High-precision LED screen-display constant-current drive circuit |
CN103702494B (en) * | 2014-01-09 | 2015-09-16 | 广德利德光电有限公司 | A kind of two pin RGB-LED control circuits |
RU2612732C2 (en) * | 2015-07-08 | 2017-03-13 | Гиа Маргович Гвичия | Light-emitting diode |
CN108601162B (en) * | 2018-07-03 | 2021-07-06 | 上海路傲电子科技有限公司 | LED lighting linear constant current driving circuit |
CN108650755B (en) * | 2018-07-31 | 2020-09-08 | 上海路傲电子科技有限公司 | Linear constant-current driving chip and multi-chip parallel LED lighting driving circuit |
CN111586936B (en) * | 2020-05-28 | 2023-04-07 | 歌尔科技有限公司 | Multi-path constant current driving circuit and multi-path constant current driving device |
CN114910690B (en) * | 2022-07-19 | 2022-09-20 | 成都市易冲半导体有限公司 | Multiplexing trimming structure and method for current high-precision sampling system in charging control chip |
CN115884468A (en) * | 2023-01-03 | 2023-03-31 | 京东方科技集团股份有限公司 | Driving circuit, driving method thereof and vehicle lamp |
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CN1630306A (en) * | 2000-04-18 | 2005-06-22 | 株式会社半导体能源研究所 | Display device |
CN1758312A (en) * | 2004-10-08 | 2006-04-12 | 三星Sdi株式会社 | Light emitting display and data driver there of |
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CN102316644A (en) * | 2011-09-05 | 2012-01-11 | 泉芯电子技术(深圳)有限公司 | High precision LED constant current drive unit |
CN202887673U (en) * | 2012-07-23 | 2013-04-17 | 重庆中科芯亿达电子有限公司 | High-precision LED screen-display constant-current drive circuit |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
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TWI260572B (en) * | 2003-03-07 | 2006-08-21 | Hon Hai Prec Ind Co Ltd | Variable driving apparatus for light emitting diode |
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- 2012-07-23 CN CN2012203558656U patent/CN202887673U/en not_active Expired - Lifetime
- 2012-07-23 CN CN201210254089.5A patent/CN103578406B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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CN1630306A (en) * | 2000-04-18 | 2005-06-22 | 株式会社半导体能源研究所 | Display device |
CN1758312A (en) * | 2004-10-08 | 2006-04-12 | 三星Sdi株式会社 | Light emitting display and data driver there of |
CN101262729A (en) * | 2008-04-11 | 2008-09-10 | 深圳市联德合微电子有限公司 | A LED constant current driving circuit |
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CN202887673U (en) * | 2012-07-23 | 2013-04-17 | 重庆中科芯亿达电子有限公司 | High-precision LED screen-display constant-current drive circuit |
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CN103578406A (en) | 2014-02-12 |
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