201143247 六、發明說明： 【發明所屬之技術領域】 本發明係有關於一種開關式電源供應器(§witched-mode power supply，SMPS)的過負載保護。 【先前技術】 電源供應器為一種電源管理裝置，用來轉換電源，以提供電源給 電子裴置或是元件。舉例來說，第1圖為一習知的電源供應器6〇，具 有返馳式架構(flyback topology) 〇橋式整流器62整流了交流電源vAC， k供輸入電源Vrn至變壓器64。開關72開啟(dose)時，變壓器64的 一次測繞組LP儲能；關閉(open)時，變壓器64的二次測繞組“透過 整流器66釋能至負載電容(l〇ad capacitor)69以建立輸出電源νουτ。誤 差放大器(error amplifier)EA比較輸出電源νουτ的電壓與目標電壓 VTarget ’並產生補償信號Vc〇M。控制器74依據補償信號％⑽以及電 流偵測信號Vcs，以控制信號VGATE控制開關72。電流偵測信號vcs 反應流經一次測繞組LP的電感電流。 省知第1圖的電源供應器都有許多種保護，像是過電壓保護(〇ver voltageprotecti〇n ’ 0VP)、過高溫保護(〇vertemperaturep她cti〇n， ◎TP) '過負載保護(over load protection，OLP)等。其中〇Lp是通产矜 出負載過大’且超過電祕應H賴定輸㈣率時，電源供應器就相 201143247 對應產生的保護措施。 OLP有許多_法。譬如說， 制流經一次測繞組Lp的電感電流。 輸的電能超過一定程度。 【發明内容】 —種是限制輸出電流，另一種是限 主要想法都是防止電源供應器所傳 本發明實施例提供一種控制方 古一刚月、 、 去顧於一電源供應器，其包含 有開關以及一電感元件。該方法句八古.a 感電流；依據-#㈣ 侧流_賴元件之電 過·能·料/吏"電供應器操作於一正常載狀態或-、載狀心，於s亥正韦载狀態時，使流 於-1 口“ 卞使机、士°亥電感几件之-電流峰值不大 仪、士卜 、 α貝手马第一頻率；於該過載狀鵰日奔， 使>;IL經該電感元件之—電流峰值& 為一第二頻率’且該第二頻率高 只午 於兮過祕貞w ± 第神；計算該電源供應器處 、。次载狀心、的持、’時間；該持續時間超過— 感電流；其中，該容許時門。、a，，7止5亥電 Y〆合。f時間不文缸作頻率變化而影響。 本發明實施例提供-種電源供應器。 Μ ^ ^工制态控制流經一電感元 件之電感電流。該控制器包含有一工作拄％ ^ ^ 一過載保護器。該工作時脈產生咢用 及 使、、古料W 一心㊉ ㈣Μ生一工作頻率。該限流器可 蚀 疋值° * S亥限流器使該電流峰 值，，々為該定值時，該工作頻率不低於— 第—頻率。於該 一過载辨識器，依據一回饋信號，可辨戟忏隻裔中 頌域了辨識該電源供應器是否應進入一 201143247 過載狀,4。以電源供應器操作於該過載狀態時，該工作頻率為一第 二頻率’高於該第-鮮。-電流供應器提供—外接電容充放電電流， 可用以計算該電源供應器處於該過載狀態的持續時間。當該持續時間 超過-容許時間時，該控㈣停止該械電流，且該料時間不受該 工作頻率改變而影響。 本^月實關提供-種電源供應器，適用於—電源供應器。該電 源供應$具有—電感元件，與—_。該電源控制器包括—第一比較 ==產生器、以及一過載保護器。該第-比較器接收-補 〜、1制信·控_。該電流偵 元件之-電感電流。該補償信號相對應於該電源供 之電第—比較關以依據該補償信號來大約蚊該電感電流 關之^工作時脈產生關以依據·償信號來大致提供該開 作頻率。當該補償健對應之該貞触態為重_，使該工 無二寺為使;=作頻率i當該補償信號對應之該負載狀態為輕載或 電写她/工頻率為—低頻工作頻率。該過載保具有一充放 ^接至-外部，__補軸 谷許時間，且該容料間*受該震lUf彡響。 以决疋4 本發明實施例提供一種電源控制方法，適用於 電源供應器包括有-電感綠。該方法包括：依據—補償信^判: 201143247 二:負栽狀態為重載時，使該開關操作 载狀態為輕戟或無載時，使該開關操作於一 :工作頻率；以及，當該補償信號超過—臨界值時，判斷該負載狀能 獅持續1糊後，咖開關； 合柄間由-外接電谷喊，與該開關操作之該高、低卫作頻率無關。 雷實關難—觀源控制转，適祕—電祕應器。該 二4包括有-電感讀’其受—咖控制以儲能或釋能，以產 生-輸出《。财法包括：提供—卫作時 :r工作頻率;偵測該電源供應器之-負載狀態：= 二來調整虹作頻率，其中該負載狀態為_重载時，其該工作頻率為 頻率；當該負载狀態為過載時，於—容許時間内，使該工作頻 2約為-第二頻率，該第二頻率高於該第—頻率；以及，並於該容 許時間結紐，停止關關之操作。該料時間不找震盪器影響。 【實施方式】 4 2圖為依據本發明實施的-電源供應器9〇。第2圖與第！圖中 目问的符號表不相同或相似的元件、㈣、或信號，為習知技術，在 =不多加累述。第2圖僅僅為-實施例，實施本發明並非—定要使用 弟1圖中相同或相似的元件、裝置、哎作 次彳。唬。本發明的權利範圍應以 申凊專利範圍解讀為限制。 於一 實施例中’第2圖中的控制器73用單1體電路實施；镇 7 201143247 一個實施例中，控制器73與開關72 —起以單一積體電路實施。與第 1圖之控制器74不同的，第2圖中的控制器73 ’多了一個接腳(pin)CT， 連接到外接電容75，其功能將於稍作說明。 第3圖則例示控制器73中部份的電路與外接電容75。比較器82 提供過電流保護(0CP)，也是一峰值限定器’控制第2圖中的電流僧測 信號Vcs的電壓峰值不超過Vc；s-LIMIT，也相對的限制了流經—次側繞組 LP的電流峰值(peakcurrent)不大於(= Vcslimit/Rcs)，其中^為電 阻cs的阻值。比較器84則是依據補償信號Vc〇m來大約決定一次側 繞組LP的電齡值，遞魏v_的電紐可以視騎持當時輸出 電壓所需之對應功率，或^目應於輸出的貞載狀態。補償信號 不只是大約決定-次側繞组Lp的電流峰值，也決定了工作日寺脈產:器 %所輸出駐細率，也就是第2财_ 72的工作辦。舉例來 t補償信號V⑽的電壓值低時，為輕載/無載，所輸 約為20kHz;補償作辦v . ΦΛ F月千 率私咖 為重載，所輸出的工作頻 …版。獨是重載或是輕載/無載，都是視较常載狀態。 電提供充放電電流，透過接腳CT，給外接電容乃。 卜㈣容75 —㈣視為—物^時_ 過載情形嶋界值Vp時，奴當下有輪出 依據時脈it。t _，比較器88使計數器(__ 媒時脈震盧為所輸出的時脈 數器92的輸出但比較H 94判別計 間，比π '條件’也就是過錄形持續超過-段容許時 匕幸父β 94就輸出過載伴嘈 D午手 幻戰保紅破，觸發0LP，邏輯控制單元％持 201143247 續關閉開關72，僖,卜^*&从&_^, 補償H v T止電㈣轉換與傳遞。如果在料日Hi·之前， 二=rr_QLP_v。一下，意味著電源供綱 產生号96: 4數$ %紐重置歸零，關72還是工作時脈 產裔6所輸出的工作頻率而持續操作。電流供應器μ、比較㈣、 計數器92、以及比較器94可以一起視為一過載保護器。在另-種實 94可咐，直翻咖％的―個輸出 ⑽之邏輯叩，或，，〇，，來作為〇Lp的觸發判斷。 由以上電路可知，這容許時間指的是容許電源供應器90處於過載 =態1的持續時間，是由電流供應㈣跟外接電容75所構成的時脈 」盪續產生㈣細及比較^4所設定_設條制蚊。這段容 卉時間不又工作時脈產生器96的工作頻率變化所影響。舉例來說，設 計上，比較器94之預設條件是在積體電路中内建而不受外在元件數值 而改變，而OLP震盪器的頻率可由外接電容％的電容值決定。因此， 系，、先。又。十上’可以方便地透過挑選適當之外接電容Μ冑容值來決定容 φ 許時間。 在-實施例中，OLP被觸發後，當補償信號回到低於〇Lp 臨界值V〇L4，就解除〇Lp，而重新開始電能轉換與傳遞；在另一實 %例中’只有控㈣了3的錢電源瓣與錢供電啟動(restart)才 能解除0LP。 第4圖顯示工作時脈產生胃96的工作頻率與補償信號Vc〇M的關 係。當補償信號VCOM的電壓值對應到ν_ιτ時，可以視為重載，祕 9 201143247 時脈產生器96的工作頻率，比如說，為一重裁頻率fHEAvy (譬如 65Khz);當補償信號201143247 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to an overload protection of a sawed-mode power supply (SMPS). [Prior Art] A power supply is a power management device for converting a power supply to supply power to an electronic device or component. For example, Figure 1 shows a conventional power supply 6〇 with a flyback topology. The bridge rectifier 62 rectifies the AC power supply vAC, k for the input power supply Vrn to the transformer 64. When the switch 72 is open, the primary winding LP of the transformer 64 is stored; when it is open, the secondary winding of the transformer 64 is "discharged through the rectifier 66 to the load capacitor 69 to establish an output. The power supply νουτ. The error amplifier EA compares the voltage of the output power source νουτ with the target voltage VTarget′ and generates a compensation signal Vc〇M. The controller 74 controls the switch with the control signal VGATE according to the compensation signal %(10) and the current detection signal Vcs. 72. The current detection signal vcs reacts through the inductor current of the winding LP. It is known that the power supply of Figure 1 has many kinds of protections, such as overvoltage protection (〇ver voltageprotecti〇n '0VP), over temperature Protection (〇vertemperaturep her cti〇n, ◎TP) 'Over load protection (OLP), etc.. 〇Lp is the output of the production is too large and exceeds the frequency of the electricity The supply corresponds to the protection measures generated by the 201143247. The OLP has many methods. For example, the inductor current flowing through the winding Lp is measured. The power transmitted exceeds a certain level. The other is to limit the output current, and the other is to prevent the power supply from being transmitted. The embodiment of the present invention provides a control method, which is a power supply, which includes a switch and an inductor. Component. The method is sentenced to eight. A sense current; according to -# (four) side stream _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ When Haizheng Wei loaded the state, it made the flow of -1 port "卞 机, machine, _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ , causing >; IL through the inductive component - the current peak & is a second frequency ' and the second frequency is high only after passing the secret w ± god; calculate the power supply at . The secondary load, the hold, the 'time; the duration exceeds the sense current; wherein the allowable time gate. , a,, 7, 5, 5, and Y. f time is not affected by the frequency change of the cylinder. Embodiments of the present invention provide a power supply. The 制 ^ ^ industrial state controls the inductor current flowing through an inductive component. The controller contains a working 拄% ^ ^ an overload protector. The working clock is used to make use, and the ancient material W is one heart ten (four) to produce a working frequency. The current limiter is etched and depreciated. * The current limit is set by the S-hei current limiter. When 々 is the fixed value, the operating frequency is not lower than the -first frequency. In the overload identifier, according to a feedback signal, it is possible to identify whether the power supply should enter a 201143247 overload state, 4 . When the power supply is operated in the overload state, the operating frequency is a second frequency 'before the first freshness. - The current supply provides - an external capacitor charge and discharge current that can be used to calculate the duration of the power supply in the overload state. When the duration exceeds the allowable time, the control (4) stops the mechanical current, and the material time is not affected by the change of the operating frequency. This ^ month real off provides a kind of power supply, suitable for - power supply. The power supply has $inductive components, and -_. The power controller includes a first comparison == generator and an overload protector. The first comparator receives -compensation ~, 1 signal control and control. The current sense component - the inductor current. The compensation signal is corresponding to the power supply of the power supply. The comparison is based on the compensation signal to approximate the operating current of the inductor current to provide the activation frequency according to the compensation signal. When the compensation state corresponds to the 贞 为 为 , , , , = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = . The overload protection has a charge and discharge to the external, __ complement axis time, and the volume* is slammed by the shock. The invention provides a power control method suitable for a power supply including - inductive green. The method comprises: according to the compensation signal: 201143247 2: when the load state is a heavy load, when the switch operation state is light or no load, the switch is operated at a working frequency; and, when When the compensation signal exceeds the -threshold value, it is judged that the load-like lion can last for one paste, and the coffee switch; the shank is shunted by the external electric valley, regardless of the high and low frequency of the switch operation. Lei Shiguan difficult - Guanyuan control transfer, appropriate secret - electric secrets. The two 4 include a -inductive read 'the receiver is controlled to store or release energy to produce an output." The financial method includes: providing - the security: r working frequency; detecting the power supply - load state: = two to adjust the rainbow frequency, wherein the load state is _ heavy load, the working frequency is the frequency; When the load state is overloaded, the operating frequency 2 is about - the second frequency, the second frequency is higher than the first frequency in the allowable time; and, at the allowable time, the closing is stopped. Operation. The material time is not affected by the oscillator. [Embodiment] FIG. 2 is a diagram of a power supply 9〇 implemented in accordance with the present invention. Figure 2 and the first! The symbols in the figure that are not identical or similar to the components, (4), or signals are conventional techniques, and are not included in the description. Fig. 2 is merely an embodiment, and the implementation of the present invention is not intended to be the same or similar components, devices, and operations. fool. The scope of the invention should be construed as limiting the scope of the claims. In one embodiment, the controller 73 of Fig. 2 is implemented with a single 1-body circuit; Town 7 201143247 In one embodiment, controller 73 is implemented with a single integrated circuit in conjunction with switch 72. Unlike the controller 74 of Fig. 1, the controller 73' in Fig. 2 has a pin CT connected to the external capacitor 75, the function of which will be described later. The third figure illustrates a part of the circuit of the controller 73 and an external capacitor 75. Comparator 82 provides overcurrent protection (0CP), which is also a peak limiter's control. The voltage peak value of current sense signal Vcs in Fig. 2 does not exceed Vc; s-LIMIT, which also limits the flow through the secondary winding. The peak current of LP is not greater than (= Vcslimit/Rcs), where ^ is the resistance of resistor cs. The comparator 84 determines the age value of the primary winding LP according to the compensation signal Vc〇m, and the power of the Wei V_ can be regarded as the corresponding power required to ride the current output voltage, or the output should be Unloaded state. The compensation signal is not only about determining the current peak value of the secondary winding Lp, but also determines the duty ratio of the working day of the temple: the output of the device is the second fiscal _ 72 work. For example, when the voltage value of the t compensation signal V(10) is low, it is light load/no load, and the input is about 20 kHz; the compensation is done by v. ΦΛF month thousand private coffee is the heavy load, and the output frequency is output. It is overloaded or lightly loaded/unloaded, and it is more often loaded. The electric charge and discharge current is supplied to the external capacitor through the pin CT. Bu (4) Rong 75 - (4) regarded as - matter ^ time _ overload situation when the boundary value Vp, the slave has a turn according to the clock it. t _, the comparator 88 causes the counter (__ media clock swell to be the output of the output clock 92 but compares the H 94 discriminator, the ratio π 'condition' is that the over-recording continues to exceed the - period allowable time Fortunately, the father β 94 output overload with 嘈D noon hand phantom protection red break, trigger 0LP, logic control unit% held 201143247 continued to close switch 72, 僖, 卜^*& from &_^, compensate H v T Power-off (four) conversion and transmission. If before the material Hi Hi, two = rr_QLP_v. This means that the power supply generation number 96: 4 number $ % New reset to zero, off 72 or work clock generation 6 The operating frequency of the output continues to operate. The current supply μ, the comparison (4), the counter 92, and the comparator 94 can be regarded together as an overload protector. In another type, the output is (10) The logic 叩, or, 〇,, is used as the trigger judgment of 〇Lp. It can be seen from the above circuit that the allowable time refers to the duration in which the power supply 90 is allowed to be in the overload state 1 and is supplied by the current supply (4) and externally. The clock formed by the capacitor 75 is generated continuously (four) and compared with the setting of ^4 This period of time is not affected by the change in the operating frequency of the operating clock generator 96. For example, the preset condition of the comparator 94 is designed to be built in the integrated circuit without being changed by the external component value. The frequency of the OLP oscillator can be determined by the capacitance of the external capacitor %. Therefore, the system can be easily determined by selecting the appropriate external capacitor capacitance value to determine the tolerance time. In the example, after the OLP is triggered, when the compensation signal returns below the threshold value of 〇Lp V〇L4, 〇Lp is released, and the power conversion and transmission are restarted; in another real case, 'only control (4) is 3 The power supply flap and the money power supply restart (restart) to release the 0LP. Figure 4 shows the relationship between the working frequency of the working pulse 96 and the compensation signal Vc〇M. When the voltage value of the compensation signal VCOM corresponds to ν_ιτ, it can be regarded as For heavy load, the operating frequency of the clock generator 96 201143247, for example, is a re-cutting frequency fHEAvy (such as 65Khz); when the compensation signal
Vc〇M 的電壓值對應到OLP臨界值v〇Lp時，可以 視為過載狀態發生，工作時脈產生器96的工作頻率為一過載頻率 fcveruad(譬如i3〇KhZ)。第4圖也顯示了，當一次側繞組^的電流峰值 大U伽時，工作頻率至少是重載頻率Wvy。在容許時間時， 也就是補償減VcOM高過OLP臨界值Vqlp時，流經―讀嫩組^ 的電流峰值，因為比較器82的限制，將大約固^在”但是工作 ΙίΓ不再是重載辦Wvy，而是—個更高的過載_。舉 Ί，過載頻率f0verLoad可以是重載頻率Ww的兩倍或是三倍。 以上的實施例，可以得到兩個好處： 2. ^避㈣壓器64產生飽和現象：可以選擇在使變壓突 64不飽和（saturate)的最大電流，這樣，就可以在變壓^ 64沒有飽和時，單單利用提高控制器73的工作頻率至場 载頻率f〇verLoad ’來暫時地增加輸出功率。 ^午時間可以外調：如同紐所述，容許時間跟工作頻 二關。’。且是由電流供應器85跟外接電容乃所構 盪益所決定。因此，適當的選取外 了 Γ< 可以、W h P * 4 * 7 5的電容值個 ^决W树間。外接電容75還有另—個好處。 :器:==，相對應完全以積體電路所建構之心 更曰而要鳥人的面積成本。但是，以外接電容乃 ，’便能適當的節省成本，讓積體電路所構建的部份、 地小非常多。 ” 201143247 本發明雖以一反馳式架構之SMPS為例，但本發明也可以適用於 降壓電源轉換器、昇壓電源轉換器等類似的SMPS。 以上所述僅為本發明之較佳實施例，凡依本發明申請專利〜 做之均等變化與修飾，皆應屬本發明之涵蓋範圍。 圍所 【圖式簡單說明】 第1圖為一習知的電源供應器。 第2圖為依據本發明實施的一電源供應器。 第3圖則例示控制器中部份的電路與外接電容。 第4圖顯示工㈣脈產生器駐作頻顿信號％⑽的關係。 【主要元件符號說明】 電源供應器 橋式整流器 變壓器 整流器 負栽電容 開關 控制器 外接電容 # 60 > 90 62 64 66 69 72 73、74 75 201143247 82、84、88、94 比較器 85 電流供應器 86 邏輯控制單元 92 計數器 96 工作時脈產生器 CT 接腳 EA 誤差放大器 fHEAVY 重載頻率 f〇verLoad 過載頻率 LP 一次側繞组 Ls 二次側繞組 Vac 交流電源 Vc〇M 補償信號 Vcs 電流偵測信號 Vgate 控制信號 V〇LP OLP臨界值 V〇UT 輸出電源 V Target 目標電壓When the voltage value of Vc〇M corresponds to the OLP threshold value v〇Lp, it can be regarded as an overload state, and the operating frequency of the working clock generator 96 is an overload frequency fcveruad (such as i3〇KhZ). Figure 4 also shows that when the current peak of the primary winding ^ is large U gamma, the operating frequency is at least the reload frequency Wvy. At the allowable time, that is, when the compensation minus VcOM is higher than the OLP threshold Vqlp, the current peak flowing through the "reading group" will be approximately fixed because of the limitation of the comparator 82. However, the operation is no longer a heavy load. Wvy, but a higher overload _. As a matter of fact, the overload frequency f0verLoad can be twice or three times the reload frequency Ww. In the above embodiment, two benefits can be obtained: 2. ^ Avoid (four) pressure The 64 is saturated: the maximum current that saturates the transformer 64 can be selected, so that the operating frequency of the controller 73 can be increased to the field carrier frequency f when the transformer 64 is not saturated. 〇verLoad 'to temporarily increase the output power. ^The afternoon time can be adjusted externally: as described in New Zealand, the allowable time is the same as the working frequency. '. It is determined by the current supply 85 and the external capacitor. Therefore, the appropriate selection of Γ< can, the value of the capacitance of W h P * 4 * 7 5 is determined between the W trees. The external capacitor 75 has another advantage. : Device: ==, correspondingly completely The heart of the body circuit is more ambiguous and the area cost of the bird However, the external capacitor is, 'the cost can be appropriately saved, and the part and the ground of the integrated circuit are very small." 201143247 The present invention uses an SMPS of a reverse architecture as an example, but the present invention also It can be applied to similar SMPSs such as buck power converters, boost power converters, and the like. The above description is only the preferred embodiment of the present invention, and all the equivalent changes and modifications of the invention are subject to the scope of the present invention. Enclosure [Simple description of the diagram] Figure 1 shows a conventional power supply. Figure 2 is a power supply in accordance with the practice of the present invention. Figure 3 illustrates some of the circuits and external capacitors in the controller. Figure 4 shows the relationship of the frequency (10) of the generator (four) pulse generator stationed as the frequency signal. [Main component symbol description] Power supply bridge rectifier transformer rectifier negative capacitance switch controller external capacitor # 60 > 90 62 64 66 69 72 73, 74 75 201143247 82, 84, 88, 94 Comparator 85 Current supply 86 Logic Control Unit 92 Counter 96 Operating Clock Generator CT Pin EA Error Amplifier fHEAVY Heavy Load Frequency f〇verLoad Overload Frequency LP Primary Side Winding Ls Secondary Side Winding Vac AC Power Supply Vc〇M Compensation Signal Vcs Current Detecting Signal Vgate control signal V〇LP OLP threshold V〇UT output power V Target target voltage
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