45304 0 A7 B7 經濟部智慧財產局員工消費合作钍印封 五、發明說明（/) 【發明之應用範疇】 本發明是關於一種電壓控制震盪器（ν〇丨 Oscilator-VCO)之改良，特別是關於一種具有改良電源電壓變動 影響（Power Supply Rejection Ratio-PSRR)之電壓控制震盡器。 【發明之背景】 習用之電歷控制震盪器（VCO)電路，係如第1圖所示。這 種PLL (鎖相迴路）之VCO電路中，其PSRR特性，往往決定了 Jitter的大小。在第1圖中，一個VCO電路係包括一電荷泵（charge pump)電路（10)及一環形震盪器（20)。在電荷泵電路（1〇)中， 具有兩個電荷泵（PUMPup)及（PUMPdown)。利用兩開關（up) 及（down)輪流開關，控制至（PUMP)點之電壓。VDD為電源。 在此種電路中，PUMP點之電壓係相對於VDD之電壓而變化。該 電壓值經由電晶體（1】）轉換成電流，經由電晶體（〗2)產生偏 壓’提供於環形震盪器（20)。環形震盪器（20)具有數個形成迴 路之震盪器電路（21) (22) (23)。由該電晶體（12)所提供+ 偏磨，奥使該環形震堡器（20)發生震盪。藉此，可以使該環形 震盪器（20)依據PUMP點相對於電源vdd之電壓，而產生一 定頻率之震盪。 3 木紙張尺度適用中®國家標準（CNS)Al規格（210 x 297公;^ ) -------It--I I * -----I I ^---------- (請先W讀背面之注意事項再填寫本頁) 45304 0 A7 B7 五、發明說明（丄） 上述習用之電壓控制震盪器雖能產生隨輸入電壓而改變之震 盪頻率’但是當電源之電壓瞬間發生變動時，因為環形震盪器本 身隨VDD升高，其震盪器頻率上升，導致環形震盪器之震盪頻率 發生所不希望之變化。 因此目前亟需有一種改良的電壓控制震盪器，可以具有較佳 之電源電壓變動影準，以緩和電源電壓變動對震盪器震盪頻率的 影響。 【發明之目的】 本發明之目乃在提供一種改良的電壓控制震盪器，可以減少 電源電壓變動對震盪器震盪頻率之影響。 — 本發明之目的也在提供一種對電源電壓變動具有自動補償效 果的電壓控制震盪器。 【發明之簡述】 經濟部智慧財產局員工消費合作社印製 依據本發明之電壓控制震盪器，係提供一電壓補償用電晶 體’以在電源電壓突然升高時，由於補償電晶體之等效電阻降低， 而降低鎖相電路之信號電壓，因此，提供偏壓電壓至環形震盪器 之電晶體工作頻率可以隨之降低，以修正環形震盪器之震盪頻率。 上述及其他本發明之目的及優點，可由以下詳細說明並參照 4 本紙張尺度洎用中围囡家標準（CNS)yy規格（2]〇 X 297公坌） 經濟部智慧財產局員工消費合作社印製45304 0 A7 B7 Consumption cooperation between employees of the Intellectual Property Bureau of the Ministry of Economic Affairs and seals. 5. Description of the invention (/) [Application scope of the invention] The present invention relates to the improvement of a voltage controlled oscillator (ν〇 丨 Oscilator-VCO), especially A voltage controlled shaker with improved power supply rejection ratio (PSRR). [Background of the Invention] The conventional calendar control oscillator (VCO) circuit is shown in Figure 1. In the VCO circuit of this PLL (Phase Locked Loop), the PSRR characteristic often determines the size of the Jitter. In Figure 1, a VCO circuit system includes a charge pump circuit (10) and a ring oscillator (20). The charge pump circuit (10) includes two charge pumps (PUMPup) and (PUMPdown). Use two switches (up) and (down) to switch in turn to control the voltage to the (PUMP) point. VDD is the power supply. In such a circuit, the voltage of the PUMP point is changed relative to the voltage of VDD. The voltage value is converted into a current through the transistor (1), and a bias voltage is generated through the transistor (2) to provide the ring oscillator (20). The ring oscillator (20) has several oscillator circuits (21) (22) (23) forming a circuit. Provided by the transistor (12) + eccentric wear, the ring oscillator (20) oscillates. Thereby, the ring oscillator (20) can be caused to generate a certain frequency of oscillation based on the voltage of the PUMP point relative to the power supply vdd. 3 Wood Paper Standard Applicable® National Standard (CNS) Al Specification (210 x 297 male; ^) ------- It--II * ----- II ^ --------- -(Please read the precautions on the back before filling this page) 45304 0 A7 B7 V. Description of the invention (丄) Although the conventional voltage-controlled oscillator can generate an oscillation frequency that changes with the input voltage, but when the voltage of the power supply When the change occurs instantaneously, because the ring oscillator itself increases with VDD, the frequency of the ring oscillator rises, resulting in undesired changes in the ring oscillator frequency. Therefore, there is an urgent need for an improved voltage-controlled oscillator, which can have better power supply voltage fluctuations to mitigate the impact of power supply voltage fluctuations on the oscillator's oscillation frequency. [Objective of the Invention] The purpose of the present invention is to provide an improved voltage-controlled oscillator, which can reduce the influence of power supply voltage fluctuations on the oscillator's oscillation frequency. — The object of the present invention is also to provide a voltage controlled oscillator having an automatic compensation effect for power supply voltage fluctuations. [Brief description of the invention] The Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs printed a voltage-controlled oscillator according to the present invention, which provides a voltage compensation transistor to compensate for the equivalent of the transistor when the power supply voltage suddenly rises. The resistance decreases and the signal voltage of the phase-locked circuit is reduced. Therefore, the operating frequency of the transistor that provides the bias voltage to the ring oscillator can be reduced accordingly to correct the ring frequency of the ring oscillator. The above and other objects and advantages of the present invention can be described in detail below with reference to 4 paper standards (CNS) yy specifications (2) 0X 297 public stamps printed by employees' cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs system
530 4 C A7 B7 Μ- 1 — 五、發明說明（^ ) 下列圖式而更形清楚： 【圖式之說明】 第1囷表示一種習用電壓控制震盪器之電路方塊圖。 第2圖表示本發明電壓控制震盪器之電路方塊圖。 第3圖表示以電膜模擬所得之本發明與習用之電麼控制震烫 器中，電源電壓變動與震盪器頻率關係圊。 【發明之詳細說明】 以下說明本發明之電壓控制震盪器。第2圈表示一種本發明 電壓控制震盪器之電路方塊圖。在圖中，與第1圖相同之元件均 標以相同之編號。 如圖所示，本發明之電壓控制震盪器，在電路設計上大致與 第1圖所示之習用電壓控制震盪器相同，也包括一個電荷泵電路 (10)及一個環形震盪器（20)。在電荷泵電路（10)中，也具有 兩個電荷泵（pumpup)及（pumpdown)。由開關（up)及（down) 交互開關，以控制由電源（VDD)送至（PUMP)點之電壓。若 電荷泵之電壓不變時，（PUMP)點之電壓相對於電源（VDD)的 電壓（VDD-PUMP)也不變。該電壓值經電晶體（11)轉換成電 流，經由電晶體（12)之動作，對環形震盪器（20)提供偏壓。 5 本紙張尺度適用中S國家標準（CNSM4規格（210 x 297公釐） 1 ------- ^ ϋ I I I I I I » ! I I----- (請先閱讀背面之注意事項再填寫本頁) 45304 0 Α7 Β7 經濟部智慧財產局員工消費合作社印敦 五、發明說明（¥ ) 環形震盪器（20)含有形成迴路之震盪器電路（21) (22) (23)， 由於該偏壓而產生震重。由於電晶體（12 )之偏壓與（VDD-PUMP ) 之電壓成正比，故可使環形震盪器（20)之震盪頻率與該 (VDD-PUMP)之電壓成正比。 本發明之電壓控制震盪器與習用裝置最大的不同在於設置了 一個電壓補償用電晶體（13)。該電壓補償用電晶體（13)係與該 電晶體（12)串聯，其源極則為接地。 當該電源（VDD)之電壓突然上升時，補償電晶體（13)所 形成之等效電阻即隨之下降，而將由該電晶體（12)提供之偏壓 電壓下拉，結果使震盪器（20)之工作頻率降低。 換言之’由於本發明設置了補償電晶體（13)，可以修正因為 電源電壓升高而對震盪器（20)震盪頻率之影響，使得其震逢頻 率只受（VDD-PUMP)電壓之控制，故可改善其對電源電壓變化 之敏感度。 【發明之效果】 利用電腦模擬’假設（PUMP)點相對於電源（VDD)之電壓 不變，改變電源（VDD)電壓，量測環形震盪器之震盪頻率，其 結果如第3圖所示。第3圖顯示本發明之電路確可改善電源電壓 6 本紙張尺度翻中s ®家標車（CNS)A.l規格⑵ϋ X 297找） (請先閱讀背面之注意事項再填寫本頁) 裝 訂， ;線. 4 53 04 0 A7 B? 五、發明說明（t) 變動對環形震盪器震盪頻率之影審。 以上是對本發明電壓控制震盪器之改良實施例之說明。習於斯 藝之人士，應可由以上說明得知本發明之精神，並據以作出各種變 化與衍生。唯只要不脫離本發明之精神，均應包含於其申請發明專 利範圍之内。 11 it-----I--^ · I ------^ · ----.-----線 (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 7 【元件符號之說明】 (10) 電荷泵電路 (11) (12) 電晶體 (13) 補償電晶體 (20) 環形震盪器 (21 ) (22) (23) 震盪器電 本纸張尺度中關家標準（CNSM4祕⑵ϋ X 297公复) ----530 4 C A7 B7 MH- 1 — V. Description of the invention (^) The following diagrams are more clear: [Explanation of the diagrams] Section 1 shows the circuit block diagram of a conventional voltage controlled oscillator. Fig. 2 is a block diagram showing a circuit of a voltage controlled oscillator according to the present invention. Fig. 3 shows the relationship between the power supply voltage fluctuation and the oscillator frequency in the present invention and the conventional electric-mechanism-controlled scalder obtained by simulation with an electric film. [Detailed description of the invention] The voltage controlled oscillator of the present invention will be described below. The second circle shows a circuit block diagram of the voltage controlled oscillator of the present invention. In the figure, the same components as those in Figure 1 are marked with the same numbers. As shown in the figure, the voltage-controlled oscillator of the present invention is substantially the same in circuit design as the conventional voltage-controlled oscillator shown in FIG. 1, and also includes a charge pump circuit (10) and a ring oscillator (20). The charge pump circuit (10) also has two charge pumps (pumpup) and (pumpdown). The switches (up) and (down) are switched alternately to control the voltage sent from the power supply (VDD) to the (PUMP) point. If the voltage of the charge pump does not change, the voltage at the (PUMP) point relative to the voltage (VDD-PUMP) of the power supply (VDD) also does not change. This voltage value is converted into a current by the transistor (11), and the ring oscillator (20) is biased by the action of the transistor (12). 5 This paper size applies to the national S standard (CNSM4 specification (210 x 297 mm) 1 ------- ^ ϋ IIIIII »! I I ----- (Please read the precautions on the back before filling in this Page) 45304 0 Α7 Β7 Intellectual Property Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, Consumer Cooperative, India. V. Invention Description (¥) The ring oscillator (20) contains the oscillator circuit (21) (22) (23) that forms a loop. The vibration weight is generated. Because the bias voltage of the transistor (12) is proportional to the voltage of (VDD-PUMP), the oscillation frequency of the ring oscillator (20) can be proportional to the voltage of (VDD-PUMP). The biggest difference between the voltage controlled oscillator of the invention and the conventional device is that a voltage compensation transistor (13) is provided. The voltage compensation transistor (13) is connected in series with the transistor (12), and its source is grounded. When the voltage of the power supply (VDD) suddenly rises, the equivalent resistance formed by the compensating transistor (13) decreases accordingly, and the bias voltage provided by the transistor (12) is pulled down. As a result, the oscillator ( 20) The operating frequency is reduced. In other words, 'the compensation transistor is provided in the present invention. (13), it can correct the influence of the oscillation frequency of the oscillator (20) due to the increase of the power supply voltage, so that its oscillation frequency is only controlled by the (VDD-PUMP) voltage, so it can improve its sensitivity to changes in power supply voltage [Effects of the invention] Using computer simulation, it is assumed that the voltage of the "PUMP" point relative to the power supply (VDD) does not change, change the voltage of the power supply (VDD), and measure the oscillation frequency of the ring oscillator. The result is shown in Figure 3. . Figure 3 shows that the circuit of the present invention can indeed improve the power supply voltage. 6 Paper size s ® standard car (CNS) Al specifications ⑵ϋ X 297) (Please read the precautions on the back before filling this page) Binding, Line. 4 53 04 0 A7 B? 5. Description of the invention (t) The shadow review of the oscillation frequency of the ring oscillator. The above is the description of the improved embodiment of the voltage controlled oscillator of the present invention. Those skilled in arts should be able to learn the spirit of the present invention from the above description, and make various changes and derivatives based thereon. As long as it does not depart from the spirit of the present invention, it should be included in the scope of the invention patent application. 11 it ----- I-^ · I ------ ^ · ----.----- line (Please read the notes on the back before filling out this page) Intellectual Property Bureau of the Ministry of Economic Affairs Printed by employee consumer cooperatives [Description of component symbols] (10) Charge pump circuit (11) (12) Transistor (13) Compensation transistor (20) Ring oscillator (21) (22) (23) Oscillator circuit Guan Jia standard in this paper standard (CNSM4 secret X 297 public reply) ----