TW200824293A - Automatic switching phase-locked loop - Google Patents

Abstract

An automatic switching phase-locked loop (PLL) is disclosed, including a phase detector, a charge pump generating a pump current, a band selector receiving a control voltage to produce a band selection signal and a voltage setting signal according to the control voltage, a loop filter generating the control voltage corresponding to the pump current and setting the control voltage based on the voltage setting signal, and a multi-band voltage control oscillator (VCO) coupled to the control voltage and the band selection signal, selecting one of a plurality of operating bands based on the band selection signal, and providing an output signal of a frequency within the selected operating band based on the control voltage.

Description

200824293 IX. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a phase-locked loop (Phase_L〇cked L〇〇p; pll), and is related to the use of a multi-band voltage controlled oscillator (touch ti_band Voltage Control 〇SCillat〇r) phase-locked loop.

[Prior Art J, the controlled oscillator must have the ability to modulate or adjust the frequency sufficiently 笳囹 rn — b X to cover the operating frequency consumption in the worst case expected. It is commonly used in phase-locked loops. . According to the phase-locked loop t, this special line can be used to solve the problem. The situation of "taking evil" may be caused by factors such as supply voltage changes, chemical changes, and changes in meta-tolerance. θ Traditionally, most of the phase-locked loops use a single-band voltage-controlled oscillator to provide a single-rate _ (ie, single-operating frequency band) single-band voltage control, "II pass (four) road (four), which Ying Chou 1 (four) inferior situation τ shape operation frequency money. The voltage is reduced by the gain of the necessary phase tA to achieve a sufficiently large modulation range. However, large gains can cause the voltage-controlled vibrator to be sensitive to noise and output jitter to be inferior. The multi-band voltage controlled oscillation n provides a plurality of frequency ranges (i.e., a plurality of falling frequency bands) which collectively represent the complete modulation range of the voltage controlled center. The multi-band voltage controlled oscillator cuts the variable frequency band into a complex number. The control signal received by the voltage controlled center is TT^ Docket No: 0697-A40700-TW/f/ChingYen/2006-l 1-11 6 200824293 The frequency range is only small for one of the operating bands, so the gain of the multi-band voltage controlled oscillator can be reduced. Multi-band voltage controlled oscillators can thus improve many of the shortcomings of single-band voltage controlled oscillators. Since the multi-band voltage controlled oscillator can operate in any of a plurality of operating frequency bands, the appropriate operating frequency band must be selected at any given time. Therefore, there is a need for a phase locked loop that utilizes a multi-band voltage controlled oscillator and has an automatic switching mechanism to properly switch the operating frequency band. In the first embodiment of the present invention, an automatic switching phase locked loop includes a phase debt detector, a charge pump, a band selector, a filter, and a band selector. The phase detector has a first input terminal for receiving a reference signal and a second input terminal for receiving a feedback signal, and outputs a phase detection signal corresponding to a phase difference between the reference signal and the feedback signal. The charge pump receives the phase detection signal and generates a pump current based on the phase detection signal. The band selector receives a control voltage and generates a band selection signal and a voltage setting signal based on the control voltage. The filter generates the control voltage based on the pump current and sets a signal according to the voltage to reset the control voltage. The multi-band voltage controlled oscillator is coupled to the control voltage and the frequency band selection signal for selecting one of a plurality of operating frequency bands according to the frequency band selection signal, and providing an output signal according to the control voltage, the output signal The frequency is within the frequency range of the selected operating band. The band selector detects whether the control voltage falls on a reference voltage

Client Docket N〇.:P2005-040 TT^ Docket No:0697-A40700-TW/f/ChingYeii/2006-l Μ1 200824293 In the range, if it is, neither the operating band of the band hard oscillator nor the production 2 is produced. The multi-frequency control power m is generated to generate the frequency number to set the frequency band of the voltage-controlled oscillations and to generate the control voltage of the emperor and the emperor. / % 1 port and the number to set the invention also provides an automatic switching phase-locked loop embodiment and the first embodiment of the difference between the examples, the method for detecting whether the automatic switching circuit is locked, The 贞^ device further receives the lock signal and further selects a band selection signal and the voltage setting signal according to the lock. The frequency band selector detects whether the control voltage falls within the range of ~ or at least one of the additional reference voltage ranges, and the reference voltage external reference voltage range is adjacent to the reference mine # /, medium 5 The frequency band when the head falls within the reference voltage range. The control voltage is selected to convert the multi-band voltage-controlled vibration to generate the frequency band. The voltage setting signal is used to set the control voltage. And, at least one of the additional reference voltage ranges is not generated - the voltage of the Putian two air system falls within the inch of the frequency band, and the lock signal is received to indicate the automatic switching phase-locking thin path, the selector After the connection, the band selection signal is generated and the maternal is in the locked state, and the voltage setting signal is set.

When the control voltage does not fall within the residual voltage range of the reference voltage nor falls within the additional reference voltage range, the band selector generates a 远#^^1 far-band selection signal to convert the multi-band voltage-controlled oscillation. The operating frequency band of the device and _A and the voltage setting signal are generated to set the control voltage. [Embodiment]

Client's Docket No. :P2005-040 TT^ Docket No:0697-A40700-TW/f/ChingYen/2006-l 1 -11 8 200824293 FIG. 1 is an automatic use of a multi-band voltage controlled oscillator provided by the present invention. One embodiment of a block diagram of a PLL 100 is switched. As shown, the automatic switching PLL 100 includes a phase detector 1A, a charge pump u, a filter 12, a multi-band voltage controlled oscillator (vc〇) 13, and a programmable frequency divider 14 And a band selector 15. The venge detector 10 receives a reference signal CLkr and a feedback signal CLKP, detects the instantaneous phase difference between the two, and outputs a phase detection signal SPD corresponding to the detected difference of the φ measured to the charge. Pump 11. The charge pump 11 in turn generates a pump current Icp whose on-time is determined by the phase difference indicated by the phase detection signal SPD and delivers the pump current to the filter 12. Filter 12 in turn generates a control voltage VCTRL corresponding to pump current Icp. When receiving the voltage setting signal svs from the band selector 15, the filter 12 sets the control voltage Vctrl to one of at least one predetermined voltage. The multi-band VCO 13 system has a plurality of operating frequency bands, each of which covers a specific frequency range. The multi-band VCO 13 is selected and operates in one of the operating bands based on a band selection signal sB from the band selector 15. The multiband ¥0313 is coupled to the control voltage VCTRL from the filter 12 and outputs an output signal CLK0. The frequency of the output signal CLK 系 falls within the individual frequency range of the selected frequency band and is controlled by the control voltage VCTRL. The output signal CLK is demultiplexed by the programmable frequency divider 14 into a feedback signal CLKF. It is noted that, as is well known in the art, the programmable frequency divider 14 can be removed and the output signal CLK 〇 can be directly used as the feedback signal CLKF.

Client *s Docket N〇.:P2005-040 TT^s Docket No:0697-A40700-TW/f/ChingYen/2006-l 1-11 200824293 Dimensions 2A and 2B show the gain conversion of a typical multi-band vc〇 The consumption of the function is used to show the change of the frequency of the round-trip CLK〇 relative to the control voltage vCTRL. Referring first to the second figure, the multi-band vC〇13 system has a plurality of operating bands B1 to the job, and each frequency (four) has its own gain conversion function. The operating band B1 covers the frequency range from the frequency fl to f3, the operating band B2 covers the frequency range of the frequencies f3 to f5, ..., and the operating band BN covers the frequency range from the deep to the sinking. Therefore, the multi-band VCO 13 as a whole has a modulation range from the lowest frequency fl to the highest frequency m. The multi-band VCO 13 selects one of the operating bands B1 to BN according to the band selection signal Sb, and rotates the output signal CLK〇. The frequency of the output signal CLK 系 falls within the individual frequency range of the selected frequency band and is controlled by the control voltage VCTRL. The difference between Fig. 2B and Fig. 2A is only that the frequency of the output signal CLK〇 increases as the control voltage vctrl rises, and does not decrease. The frequency selector 15 is for providing a frequency selection signal SB for switching the operating frequency band of the multi-band VCO 13, and for providing a voltage setting signal svs for controlling the filter 12 to set the control voltage vCTRL to one of the predetermined voltages. In the present invention, the band selector 15 generates the frequency selection signal sB and the voltage setting signal based on the control voltage VCTRL provided by the filter 12.

Svs. When the frequency selector 15 provides the frequency selection signal SB to switch the operating band of the multi-band VCO 13, the voltage setting signal Svs is also provided to control the filter 12 to set the control voltage vCTR1 to a predetermined voltage -" In an embodiment of the invention, the band selector 15 detects the control power

Clienfs Docket N〇.:P2005-040 TT^ Docket No:0697-A40700-TW/f/ChingYen/2006-l 1-11 10 200824293 Whether the voltage vCTRL falls within the reference voltage range to determine the rate selection signal sB In order to switch the operating band of the multi-band 13 and the set signal Svs to control the filter 12 to set the control voltage repeatedly control voltage vCTRL & outside the reference voltage range, then (4): 15 series provide frequency selection signal % and voltage error number ,. Otherwise, the two-band selector 15 provides neither the frequency selection signal Sb nor the voltage setting signal Svs. φ Fig. 3 is an embodiment of a block diagram of the band selector 15 of Fig. 1 provided by the present invention. As shown, in the band selector 15, a sign-off voltage generator 31 generates at least one reference voltage, wherein the at least reference voltage vREF corresponds to a reference voltage range, and then the reference private voltage VREF is provided. To comparator 32. The comparator 32 compares the control voltage vCTRL with the at least one reference voltage Vref to determine whether the control voltage falls within the reference voltage range, and then generates a comparison signal center corresponding to the comparison result. The comparison signal Sc is transmitted to the control module 33. The control module 33 then outputs the band selection signal Sb and the voltage setting signal svs based on the comparison signal sc. If the control voltage Vctrl falls outside the reference voltage range, the control module 33 generates a band selection signal % to switch the operating band of the multi-band VCO 13, and outputs a voltage setting signal Svs to control the filter 12 to set the control voltage VCTRL. Is one of at least one predetermined voltage. Otherwise, the control module 33 neither generates the band selection signal sB to convert the insertion band of the multi-band VCO 13 nor generates the voltage setting signal Svs to control the filter 12 to set the control voltage VCTRL. In an embodiment, the control module 33 determines which frequency band the multi-band VCO 13 switches to and controls.

Client's Docket No. :Ρ2005·040 TT^ Docket No:0697-A40700-TW/f/ChingYen/2006-l 1-11 11 200824293 The voltage VcTRL is set to which of the predetermined voltages. The 4A diagram shows the reference voltage distribution map of the consistent embodiment of the present invention. Figure 4B-4C shows the operating band switching mechanism of the multi-band VCO of Figure 2A-2B when the reference voltage is as shown in Figure 4A. In Fig. 4A, the reference voltage vREF includes first and second reference voltages vren and Vref2. The comparator 32 compares the control voltage VCTRL with the first and second reference voltages Vref1 and Vref2 to determine which of the voltage regions A, B, and C the control voltage VCTRL falls in, and transmits the comparison result to the comparison signal Sc to Control module 33. Referring to Fig. 4B, if the control voltage Vctrl falls within the voltage range A, the control module 33 generates a band selection signal SB to switch the multi-band VCO 13 to the next higher frequency band. At the same time, the control module 33 outputs the voltage setting signal Svs to control the filter 12 to pull the control voltage VCTR1 to a first predetermined voltage. Similarly, if the control voltage VCTRL falls within the voltage range C, the control module 33 generates a band selection signal SB to switch the multi-band VCO 13 to the next lower frequency band, and simultaneously outputs the voltage setting signal Svs to control The filter 12 pulls the control voltage to a second predetermined voltage. However, if the control voltage VCTRL falls within the voltage range B, the control module 33 neither generates the band selection signal SB to change the operating band of the multi-band VCO 13, nor generates the voltage setting signal Svs to control the ferristor 12 to set the control. Voltage VCTRL. In one embodiment, the first and second predetermined voltages are the first and second reference voltages Vref 1 and Vref2, respectively. The difference between Fig. 4c and Fig. 4B is only that if the control voltage VCTRL falls within the area a, the control module 33 generates the band selection signal SB to switch the multiband vco to the lower level.

Client's Docket No. :P2005-040 TT^ Docket No:0697-A40700-TW/f/ChingYen/2006-11-11 12 200824293 instead of the higher operating band; and if the control voltage vCTRL falls in the area c, then control The module 33 generates a frequency to be selected signal SB to switch the multi-band VC0 to a higher, but lower, operating band. The relevant details are quite similar to those described in Figure 4B and will not be repeated here for the sake of brevity. Figure 5 is another embodiment of a block diagram of the automatic switching PLL 500 provided by the present invention. The difference between this figure and the automatic switching PLL 100 of Fig. 1 is only the addition of a lock detector 51. The lock detector 51 receives the reference signal CLKr and the feedback signal CLKF, detects whether the automatic switching PLL 500 is locked, and transmits a lock signal sL corresponding to the detection result to the band selector 12. The band selector 12 receives the lock signal SL in addition to the control voltage VCTRL, and generates the band selection signal SB and the voltage setting signal svs according to both the control voltage vCTRL and the lock signal SL. It should be noted that the connection between the lock detector 51 and the remaining blocks in Fig. 5 is only an example. For example, the lock detector 51 can separately receive the output signal S〇 to detect whether the automatic switching PLL 500 is locked. Figure 6 is an embodiment of a block diagram of the band selector 丨 5 of Figure 5 of the present invention. The difference between this figure and the third figure is that the control module 33 receives the lock signal S1 in addition to the comparison signal Sc, and outputs the band selection signal % and the voltage setting signal Svs according to both the comparison signal Sc and the lock signal SL. The detailed description of each block is omitted here for brevity. In this embodiment, the reference voltage generator 31 generates at least one reference voltage vREF, wherein the at least one reference voltage Vref corresponds to a reference voltage range and at least one additional reference voltage range, wherein the additional reference voltage

Client's Docket No: P2005-040 TT^ Docket No: 0697-A40700-TW/f/ChingYen/2006-l 1>ι! 13 200824293 The range is adjacent to the reference voltage range, and the reference voltage generator 31 is This reference voltage VREF is supplied to the comparator 32. The comparator 32 compares the control voltage VcTRL with the at least one reference voltage VreF to determine whether the control voltage VcTRL falls within the reference voltage range or one of the at least one additional reference voltage range, and then generates a corresponding The comparison signal Sc of the comparison result. The comparison signal Sc is transmitted to the control module 33. After receiving the comparison signal Sc, the control module 33 outputs the band selection signal SB and the voltage setting signal Svs according to both the comparison signal Sc and the lock signal SL. Similar to Figure 4, if the comparison signal Sc indicates the control voltage

When VcTRL falls outside the reference voltage range, the control module 33 generates a band selection signal SB to switch the operating band of the multi-band VCO 13, and outputs a voltage setting signal Svs to control the filter 12 to set the control voltage VcTRL. At least one of the established voltages. Otherwise, the control module 33 neither generates the band selection signal SB to convert the operating band of the multi-band VCO 13 nor generates the voltage setting signal Svs to control the filter 12 to set the control voltage VcTRL. However, FIG. 6 and FIG. The picture is a little different. In this embodiment, if the comparison signal Sc indicates that the uncontrolled voltage VcTRL falls outside the reference voltage range, the two cases are distinguished. In the first case, the control voltage VCTRL falls within one of the at least one additional reference voltage range. In this case, the control module 33 will again refer to the lock signal SL to check if the automatic switching PLL is in the locked state. The control module 33 neither generates the band selection signal Sb nor generates the voltage setting signal Svs until the lock signal SL is received to indicate that the automatic switching PLL 500 is in the locked state. In the second case, the control voltage Vctrl is not within the range of an additional reference voltage. In this situation

Client's Docket No.: P2005-040 TT^s Docket No: 0697-A40700-TW/f/ChingYen/2006-ll-ll 200824293 In case, the control module 33 immediately generates the band selection signal SB without checking the lock signal SL. Voltage setting signal Svs. In one embodiment, in both the first and second cases, the control module 33 determines which frequency band the multi-band VCO 13 switches to and the control voltage V CTRL is set to which of the predetermined voltages. Fig. 7A is a view showing a reference voltage distribution diagram of another embodiment of the present invention, respectively. The 7B-7C diagram shows the operating band switching mechanism of the multi-band VCO of the 2A-2B diagram when the reference voltage is as shown in FIG. 7A. The difference between the 7A and 4A is only that the voltage range A is divided into two sub-voltage regions A1 and A2 by a third reference voltage Vref3, and similarly, the voltage range C is divided by a fourth reference voltage Vref4. Two sub-voltage regions C1 and C2. This means that the reference voltage generator 31 generates the reference voltages Vref1 to Vref4. The voltage region B between the reference voltages Vref1 and Vref2 is used as the reference voltage region, and the voltage range A is within the secondary voltage range A2 between the reference voltages Vref3 and Vref1, and the voltage range C is between the reference voltage Vref2 and The secondary voltage C1 between Vref4 is used as an additional voltage range. The comparator 32 then compares the control voltage V CTRL with the first to fourth reference voltages Vref1 to Vref4 to determine which of the voltage regions A1, A2, B, C1, and C2 the control voltage VCTRL falls in, and compares the comparison results. The signal Sc is transmitted to the control module 33. As shown in FIG. 7B, similar to FIG. 4B, if the control voltage VcTRL falls within the voltage range B, the control module 33 neither generates the band selection signal SB to convert the operating band of the multi-band VCO 13, nor does it generate a voltage setting. Signal Svs to control the filter

Client’s Docket No. :P2005-040 TT5s Docket No:0697-A40700-TW/f/ChingYen/2006-l 1-11 15 200824293 12Set the control voltage vctrl. Similarly, if the control module 33 receives the comparison signal Sc and the control voltage Vctrl falls within the voltage ranges A and C, the control module 33 generates a frequency band selection signal SB to respectively switch the multi-band VCO 13 to Next to the south and the next lower frequency band, and the output voltage setting signal Svs = control filter 12 pulls the control voltage Vctrl* high to the first predetermined voltage and pulls down to the second predetermined voltage. In one embodiment, the first and second φ predetermined voltages are the first and second reference voltages Vref1 and Vref2, respectively. However, the difference between FIG. 7B and FIG. 4B is that if the control voltage Vctrl is within the voltage range A2 of the voltage range A and the voltage C1 of the voltage range C, respectively, the control module 33 does not receive the lock signal S1. The band selection signal sB and the voltage setting signal Svs are generated only when the automatic switching PLL is in the locked state. More specifically, if the control module 33 receives the comparison signal sc and the control voltage Vctrl falls within the voltage ranges A1 and C2, the control module Lu 33 generates a band selection signal heart to switch the multi-band vc〇13 respectively. The next higher and lower lower frequency bands are output and the voltage setting signal Svs is output to control the filter 12 to pull the control voltage vCTRL high and low, respectively. However, if the control module 33 receives the comparison signal Sc indicating that the control voltage Vctrl falls within the voltage ranges A2 and C1, the control module 33 further checks the lock signal SL to detect whether the automatic switching PLL 500 has been locked. If the lock signal SL indicates that the automatic switching PLL 500 is currently in the locked state, the control module 33 also generates the band selection signal SB to switch the multi-band VCO to the next higher and lower lower frequency bands, respectively, and output.

Client’s Docket No. :P2005-040 TT's Docket No:0697-A40700-TW/f/ChingYen/2006-l 1 -11 16 200824293

: Press 5 signal svs to control filter i 2 to pull and pull control voltage VcT; otherwise, control mode, ,,,, 3 until the lock signal s = automatic switching PLL5GG is locked, Select signal SB and voltage setting signal Svs. A々 ′ The difference between Figure 7C and Figure 4C is: If control

Voltage range ^2 voltage range A2 and voltage range C

In ΪΪ3, the control unit 33 will not generate the voltage signal setting signal ^ until the time when the lock signal is received and the PLL is locked. The difference between the %th image and the first: the control voltage U-human area A' controls the module phantom, 咿 selects the signal SB to switch the multi-band VC0 to the lower car ft operating band; and if the control voltage The % drop zone control ^33 system generates the frequency to be selected signal SB to switch the multi-band vc〇 to a relatively low and low operation. The relevant details and those described in the TB diagram #当类# ' are not described here for the sake of brevity. Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the invention to those skilled in the art, and the invention may be modified and modified without departing from the spirit of the invention. The offense is subject to the definition of the scope of the patent application attached. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an embodiment of a block diagram of an automatic switching phase-locked loop using a multi-band voltage controlled oscillator according to the present invention; FIGS. 2A and 2B show typical multi-band voltage control Oscillator gain

Client's Docket No.: P2005-040 TT's Docket No-T-AWOO-THAW/a^Ye^oob-Un 200824293 Example of a change function; Figure 3 is a block diagram of the band selector of Figure 1 provided by the present invention FIG. 4A shows a reference voltage distribution diagram of an embodiment of the present invention; FIG. 4B-4C shows a multi-band of the second A-2B diagram when the reference voltage is as shown in FIG. 4A. The operating band switching mechanism of the VCO; FIG. 5 is another block diagram of the block diagram of the automatic switching phase-locked loop provided by the present invention; FIG. 6 is a block diagram of the band selector of the fifth figure provided by the present invention. One embodiment; FIG. 7A shows a reference voltage distribution diagram of another embodiment of the present invention; and FIG. 7B-7C shows that when the reference voltage is as shown in FIG. 7A, the second FIG. The operating band switching mechanism of the band VCO. [Main component symbol description], 10 to phase detector 12 to loop filter 14 to programmable frequency divider 31 to reference voltage generator 33 to control module A, A1, A2 to voltage range B1-BN to band Π ~ Charge pump 13 ~ multi-band voltage controlled oscillator 15 ~ band selector 3 2 ~ comparator 51 ~ lock detector B ~ reference voltage range C, Cl, C2 ~ voltage range

Client5s Docket N〇.:P2005-040 TT^ Docket No:0697-A40700-TW/f/ChingYen/2006-l 1-11 200824293 CLKp~Response signal CLKR~reference signal

Icp ~ Li current sc ~ control signal Spd ~ lock 彳贞 signal VcTRL ~ control voltage Vrefl-Vref4 ~ reference voltage CLK 〇 ~ output signal fl-f6, fM, fN ~ band boundary frequency SB ~ band selection signal Sl ~ lock Signal Svs~Voltage setting signal Vref~reference voltage

Client’s Docket No. :P2005-040 TT^ Docket No:0697-A40700-TW/f/ChmgYen/2006-l 1-11 19

Claims (1)

200824293 X. Patent application scope: Automatic switching phase-locked loop-phase detector, receiving-out-phase detection signal> test subtraction and feedback signal, and bit difference; object^ reference subtraction signal = one charge pump, Picking up the sill stone ~ phase detection signal and generating a pump current according to the phase >&;; 豕豕 phase detection signal band selector, and then generating a -band selection ^ control voltage, and according to The control power - #u and - voltage error signal; 0 is willing to state, according to the voltage setting signal to weight two:: to generate the control voltage 'and the root phase ^ 垔 new setting the control voltage; proud - The eve band voltage controlled oscillator selects the signal for the root, ",, the coupler to the private voltage and the 谤 band Λ according to the frequency band selection, one of the shoulders, and one, with a number of operations of 4 士W The mountain outputs a signal according to the control voltage to provide the frequency of the output signal in the round-to-wheel, and the frequency is in the frequency range of the four fine-grained frequency bands, as described in the "Patent Model Item" Automatically, the band selector is detected Whether the control voltage is "2 = way, within the range, if so, neither the band selection signal is generated = the operating band of the ring voltage controlled oscillator is generated by the forest to generate the power signal ί = the control voltage; if not, then Generating the band selection signal to convert the operating band of the multi-band voltage controlled oscillator and generating the voltage setting signal to control the voltage. ΙΑ 3. The automatic switching phase-locked loop as described in claim 2, Client's Docket No.: P2005-040 TT's Docket No: 0697-A40700-TW/£OiingYen/2006-ll-l 1 20 200824293 wherein the frequency band selector comprises: a reference voltage generating crying, the user is using her... less reference voltage, wherein the cup test (4) should refer to the power range; the vehicle six is used to control the voltage and the At least - the reference voltage ratio =: to detect whether the electric drum falls within the reference electric power square, and generate a comparison nickname corresponding to the detection result; a control module receives the specific motion ^ ^ 匕The right comparison signal indicates the voltage range of the test, and neither of the band selection signals is generated: the thorns f5 hai voltage setting signal, otherwise, the frequency band selection signal is generated, and the operating frequency band of the voltage control device is generated and the electricity is generated. The signal is set to set the control voltage. 4. The automatic switching phase-locked loop of claim 3, wherein the reference voltage generator generates a first reference voltage and a second reference voltage corresponding to the first reference voltage; Comparing the control voltage with the first and second reference voltages to detect whether the control voltage falls between the first and second reference voltages, and generating the comparison signal corresponding to the detection result; When the control module receives the comparison signal indicating that the control voltage is the first reference voltage, if the frequency of the output signal increases or decreases with the control voltage, the frequency band selection signal is generated to The multi-frequency π voltage-controlled oscillator is respectively switched to a lower or higher operating frequency band, and a voltage control signal is generated to control the filter to pull the control voltage high; the middle control module receives the comparison When the signal indicates that the control voltage is higher than the second reference voltage, if the frequency of the output signal follows the control Clienfs Docket No.: P2〇〇5-〇4〇TT s Docket No:〇697-A4070〇-TWfiOiin gYen/2006-l 1-11 21 200824293 Zeng Li: f (4), the generation of the band selection signal to switch the reading ~ ▼ Gongzheng Zhai to higher or lower respectively - operate and generate voltage control The signal is controlled to pull the filter low and the control module receives the voltage of the comparison signal; when the voltage is between the first and second reference voltages, the system is controlled by: The voltage setting signal is also not generated by the signal.礒 Band 5. The automatic switching phase lock as described in item 4 of the patent application. The control module is configured to receive the control signal when the comparison signal indicates that the control voltage is lower than the second reference voltage. The voltage is lower than the set signal to control the filter to respectively set the control voltage and the second reference voltage. . Far first 6 · If you apply for a patent range! The automatic switching lock described in the item further comprises: a locker for detecting whether the automatic switching circuit is locked, and a locking signal corresponding to the detection result; and determining, wherein the band selector is further received The lock signal and the lock signal are used to generate the frequency band selection signal and the voltage machine ~i is further based on the port and the signal. 7. The automatic switching phase as described in claim 2, further comprising: a locker detecting whether the automatic switching circuit locks the second circuit, and a locking signal corresponds to the detection result; and V & 'and The frequency band selector further receives the lock signal to control whether the voltage falls within at least one additional reference voltage range. The additional reference voltage range is adjacent to the reference voltage range, and the detected The control voltage falls within the at least one additional reference ten and when the private range is at a time, the lock signal is received to indicate that the automatic cut-field η 颂 颂 phase loop virtual Client's Docket Νο.:Ρ20〇5-〇40 ^ ^ TT^ Docket No: 0697-A40700-TW/f/ChingYen/2006- 22 200824293 After the lock state, the band selection message is generated. μ 8 · The heart 144 voltage setting signal as claimed in claim 4 . The method further includes: a locker for detecting the automatic cutting of the wing to change the phase locked loop, and a locking signal corresponding to the detection result; and ^疋 no locking 'and the wheel wherein the voltage generator generates a lower value than the #^ a third reference voltage and a higher than the second reference voltage _ tea test voltage, wherein the comparator system further controls the control voltage to the east; comparing to detect whether the control voltage falls within the first -& between the four voltage voltages or between the second and fourth reference lightning segments - and the first reference power t, and the signal system corresponds to the comparison result; and the long-term comparison and when receiving The control module further receives the lock signal, and the control signal indicates that the control voltage falls between the second and the field / and the gate of the second and fourth reference voltages is locked. The signal indicates that the automatic switching phase-locked loop is in error A. The team determines that the frequency band selection signal and the voltage setting signal are generated. 9. The automatic switching phase-locking control module described in claim 8 is Received the comparison The number indicates that the control voltage is lower than the second reference voltage, and the system is lower than the first king voltage and the reference to control the filter to respectively set the control voltage for the first sigh疋 Signal voltage. Client^ Docket N〇.:P2005-040 TT^s Docket No:0697-A40700-TW/f/ChingYen/2006-l M1 23