CN100544172C - The operating frequency production method and the circuit of switch type electric voltage converter - Google Patents
The operating frequency production method and the circuit of switch type electric voltage converter Download PDFInfo
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- CN100544172C CN100544172C CNB2006101362255A CN200610136225A CN100544172C CN 100544172 C CN100544172 C CN 100544172C CN B2006101362255 A CNB2006101362255 A CN B2006101362255A CN 200610136225 A CN200610136225 A CN 200610136225A CN 100544172 C CN100544172 C CN 100544172C
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Abstract
The operating frequency production method and the operating frequency that the invention discloses a kind of switch type electric voltage converter produce circuit.The method comprises the following steps: to receive reference clock pulse signal and digit period signal; The phase place of the digit period of delay signal produces at least one delay period signal according to this according at least one different time of delay; Just select digit period signal or one of them operating frequency of above-mentioned delay period signal every a Preset Time as switch type electric voltage converter.
Description
Technical field
The present invention produces circuit relevant for a kind of operating frequency production method of switch type electric voltage converter and operating frequency, and is particularly to eliminate the operating frequency production method and operating frequency generation circuit of a kind of switch type electric voltage converter of phenomenons such as the inhomogeneous and flicker of ripples line, the regional luminance of LCD.
Background technology
In the drive circuit of display, for example the source electrode driver of LCD and gate drivers all can need switch type electric voltage converter to produce source electrode driver and the required voltage of gate drivers.Switch type electric voltage converter mainly can be divided into charge pump (Charge Pump) and pulse-width modulation (Pulse Width Modulation) two big classes.
In general, switch type electric voltage converter need receive the operating frequency that a clock pulse signal is used as its internal switch.This clock pulse signal has two common sources.First is from voltage-controlled oscillator (Voltage-Controlled Oscillator independently, VCO), second is certain the digit period signal from drive circuit inside, for example Dot Clock pulse signal (Dot Clock), horizontal-drive signal or horizontal initial pulse signal (Horizontal Start Pulse is also referred to as STH).The operating frequency of switch type electric voltage converter can directly adopt the clock pulse signal in above source, or with the signal frequency elimination in above source to produce required operating frequency.
Fig. 1 shows existing switch type electric voltage converter clock pulse signal and horizontal-drive signal, vertical synchronizing signal, Dot Clock pulse signal three's clock pulse figure.In this Fig. 1, Hsync represents horizontal-drive signal, and Vsync represents vertical synchronizing signal, DOTCLK representative point clock pulse signal, and CPCK then represents the switch type electric voltage converter clock pulse signal.
Switch type electric voltage converter is when work, because the switching of its internal switch usually can produce noise, and the supply voltage of the as easy as rolling off a log interferoscope drive circuit of these noises and other control signals.When the operating frequency of switch type electric voltage converter and the control signal of drive circuit have macroscopic correlation on sequential, will on display, produce many display defects, for example on display, produce the phenomenon of similar water ripple, perhaps produce regional luminance inhomogeneous (MURA), scintillation (Flicker) or the like.
Therefore, the operating frequency that needs a switch type electric voltage converter produces circuit and operating frequency production method, to address the above problem.
Summary of the invention
Purpose of the present invention just provides a kind of operating frequency production method of switch type electric voltage converter and operating frequency produces circuit, and it can eliminate phenomenons such as the inhomogeneous and flicker of ripples line, the regional luminance of display.
Based on above-mentioned and other purpose, the present invention proposes a kind of operating frequency production method of switch type electric voltage converter, and the method comprises the following steps: that a. receives reference clock pulse signal and digit period signal; B. the phase place of the digit period of delay signal produces at least one delay period signal according to this according at least one different time of delay; C. every a Preset Time just select digit period signal or above-mentioned delay period signal one of them as clock pulse signal, make clock pulse signal operate an internal switch of this switch type electric voltage converter, to produce a voltage.
Based on above-mentioned and other purpose, the present invention proposes a kind of switch type electric voltage converter, and it comprises that operating frequency produces circuit and internal switch.Operating frequency produces circuit and comprises delay circuit and select circuit.Delay circuit is in order to receiving reference clock pulse signal and digit period signal, and postpones the phase place of digit period signal according to reference clock pulse signal, produces at least one delay period signal according to this.Select circuit in order to receiving digit period signal and above-mentioned delay period signal, and select to export digit period signal or above-mentioned delay period signal one of them, produce a clock pulse signal, the phase place of clock pulse signal is constantly changed.Internal switch operates with clock pulse signal, to produce a voltage.
According to the described operating frequency production method of one embodiment of the invention, present the multiple relation above-mentioned time of delay each other.
According to the described operating frequency production method of one embodiment of the invention, the selection mode among the above-mentioned steps c. comprises: with a default sequence mode select in regular turn digit period signal or above-mentioned delay period signal one of them.
According to the described operating frequency production method of one embodiment of the invention, the selection mode among the above-mentioned steps c. comprises: with random number way circulation select digit period signal or above-mentioned delay period signal one of them.
According to the described switch type electric voltage converter of one embodiment of the invention, above-mentioned delay circuit comprises first trigger.The input of first trigger and clock pulse input terminal receive digit period signal and reference clock pulse signal respectively, export the first delay period signal according to this, wherein the rising edge of the first delay period signal is synchronized with first edge of reference clock pulse signal.
According to the described switch type electric voltage converter of one embodiment of the invention, above-mentioned delay circuit also comprises second trigger.The input of this second trigger and clock pulse input terminal receive first delay period signal and the reference clock pulse signal respectively, export the second delay period signal according to this, wherein the rising edge of the second delay period signal is synchronized with first edge of reference clock pulse signal.
According to the described switch type electric voltage converter of one embodiment of the invention, wherein select circuit also to select according to the selection signal that provides by a counting circuit.
According to the described switch type electric voltage converter of one embodiment of the invention, above-mentioned counting circuit produces the alternative of above-mentioned selection signal with the random number way circulation.
According to the described switch type electric voltage converter of one embodiment of the invention, above-mentioned counting circuit produces the alternative of above-mentioned selection signal in regular turn in default sequence mode.
The present invention does displacement because of the phase place of the clock pulse signal (being above-mentioned digit period signal) switch type electric voltage converter originally being desired receive, produce at least one delay period signal according to this, and then digit period signal or one of them operating frequency as switch type electric voltage converter of above-mentioned delay period signal are selected in circulation, also promptly constantly change the phase place of the clock pulse signal that switch type electric voltage converter received, therefore the noise that is produced in the time of the internal switch of switch type electric voltage converter can being switched is evenly distributed in each level and vertical display cycle, so as to eliminating the ripples line that produces on the display, regional luminance is inhomogeneous, or phenomenon such as flicker.
State with other purposes, feature and advantage and can become apparent on the present invention for allowing, preferred embodiment cited below particularly, and conjunction with figs. is described in detail below.
Description of drawings
Fig. 1 is for having switch type electric voltage converter clock pulse signal and horizontal-drive signal, vertical synchronizing signal, Dot Clock pulse signal three's clock pulse figure now.
Fig. 2 is the circuit diagram that produces circuit according to the operating frequency of one embodiment of the invention.
Fig. 3 is the flow chart according to the operating frequency production method of one embodiment of the invention.
Fig. 4 is according to the digit period signal of one embodiment of the invention and the sequential chart of delay period signal.
Embodiment
Fig. 2 is the circuit diagram that produces circuit according to the operating frequency of one embodiment of the invention.Fig. 3 is the flow chart according to the operating frequency production method of one embodiment of the invention.If circuit shown in Figure 2 and method flow shown in Figure 3 be when being used to produce the operating frequency of switch type electric voltage converter, phenomenons such as the inhomogeneous or flicker of ripples line, the regional luminance that then can eliminate on the display to be produced.To illustrate below why the present invention can reach above-mentioned functions, and please need and with reference to Fig. 2 and Fig. 3 according to explanation.
At first please refer to Fig. 2.Circuit shown in Figure 2 comprises delay circuit 210, selects circuit 220 and counting circuit 230.Delay circuit 210 is in order to receive reference clock pulse signal CLK and digit period signal IN (as the step a) of Fig. 3, and postpone the phase place (time that also promptly postpones digit period signal IN) of digit period signal IN according to reference clock pulse signal CLK, produce at least one delay period signal according to this, and the delay period signal that is produced is neither identical (as the step b) of Fig. 3 time of delay each other.Digit period signal IN just is meant the work clock pulse signal of traditional switch type electric voltage converter.In addition, one of above-mentioned reference clock pulse signal CLK relatively more special restriction is that the frequency of reference clock pulse signal CLK must be greater than the frequency of digit period signal IN.
Select circuit 220 in order to receive the selection signal SEL that digit period signal IN, above-mentioned delay period signal and counting circuit 230 are exported, and according to select signal SEL select output digit period signal IN or above-mentioned delay period signal one of them, with operating frequency as switch type electric voltage converter.OUT is expressed as the output of selecting circuit 220, in order to couple switch type electric voltage converter, so that the operating frequency of switch type electric voltage converter to be provided.
The delay circuit 210 of this embodiment with two just along the D flip- flop 211 and 212 that triggers, and the D flip- flop 213 and 214 of two negative edge triggerings is realized.Digit period signal IN sees through trigger 211 and 213 and does signal delay, and produce delay period signal S2 and S1 respectively, then trigger 212 and 214 receive delay periodic signal S2 and S1 and the signal delay that tries again respectively is to produce delay period signal S4 and S3 respectively.Can see the sequential of these signals by Fig. 4.
Fig. 4 is according to the digit period signal of one embodiment of the invention and the sequential chart of delay period signal.Wherein CLK and IN are respectively the sequential of reference clock pulse signal and digit period signal, and S1, S2, S3 and S4 then are expressed as the sequential of each delay period signal.Because delay period signal S2 and S4 are respectively just along trigger 211 that triggers and 212 output signal, so the rising edge of delay period signal S2 and S4 can be synchronized with the rising edge of reference clock pulse signal CLK.And because delay period signal S1 and S3 are respectively the trigger 213 of negative edge triggering and 214 output signal, so the rising edge of delay period signal S1 and S3 can be synchronized with the trailing edge of reference clock pulse signal CLK.
Referring again to Fig. 2, the selection circuit 220 of this embodiment realizes that with a multiplexer 221 this multiplexer 221 has a plurality of inputs and a selecting side, and the output of multiplexer 221 is exactly the output OUT that selects circuit 221.Above-mentioned input is in order to receive digit period signal IN and the delay period signal S1, S2, S3 and the S4 that are produced by delay circuit 210, and the selecting side is then in order to receive the selection signal SEL that is exported by counting circuit 230.This multiplexer 221 export according to selecting signal SEL digit period signal IN or above-mentioned delay period signal S1, S2, S3 and S4 one of them.
Please refer to Fig. 2 and Fig. 3.The counting circuit 230 of Fig. 2 produces the alternative of selecting signal SEL in regular turn in default sequence mode.With this embodiment, the arrangement mode of default sequence is in regular turn: digit period signal IN, delay period signal S1, delay period signal S2, delay period signal S3, be delay period signal S4 at last.
Though the foregoing description produces circuit to operating frequency and has depicted a possible kenel, but those of ordinary skills should know, delay circuit 210 can adopt other designs with counting circuit 230, and therefore application of the present invention is when being not restricted to the possible kenel of this kind.In other words, so long as utilize reference clock pulse signal CLK to produce the delay period signal of at least one different time of delay with digital all device signal IN, just selecting digit period signal IN or one of them operating frequency as switch type electric voltage converter of above-mentioned delay period signal every a Preset Time then, has been to have met spiritual place of the present invention just.Below enumerate other possible execution modes of a part simply again, do reference for the user.
For the part of delay circuit 210, the user can be according to actual needs the design of conversion its internal circuit, with the combination of the delay period signal that is provided other different time of delays.With Fig. 2 is example, and the user can use one separately just along the trigger 211 that triggers, or the trigger 213 of a negative edge triggering is done delay voltage.Certainly, the trigger that uses a plurality of just edges to trigger, or the trigger that a plurality of negative edge triggers can be operated too.In a word, in delay circuit 210, just along triggering the two number of trigger and negative edge triggering trigger, can change along with designer's needs, yet for the problem that desire of the present invention solves, design is as shown in Figure 4 preferably, makes to present time of delay of each delay period signal the multiple relation each other.In addition, the user also can cooperate the needs of above-mentioned change and change the frequency of reference clock pulse signal CLK.
For the part of counting circuit 230, if its mode with default sequence produces the alternative of selecting signal SEL in regular turn, the arrangement mode of so default sequence also can be to be in regular turn: digit period signal IN, delay period signal S2, delay period signal S1, delay period signal S3, be delay period signal S4 at last, or be in regular turn: delay period signal S2, digit period signal IN, delay period signal S1, delay period signal S4, be delay period signal S3 at last, or be other sortord, then by the phase retardation that constantly repeats above-mentioned wherein a kind of operating frequency of constantly changing switch type electric voltage converter of putting in order.
Certainly, the counting circuit 230 of Fig. 2 also can circulate with the mode of random number and produce the alternative of selecting signal SEL.If implement in this way, the arrangement mode of selecting at random may be so for the first time: delay period signal S3, delay period signal S2, delay period signal S1, digit period signal IN, be delay period signal S4 at last, the arrangement mode of selecting at random may be for the second time: delay period signal S2, delay period signal S1, digit period signal IN, delay period signal S4, be delay period signal S3 at last, and selected afterwards arrangement mode may be other arrangement mode, also may be with the arrangement mode of selection is the same, unpredictable in a word at random for the first time or for the second time.About the function of the counting circuit 230 of this kind mode, the user can use random counter (Random Counter) to realize.
In sum, the present invention does displacement because of the phase place of the clock pulse signal (being above-mentioned digit period signal) switch type electric voltage converter originally being desired receive, produce at least one delay period signal according to this, and then digit period signal or one of them operating frequency as switch type electric voltage converter of above-mentioned delay period signal are selected in circulation, also promptly constantly change the phase place of the clock pulse signal that switch type electric voltage converter received, therefore the noise that is produced in the time of switch type electric voltage converter can being worked is evenly distributed in each level and vertical display cycle, so as to the ripples line that produces on the elimination display, regional luminance is inhomogeneous, or phenomenon such as flicker.
Though the present invention discloses as above with preferred embodiment; right its is not in order to limit the present invention; any those of ordinary skills without departing from the spirit and scope of the present invention, when can doing a little change and retouching, so protection scope of the present invention is when with being as the criterion that claim was defined.
Claims (10)
1. the operating frequency production method of a switch type electric voltage converter, this method comprises the following steps:
A. receive a reference clock pulse signal and a digit period signal;
B. postpone the phase place of this digit period signal according at least one different time of delay, produce at least one delay period signal according to this; And
C. every a Preset Time just select this digit period signal or above-mentioned delay period signal one of them as clock pulse signal, make the phase place of this clock pulse signal constantly change; And operate an internal switch of this switch type electric voltage converter with this clock pulse signal, to produce a voltage.
2. the operating frequency production method of switch type electric voltage converter as claimed in claim 1 is characterized in that, presents the multiple relation described time of delay each other.
3. the operating frequency production method of switch type electric voltage converter as claimed in claim 1 is characterized in that, the selection mode in step c comprises:
With a default sequence mode select in regular turn this digit period signal or above-mentioned delay period signal one of them.
4. the operating frequency production method of switch type electric voltage converter as claimed in claim 1 is characterized in that, the selection mode in step c comprises:
Produce random number, and utilize this random number circulation select this digit period signal or above-mentioned delay period signal one of them.
5. switch type electric voltage converter, it comprises:
One operating frequency produces circuit, and described operating frequency produces circuit and comprises:
One delay circuit receives a reference clock pulse signal and a digit period signal, and postpones the phase place of this digit period signal according to this reference clock pulse signal, produces a plurality of delay period signals according to this, and
One selects circuit, receives this digit period signal and above-mentioned a plurality of delay period signal, and select to export this digit period signal or above-mentioned delay period signal one of them, produce a clock pulse signal, the phase place of this clock pulse signal is constantly changed; And
One internal switch is with this clock pulse signal running, to produce a voltage.
6. switch type electric voltage converter as claimed in claim 5 is characterized in that, this delay circuit comprises:
One first trigger, its input and clock pulse input terminal receive this digit period signal and this reference clock pulse signal respectively, export one first delay period signal according to this, wherein the rising edge of this first delay period signal is synchronized with one first edge of this reference clock pulse signal.
7. switch type electric voltage converter as claimed in claim 6 is characterized in that, this delay circuit also comprises:
One second trigger, its input and clock pulse input terminal receive this first delay period signal and this reference clock pulse signal respectively, export one second delay period signal according to this, wherein the rising edge of this second delay period signal is synchronized with this first edge of this reference clock pulse signal.
8. switch type electric voltage converter as claimed in claim 5 is characterized in that, this selection circuit is also selected according to the selection signal that is provided by a counting circuit.
9. switch type electric voltage converter as claimed in claim 8 is characterized in that, this counting circuit is a random counter, in order to produce random number, produces the alternative that this selects signal with circulation.
10. switch type electric voltage converter as claimed in claim 8 is characterized in that, this counting circuit produces the alternative of this selection signal in regular turn in default sequence mode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CNB2006101362255A CN100544172C (en) | 2006-10-13 | 2006-10-13 | The operating frequency production method and the circuit of switch type electric voltage converter |
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| CNB2006101362255A CN100544172C (en) | 2006-10-13 | 2006-10-13 | The operating frequency production method and the circuit of switch type electric voltage converter |
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| CN101162865A CN101162865A (en) | 2008-04-16 |
| CN100544172C true CN100544172C (en) | 2009-09-23 |
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| CN101577097A (en) * | 2008-05-08 | 2009-11-11 | 奇美电子股份有限公司 | Liquid crystal display device module and voltage generating circuit thereof |
| CN102541643A (en) * | 2011-12-30 | 2012-07-04 | 上海新时达电气股份有限公司 | Logic signal delayed processing method for embedded system |
| CN103594060B (en) * | 2012-08-14 | 2016-12-07 | 通嘉科技股份有限公司 | There is adjustable Phase delay and the circuit of feedback voltage and relevant method thereof |
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Address after: No. 2, 2 East Road three, Zhu Nan Town, Miaoli County, Taiwan, China Patentee after: Himax Semiconductor, Inc. Address before: No. 2, 2 East Road three, Zhu Nan Town, Miaoli County, Taiwan, China Patentee before: ZHIBAO TECHNOLOGY Co.,Ltd. |
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Effective date of registration: 20180801 Address after: Tainan City, Taiwan, China Patentee after: Himax Technologies, Inc. Address before: No. 2, 2 East Road three, Zhu Nan Town, Miaoli County, Taiwan, China Patentee before: Himax Semiconductor, Inc. |
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Granted publication date: 20090923 Termination date: 20181013 |