201208463 六、發明說明： 【發明所屬之技術領域】 本發明關於一種電路，特別是一種光源驅動電路、驅 動方法及控制器。 【先前技術】 如發光二極體（LED)或冷陰極螢光燈（CCFL)等光源 在照明產業中得到廣泛應用，特別是應用在液晶顯示/器 (LCD)背光、街道照明和家用電器等。光源驅動電路>可^ 據一調光信號（例如，脈波寬度調變信號）調節傳送至 源的能量。 ' 圖1所示為現有技術之光源驅動電路100示意圖。光 源驅動電路100包括交流/直流轉換器104、功率轉換器1〇6 和調光模組112。交流/直流轉換器104將一交流電源1〇2 所提供的一輸入交流電壓轉換為一第一直流電壓。功率轉 換器106將第一直流電壓變換為適合對發光二極體串 供電的第二直流電壓。調光模組112可工作於脈衝調光 (burst di麵ing)模式。在脈衝調光模式下，調光模組 Π2產生一脈波寬度調變信號120’以調節傳送到發光二極 體串108的能量，進而調節發光二極體串jog的亮产。更 具體而言’光源驅動電路100還包括耦接至發光二極體串 108的開關110,用於根據脈波寬度調變信號ι2〇控制流經 發光二極體串108的電流Ilight，進而進一步決定發光二極 體串108的亮度。 圖2所示為現有技術之光源驅動電路1〇〇所產生的信 0660-TW-CH Spec+Claim(filed-20100810).doc 4 201208463 號時序圖200。圖2將結合圖1進行描述。在圖2的實施 例:，時序圖2〇〇描述了脈波寬度調變信號12〇和流經發 ，一極體串108的電流1⑽τ。當脈波寬度調變信號120為 南電位時，例如：在時刻tl至t2的時間間隔T〇N中，開關 110導通。電流Ilight流經發光二極體串且具有預設電 流值11。當脈波寬度調變信號120為低電位時，例如：在 時刻t2至t3的時間間隔T㈣中，開關110斷開。電流lL1GHT 下降至零安培。因此，透過調節脈波寬度調變信號120的 • ♦任週期，電流的平均電流值會發生變化，進而可調 節發光二極體串108的亮度。 然而，根據半導體元件（例如，功率轉換器1〇6)的 特性，待開關11〇導通（例如：在tl或切時刻）以後， 電流IuGHT需經過一延遲時間Tdelay方能達到預設電流值 Ιι因此發光一極體串108的調光控制會受到光源驅動 電路100的頻率雜訊的影響。例如，當責任週期相對較小 (例如’責任週期在0〜5%的範圍内）且脈波寬度調變信 • !虎120的頻率大於預設臨限值Fmm時，時間_ T〇N接近甚 至小於延遲時間τ_。因此，電流ILIGHT的平均電流值不會 根據脈波寬度調變信號120的責任週期發生變化，進而引 起光源驅動電路100的調光控制發生錯誤。 【發明内容】 本發明的目的為提供一種光源驅動電路，包括：一頻 率控制器，接收一第一調光信號，以控制一光源達到一預 設亮度，且當該第一調光信號的一頻率介於一預設範圍以 m 0660-TW-CH Spec+Claim(filcd-2〇]〇〇81〇Xdoc 5 201208463 内時，該頻率控制器根據該第一調光信號產生一第二調光 信號’其中，該第二調光信號的一頻率介於該預設範圍以 外；以及一開關模組，耦接至該頻率控制器，其中，當該 第一調光信號的該頻率介於該預設範圍以内時，該開關模 組根據該第二調光信號交替地導通和斷開，且當該第一調 光信號的頻率介於該預設範圍以外時，該開關模組根據該 第一調光信號交替地導通和斷開，以使該光源達到該預設 亮度。 本發明還提供一種光源驅動方法，包括：接收一第一 調光信號以控制一光源達到一預設亮度；當該第一調光信 號的一頻率介於一預設範圍以内時，則根據該第一調光信 號產生一第二調光信號，其中，該第二調光信號的一頻率 介於該預設範圍以外；當該第一調光信號的該頻率介於該 預設範圍以内時’則根據該第二調光信號控制該光源’以 達到該預設亮度；以及當該第一調光信號的該頻率介於該 預設範圍以外時，則根據該第一調光信號控制該光源，以 達到該預設亮度。 本發明還提供一種光源調光控制器，包括：一頻率控 制器，接收一第一調光信號以控制傳遞至一光源之一能 量，以使該光源達到一預設亮度，當該第一調光信號之一 頻率介於一預設範圍内時，根據該第一調光信號產生介於 該預設範圍之外之一頻率之一第二調光信號，且根據一所 選調光信號交替地導通和斷開耦接至該光源之一開關’以 使該光源達到該預設亮度，其中，當該第一調光信號之該 頻率介於該預設範圍之外時，該所選調光信號包含該第一 0660-TW-CH Spec+Claim(filed-2010081〇).doc 6 201208463 ’當該第-賊㈣之該辭介於該預設範圍之 時，’該所選調光信號包含該第：軸信號；以及一邏輯 ㈣、㈣^賴率㈣11，檢卿所賴光信號，且當 =選=信號表示該開關斷開時，停止該功率轉換器的 ^源該功率轉換器的操作包括提供—電壓以驅動 【實施方式】 明將社本發明的實施例給出詳細的說明。雖然本發 月將心實施例進行闡述，但應 限定於這些實施例。相反地，本發明本:明 化、修改和均等物。 神和範圍内所定義的各種變 此外，在以下對本發明的詳細 本發明的完全的理解，提供了大丄“ 7供針對 ，技術領域令具有通常知識者_的解體:^=，於 即，本發明同樣可以實施。在 坆一、體細 家熟知的方法、程序、元株^的―些實例中’對於大 凸顯本發明之主旨。 路未作詳細描述，以便於 本發明實施例提供了 一種光 路包括頻率控制器和開關模組+d電路。光源驅動電 信號（例如，脈波寬度調變信㈤接收第一調光 制光源，光源則發出預設亮度。優點=第2光信號控 號的頻率介於一或多個預設範固以内；調光信 第一調光信號產生第二調光信號，其^ =控制器根據 、甲第一調光信號的 S] 0660-TW.CHSpec+Claim(filed-2〇l〇〇810).d〇c 201208463 頻率介於上述-或多個預設範圍以外。例如，預設範圍可 大於-最大頻率臨限值。此外，第一調光信號和第二調光 信號的責任週期相同。 因此胃帛一調光信號的頻率介於一或多個預設範圍 以内時㈤關模組根據第二調光信號交替地導通和斷開， 以達到預设免度；當第一調光信號的頻率介於一或多刪 設範圍以外時，開關模組根據第一調光信號交替地導通和 斷開，以達到預設亮度。因此’光源的調光控制不會受到 頻率雜訊的影響’進而提高了光源驅動電路的精確度。 圖3所不為根據本發明一實施例光源驅動電路3〇〇的 不意圖。在一實施例中，光源驅動電路3〇〇包括交流/直流 轉換器304、功率轉換器306、開關31〇、調光模組312和 頻率控制器320。父流電源302提供光源驅動電路3〇〇 一 輸入交流電壓，例如：12〇伏商用電壓。光源可包括一或 多個光源串，例如：多個相互串聯耦接的發光二極體所形 成之發光二極體串308。儘管圖3的例子中僅採用了一個 光源串，光源還可包含其他數目的光源串。耦接至交流電 源302的父流/直流轉換器304將輸入交流電壓轉換為第一 直流電壓。功率轉換器306將第一直流電壓變換為適合對 發光二極體串3 0 8供電的第二直流電壓。交流/直流轉換器 304和功率轉換器306的操作將在圖4中進一步描述。 在一實施例中’開關310耦接至發光二極體串308， 根據調光信號控制傳輸到發光二極體串308的能量，進而 使發光二極體串308發出預設亮度。更具體而言，在一實 施例中’調光信號可為脈衝信號，例如，脈波寬度調變信 0660-TW-CH Spec+Claim(filed-20100810).doc g 201208463 號。當調光信號具有邏輯高電位，開關310導通。因此， 電流IUGHT流經發光二極體串3〇8,進而使發光二極體串3肋 發光，此時稱為發光二極體串3〇8的導通狀態。當調光作 號具有邏輯低電位，開關310斷開。因此，電流Iught下^ 至大致零安培，因此，發光二極體串3〇8停止發光，此時 稱為發光二極體串308的斷開狀態。當開關31〇的開關頻 率大於一預设最小臨限值Fmin時，人類的肉眼不會察覺到 發光二極體串308的閃爍（例如，發光二極體串3〇8在導 通狀態和斷開狀態之間切換所引起的閃爍）。此時，可調節 調光信號的責任週期以調節電流Ilight的平均電流值，進而 進一步調整發光二極體串308的亮度。 在一實施例中，調光模組312可為一信號產生器，用 於產生一調光信號DIM1 (例如，PWM信號）以控制傳送至 發光二極體串308的電能，進而達到發光二極體串3〇8的 預設亮度。例如，使用者可透過設定調光信號DIM1的責任 週期來設定預設亮度。 輕接於調光模組312和開關310之間的頻率控制器 320接收調光信號DIM1，並判斷調光信號DIM1的頻率Fduh 是否介於一或多個預設範圍内。舉例說明，預設範圍可為 大於一預設最大臨限值Fmax。在某些情況下，如果調光信號 DIM1的頻率FdIMI介於預設範圍内（例如’大於FmAX)，則頻 率雜訊會影響調光控制的精確度。為方便說明，本文將結 合大於Fmax的預設範圍進行描述。然而，本發明並不局限 於此。在其他實施例中，上述一或多個預設範圍還可包括 其他範圍，例如：小於F1的範圍和/或大於F2且小於F3 [s 0660-TW-CH Spec+Claim(filed-20100810).doc 9 201208463 的範圍9其中，F1 < F2 <F;^ 在一實施例中，如果調光信號DIM1的頻率Fduji介於預 設範圍内（例如，大於F«AX)，則頻率控制器320根據調光信 號DIM1產生另一調光信號DIM2<>調光信號以脱的頻率 與調光信號DIM1的頻率Fduh不同（例如，Fdim2小於最大臨 限值FMAX)。因此，FdIM2介於預設範圍以外。此外，頻率控 制器320保持調光信號dimi和調光信號DIM2的責任週期 相同。因此，根據調光信號DIM2之控制傳送至發光二極體 串308的電能，也可得到預設亮度。在這種情況下，頻率 控制器320將調光信號DIM2傳送至開關310。開關31〇根 據調光信號DIM2控制傳送至發光二極體串3〇8的電能，例 如，透過控制電流 I LIGHT 0 如果調光js號DIM1的頻率Fdimi介於預設範圍以外（例 如，小於FMAX)，則頻率控制器32〇將調光信號DIM1傳送 至開關310。在這種情況下，開關31〇根據調光信號Dmi 控制電流IuGHT，以控制傳送至發光二極體串3〇8的電能， 進而達到預設亮度。 b 因此’基於調光信號DIM1的頻率FdiM1，開關310至少 根據調光信號DIM1或調光信號DIM2控制傳送至發光二極 體串308的電能。因此，控制發光二極體串3〇8的調光作 號（DIM1或DIM2)的頻率始終小於fmax。因此，頻率雜訊^ 會影響流經發光二極體串308的電流IL1GHT。例如，儘管電 流Light在開關310導通以後需要經過一段延遲時間L麗 之後方能上升至預設電流值II，且儘管調光信號（dim或 DIM2)的責任週期可能相對較小，例如：〇〜5%，發光二極 0660-TW-CH Spec+Claim(fiIed-20100810).doc 201208463 體串308導通狀態的持續時間Tqn可始終大於延遲時間 Tdelay。因此’提向了光源驅動電路的精度。 圖4所示為根據本發明一實施例光源驅動電路的 示意圖° ®4中與圖3標號相_元件具有相同的功能。 圖4將結合圖3進行描述。201208463 VI. Description of the Invention: [Technical Field] The present invention relates to a circuit, and more particularly to a light source driving circuit, a driving method and a controller. [Prior Art] Light sources such as light-emitting diodes (LEDs) or cold cathode fluorescent lamps (CCFLs) are widely used in the lighting industry, especially in liquid crystal display (LCD) backlights, street lighting, and household appliances. . The light source driving circuit > adjusts the energy delivered to the source according to a dimming signal (e.g., a pulse width modulation signal). FIG. 1 is a schematic diagram of a prior art light source driving circuit 100. The light source driving circuit 100 includes an AC/DC converter 104, a power converter 1〇6, and a dimming module 112. The AC/DC converter 104 converts an input AC voltage supplied from an AC power source 1〇2 into a first DC voltage. Power converter 106 converts the first DC voltage to a second DC voltage suitable for powering the LED string. The dimming module 112 can operate in a burst dim ing mode. In the pulse dimming mode, the dimming module Π2 generates a pulse width modulation signal 120' to adjust the energy delivered to the LED string 108, thereby adjusting the illumination of the LED string jog. More specifically, the light source driving circuit 100 further includes a switch 110 coupled to the LED string 108 for controlling the current Ilight flowing through the LED string 108 according to the pulse width modulation signal ι2, thereby further The brightness of the LED string 108 is determined. 2 is a timing diagram 200 of the letter 0660-TW-CH Spec+Claim(filed-20100810).doc 4 201208463 generated by the prior art light source driving circuit 1〇〇. Figure 2 will be described in conjunction with Figure 1. In the embodiment of Fig. 2, the timing diagram 2A describes the pulse width modulation signal 12 〇 and the current 1 (10) τ flowing through the transistor 108. When the pulse width modulation signal 120 is at the south potential, for example, in the time interval T〇N from time t1 to t2, the switch 110 is turned on. The current Ilight flows through the light emitting diode string and has a preset current value of 11. When the pulse width modulation signal 120 is at a low potential, for example, in the time interval T (four) from time t2 to time t3, the switch 110 is turned off. The current lL1GHT drops to zero amps. Therefore, by adjusting the period of the pulse width modulation signal 120, the average current value of the current changes, thereby adjusting the brightness of the LED string 108. However, according to the characteristics of the semiconductor component (for example, the power converter 1〇6), after the switch 11 is turned on (for example, at time t1 or time), the current IuGHT needs to pass a delay time Tdelay to reach the preset current value Ιι. Therefore, the dimming control of the light-emitting diode string 108 is affected by the frequency noise of the light source driving circuit 100. For example, when the duty cycle is relatively small (for example, 'the duty cycle is in the range of 0 to 5%) and the pulse width modulation signal • The frequency of the tiger 120 is greater than the preset threshold Fmm, the time _ T〇N is close. Even less than the delay time τ_. Therefore, the average current value of the current ILIGHT does not change according to the duty cycle of the pulse width modulation signal 120, which causes an error in the dimming control of the light source driving circuit 100. SUMMARY OF THE INVENTION An object of the present invention is to provide a light source driving circuit, comprising: a frequency controller, receiving a first dimming signal to control a light source to reach a predetermined brightness, and when the first dimming signal is When the frequency is within a preset range of m 0660-TW-CH Spec+Claim(filcd-2〇]〇〇81〇Xdoc 5 201208463, the frequency controller generates a second dimming according to the first dimming signal. a signal 'where a frequency of the second dimming signal is outside the preset range; and a switch module coupled to the frequency controller, wherein when the frequency of the first dimming signal is between When the preset range is within, the switch module is alternately turned on and off according to the second dimming signal, and when the frequency of the first dimming signal is outside the preset range, the switch module is configured according to the first A dimming signal is alternately turned on and off to enable the light source to reach the preset brightness. The present invention also provides a light source driving method, comprising: receiving a first dimming signal to control a light source to reach a predetermined brightness; The first dimming signal When the frequency is within a predetermined range, a second dimming signal is generated according to the first dimming signal, wherein a frequency of the second dimming signal is outside the preset range; when the first tune When the frequency of the optical signal is within the preset range, 'the light source' is controlled according to the second dimming signal to achieve the preset brightness; and when the frequency of the first dimming signal is between the preset range In addition, the light source is controlled according to the first dimming signal to achieve the preset brightness. The invention further provides a light source dimming controller, comprising: a frequency controller, receiving a first dimming signal to control transmission Energy to one of the light sources to cause the light source to reach a predetermined brightness. When one of the first dimming signals has a frequency within a predetermined range, the first dimming signal is generated according to the preset range. a second dimming signal of one of the frequencies, and alternately turning on and off a switch coupled to the light source according to a selected dimming signal to cause the light source to reach the preset brightness, wherein The frequency of the first dimming signal When the value is outside the preset range, the selected dimming signal includes the first 0660-TW-CH Spec+Claim(filed-2010081〇).doc 6 201208463 'When the first-thief (four) is between At the preset range, the selected dimming signal includes the first:axis signal; and a logic (four), (four)^ rate (four)11, the light signal of the prosecutor, and when the =select=signal indicates that the switch is off When the power converter is stopped, the operation of the power converter includes providing a voltage to drive. [Embodiment] A detailed description will be given of an embodiment of the present invention. Rather, the invention is to be construed as being limited to the details of the embodiments of the invention. The "7" is targeted, and the technical field has the disintegration of the general knowledge: ^=, that is, the present invention can be implemented as well. In the "some examples" of the methods, programs, and meta-systems well known to those skilled in the art, the gist of the present invention is highlighted. The road is not described in detail, so that the embodiment of the present invention provides an optical path including a frequency controller and a switch module +d circuit. The light source drives the electrical signal (for example, the pulse width modulation signal (5) receives the first dimming light source, and the light source emits a preset brightness. Advantages = the frequency of the second optical signal control number is within one or more preset ranges The first dimming signal of the dimming signal generates a second dimming signal, wherein the controller is based on S1 0660-TW.CHSpec+Claim(filed-2〇l〇〇810) of the first dimming signal. D〇c 201208463 The frequency is outside the above- or more than the preset range. For example, the preset range can be greater than - the maximum frequency threshold. In addition, the duty cycle of the first dimming signal and the second dimming signal are the same. When the frequency of the gastric dimming signal is within one or more preset ranges (5) the off module is alternately turned on and off according to the second dimming signal to achieve the preset degree of exemption; when the first dimming signal is When the frequency is outside the range of one or more deletions, the switch module is alternately turned on and off according to the first dimming signal to achieve the preset brightness. Therefore, the dimming control of the light source is not affected by the frequency noise. Further improving the accuracy of the light source driving circuit. In one embodiment, the light source driving circuit 3 includes an AC/DC converter 304, a power converter 306, a switch 31, a dimming module 312, and a frequency. The controller 320 provides a light source driving circuit 3 for inputting an alternating voltage, for example, a 12 volt commercial voltage. The light source may include one or more light source strings, for example, a plurality of light emitting diodes coupled in series with each other. Light-emitting diode string 308 formed by the body. Although only one light source string is used in the example of Figure 3, the light source may also include other numbers of light source strings. The parent/DC converter 304 coupled to the AC power source 302 will input The AC voltage is converted to a first DC voltage. Power converter 306 converts the first DC voltage to a second DC voltage suitable for powering LED string 3 0. Operation of AC/DC converter 304 and power converter 306 It will be further described in Figure 4. In an embodiment, the switch 310 is coupled to the LED string 308, and controls the energy transmitted to the LED string 308 according to the dimming signal, thereby enabling the LED to emit light. The body string 308 emits a predetermined brightness. More specifically, in one embodiment, the 'dimming signal can be a pulse signal, for example, a pulse width modulation signal 0660-TW-CH Spec+Claim(filed-20100810).doc g 201208463. When the dimming signal has a logic high potential, the switch 310 is turned on. Therefore, the current IUGHT flows through the light emitting diode string 3〇8, thereby causing the light emitting diode string 3 rib to emit light, which is called the light emitting diode The conduction state of the body string 3〇8. When the dimming signal has a logic low potential, the switch 310 is turned off. Therefore, the current Iught is down to substantially zero amperes, and therefore, the light emitting diode string 3〇8 stops emitting light. This is called the off state of the light emitting diode string 308. When the switching frequency of the switch 31〇 is greater than a preset minimum threshold Fmin, the human eye does not perceive the blinking of the LED string 308 (for example, the LED string 3〇8 is in the on state and disconnected). Blinking caused by switching between states). At this time, the duty cycle of the dimming signal can be adjusted to adjust the average current value of the current Ilight, thereby further adjusting the brightness of the LED string 308. In an embodiment, the dimming module 312 can be a signal generator for generating a dimming signal DIM1 (eg, a PWM signal) to control the power transmitted to the LED string 308 to achieve the LED. The preset brightness of the body string 3〇8. For example, the user can set the preset brightness by setting the duty cycle of the dimming signal DIM1. The frequency controller 320 connected between the dimming module 312 and the switch 310 receives the dimming signal DIM1 and determines whether the frequency Fduh of the dimming signal DIM1 is within one or more preset ranges. For example, the preset range may be greater than a preset maximum threshold Fmax. In some cases, if the frequency FdIMI of the dimming signal DIM1 is within a preset range (eg, greater than FmAX), the frequency noise will affect the accuracy of the dimming control. For convenience of explanation, this article will describe the preset range larger than Fmax. However, the invention is not limited thereto. In other embodiments, the one or more preset ranges may further include other ranges, such as: a range less than F1 and/or greater than F2 and less than F3 [s 0660-TW-CH Spec+Claim(filed-20100810). Doc 9 201208463, range 9 where F1 < F2 <F; ^ In an embodiment, if the frequency Fduji of the dimming signal DIM1 is within a preset range (eg, greater than F«AX), the frequency controller 320 generates another dimming signal DIM2 according to the dimming signal DIM1; the dimming signal is different in frequency from the frequency Fduh of the dimming signal DIM1 (for example, Fdim2 is smaller than the maximum threshold FMAX). Therefore, FdIM2 is outside the preset range. Further, the frequency controller 320 maintains the duty cycle of the dimming signal dimi and the dimming signal DIM2 to be the same. Therefore, the preset brightness can also be obtained by the power transmitted to the light-emitting diode string 308 according to the control of the dimming signal DIM2. In this case, the frequency controller 320 transmits the dimming signal DIM2 to the switch 310. The switch 31〇 controls the power transmitted to the LED string 3〇8 according to the dimming signal DIM2, for example, through the control current I LIGHT 0 if the frequency Fdimi of the dimming js number DIM1 is outside the preset range (for example, less than FMAX) Then, the frequency controller 32 transmits the dimming signal DIM1 to the switch 310. In this case, the switch 31 控制 controls the current IuGHT according to the dimming signal Dmi to control the power transmitted to the LED string 3 〇 8 to reach the preset brightness. b Therefore, based on the frequency FdiM1 of the dimming signal DIM1, the switch 310 controls the power transmitted to the LED string 308 based at least on the dimming signal DIM1 or the dimming signal DIM2. Therefore, the frequency of the dimming signal (DIM1 or DIM2) controlling the LED string 3〇8 is always smaller than fmax. Therefore, the frequency noise ^ affects the current IL1GHT flowing through the LED string 308. For example, although the current Light needs to pass a delay time L after the switch 310 is turned on, it can rise to the preset current value II, and although the duty cycle of the dimming signal (dim or DIM2) may be relatively small, for example: 〇~ 5%, illuminating diode 0660-TW-CH Spec+Claim(fiIed-20100810).doc 201208463 The duration Tqn of the body string 308 conduction state can always be greater than the delay time Tdelay. Therefore, the accuracy of the light source driving circuit is raised. Fig. 4 is a view showing a schematic diagram of a light source driving circuit according to an embodiment of the present invention, which has the same function as that of Fig. 3. Figure 4 will be described in conjunction with Figure 3.
在一實施例中，交流/直流轉換器304包括整流電路和 漉波器。整流電路可包括半錢流H、全波整流器或橋式 整流器’但不以此為限。整流電路整流輸人交流電壓，以 提供第-直流電壓。例如，紐電路可刪除輸人交流電壓 的負電壓㈣’或者將負電觀形轉換為對應的正電壓波 形直=题整2路的輪出端得到一具有正電壓波形的第 交流電源3°2和交流7直流轉_ 可由一直k電源代替。例如，第一亩 (例如，電池組）提供。帛直机電壓可由直流電源 極體:直流電壓轉換為適合對發光二 流電壓。在圖4的實施例中，功 雪玄c】知Λ 包括電m、二極體D1、 電夺ci和開關s卜透過調節開關 間（例如，根據PWM信號CP進 導，時間和斷開時 可調節儲存在電感L1和電容C1卩’功率轉換器306 功率轉換H 306透過這種方^ #電心在一實施例中， 二直流電I。當開關31〇導^生^於第—直流電壓的第 偏置發光二極體串308。功率轉換^直流電壓能夠正向 例如，降壓轉換器、升降壓 y 可具有其他結構’ 局限於圖4中的實施例。換器或返馳式轉換器，且不 0660-TW-CH Spec+Claim(filed-20 丨00810).doc 201208463 一調光模組312產生調光信號DiM1。例如，讥叽可為脈 衝信號（例如，PM信號），且調光信號_的責任週、 表不發光二極體串308的預設亮度。使用者可設定 號順的責任週期。頻率控制器320接收調光信號 在實施例中，頻率控制器32〇包括頻率檢測器4〇2、 率轉換器404和邏輯電路406。 頻率檢測器402檢測調光信號DIM1的頻率fdim1，以判 疋Fimn疋否介於預辑範圍内，例如，預設範圍為至無 窮大。在一實施例中，頻率檢測器4〇2包括一計數器 用於叶算調光彳§號DIM1的頻率Fdimi。更具體而言，調光信 號Dim與一預設採樣時脈信號同步。在一實施例中，預設 採樣時膦信號可為一具有固定週期TCUK;K的週期性方波信 號。在工作中，計數器420計算在調光信號DIM1的一個^ 期内發生的預設採樣時脈信號的迴圈個數M。根據迴圈個 數Μ和採樣時脈信號的固定週期Tclqck可計算出調光信號 DIM1的頻率pDIM1，可由方程式（1)表示之：In an embodiment, the AC/DC converter 304 includes a rectifier circuit and a chopper. The rectifier circuit may include a half-current stream H, a full-wave rectifier or a bridge rectifier 'but is not limited thereto. The rectifier circuit rectifies the input AC voltage to provide a first DC voltage. For example, the circuit can delete the negative voltage of the input AC voltage (4)' or convert the negative electric power into the corresponding positive voltage waveform. The round output of the whole 2 channel is obtained. The AC power supply with positive voltage waveform is 3°2. And AC 7 DC _ can be replaced by a constant k power supply. For example, the first acre (for example, a battery pack) is provided. The straightening machine voltage can be converted from a DC power source: the DC voltage is suitable for the illuminating current. In the embodiment of FIG. 4, the function of the power snow includes the electric m, the diode D1, the electric ci, and the switch s through the adjustment switch (for example, according to the PWM signal CP, when and when disconnected) Adjustable storage in inductor L1 and capacitor C1 卩 'power converter 306 power conversion H 306 through this square ^ #电心 In one embodiment, two DC I. When the switch 31 ^ ^ ^ ^ ^ ^ The first biased light-emitting diode string 308. The power conversion ^ DC voltage can be forward, for example, the buck converter, the buck-boost y can have other structures' limited to the embodiment of Figure 4. Converter or flyback conversion , and not 0660-TW-CH Spec+Claim(filed-20 丨00810).doc 201208463 A dimming module 312 generates a dimming signal DiM1. For example, 讥叽 can be a pulse signal (for example, a PM signal), and The duty cycle of the dimming signal _ indicates the preset brightness of the LED string 308. The user can set the duty cycle of the number. The frequency controller 320 receives the dimming signal. In an embodiment, the frequency controller 32 includes Frequency detector 4〇2, rate converter 404 and logic circuit 406. Frequency detector 402 detects the frequency fdim1 of the dimming signal DIM1 to determine whether the Fimn疋 is within the pre-range range, for example, the preset range is to infinity. In an embodiment, the frequency detector 4〇2 includes a counter for the leaf. The dimming signal Dim is synchronized with a predetermined sampling clock signal. In an embodiment, the phosphine signal can be a fixed period TCUK when the sampling is preset; The periodic square wave signal of K. In operation, the counter 420 calculates the number M of loops of the preset sampling clock signal occurring during one period of the dimming signal DIM1. According to the number of loops and the sampling clock The fixed period Tclqck of the signal can calculate the frequency pDIM1 of the dimming signal DIM1, which can be expressed by equation (1):
Fdihi - 1 / (M ^ Tclock)----(1) 此外’頻率檢測器402還包括比較器422，用於比較 檢測出的頻率Fdimi和一或多個預設臨限值之間的大小，以 決定頻率Fdimi是否介於預設範圍以内。在一實施例中，比 較器422比較頻率Fdimi和預設最大臨限值Fmax。如果Fdimi 大於Fmax ’則表示Fdim1介於預設範圍以内。此時，比較器 422將調光信號DIM1傳送至頻率轉換器404。如果Fimn小 於Fmax，則表示Fdimi介於預設範圍以外。此時，比較器422 將調光彳§號DIM1傳送至邏輯電路406。邏輯電路406將調 0660-TW-CH Spec+Claim(filed-20100810).doc 12 201208463 光信號DIM1傳送至開關310。開關31〇據此調節流經發光 二極體串308的電流ILICHT。頻率檢測器4〇2可包括其他元 件，且不局限於圖4的實施例。 、 頻率轉換器404根據調光信號_產生調光信號 DIM2。在-實施例中’頻率轉換器綱變換調光信號醒 的頻率Fdhh並保持其責任週期！，以產生調光信號 DIM2。調光信號DIM2具有頻率心们和責任週期D_。頻率 F喔小於Fmax。並且，責任週期DdiM2等於調光信號mmi之 • 責任週期Ddimi。因此，調光信號DIM1表示的預設亮度也可 以由調光信號DIM2表示。 更具體地說’頻率轉換器404可採用第一採樣時脈信 號SIGNAL1和第二採樣時脈信號SIGNAL2產生調光信號 DIM2’其中，調光信號DIM2的頻率fDIM2是diM1的頻率Fdimi 的分數（fraction)。在一實施例中，第一採樣時脈信號 SIGNAL1和第二採樣時脈信號SIGNAL2可為具有固定頻率 的週期性方波仏號。第一採樣時脈信號SIGNAL2的頻率 φ Fc_是第一採樣時脈信號SIGNAL1的頻率fc_的分數， 如方程式（2)所示：Fdihi - 1 / (M ^ Tclock)----(1) Further, the frequency detector 402 further includes a comparator 422 for comparing the magnitude between the detected frequency Fdimi and one or more preset thresholds. To determine if the frequency Fdimi is within the preset range. In an embodiment, comparator 422 compares frequency Fdimi with a preset maximum threshold Fmax. If Fdimi is greater than Fmax ', then Fdim1 is within the preset range. At this time, the comparator 422 transmits the dimming signal DIM1 to the frequency converter 404. If Fimn is less than Fmax, it means that Fdimi is outside the preset range. At this time, the comparator 422 transmits the dimming code DIM1 to the logic circuit 406. Logic circuit 406 transmits a 0660-TW-CH Spec+Claim(filed-20100810).doc 12 201208463 optical signal DIM1 to switch 310. The switch 31 adjusts the current ILICHT flowing through the LED string 308 accordingly. The frequency detector 4〇2 may include other elements and is not limited to the embodiment of Fig. 4. The frequency converter 404 generates a dimming signal DIM2 according to the dimming signal_. In the embodiment - the frequency converter class converts the frequency of the dimming signal to the frequency Fdhh and maintains its duty cycle! To generate the dimming signal DIM2. The dimming signal DIM2 has a frequency center and a duty cycle D_. The frequency F喔 is less than Fmax. Also, the duty cycle DdiM2 is equal to the duty cycle Ddimi of the dimming signal mmi. Therefore, the preset brightness indicated by the dimming signal DIM1 can also be represented by the dimming signal DIM2. More specifically, the frequency converter 404 can generate the dimming signal DIM2' using the first sampling clock signal SIGNAL1 and the second sampling clock signal SIGNAL2, wherein the frequency fDIM2 of the dimming signal DIM2 is the fraction of the frequency Fdimi of diM1 (fraction ). In an embodiment, the first sampled clock signal SIGNAL1 and the second sampled clock signal SIGNAL2 may be periodic square wave apostrophes having a fixed frequency. The frequency φ Fc_ of the first sampling clock signal SIGNAL2 is a fraction of the frequency fc_ of the first sampling clock signal SIGNAL1, as shown in equation (2):
FcL0CK2 = (1/N) * Fclocki----(2) 頻率轉換器404計算第一採樣時脈信號^⑽人。的迴 圈個數，以獲取表示DIM1的週期和責任週期的結果資料， 然後根據資料和第二採樣時脈信號SIGNAL2產生調光信號 DIM2。 在圖4的實施例中，頻率轉換器404包括多工器414 和一或多個計數模組（例如，計數模組410和計數模組 0660-TW-CHSpec+Claim(filed-20100810).doc 13 201208463 412)。在一實施例中告其 D腿的週期和責任;===組檢_光信號 號臟的週期和責任週期 ^數模組則決定調光信 和計數模組412中的每—個模 ，計數模組410 週期計數器（圖令未示）。當對鹿週期計數器和責任 410為例)檢測調光信號_二;且 計數器計算在調光信號_的-個t二41^的週期 脈信號SIGNAL1迴圈的個數NM。以這種方2 樣時 器得到絲縣錢麵的週 十數 週期計數器計算T_ 此外，， SIGML1的迴圈個數Ν1β，其 弟鉍樣時脈信號 的一個週期内且DIM1户於L ΓΤΕ1示在調光信號DiMl =獲=調光信號DIM1的責任週期的責/_= ^ ’如果τ咖表示調光信號麵的邏 4 :，可結合和削得到表示_的責任週期= 任週期資料’例如mB/ NU。如果Ts_表示 信號DIM1的邏輯低電位的持續時間’可結合Nu和 得到表示DHH的責任週__的責任週期資料，例如：d_ =卜（NIB/ N1A)。因此，則得到包括週期資料和責任週期 資料的結果資料。計數模組檢測調光信號贿的操 圖5進一步描述。 、 當對應的計數模組（以計數模組412為例）用於產生 調光信號DIM2時，計數模組412巾的週期計數器根據週期 _貝料（例如· N1A) §十算第二採樣時脈信號肌飢2的迴圈 0660-TW'CH Spec+Claim(filed-20100810).doc 201208463 個數，以決定調光信號臓的週期τ_。例如，τ_等於 第二採樣時脈信號謂AL2的週期的NU倍。此外，計數 模組412的責任週期計數器根據責任週期資料（例如：ν⑻ t算第二採樣時脈信號SIG亂2的迴酬數，以決定調光 仏號DIM2的貝任週期ddi„2。例如，調光信號則2的對應 預設狀態（例如：邏輯高電位和邏輯低電位）的持續時間 τ:等於第二採樣時脈㈣SIG_的週期的_倍。調 光信號DIM2的責任週期d_可表示為D_= Tw τ_(當 • Τ聰對應於则2的邏輯高電位）或者D_= 1-TstW Τ麗 (當TSTATEZ對應於DIM2的邏輯低電位 >計數模組用於產生 調光信號DIM2的操作將在圖5中進一步描述。 結果，調光信號DIM1的T»IM1和TSTATE1都乘以了相同的 數值N，進而得到調光信號DIM2的Τμ2和TstATE2,其中，根 據式（2)得出N。因此，頻率fdimz是頻率fdim1的分數，其 可由方程式（3)表示之： ’FcL0CK2 = (1/N) * Fclocki----(2) The frequency converter 404 calculates the first sample clock signal ^(10) person. The number of loops is obtained to obtain the result data indicating the period and duty cycle of DIM1, and then the dimming signal DIM2 is generated according to the data and the second sampling clock signal SIGNAL2. In the embodiment of FIG. 4, the frequency converter 404 includes a multiplexer 414 and one or more counting modules (eg, counting module 410 and counting module 0660-TW-CHSpec+Claim(filed-20100810).doc 13 201208463 412). In one embodiment, the period and responsibility of the D leg are reported; === group inspection _ optical signal number dirty cycle and responsibility cycle system module determines each mode in the dimming signal and counting module 412, counting Module 410 cycle counter (not shown). When the deer period counter and the responsibility 410 are taken as an example, the dimming signal _2 is detected; and the counter calculates the number NM of the period of the pulse signal SIGNAL1 of the dimming signal _. In this way, the square meter counter of the silk county is calculated by the square meter. T_ In addition, the number of loops of SIGML1 is β1β, and the period of the clock signal of the younger brother is shown in L ΓΤΕ1. In the duty cycle of the dimming signal DiMl = get = dimming signal DIM1 / _ = ^ ' If τ coffee represents the dimming signal surface of the logic 4:, can be combined and cut to obtain the responsibility cycle of _ = cycle data ' For example mB/ NU. If Ts_ indicates the duration of the logic low of the signal DIM1', the duty cycle data of the duty cycle __ indicating DHH can be combined, for example: d_ = 卜 (NIB/N1A). Therefore, the result data including the cycle data and the responsibility cycle data is obtained. The counting module detects the dimming signal bribery. Figure 5 is further described. When the corresponding counting module (for example, the counting module 412 is used) is used to generate the dimming signal DIM2, the period counter of the counting module 412 is calculated according to the period_before (for example, N1A) The pulse signal muscle starving 2 loop 0660-TW'CH Spec+Claim(filed-20100810).doc 201208463 number to determine the period τ_ of the dimming signal 臓. For example, τ_ is equal to NU times the period of the second sample clock signal, AL2. In addition, the duty cycle counter of the counting module 412 calculates the number of returns of the second sampling clock signal SIG chaos 2 according to the duty cycle data (for example: ν(8) t to determine the beid period ddi „2 of the dimming nickname DIM2. For example. The duration τ of the corresponding preset state (for example, logic high potential and logic low potential) of the dimming signal 2 is equal to _ times of the period of the second sampling clock (four) SIG_. The duty cycle d_ of the dimming signal DIM2 It can be expressed as D_= Tw τ_ (when • Τ聪 corresponds to the logic high of 2) or D_= 1-TstW ( (when TSTATEZ corresponds to the logic low of DIM2), the counting module is used to generate the dimming signal The operation of DIM2 will be further described in Fig. 5. As a result, both T»IM1 and TSTATE1 of the dimming signal DIM1 are multiplied by the same value N, thereby obtaining Τμ2 and TstATE2 of the dimming signal DIM2, wherein, according to equation (2) N is obtained. Therefore, the frequency fdimz is the fraction of the frequency fdim1, which can be expressed by the equation (3):
Fdim2 = (1/N) * Fdimi----(3) φ 如方程式（3)所示，分數1/Ν也是由根據方程式（2) 所得的第二採樣時脈信號SIGNAL2的頻率和第一採樣時脈 信號SIGNAL1的頻率之間的比例決定。此外，責任週期Ddimi 等於責任週期Ddim2，其可由方程式（4)得之：Fdim2 = (1/N) * Fdimi----(3) φ As shown in equation (3), the fraction 1/Ν is also the frequency and first of the second sampling clock signal SIGNAL2 obtained according to equation (2) The ratio between the frequencies of the sampling clock signal SIGNAL1 is determined. In addition, the duty cycle Ddimi is equal to the duty cycle Ddim2, which can be obtained by equation (4):
DdIM2 - TSTATE2/ TdIM2 = (N^TsTATEl)/ (N^TDIMl) = TsTATEl/ TdIHI "Ddimj----(4) 圖5所示為根據本發明一實施例頻率轉換器（例如，圖 4中所示之頻率轉換器404)接收和產生的信號之時序圖 500。在圖5的實施例中，時序圖500描述了調光信號DdIM2 - TSTATE2 / TdIM2 = (N^TsTATEl) / (N^TDIMl) = TsTATEl / TdIHI "Ddimj----(4) Figure 5 shows a frequency converter according to an embodiment of the invention (for example, Figure 4 A timing diagram 500 of the received and generated signals is shown by frequency converter 404). In the embodiment of FIG. 5, timing diagram 500 depicts a dimming signal
SI 0660-TW-CH Spec+Claim(filed-20100810).doc 15 201208463 DIMl、第一採樣時脈信號SIGNAL1和第二採樣時脈信號 SIGNAL2。此外，第二採樣時脈信號SIGNAL2的頻率fCL0CK2 是第一採樣時脈信號SIGNAL1的頻率Fa〇CK1的1/N。例如， 在圖 5 中 ’ FcL0CK2=l/2 * Fclocki 〇 在tl至t7的時間間隔中，一或多個計數模組透過執 行计數操作獲取結果資料。在tl時刻，對應的計數模組計 算第一採樣時脈信號SIGNAL1的迴圈個數。在圖5的實施 例中，在調光彳s號DIΜ1的一個週期（例如：^ 1至13或者 t3至t5)内，第一採樣時脈信號SIGNAU具有5個迴圈週 期。因此，週期計數器得到週期資料為5。並且，在調光 信號DIM1的-個週期中，調光信號DIm為邏輯高電位 的持續時間（例如·· tl至t2、t3至t4或者t5至 第-採樣時脈信號S職L1具有2個迴圈週期 示調光信號則1的責任週期的責任週期數據為她。 採二;Γ包:週多個計數模組透過 :時脈，SI_產生調光信號 j = 中’調光信號_的軸（例如η， 至t2，、t3，至t4，或者^，電位的持續時間（例如：tl， 脈信號蠢2的週期的2:::二採樣時 任週期也為40%。 ^此調先仏嬈DIM2的責 因此’為了產生調光 期和邏輯高電位的持續_ 調先k唬DIM1的週 都乘以相同的預設數值ΓΚ例 0660-TW-CH Spec+Claim(filed-2010081 201208463 如，在圖5中N等於2)。預設數值N是根據方程式（2) 由第一採樣時脈信號SIGNAL1和第二採樣時脈信號 SIGNAL2所決定之。結果，調光信號DIM2的頻率是調光作 號DIM1的頻率的1/N。 在一實施例中’調光信號DIM1和調光信號{)iM2具有 由使用者預設或編程設定的固定頻率。例如，使用者可將 數值N設定為實質恒定的數值。或者，第一採樣時脈信號 SIGNAL1和第二採樣時脈信號SIGNAL2可由信號產生器產 鲁 生。此時’可根據調光信號DIM1的頻率Fdimi決定數值n 或者分數1/N。也就是說，數值N可根據頻率pDIM1變化。 例如，如果頻率Fdw大於F«AX且小於F1，例如：fmax<F圓<F1， 數值N等於N1。如果頻率Fdimi大於F1，例如：Fmax>F1，數 值N等於N2，其中，N2大於N1。 結合圖4和圖5進行描述。在一實施例中，計數模組 410和計數模組412可交替地計算第一採樣時脈信號 SIGNAL1的迴圈個數（獲取結果資料）和根據結果資料計 φ 舁第二採樣時脈信號SIGNAL2 (產生調光信號DIM2)。舉例 說明’在tl至t3的時間間隔中，計數模組41〇透過計算 第一採樣時脈信號SIGNAL1的迴圈個數來檢測調光信號 DIM1。在時刻切，計數模組410得到週期資料和責任週期 資料。然後，計數模組41〇進入tl，至t3，的時間間隔中， 即計數模組410透過計算第二採樣時脈信號SIGNAL2的迴 圈個數來產生調光信號DIM2。在此實施例中，時刻tl，對 應於時刻t3、且時刻t3，對應於時刻t7。因此，在時刻 t3或tl’ ’計數模組412開始透過計算第一採樣時脈信號 0660.TW-CH Spec+Claim(filed-201〇〇81〇) d〇c 17 201208463 SIGNAL1的迴圈個數來檢測調光信號DIM1。同樣地，在時 刻’計數模組412得到週期資料和責任週期資料。在時 刻ΐ3或t7 ’當計數模組410完成產生調光信號d〖M2的 操作，計數模組410開始檢測調光信號DIM1，而計數模組 412開始產生調光彳㊂被DIM2。透過這種方式，調光信號 可為一連續PWM信號。 多工器414將計數模組410或計數模組412所產生的 調光信號DIM2傳送至邏輯電路406。邏輯電路4〇6將頻率 介於預設範圍之外的調光信號DIM2傳送給開關31〇。 圖6所示為根據本發明一實施例頻率控制器320的另 一示意圖。圖6中與圖4標號相同的元件具有相同的功能。 圖6將結合圖3至圖5進行描述。 在圖6的實施例中，頻率轉換器4〇4包括計數模組 510、暫存器514和計數模組512。計數模組51〇透過計算 第一採樣時脈信號SIGNAL1的迴圈個數來檢測調光; DIMi (例如，在圖5中的時刻tl至t7進行），並將包 期資料和責任週期資料的結果資料存入耦接至計數模組 \10的暫存器514中。耦接至暫存器514的計數模組512 讀取結果資料，並透過計算第二採樣時脈信號signal2的 迴圈個數來產生調光信號DIM2(例如，在圖5中的時刻衍， 至t6進行）。因此，在此實施例中，時刻u，對應時刻 tl且時刻t3對應時刻t5。 頻率控制器320可具有其他結構，且不局限於圖4和 圖6的實施例。在另一實施例中，可將計數模組5ι〇從頻 率控制器32G中移除，並將計數模組51()的功能併入頻率 0660-TW-CH Spec+Claim(filed-20100810).doc 201208463 檢測器402中。例如，頻率檢測器402可透過計數第一採 樣時脈信號SIGNAL1來檢測調光信號DIM1的頻率和責任週 期。如果檢測到的調光信號DIM1的頻率大於Fmax，頻率檢 測器402儲存週期資料和責任週期資料至暫存器514。計 數模組512採用第二採樣時脈信號sIGNAL2和結果資料來 產生調光彳s號DIM2 ’並將DIM2傳送至頻率檢測器402。如 果調光信號DIM1的頻率小於fmax，頻率檢測器402將調光 信號DIM1傳送至邏輯電路4〇6 » 鲁 圖7所示為根據本發明另一實施例光源驅動電路7〇〇 的示意圖。圖7中與圖3和圖4標號相同的元件具有相同 的功能。圖7將結合圖3、圖4和圖6進行描述。在圖7 的實施例中，驅動電路700包括交流/直流轉換器3〇4、功 率轉換器306、開關310、調光模組312和控制器702。控 制器702耦接於開關310和功率轉換器306之間，並可整 合在一積體電路晶片上。控制器γ〇2透過控制開關310和 功率轉換器306來控制發光二極體串308的調光。 # 在一實施例中，控制器702包括頻率控制器320、轉 換控制器704和邏輯模組7〇6 ^頻率控制器320採用類似 圖4和圖6中的架構。因此，控制器7〇2可根據選擇出的 調光信號DIM1/DIM2導通或斷開開關310 ,以控制流經發 光二極體串308的電流lLIGHT，進而使發光二極體串3〇8具 有預設亮度。當調光信號DIM1的頻率{^⑻介於預設範圍以 外時，例如，小於Fmax，則所選的調光信號為DIM1。當調 光、號DIM1的頻率Fdimi介於預設範圍以内時，例如，大於 Fmax，則所選的調光信號為DIM2 〇 [Si 0660-TW-CH Spec+CIaim(filed.201〇〇81〇).d〇c 19 201208463 轉換控制器704用於產生_ PWM信號cp ,以轉功率 轉換器306。輕接至轉換控制器704和頻率控制器32〇的 邏輯模組706檢測所選的調光信號（例如，DIM1或MM2), 以獲取開關310的開關狀態，並據此控制功率轉換器3〇6。 更具體地說’在-實施财，當輯的誠信絲示開關 310導通時，邏輯模組706將PWM信號cp傳送給功率轉換 器306 ^然後，功率轉換器306根據pwM信號cp調節開關 si的導通和斷開時間’以調節儲存在電感u和電容ci中 的能量。結合圖4中的描述，第一直流電壓轉換為第二直 流電壓’以正向偏置發光二極體串3〇8。 當所選的調光信號表示開關31〇斷開時，電流Ilight下 降到大致零安培。此時，邏輯模組7〇6產生一結束信號（例 如，邏輯1)，並將結束信號傳送給開關S1，用於停止功率 轉換器306的操作。例如，開關S1根據狀態為邏輯丨之結 束k號保持導通，進而使儲存在電感Li和電容ci中的能 量耗盡。這樣，功率轉換器306停止將第一直流電壓轉換 為第二直流電壓。並且，功率轉換器3〇6不再消耗從交流 電源302吸收的能量’進而降低了光源驅動電路7〇〇的功 耗。 總之’當開關310導通時，功率轉換器306提供第二 直流電壓’以驅動發光二極體串3〇8 ;而當開關31〇斷開 時，功率轉換器306停止工作。因此，提高了光源驅動電 路700的能量效率。 圖8所示為根據本發明一實施例光源驅動電路3〇〇、 400或700的操作流程圖8〇〇。圖8將結合圖3至圖γ進行 0660-TW-CH Spec+Claim(filed-20100810).doc 20 201208463 描述。圖8所涵蓋的具體步驟僅僅作為賴。 本發明適用於其他合理的絲或對圖8進行改=驟’ 在步驟802中，接收第一調光信號（例如， 在步驟804中，捻，目,丨筮# ^ 〇. ^DlM1)〇 的獅^ 關㈣—調光信號 、頻率（例如，F_)是否介於—預設範圍（例如：大於 F«ax)以内H調光信號的頻率介於預設範圍以 ，程圖800進入步驟8〇6。在步驟8〇6巾，根據第一調光SI 0660-TW-CH Spec+Claim(filed-20100810).doc 15 201208463 DIM1, first sampling clock signal SIGNAL1 and second sampling clock signal SIGNAL2. Further, the frequency fCL0CK2 of the second sampling clock signal SIGNAL2 is 1/N of the frequency Fa CK1 of the first sampling clock signal SIGNAL1. For example, in Fig. 5 'FcL0CK2=l/2 * Fclocki 〇 In the time interval from t1 to t7, one or more counting modules obtain the result data by performing the counting operation. At time t1, the corresponding counting module calculates the number of loops of the first sampling clock signal SIGNAL1. In the embodiment of Fig. 5, the first sampling clock signal SIGNAU has five loop periods in one period (e.g., ^1 to 13 or t3 to t5) of the dimming 彳s number DIΜ1. Therefore, the cycle counter gets a cycle data of 5. And, in the period of the dimming signal DIM1, the dimming signal DIm is a logic high duration (for example, tl to t2, t3 to t4 or t5 to the first sampling clock signal S, L1 has 2 The loop cycle shows the dimming signal, and the duty cycle data of the duty cycle of 1 is her. The second is: the package: the weekly multiple counting module transmits: the clock, SI_ produces the dimming signal j = the middle dimming signal _ The axis (for example, η, to t2, t3, to t4, or ^, the duration of the potential (for example: tl, the period of the pulse signal 2::: the second cycle is also 40%. ^This tune First, the responsibility of DIM2 is therefore 'in order to generate the duration of dimming period and logic high level _ first k唬DIM1 weeks are multiplied by the same preset value example 0660-TW-CH Spec+Claim(filed-2010081 201208463 For example, N is equal to 2 in Fig. 5. The preset value N is determined by the first sampling clock signal SIGNAL1 and the second sampling clock signal SIGNAL2 according to equation (2). As a result, the frequency of the dimming signal DIM2 is Dimming the frequency of the signal DIM1 by 1/N. In an embodiment, the 'dimming signal DIM1 and the dimming signal {) iM2 have a user Preset or programmed fixed frequency. For example, the user can set the value N to a substantially constant value. Alternatively, the first sampling clock signal SIGNAL1 and the second sampling clock signal SIGNAL2 can be generated by the signal generator. The time ' can be determined according to the frequency Fdimi of the dimming signal DIM1 or the fraction 1/N. That is, the value N can be varied according to the frequency pDIM1. For example, if the frequency Fdw is greater than F«AX and less than F1, for example: fmax<F Circle <F1, value N is equal to N1. If the frequency Fdimi is greater than F1, for example: Fmax>F1, the value N is equal to N2, where N2 is greater than N1. It is described in connection with Figures 4 and 5. In one embodiment, the counting mode The group 410 and the counting module 412 can alternately calculate the number of loops of the first sampling clock signal SIGNAL1 (acquisition result data) and the second sampling clock signal SIGNAL2 (generating the dimming signal DIM2) based on the result data. For example, in the time interval from t1 to t3, the counting module 41 detects the dimming signal DIM1 by calculating the number of loops of the first sampling clock signal SIGNAL1. At the time of the cutting, the counting module 410 obtains the periodicity. And the duty cycle data. Then, the counting module 41 enters the interval of t1 to t3, that is, the counting module 410 generates the dimming signal DIM2 by calculating the number of loops of the second sampling clock signal SIGNAL2. In this embodiment, the time t1 corresponds to the time t3 and the time t3 corresponds to the time t7. Therefore, at time t3 or tl' 'the counting module 412 starts to calculate the number of loops of the first sampling clock signal 0660.TW-CH Spec+Claim(filed-201〇〇81〇) d〇c 17 201208463 SIGNAL1 To detect the dimming signal DIM1. Similarly, the cycle's counting module 412 obtains cycle data and responsibility cycle data. At time ΐ3 or t7', when the counting module 410 completes the operation of generating the dimming signal d〖M2, the counting module 410 starts detecting the dimming signal DIM1, and the counting module 412 starts generating the dimming 被3 by the DIM2. In this way, the dimming signal can be a continuous PWM signal. The multiplexer 414 transmits the dimming signal DIM2 generated by the counting module 410 or the counting module 412 to the logic circuit 406. The logic circuit 4〇6 transmits the dimming signal DIM2 having a frequency outside the preset range to the switch 31A. Figure 6 shows another schematic diagram of frequency controller 320 in accordance with an embodiment of the present invention. Elements labeled the same as in Figure 4 have the same function. Figure 6 will be described in conjunction with Figures 3 through 5. In the embodiment of FIG. 6, the frequency converter 4〇4 includes a counting module 510, a register 514, and a counting module 512. The counting module 51 detects the dimming by calculating the number of loops of the first sampling clock signal SIGNAL1; DIMi (for example, at times t1 to t7 in FIG. 5), and the data of the instalment data and the duty cycle data The resulting data is stored in a register 514 coupled to the counting module \10. The counting module 512 coupled to the register 514 reads the result data, and generates the dimming signal DIM2 by calculating the number of loops of the second sampling clock signal signal2 (for example, at time in FIG. 5, T6 is performed). Therefore, in this embodiment, the time u corresponds to the time t1 and the time t3 corresponds to the time t5. Frequency controller 320 can have other configurations and is not limited to the embodiments of Figures 4 and 6. In another embodiment, the counting module 5ι can be removed from the frequency controller 32G and the function of the counting module 51() is incorporated into the frequency 0660-TW-CH Spec+Claim (filed-20100810). Doc 201208463 Detector 402. For example, the frequency detector 402 can detect the frequency and duty cycle of the dimming signal DIM1 by counting the first sampling clock signal SIGNAL1. If the frequency of the detected dimming signal DIM1 is greater than Fmax, the frequency detector 402 stores the period data and the duty cycle data to the register 514. The counting module 512 uses the second sampled clock signal SIGNAL2 and the resulting data to generate the dimming s number DIM2' and transmits the DIM2 to the frequency detector 402. If the frequency of the dimming signal DIM1 is less than fmax, the frequency detector 402 transmits the dimming signal DIM1 to the logic circuit 4〇6 » Figure 7 is a schematic diagram of the light source driving circuit 7A according to another embodiment of the present invention. Elements labeled the same as in Figures 3 and 4 have the same function. Figure 7 will be described in conjunction with Figures 3, 4 and 6. In the embodiment of FIG. 7, the driver circuit 700 includes an AC/DC converter 3〇4, a power converter 306, a switch 310, a dimming module 312, and a controller 702. The controller 702 is coupled between the switch 310 and the power converter 306 and can be integrated on an integrated circuit chip. The controller γ〇2 controls the dimming of the LED string 308 through the control switch 310 and the power converter 306. In one embodiment, controller 702 includes frequency controller 320, conversion controller 704, and logic module 7〇6. Frequency controller 320 employs an architecture similar to that of Figures 4 and 6. Therefore, the controller 7〇2 can turn on or off the switch 310 according to the selected dimming signal DIM1/DIM2 to control the current lLIGHT flowing through the LED string 308, thereby enabling the LED string 3〇8 to have Preset brightness. When the frequency {^(8) of the dimming signal DIM1 is outside the preset range, for example, less than Fmax, the selected dimming signal is DIM1. When the frequency of the dimming, number DIM1 Fdimi is within the preset range, for example, greater than Fmax, the selected dimming signal is DIM2 〇[Si 0660-TW-CH Spec+CIaim(filed.201〇〇81〇) ).d〇c 19 201208463 The conversion controller 704 is configured to generate a _PWM signal cp for the power converter 306. The logic module 706, which is connected to the conversion controller 704 and the frequency controller 32A, detects the selected dimming signal (for example, DIM1 or MM2) to obtain the switching state of the switch 310, and controls the power converter 3〇 accordingly. 6. More specifically, in the implementation, when the integrity of the switch 310 is turned on, the logic module 706 transmits the PWM signal cp to the power converter 306. Then, the power converter 306 adjusts the switch si according to the pwM signal cp. Turn on and off time' to adjust the energy stored in inductor u and capacitor ci. In conjunction with the description in Figure 4, the first DC voltage is converted to a second DC voltage' to forward bias the LED strings 3?8. When the selected dimming signal indicates that switch 31 is off, current Ilight drops to approximately zero amps. At this time, the logic module 7〇6 generates an end signal (e.g., logic 1) and transmits an end signal to the switch S1 for stopping the operation of the power converter 306. For example, the switch S1 is kept turned on according to the state of the logical 丨, and the energy stored in the inductor Li and the capacitor ci is depleted. Thus, power converter 306 stops converting the first DC voltage to the second DC voltage. Moreover, the power converter 3〇6 no longer consumes the energy absorbed from the alternating current power source 302, thereby reducing the power consumption of the light source driving circuit 7〇〇. In summary, when the switch 310 is turned on, the power converter 306 provides a second DC voltage ' to drive the LED string 3〇8; and when the switch 31 is turned off, the power converter 306 stops operating. Therefore, the energy efficiency of the light source driving circuit 700 is improved. Figure 8 is a flow chart showing the operation of the light source driving circuit 3, 400 or 700 in accordance with an embodiment of the present invention. Figure 8 will be described in conjunction with Figures 3 through γ in the description of 0660-TW-CH Spec+Claim(filed-20100810).doc 20 201208463. The specific steps covered in Figure 8 are only for Lai. The present invention is applicable to other reasonable wires or to the modification of Figure 8. In step 802, the first dimming signal is received (e.g., in step 804, 捻, 目, 丨筮#^ 〇. ^DlM1)〇 Lion ^ Off (4) - whether the dimming signal, frequency (for example, F_) is between - the preset range (for example: greater than F«ax), the frequency of the H dimming signal is within the preset range, and the process chart 800 enters the step 8〇6. In step 8〇6 towel, according to the first dimming
信號控制-光源，以達到一預設亮度。反之，當第一^光 信號的頻率介於預設範圍以内時，流_ 8⑽進入步驟 808。 〇在步驟808中，根據第一調光信號產生一第二調光信 號’其中’第二調光信號_率介於預設範圍以外。在一 實施例中帛e周光彳g號和第二調光信號係為脈波寬度調 變化號。第一調光信號和第二調光信號的責任週期保持相 同在實施例中，將第一調光信號的週期和導通時間乘 以一相同的數值，以產生第二調光信號。在一實施例中， 根據第一調光信號的頻率調節該數值。在一實施例中，計 算第一採樣時脈信號（例如，SIGNAL1)的迴圈個數，以得 到表示第一調光信號的週期和責任週期的結果資料。並 且，根據結果資料計算第二採樣時脈信號的迴圈個數，以 產生第二調光信號。其中，第二調光信號的頻率是第一調 光信號的頻率的分數，並且，該分數是由第二採樣時脈信 號的頻率和第一採樣時脈信號的頻率之間的比例決定。 在步驟810中’根據第二調光信號控制光源，以達到 預設亮度。The signal controls the light source to achieve a predetermined brightness. On the other hand, when the frequency of the first optical signal is within the preset range, the stream _ 8 (10) proceeds to step 808. In step 808, a second dimming signal 'where the second dimming signal _ rate is generated outside the preset range is generated according to the first dimming signal. In one embodiment, the 周e 彳g and the second dimming signal are pulse width modulation numbers. The duty cycle of the first dimming signal and the second dimming signal remain the same. In an embodiment, the period and the on-time of the first dimming signal are multiplied by the same value to produce a second dimming signal. In an embodiment, the value is adjusted based on the frequency of the first dimming signal. In one embodiment, the number of loops of the first sampled clock signal (e.g., SIGNAL1) is calculated to obtain a result data representative of the period and duty cycle of the first dimming signal. And, calculating the number of loops of the second sampling clock signal according to the result data to generate a second dimming signal. Wherein the frequency of the second dimming signal is a fraction of the frequency of the first dimming signal, and the fraction is determined by a ratio between the frequency of the second sampling clock signal and the frequency of the first sampling clock signal. In step 810, the light source is controlled in accordance with the second dimming signal to achieve a preset brightness.
ί SI 0660-TW-CHSpec+Claim(filed-20100810).doc 21 201208463 上文具體實施方式和附圖僅為本發明之常用實施 例H然，在不脫離權利要求書所界定的本發明精神和^ 明fe圍的前提下可以有各種增補、修改和替換。本領域技 術人員應該理解，本發明在實際應用中可根據具體的環境 和工作要求在不背離發明準則的前提下在形式、結構、佈 局、比例、材料、元素、元件及其它方面有所變化❶因此， 在此披露之實施例僅用於說明而非限制，本發明之範圍由 後附權利要求及其合法等同物界定，而不限於此前之描 述。 【圖式簡單說明】 以下結合附圖和具體實施例對本發明的技術方法進 行詳細的描述，以使本發明的特徵和優點更為明顯。其中： 圖1所示為現有技術之光源驅動電路示意圖。 圖2所不為現有技術之光源驅動電路所產生的作號時 序圖。 圖3所示為根據本發明一實施例光源驅動電路的示音 圖。 圖4所示為根據本發明一實施例光源驅動電路的示音 圖。 圖5所示為根據本發明一實施例頻率轉換器接收和產 生的信號之時序圖。 圖6所示為根據本發明一實施例頻率控制器的另_示 意圖。 圖7所示為根據本發明另一實施例光源驅動電路的示 0660-TW-CH Spcc+Claim(filed-20100810).doc 22 201208463 意圖。 圖8所示為根據本發明一實施例光源驅動電路的操作 流程圖。 【主要元件符號說明】 100 :光源驅動電路 102 :交流電源 104 :交流/直流轉換器 106 :功率轉換器 108 :發光二極體串 110 :開關 112 :調光模組 120 :脈波寬度調變信號 200 :時序圖 300 :光源驅動電路 302 :交流電源 304 :交流/直流轉換器 306 :功率轉換器 308 :發光二極體串 310 :開關 312 :調光模組 320 :頻率控制器 400 :光源驅動電路 402 :頻率檢測器 404 :頻率轉換器 0660-TW-CHSpec+Claim(filed-20100810).doc 23 201208463 406 :邏輯電路 410、412 :計數模組 414 :多工器 420 :計數器 422 :比較器 500 .時序圖 510、512 :計數模組 514 :暫存器 700 :光源驅動電路 702 :控制器 704 :轉換控制器 706 :邏輯模組 800 :流程圖 802、804、806、808、810 :步驟 0660-TW-CH Spec+Claim(flled-20100810).doc 24ί SI 0660-TW-CHSpec+Claim(filed-20100810).doc 21 201208463 The above detailed description and the accompanying drawings are only a typical embodiment of the present invention, without departing from the spirit and scope of the invention as defined by the appended claims ^ There are various additions, modifications and replacements under the premise of Ming Fe. It should be understood by those skilled in the art that the present invention may be modified in form, structure, arrangement, ratio, material, element, component and other aspects in accordance with the specific environmental and working requirements in the actual application. Therefore, the embodiments disclosed herein are intended to be illustrative and not restrictive, and the scope of the invention is defined by the appended claims BRIEF DESCRIPTION OF THE DRAWINGS The technical method of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, in which the features and advantages of the invention are more apparent. Wherein: FIG. 1 is a schematic diagram of a light source driving circuit of the prior art. Figure 2 is a timing diagram of the prior art light source driving circuit. Fig. 3 is a diagram showing the sound source driving circuit in accordance with an embodiment of the present invention. Fig. 4 is a diagram showing the sound source driving circuit in accordance with an embodiment of the present invention. Figure 5 is a timing diagram of signals received and generated by a frequency converter in accordance with an embodiment of the present invention. Figure 6 is a diagram showing another embodiment of a frequency controller in accordance with an embodiment of the present invention. Figure 7 is a diagram showing the light source driving circuit according to another embodiment of the present invention. 0660-TW-CH Spcc+Claim(filed-20100810).doc 22 201208463. Figure 8 is a flow chart showing the operation of a light source driving circuit in accordance with an embodiment of the present invention. [Main component symbol description] 100: Light source driving circuit 102: AC power supply 104: AC/DC converter 106: Power converter 108: Light-emitting diode string 110: Switch 112: Dimming module 120: Pulse width modulation Signal 200: Timing diagram 300: Light source driving circuit 302: AC power supply 304: AC/DC converter 306: Power converter 308: Light-emitting diode string 310: Switch 312: Dimming module 320: Frequency controller 400: Light source Drive circuit 402: frequency detector 404: frequency converter 0660-TW-CHSpec+Claim (filed-20100810).doc 23 201208463 406: logic circuit 410, 412: counting module 414: multiplexer 420: counter 422: comparison 500. Timing diagrams 510, 512: counting module 514: register 700: light source driving circuit 702: controller 704: switching controller 706: logic module 800: flowcharts 802, 804, 806, 808, 810: Step 0660-TW-CH Spec+Claim(flled-20100810).doc 24