1263792 玖、發明說明 【發明所屬之技術領域】 本發明是有關於霍爾積體電路（Hall integI^ated circuit，霍爾IC)，且特別是有關於一種具有低工作電壓以 及逆向保護功能的霍爾1C與其電壓調節器電路。 【先如技術】 為人熟知的是，霍爾元件（Hall element)可以是霍爾感 測器（Hall sensor)或是霍爾ic，其中此兩者的差別是霍爾IC 更提供了信號放大的功能，以致於霍爾1C的輸出信號可不 經過放大就被應用到某電路。霍爾IC可被使用於例如一電 動機之驅動電路（motor drive circuit)中，用以偵測此電動機 中轉子（rotor)的磁極性（magnetic polarity)。 第1圖是一傳統的霍爾ic的電路示意圖。在第j圖中 的霍爾1C包含電壓調節器（voltage regulator)1〇2、霍爾感測 器106、放大器（amplifier)l〇8以及預先驅動電路 (pre-driver)ll〇。放大器108接收霍爾感測器1〇6的一輸 出信號，且產生一被放大的輸出信號。預先驅動電路i i 〇 接收來自放大器1 08之被放大的輸出信號，且其輪出端 連接到一外部驅動電路（未繪出），以提供驅動信號例如 日T脈化號（clock signal)到此驅動電路。此霍爾IC的低參 考電位Vss也顯示於第1圖中。在傳統的設計上，霍爾 感測态1 06、放大器1 〇8以及預先驅動電路丨丨〇共用一組 供應電壓vdd，而此供應電壓Vdd是由電壓調節器1〇2 1263792 所提供。請參照第1圖，電壓調節器102的電源（p〇wer s〇urce) 電壓Vcc通常經由一個二極體（diode) 104連接到電壓調節器 102。因為常見的問題是將電源線反接，使vss成為高電位 而Vdd成為低電位，造成霍爾ic的燒毀，所以為了逆向 (reverse)保護的目的而使用二極體1〇4。 第2圖是第1圖中霍爾感測器106與放大器108的電 路示意圖。第i圖中的霍爾感測器1〇6的等效電路被顯示 於第2圖中的左侧，其具有四個相等的電阻r，而放大器 108疋一差動放大器（differentiai amplifier)，此差動放大器 包含雙極接面電晶體（Bipolar Junction Transistor，BJT)Q1 與Q2、四個電阻R1、R2、R3與r4以及電流源112。請參 照第2圖，由於跨於電流源丨丨2的電壓，也就是c點電位1263792 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 发明 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔 霍尔1C and its voltage regulator circuit. [First as technology] It is well known that the Hall element can be a Hall sensor or a Hall ic. The difference between the two is that the Hall IC provides signal amplification. The function is such that the output signal of Hall 1C can be applied to a circuit without amplification. The Hall IC can be used, for example, in a motor drive circuit to detect the magnetic polarity of a rotor in the motor. Figure 1 is a schematic diagram of a conventional Hall ic circuit. The Hall 1C in Fig. j includes a voltage regulator 1, a Hall sensor 106, an amplifier l8, and a pre-driver. Amplifier 108 receives an output signal from Hall sensor 1 〇 6 and produces an amplified output signal. The pre-driver circuit ii 〇 receives the amplified output signal from the amplifier 108, and its wheel terminal is connected to an external drive circuit (not shown) to provide a drive signal such as a day T clock signal. Drive circuit. The low reference potential Vss of this Hall IC is also shown in Figure 1. In the conventional design, the Hall sense state 106, the amplifier 1 〇8, and the pre-driver circuit 丨丨〇 share a set of supply voltages vdd, which is supplied by the voltage regulator 1〇2 1263792. Referring to FIG. 1, the power supply voltage of the voltage regulator 102 is generally connected to the voltage regulator 102 via a diode 104. Since the common problem is that the power supply line is reversed, the vss becomes high, and Vdd becomes low, causing the Hall ic to burn out, so the diode 1〇4 is used for the purpose of reverse protection. Fig. 2 is a circuit diagram of the Hall sensor 106 and the amplifier 108 in Fig. 1. The equivalent circuit of the Hall sensor 1〇6 in Fig. i is shown on the left side in Fig. 2, which has four equal resistances r, and the amplifier 108 is a differential amplifier. The differential amplifier includes Bipolar Junction Transistors (BJT) Q1 and Q2, four resistors R1, R2, R3 and r4, and a current source 112. Please refer to Figure 2, because of the voltage across the current source 丨丨2, that is, the potential at point c.
對低蒼考電位Vss的電壓，約為〇·2至0.3伏（V)，而且A 點電位對C點電位的直流電壓約為〇·7伏，所以可知a點 的直流電壓約為1 ·0伏。同樣地，B點的直流電壓也是約為 1.0伏。因為低參考電位VSS 一般來說是〇伏，由第2圖中 隹爾感測器的等效電路可知，供應電壓Vdd至少約為2.0 伏0 由以上的分析可知，霍爾感測器106之最低的工作電 壓（operating v〇itage)約為2 〇伏。再者，因為霍爾感測器 1 〇6、放大器1〇8以及預先驅動電路丨1()共用同一供應電 I Vdd ’故在設計上亦需考慮供應電壓vdd的驅動能力 問題’亦即能夠提供霍爾感測器1 〇6、放大器丨〇8以及預 先驅動電路11 〇所需要的電流大小，所以目前市面上的霍 1263792 爾ic實際的最低工作電壓，亦即最低的供應電壓vdd,約 為2.7至2.8伏。 【發明内容】 因此本發明的目的就是在提供一種具有低工作電壓及 逆向保護功能之霍爾1C，用以降低霍爾Ic的最低工作電 壓。 一 本發明的另一目的是在提供一種具有低工作電壓及逆 向保護功能之電壓調節器，作為霍爾1C的一部份，用以 降低霍爾1C的最低工作電壓。 根據本發明之上述目的，提出一種具有低工作電壓之 霍爾1C。此霍爾1C包括一霍爾感測器、一放大電路、一 預先驅動電路以及一電壓調節器。此放大電路接收此霍爾 感測器的一輸出信號，且產生一被放大的輸出信號。此預 先驅動電路接收來自此放大電路之此被放大的輸出信 號，且其輸出端連接到一驅動電路，以提供驅動信號到 此驅動電路。此電壓調節器耦接於此霍爾感測器、此放大 電路以及此預先驅動電路。此電壓調節器供給此預先驅動 電路一第一供應電壓，且供給此霍爾感測器與此放大電路 一第二供應電壓。 依照本發明一較佳實施例，此電壓調節器包含一第一 參考電位端點、一第二參考電位端點、一能帶間隙電壓參 考（bandgap voltage reference)電路、一起動電路（start-up circuit)、一第一 NPN電晶體、一第一 PNP電晶體、一第二 1263792 p，曰日體以及-電流源。此霍爾Ic的—電源電壓被施加 到此第*考電位端點，而-低參考電位被施加到此第二 考電位端點。此此帶間隙電壓參考電路連接到第二參考 電位端點且且右一絡φ *山 n lf ^ _ ’ ^ 衿出而，且此月b T間隙電壓參考電路在 此輸^輸出上述的第一供應電壓。此輸出端係作為此電 [調即益的-第—輸出端。此起動電路連接到第二參考電 位端點。第—NPN電晶體的射極端（emitter)連接到第一輸 出端。第一/NP電晶體的集極端（c〇iiect〇r)連接到基極端 (base)以及第一 NPN電晶體的集極端，且第一 pNp電晶體 的射極端連接到第一參考電位端點，基極端連接到此起動 電路。此電流源連接於第—參考電位端點與㈣電路之 間。第一 PNP電晶體的射極端連接到第一參考電位端點， ^ 2連接到第^ NPN電晶體的基極端’而基極端麵接於 4带、抓源’以使流經其射極端的電流實質上反映㈤叫出 1匕：：二的：：電流’而且第一 npn電晶體的基極端係作 :卜堅凋即态的一第二輸出端。此電壓調節器在此第二 ==出上述的第二供應電屢。再者，上述的電源電塵 的琅低值約為2 · 1伏。 由本發明較佳實施例可知，應用本發明 點。使用本發明的霍_ ΤΓ ιν Β # _ ㈣隹S 1C以及其中的電壓調節器可以將最 低的電源電屋降低到約2·1伏，所以能達到低工作電壓(low operating v〇ltage)、低功率（1〇w卩〇爾）的目的。此外本發 :的：爾！C:及其中的電屢調節器還具有逆向保護㈣ 月匕”並不需要使用傳統霍爾1C所使用的二極體。 1263792 【實施方式】 第3圖是根據本發明的霍爾IC的電路示意圖。在第3 圖中的霍爾IC包含錢調節器3Q2、霍爾感測器、放 大電路（ampllfying clrcuit)308以及預先驅動電路3 i 〇。此 霍爾IC的低參考電位Vss也顯示於第3圖中。放大電路 3 08接收霍爾感測器306的一輸出信號，且產生一被放大 的輸出信號。此放大電路308包含例如一放大器，適用 於放大霍爾感測器306的此輸出信號，且產生此被放大的 輸出信號。此放大器可能是一預先放大器（preampHfier)。 預先驅動電路310接收來自放大電路3〇8之此被放 大的輸出信號’且其輸出端連接到一驅動電路（未繪 出）’以提供驅動h號到此驅動電路。此驅動電路例如用 以驅動一直流無刷電動機（DC brushless motor)，而此直 流無刷電動機使用兩定子線圈（stat〇r coils)，以產生轉動的 磁場以旋轉一風扇的轉子（r〇t〇r)。此外，預先驅動電路3 j 〇 例如包含一史密特觸發電路（Schmitt Trigger)。此史密特觸 發電路包含一比較器（comparator)，而此比較器適用於比較 此被放大的輸出信號與一參考電壓（reference v〇ltage)， 且提供轉換遲滯（switching hysteresis)特性以達到拒斥 雜訊（noise)的目的。 本發明的電壓調節器302耦接於霍爾感測器306、放大 電路308以及預先驅動電路310。此電壓調節器302係被 設計供給預先驅動電路3 1 0 —第一供應電壓Vdd 1，且供給 1263792 二=器Γ;Γ大電路3°8-第二供應電壓。這 ,:電m又计疋為了有效降低此霍爾π的最低工作 電壓，亦即最低的電源電壓ν 一 一 木ΛΑ I 叙來呪，為了提供適 S的驅動信號到外部驅動 I L勡電路，預先驅動電路31〇需 約8mA至10mA的佴雍雪沒 ^ ^ 應電々丨L，而萑爾感測器306與放大 電路308都只需要約4 a至5πίΑ沾灿_ + 至5mA的供應電流。所以這種 雙供應電壓設計也就是蔣^· i _ 疋將而要較大電流的預先驅動電路 31〇與需要較小電流的霍爾感測器3〇6與放大電路綱 開來。 此外，如第3圖所示，雖然電壓調節器3〇2的電源電 壓Vcc並未經由一個二極體連接到電壓調節器3〇2，但是此 霍爾1C仍然具有逆向保護的功能。 藉由使用本發明的電壓調節器3 G 2，可以達成降低此霍 爾1C的最低的電源電壓Vcc以及具有逆向保護功能之目 的。第4目是根據本發明一實施例之帛3目中的電壓調節 器302的電路示意圖。請參照第4圖，此電壓調節器Μ】 包含一第一參考電位端點、一第二參考電位端點、一能帶 間隙電壓參考（bandgap voltage reference)電路400、一起動 電路（start-up circuit)402、一第一 NPN 電晶體 qw、一 第一 PNP電晶體QDP、一第二pNP電晶體QR以及一電流源 404。上述的電源電壓Vcc被施加到此第一參考電位端點， 而低爹考電位Vss被施加到此第二參考電位端點。能帶間 隙電壓參考電路400連接到第二參考電位端點且具有一輪 出端，且此能帶間隙電壓參考電路400在此輸出端輪出上 10 1263792 述的第一供應電壓VddL·此輸出端係作為此電壓調節器302 的一第一輸出端。起動電路402連接到第二參考電位端點。 第一 NPN電晶體QW的射極端（emitter)連接到第一輸出 端。第一 PNP電晶體QDP的集極端（collector)連接到基極 端（base)以及第一 NPN電晶體QW的集極端，且第一 PNP 電晶體QDP的射極端連接到第一參考電位端點，基極端連 接到起動電路402。電流源404連接於第一參考電位端點與 起動電路402之間。第二PNP電晶體QR的射極端連接到 第一參考電位端點，集極端連接到第一 NPN電晶體QW的 基極端，而基極端耦接於電流源404，以使得流經其射極端 的電流實質上反映（mirror)出電流源404的輸出電流，而且 第一 NPN電晶體QW的基極端係作為電壓調節器302的一 第二輸出端。電壓調節器302在此第二輸出端輸出上述的 第二供應電壓Vdd2。再者，電壓調節器302可選擇性地包 含一負回授（negative feedback)電路406，以對抗雜訊等瞬 間變化。此負回授電路406連接到第二參考電位端點、能 帶間隙電壓參考電路400以及第二輸出端。 請參照第4圖，在此實施例中，電流源404的實現例 如使用一第三PNP電晶體QS以及一第四PNP電晶體QT。 第三PNP電晶體QS的射極端連接到第一參考電位端點，集 極端連接到起動電路402。第四PNP電晶體QT的射極端連 接到第一參考電位端點，其基極端連接到集極端、第三PNP 電晶體QS的基極端以及第二PNP電晶體QR的基極端，而 且第四PNP電晶體QT的集極端連接到起動電路402。根據 1263792 以上所述，由於第一 PNP電晶體QDP、第二PNP電晶體 QR、第三PNP電晶體QS以及第四PNP電晶體QT的P型 射極端都連接到被施加電源電壓Vcc的端點，亦即第一參 考電位端點，所以每一此四個PNP電晶體的射極端與基極 端一起作為一個二極體。因此此霍爾1C具有逆向保護的功 能。 另一方面，在此實施例中，能帶間隙電壓參考電路400 的結構例如包含一第二NPN電晶體QY、一第一阻抗RB、 一第三NPN電晶體QZ、一第二阻抗RC以及一第三阻抗 RD。第二NPN電晶體QY的射極端連接到第二參考電位端 點，基極端連接到集極端。第一阻抗RB連接於第一輸出端 與第二NPN電晶體QY的集極端之間。第三NPN電晶體 QZ的基極端連接到第二NPN電晶體QY的基極端。第二阻 抗RC連接於第一輸出端與第三NPN電晶體QZ的集極端之 間。第三阻抗RD連接於第二參考電位端點與第三NPN電 晶體QZ的射極端之間。 另一方面，在此實施例中，負回授電路406例如包含 一第四NPN電晶體QX與一第五NPN電晶體QU。第四NPN 電晶體QX的射極端連接到第二參考電位端點，基極端連接 到第三NPN電晶體QZ的集極端，而集極端連接到第二輸 出端。第五NPN電晶體QU的射極端連接到集極端以及第 二輸出端，而基極端連接到第四NPN電晶體Qx的基極端。 另外一種可能方式是用一電容性元件（capacitive element)，例如一電容器，來取代第五NPN電晶體QU，連 12 1263792 接於第二輸出端與第四NPN電晶體QX的基極端之間。 在第4圖中，起動電路4〇2是為了避免整個電壓調節 UU 302在電源電壓Vcc開始被施加的瞬間，所有電晶體不 月雀地（indefinitely)處在關閉（0ff)的狀態，而造成在此瞬間 電壓調節器302缺乏電流的問題。電源電壓Vcc被施加之 後’起動電路402先導致電流流過第一 pnp電晶體qdp與 第一 NPN電晶體qw，再產生電流源404的輸出電流，然 後此輸出電流再實質上反映到流經第二PNp電晶體qR的 電流。 在此敘述降低此霍爾1C的最低的電源電壓vcc之原 理。第5圖繪示第4圖中電壓調節器3〇2的電源電壓Vcc、 第一供應電壓Vddl以及第二供應電壓vdd2之電路模擬結 果。如第5圖所示，當電源電壓vcc小於或等於穩定工作 電壓2.4伏時，第一供應電壓vddl以及第二供應電壓Vdd2 白約P过電源電壓Vcc呈線性變化（iinear reiati〇nship)。當電 源電壓Vcc被限制在小於或等於2.4伏的情況時，第二pnp 電晶體QR會處在飽和區（saturation region)，則其射極端對 集極端的電壓Vec約等於〇· 1伏，所以The voltage of the low Cang test potential Vss is about 〇·2 to 0.3 volts (V), and the DC voltage at the point A potential to the C point potential is about 〇·7 volts, so the DC voltage at point a is about 1 · 0 volts. Similarly, the DC voltage at point B is also about 1.0 volt. Since the low reference potential VSS is generally undulating, the supply circuit Vdd is at least about 2.0 volts as seen from the equivalent circuit of the 感 sensor in Fig. 2. From the above analysis, the Hall sensor 106 The lowest operating voltage (operating v〇itage) is approximately 2 volts. Furthermore, since the Hall sensor 1 〇6, the amplifier 1〇8, and the pre-driver circuit 丨1() share the same supply voltage I Vdd ', it is also necessary to consider the drive capability of the supply voltage vdd in design] Providing the magnitude of the current required for the Hall sensor 1 〇6, the amplifier 丨〇8, and the pre-drive circuit 11 ,, so the current minimum operating voltage of the Huo 1263792 er, which is the lowest supply voltage vdd, is about It is 2.7 to 2.8 volts. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a Hall 1C having a low operating voltage and reverse protection function for reducing the minimum operating voltage of Hall Ic. Another object of the present invention is to provide a voltage regulator having a low operating voltage and reverse protection function as part of Hall 1C to reduce the minimum operating voltage of Hall 1C. In accordance with the above object of the present invention, a Hall 1C having a low operating voltage is proposed. The Hall 1C includes a Hall sensor, an amplifying circuit, a pre-drive circuit, and a voltage regulator. The amplifying circuit receives an output signal of the Hall sensor and produces an amplified output signal. The pre-driver circuit receives the amplified output signal from the amplifying circuit and its output is coupled to a driver circuit to provide a drive signal to the driver circuit. The voltage regulator is coupled to the Hall sensor, the amplifying circuit, and the pre-drive circuit. The voltage regulator supplies a pre-drive circuit to a first supply voltage and supplies the Hall sensor to the amplifying circuit to a second supply voltage. According to a preferred embodiment of the present invention, the voltage regulator includes a first reference potential terminal, a second reference potential terminal, a bandgap voltage reference circuit, and a start-up circuit. Circuit), a first NPN transistor, a first PNP transistor, a second 1263792 p, a germanium body, and a current source. The source voltage of this Hall Ic is applied to this potential terminal, and the - low reference potential is applied to this second potential terminal. The gap voltage reference circuit is connected to the second reference potential end point and the right one φ * mountain n lf ^ _ ' ^ is extracted, and the current b T gap voltage reference circuit outputs the above-mentioned first A supply voltage. This output is used as the current output. This starting circuit is connected to the second reference potential terminal. The emitter of the first-NPN transistor is connected to the first output. The collector terminal of the first /NP transistor is connected to the base and the collector terminal of the first NPN transistor, and the emitter terminal of the first pNp transistor is connected to the first reference potential terminal The base terminal is connected to this starting circuit. This current source is connected between the first reference potential terminal and the (iv) circuit. The emitter terminal of the first PNP transistor is connected to the end of the first reference potential, ^ 2 is connected to the base terminal of the ^NPN transistor, and the base terminal is connected to the 4 band, the source is pulled to pass through the emitter terminal thereof. The current substantially reflects (5) called 1匕::2::current' and the base of the first npn transistor is tied to a second output of the state. This voltage regulator is here second == out of the above second supply. Furthermore, the above-mentioned power supply dust has a low value of about 2 · 1 volt. It will be apparent from the preferred embodiment of the invention that the present invention is applied. By using the present invention, the Huo ΤΓ ιν Β # _ (4) 隹 S 1C and the voltage regulator therein can reduce the lowest power supply house to about 2.1 volts, so that low operating voltage (low operating v〇ltage) can be achieved. The purpose of low power (1〇w卩〇尔). In addition, this hair: : Seoul! C: and the electric repeater in it also has reverse protection (4) 匕 ” does not need to use the diode used in the conventional Hall 1 C. 1263792 [Embodiment] FIG. 3 is a circuit of a Hall IC according to the present invention. The Hall IC in Fig. 3 includes a money regulator 3Q2, a Hall sensor, an amplifier circuit 308, and a pre-drive circuit 3i. The low reference potential Vss of the Hall IC is also shown in In Fig. 3, an amplifying circuit 308 receives an output signal of the Hall sensor 306 and produces an amplified output signal. The amplifying circuit 308 includes, for example, an amplifier suitable for amplifying the Hall sensor 306. The signal is output and the amplified output signal is generated. The amplifier may be a preamplifier. The pre-driver circuit 310 receives the amplified output signal from the amplifying circuit 3〇8 and its output is connected to a driver. A circuit (not shown) is provided to drive the h number to the drive circuit. The drive circuit is used, for example, to drive a DC brushless motor, and the DC brushless motor is used. Two stator coils (statar coils) to generate a rotating magnetic field to rotate a rotor of a fan (r〇t〇r). Further, the pre-drive circuit 3 j 〇 includes, for example, a Schmitt Trigger. The Schmitt trigger circuit includes a comparator, and the comparator is adapted to compare the amplified output signal with a reference voltage (reference v〇ltage) and provide switching hysteresis characteristics to achieve rejection The purpose of the noise regulator 302 is coupled to the Hall sensor 306, the amplifying circuit 308, and the pre-drive circuit 310. The voltage regulator 302 is designed to supply the pre-drive circuit 3 1 0 - the first supply voltage Vdd 1, and the supply 1263792 two = Γ; Γ large circuit 3 ° 8 - the second supply voltage. This, the electric m is calculated in order to effectively reduce the minimum operating voltage of this Hall π, ie The lowest power supply voltage ν 一 ΛΑ ΛΑ 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪 呪Muir Both the sensor 306 and the amplifying circuit 308 need only about 4 a to 5 π Α _ _ + to 5 mA of supply current. Therefore, this dual supply voltage design is also the pre-drive of the larger current. The circuit 31A and the Hall sensor 3〇6 and the amplifying circuit which require a small current are integrated. Further, as shown in FIG. 3, although the power supply voltage Vcc of the voltage regulator 3〇2 does not pass through a diode The body is connected to the voltage regulator 3〇2, but this Hall 1C still has the function of reverse protection. By using the voltage regulator 3 G 2 of the present invention, it is possible to achieve the objective of lowering the minimum power supply voltage Vcc of this Hall 1C and having the reverse protection function. The fourth object is a circuit diagram of the voltage regulator 302 in the cymbal according to an embodiment of the present invention. Referring to FIG. 4, the voltage regulator includes a first reference potential terminal, a second reference potential terminal, a bandgap voltage reference circuit 400, and a start-up circuit. Circuit) 402, a first NPN transistor qw, a first PNP transistor QDP, a second pNP transistor QR, and a current source 404. The above-mentioned power supply voltage Vcc is applied to the end of the first reference potential, and the low reference potential Vss is applied to the end of the second reference potential. The band gap voltage reference circuit 400 is connected to the second reference potential end point and has a round out end, and the band gap voltage reference circuit 400 rotates the first supply voltage VddL on the output terminal 10 1263792. As a first output of the voltage regulator 302. Start circuit 402 is coupled to the second reference potential terminal. An emitter of the first NPN transistor QW is coupled to the first output. A collector of the first PNP transistor QDP is connected to a base terminal and a collector terminal of the first NPN transistor QW, and an emitter terminal of the first PNP transistor QDP is connected to a first reference potential terminal, the base Extremely connected to the starting circuit 402. Current source 404 is coupled between the first reference potential terminal and start circuit 402. The emitter terminal of the second PNP transistor QR is connected to the first reference potential terminal, the collector terminal is connected to the base terminal of the first NPN transistor QW, and the base terminal is coupled to the current source 404 such that it flows through the emitter terminal thereof. The current substantially mirrors the output current of current source 404, and the base terminal of first NPN transistor QW acts as a second output of voltage regulator 302. The voltage regulator 302 outputs the second supply voltage Vdd2 described above at the second output. Furthermore, voltage regulator 302 can optionally include a negative feedback circuit 406 to combat transient changes such as noise. The negative feedback circuit 406 is coupled to the second reference potential terminal, the band gap voltage reference circuit 400, and the second output. Referring to Figure 4, in this embodiment, the implementation of current source 404 uses, for example, a third PNP transistor QS and a fourth PNP transistor QT. The emitter terminal of the third PNP transistor QS is coupled to the first reference potential terminal and the collector terminal is coupled to the start circuit 402. The emitter terminal of the fourth PNP transistor QT is connected to the first reference potential terminal, the base terminal thereof is connected to the collector terminal, the base terminal of the third PNP transistor QS, and the base terminal of the second PNP transistor QR, and the fourth PNP The collector terminal of transistor QT is coupled to start circuit 402. According to the above 1263792, since the first PNP transistor QDP, the second PNP transistor QR, the third PNP transistor QS, and the P-type emitter of the fourth PNP transistor QT are all connected to the end point to which the power supply voltage Vcc is applied That is, the first reference potential end point, so the emitter end of each of the four PNP transistors together with the base terminal acts as a diode. Therefore, this Hall 1C has the function of reverse protection. On the other hand, in this embodiment, the structure of the band gap voltage reference circuit 400 includes, for example, a second NPN transistor QY, a first impedance RB, a third NPN transistor QZ, a second impedance RC, and a The third impedance RD. The emitter terminal of the second NPN transistor QY is coupled to the second reference potential terminal, and the base terminal is coupled to the collector terminal. The first impedance RB is coupled between the first output terminal and the collector terminal of the second NPN transistor QY. The base terminal of the third NPN transistor QZ is connected to the base terminal of the second NPN transistor QY. The second impedance RC is coupled between the first output terminal and the collector terminal of the third NPN transistor QZ. The third impedance RD is connected between the end of the second reference potential and the emitter of the third NPN transistor QZ. On the other hand, in this embodiment, the negative feedback circuit 406 includes, for example, a fourth NPN transistor QX and a fifth NPN transistor QU. The emitter terminal of the fourth NPN transistor QX is coupled to the second reference potential terminal, the base terminal is coupled to the collector terminal of the third NPN transistor QZ, and the collector terminal is coupled to the second output terminal. The emitter terminal of the fifth NPN transistor QU is coupled to the collector terminal and the second output terminal, and the base terminal is coupled to the base terminal of the fourth NPN transistor Qx. Another possibility is to replace the fifth NPN transistor QU with a capacitive element, such as a capacitor, connected between the second output and the base terminal of the fourth NPN transistor QX. In Fig. 4, the starting circuit 4〇2 is for avoiding the moment when the entire voltage regulating UU 302 is applied at the beginning of the power supply voltage Vcc, and all the transistors are indefinitely in the off state (0ff), resulting in At this moment, the voltage regulator 302 lacks the problem of current. After the power supply voltage Vcc is applied, the starting circuit 402 first causes current to flow through the first pnp transistor qdp and the first NPN transistor qw, and then generates an output current of the current source 404, and then the output current is substantially reflected to the flow through The current of the two PNp transistors qR. Here, the principle of lowering the lowest power supply voltage vcc of this Hall 1C will be described. Fig. 5 is a circuit diagram showing the simulation results of the power supply voltage Vcc, the first supply voltage Vddl, and the second supply voltage vdd2 of the voltage regulator 3〇2 in Fig. 4. As shown in Fig. 5, when the power supply voltage vcc is less than or equal to the stable operating voltage of 2.4 volts, the first supply voltage vddl and the second supply voltage Vdd2 are linearly changed from the power supply voltage Vcc by a linear change (iinear reia). When the power supply voltage Vcc is limited to less than or equal to 2.4 volts, the second pnp transistor QR will be in the saturation region, and the voltage Vec of the emitter terminal is approximately equal to 〇·1 volt, so
Vdd2 = Vcc - 0.1V ⑴Vdd2 = Vcc - 0.1V (1)
Vddl = Vdd2 - 0.7V = Vcc - 0.8V (2) 由上面第（2)式可知在第一輸出端的第一供應電廢vddl主 要疋受到弟一 NPN龟晶體qw之基極端對射極端的電壓 VBE(約等於〇·7伏）所限制，所以其比電源電壓vcc小約〇 8 伏。再者，根據前述已知被供應到霍爾感測器3〇6的第二 13 1263792Vddl = Vdd2 - 0.7V = Vcc - 0.8V (2) From the above equation (2), it can be seen that the first supply electric waste vddl at the first output terminal is mainly subjected to the voltage of the base extreme end of the NPN turtle crystal qw. VBE (approximately equal to 〇7 volts) is limited, so it is about 8 volts less than the supply voltage vcc. Furthermore, according to the aforementioned known second 13 1263792 which is supplied to the Hall sensor 3〇6
供應電壓Vdd2至少需為2·0伏，所以由第（1)式可知電源電 壓V c c至少需為2 β 1伏，此即為最低的工作電壓。因此，本 發明的霍爾1C或其中的電壓調節器之最低電源電壓vcc約 為2·1伏。再者，如果將第二pNp電晶體QR 側向的 ΡΝΡ 電晶體（lateral PNP transistor，LPNP)，則第二 PNP電晶體QR的驅動能力較差，意即流經第二pNp電j 體QR的電流不會很大。在這種情況下，第二供應電壓vdd 所能提供的最大電流（主要是流經第二pNp電晶體qr的^ 流）約為5mA，而這也符合霍爾感測器3〇6與放大電路3〇 都只需要約4mA至5mA的供應電流。另一方面，第一令 應電壓Vddi所能提供的最大電流約為2〇mA，亦可滿足男 先驅動電路31〇需要約8誕至驗的較大供應電流 由上述本發明較佳實施例可知，應用本發明具有下歹 優點。跟先前技藝中霍爾IC之最低的供應電$ (約索 ^至/.8伏）比起來，使用本發明的霍爾IC以及其中的1 =調節器可以將最低的電源電壓Vcc降低到約。伏，㈣ 作電峰W〇peratlngv〇ltage)、低功率 〇〇wp〇wer 具 此，本*明的隹爾Ic以及其中的電Μ調節器遷 /、逆向保護的功能，其中並；f ® + 用的二極體。 不而要使用傳統霍爾IC所使 于又丨土員死例揭露The supply voltage Vdd2 needs to be at least 2·0 volts, so it is known from the equation (1) that the power supply voltage V c c needs to be at least 2 β 1 volt, which is the lowest operating voltage. Therefore, the lowest power supply voltage vcc of the Hall 1C of the present invention or the voltage regulator therein is about 2.1 volt. Furthermore, if the second pNp transistor QR lateral lateral PNP transistor (LPNP) is used, the driving ability of the second PNP transistor QR is poor, that is, the current flowing through the second pNp electric body QR QR. Not too big. In this case, the maximum current that can be supplied by the second supply voltage vdd (mainly flowing through the second pNp transistor qr) is about 5 mA, which is also in accordance with the Hall sensor 3〇6 and amplification. Circuit 3 requires only about 4 mA to 5 mA of supply current. On the other hand, the maximum current that the first regulating voltage Vddi can provide is about 2 mA, and can also satisfy the larger supply current of the male first driving circuit 31, which requires about 8 annihilation to the test. The preferred embodiment of the present invention described above. It can be seen that the application of the present invention has advantages. Compared with the lowest supply power of the Hall IC in the prior art (about ～ to /. 8 volts), the lowest power supply voltage Vcc can be reduced to about using the Hall IC of the present invention and the 1 = regulator therein. . Volt, (4) electric peak W〇peratlngv〇ltage), low power 〇〇wp〇wer with this, this * Ming's Muir Ic and its electric Μ adjuster / / reverse protection function, which; + Used diodes. It is not necessary to use the traditional Hall IC to expose the mortuary
眾不發明 以限宁士八〇 v w π丄，热具並非用 神卜 任何熟習此技藝者，在不脫離本發明之产 “園當視後附之申請專利_所界定者;^ ^明之保 14 1263792 【圖式簡單說明】 為讓本發明之上述和其 顯易懂，下文特舉一較佳每 、特被、和優點能更明 細說明如下： 灵也列，並配合所附圖式，作詳 第1圖是一傳統的霍爾I 一 % 2η - ^ Λ m λ, 的電路示意圖。 弟2圖疋弟1圖中霍爾 第3 P1 θ舻搪士义 & 、與放大器的電路示意圖。 弟3圖疋根據本發明的 唾Α 隹瞷1C的電路示意圖。 弟4圖是根據本發明_ ^ 〇〇 貫知例之弟3圖中的電爆嘴g/r 斋的電路示意圖。 口 T扪电Μ凋即 第5圖繪示第4圖中雷_ 口 Υ电&凋即态的電源電壓Vcc、第一 供應電壓Vddl以及第-供靡雷灰 叹弟一仏應電壓Vdd2之電路模擬結果。 【元件代表符號簡單說明】 102 :電壓調節器 106 :霍爾感測器 11 0 :預先驅動電路 3〇2 :電壓調節器 3〇8 :放大器 QW :第一 NPN電晶體 QR :第二PNP電晶體 402 :起動電路 406 :負回授電路 104 :二極體 108 : ·放大器 112 :電流源 306 ·•霍爾感測器 3 1 0 ·預先驅動電路 QDP ··第一 PNP電晶體 400 ··能帶間隙電壓參考電路 404 :電流源 15The public does not invent the limit of Ningshi gossip vw π丄, the heat is not used by the gods, anyone who is familiar with this skill, without deviating from the invention of the invention, the patent application _ defined by the _ _ Ming 14 1263792 [Brief Description of the Drawings] In order to make the above description of the present invention easy to understand, the following description of the preferred, specific, and advantages can be more clearly described as follows: Figure 1 is a circuit diagram of a conventional Hall I -% 2η - ^ Λ m λ. Brother 2 Figure 1 shows the Hall 3 P1 θ 舻搪士义 & BRIEF DESCRIPTION OF THE DRAWINGS Fig. 3 is a circuit diagram of a sputum 隹瞷 1C according to the present invention. A diagram of a circuit diagram of a squirting g/r of the squirrel 3 according to the present invention. The mouth T 扪 即 即 即 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图Circuit simulation result [Complete description of component symbol] 102: Voltage regulator 106: Hall sensor 11 0 : Pre-driver 3〇2: Voltage regulator 3〇8: Amplifier QW: First NPN transistor QR: Second PNP transistor 402: Start circuit 406: Negative feedback circuit 104: Diode 108: • Amplifier 112: Current source 306 · Hall sensor 3 1 0 · Pre-drive circuit QDP · · First PNP transistor 400 · · Band gap voltage reference circuit 404 : Current source 15