Boost circuit and modem

Abstract

The invention discloses a booster circuit and a modem. An energy storage unit is arranged and is connected with a voltage input end, a first switch unit and a charging unit; the first switch unit can adjust the conduction duration under the action of a control signal, so that the voltage at the two ends of the energy storage unit is changed, charging energy storage is achieved, the voltage of the first node is increased relative to the voltage provided by the voltage input end, and boosting is achieved. Therefore, the voltage signal boosted by the first node is output through the output voltage end, and the voltage signal of the voltage input end is boosted and then output. The boost circuit provided by the invention does not depend on a specific boost chip, and the boost function of the chip is realized by completely utilizing existing devices, so that the circuit cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of modems, and in particular to a boost circuit and a modem. Background Art

[0002] When designing XGPON optical modem products, in order to improve the receiving sensitivity of XGPON, the receiving end uses APD (Avalanche Photodiode). The avalanche voltage of APD is usually: 25V~45V, and the optical modem is powered by 12V. The high voltage of APD requires a boost circuit, which is generally completed through a boost power chip. The cost of boost chips is relatively high, and there are few suppliers, which is restricted by the supply chain.

[0003] The boost circuit provides a reverse voltage to the avalanche photodiode of the BOSA device, making it in an avalanche multiplication state, increasing the sensitivity of photoelectric conversion. Products on the market generally use three boost chips: MAX15059, I7990, and MP3430 (only GN28L96 is available). However, boost chips are relatively special, there are fewer on the market, the price is high, and the product supply will be limited.

[0004] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present application is to provide a boost circuit and a modem, aiming to solve the problems of high cost of boost power chip and restricted product supply in the prior art.

[0006] To achieve the above-mentioned purpose, the present application provides a boost circuit, which is connected to a control unit, and the control unit has a signal adjustment pin; the boost circuit includes: an energy storage unit, connected to a voltage input terminal and a first node; a first switch unit, a first end of which is connected to the first node, a second end of which is connected to a ground terminal, and a control end that receives a control signal; a charging unit, connected to the first node and an output voltage terminal; wherein the control unit is used to output the control signal through the signal adjustment pin; the first switch unit is used to connect the first node to the ground terminal or disconnect the first node from the ground terminal in response to the control signal; the energy storage unit is used to charge when a path is formed between the first node and the ground terminal or to discharge the first node when a circuit is broken between the first node and the ground terminal; the charging unit is used to use the discharge signal of the first node to perform voltage bootstrapping to provide a boosted voltage signal to the output voltage terminal.

[0007] Optionally, the boost circuit also includes: an anti-reverse unit, connected in series between the first node and the charging unit, the anti-reverse unit and the connecting end of the charging unit forming a second node, the anti-reverse unit being used to transmit the voltage signal of the first node to the second node; a first filtering unit, connected in series between the first node and the voltage input end, the first filtering unit being used to filter the voltage signal of the voltage input end and provide a ripple-filtered voltage signal to the energy storage unit.

[0008] Optionally, the control unit also has a feedback signal pin; the control unit is also used to receive a feedback signal through the feedback signal pin, and adjust the control signal based on the feedback signal, and there is a preset voltage ratio between the feedback signal and the voltage signal output by the output voltage terminal; the first switching unit is also used to adjust the on-off time between the first node and the ground terminal in response to the control signal; the charging unit is also used to adjust the size of the boost voltage signal output to the output voltage terminal in response to the charging time of the first node.

[0009] Optionally, the boost circuit also includes: a protection unit, one end of which is connected to the second node, the other end of which is connected to the ground end, and a control end is connected to the signal feedback end, and the protection unit is used to respond to the feedback signal of the signal feedback end to connect the second node and the ground end to release the over-voltage of the boost signal of the second node.

[0010] Optionally, the boost circuit also includes: a feedback unit having a signal feedback end, one end of the feedback unit is connected to the second node, and the other end is grounded, and the feedback unit is used to extract the voltage signal of the second node and output a feedback signal through the signal feedback end.

[0011] Optionally, the protection unit includes a second resistor, a second switch unit, a first diode and a fifth resistor; one end of the second resistor is connected to the second node, the other end is connected to the first end of the second switch unit, the other end of the second switch unit is connected to the anode of the first diode, and the control end of the second switch unit is connected to one end of the fifth resistor and serves as the control end of the protection unit; the cathode of the first diode is connected to the ground end, and the other end of the fifth resistor is connected to the signal feedback end; wherein, the second switch unit turns on the second node and the ground end in response to the voltage signal of the signal feedback end.

[0012] Optionally, the boost circuit further includes: a sixth resistor, one end of which is connected to the control end of the first switch unit and the other end is grounded; wherein the energy storage unit is an inductor, and the first switch unit and the second switch unit are both N-type transistors.

[0013] Optionally, the feedback unit includes a third resistor and a fourth resistor; one end of the third resistor is connected to the second node, and the other end is connected to one end of the fourth resistor to form a signal feedback end of the feedback unit, and the other end of the fourth resistor is grounded.

[0014] Optionally, the boost circuit also includes: a current limiting unit, one end of which is connected to the second node; a second filtering unit, one end of which is connected to the other end of the current limiting unit and the other end is connected to the output voltage end, and the second filtering unit is used to filter the voltage signal of the second node and provide a ripple filtered boost signal to the output voltage end.

[0015] In addition, to achieve the above-mentioned purpose, the present application also provides a modem, including: the boost circuit described in any embodiment of the present application.

[0016] The boost circuit provided by the present application is provided with an energy storage unit, a first switch unit and a charging unit. The first switch unit is connected to the control unit and the first node. After the control unit adjusts the duty cycle of the control signal according to the feedback signal, the first switch unit can form a path between the first node and the ground terminal or disconnect the connection between the first node and the ground terminal under the action of the control signal. When the first node is connected to the ground, the energy storage unit is charged. When the first node is disconnected from the ground, the energy storage unit discharges to the first node. In this way, the energy storage unit is able to store electric energy and discharge to the first node through the action of the first switch unit, that is, the charging unit is charged, so that the voltage is self-bootstrapped under the action of the charging unit so that the output voltage terminal can output a boost voltage signal to realize the boost function. The boost circuit provided by the present application does not rely on a specific boost chip, and completely uses conventional components to realize the boost function of the chip, thereby reducing the circuit cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a principle block diagram of a boost circuit according to an embodiment of the present application; Figure 2 is a structural block diagram of a boost circuit according to another embodiment of the present application; Figure 3 A circuit diagram of a boost circuit according to an embodiment of the present application; Figure 4 It is a principle block diagram of the internal circuit of the modem according to one embodiment of the present application.

[0018] In the figure: 10, control unit; 110, energy storage unit; 120, first switch unit; 130, charging unit; 140, anti-reverse unit; 150, first filter unit; 160, protection unit; 170, feedback unit; 180, current limiting unit; 190, second filter unit; 200, modem; 201, WiFi module; 202, voice module; 203, BOB driver module; 204, BOSA module; 205, CPU module.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0021] Figure 1 is a principle block diagram of a boost circuit according to an embodiment of the present application, such as Figure 1 As shown, the boost circuit is connected to the control unit 10, and the control unit 10 has a signal adjustment pin MK and a signal feedback pin; the boost circuit may include: an energy storage unit 110, a first switch unit 120 and a charging unit 130, the energy storage unit 110 is connected to the voltage input terminal Vin and the first node N1; the first end of the first switch unit 120 is connected to the first node N1, the second end is connected to the ground terminal, and the control end receives the control signal CTR; the charging unit 130 is connected to the first node N1 and the output voltage terminal Vout; wherein the control unit 10 is used to output the control signal CTR through the signal adjustment pin MK; the first switch unit 120 is used to connect the first node N1 to the ground terminal or disconnect the connection between the first node N1 and the ground terminal in response to the control signal CTR; the energy storage unit 110 is used to charge when a path is formed between the first node N1 and the ground terminal or to discharge the first node N1 when a circuit is formed between the first node N1 and the ground terminal; the charging unit 130 is used to use the discharge signal of the first node N1 to perform voltage bootstrapping to provide a boost voltage signal to the output voltage terminal Vout.

[0022] The boost circuit provided in the present application is provided with an energy storage unit 110, a first switch unit 120 and a charging unit 130. The first switch unit 120 is connected to the control unit 10 and the first node N1. After the control unit 10 adjusts the duty cycle of the control signal CTR according to the feedback signal, the first switch unit 120 can form a path between the first node N1 and the ground terminal or disconnect the connection between the first node N1 and the ground terminal under the action of the control signal CTR. When the first node N1 is connected to the ground, the energy storage unit 110 is charged. When the first node N1 is disconnected from the ground, the energy storage unit 110 discharges to the first node N1. In this way, the energy storage unit 110 is able to store electrical energy and discharge to the first node N1 through the action of the first switch unit 120, that is, the charging unit 130 is able to be charged, so that the voltage is self-bootstrapping under the action of the charging unit 130 so that the output voltage terminal Vout can output a boosted voltage signal to achieve a boost function. The boost circuit provided in the present application does not rely on a specific boost chip, but completely utilizes conventional components to realize the boost function of the chip, thereby reducing the circuit cost.

[0023] In this exemplary embodiment, the control signal CTR may be a PWM signal, and the control unit 10 may adjust the duty cycle of the PWM signal according to the size of the received feedback signal. It should be understood that when the duty cycle of the PWM signal changes, the on-time of the first switch unit 120 also changes accordingly. Thus, by adjusting the duty cycle of the PWM signal, the on-time of the first switch unit 120 may be dynamically adjusted. When the first switch unit 120 is turned on, a path is formed between the first node N1 and the ground terminal. When the first switch unit 120 is turned off, the first node N1 and the ground terminal are disconnected. Thus, the on-off of the first switch unit 120 determines the on-off between the first node N1 and the ground terminal, thereby adjusting the potential at both ends of the energy storage unit 110, so that the voltage input terminal Vin can charge the energy storage unit 110, that is, the energy storage unit 110 can output a voltage signal after the voltage is raised to the first node N1, thereby achieving a boost output.

[0024] Further, such as Figure 1 As shown, in this exemplary embodiment, the control unit 10 also has a signal feedback pin, and the control unit 10 can also receive a feedback signal through the signal feedback pin, and adjust the control signal CTR based on the feedback signal, and there is a preset voltage ratio between the feedback signal and the voltage signal output by the output voltage terminal Vout; the first switch unit 120 can also be used to respond to the control signal CTR to adjust the on-off time between the first node N1 and the ground terminal; the charging unit 130 can also be used to respond to the charging time of the first node N1 to adjust the size of the boost voltage signal output to the output voltage terminal Vout.

[0025] Among them, there is a preset voltage ratio between the voltage value of the signal feedback pin and the voltage value output by the output voltage terminal Vout, so that the voltage value of the signal feedback pin changes linearly with the voltage value of the output voltage terminal Vout, that is, when the voltage value output by the output voltage terminal Vout increases, the voltage value of the signal feedback pin also increases; conversely, when the voltage value output by the output voltage terminal Vout decreases, the voltage value of the signal feedback pin also decreases.

[0026] The control unit 10 can dynamically adjust the size of the output control signal CTR according to the voltage of the signal feedback pin. Taking the control signal CTR as a PWM signal as an example, the control unit 10 can adjust the duty cycle of the output PWM signal according to the voltage of the signal feedback pin. In other words, the control unit 10 can dynamically adjust the duty cycle of the PWM signal according to the voltage output by the output voltage terminal Vout.

[0027] When the duty cycle of the control signal CTR changes, the on-time of the first switch unit 120 also changes accordingly, so that the on-off time of the first node N1 to the ground is changed.

[0028] It is worth noting that in the embodiment of the present application, when the boost circuit is applied to a modem product, the control unit 10 may specifically be a BOB driver chip in the modem. Of course, in other embodiments, the control unit 10 may also be an additional independent structure.

[0029] Figure 2 is a structural block diagram of a boost circuit according to another embodiment of the present application, such as Figure 2 As shown, in an exemplary embodiment, the boost circuit may further include an anti-reverse unit 140 and a first filtering unit 150, wherein the anti-reverse unit 140 is connected in series between the first node N1 and the charging unit 130, the connecting end of the anti-reverse unit 140 and the charging unit 130 forms a second node N2, and the anti-reverse unit 140 can be used to transmit the voltage signal of the first node N1 to the second node N2; the first filtering unit 150 is connected in series between the first node N1 and the voltage input terminal Vin, and the first filtering unit 150 can be used to filter the voltage signal of the voltage input terminal Vin and provide the energy storage unit 110 with a voltage signal after ripple filtering.

[0030] Specifically, the anti-reverse unit 140 can transmit the voltage signal of the first node N1 to the second node N2 and prevent the current from flowing back. In addition, the anti-reverse unit 140 can improve the voltage conversion efficiency between the first node N1 and the second node N2.

[0031] The first filtering unit 150 may filter the voltage signal of the voltage input terminal Vin to filter out the ripple interference signal in the voltage input terminal Vin.

[0032] The present application scheme is further described below in conjunction with the accompanying drawings.

[0033] Figure 3 is a circuit structure diagram of a boost circuit according to an embodiment of the present application, such as Figure 3 As shown, in an exemplary embodiment, the first switch unit 120 may be a MOS tube, and may specifically be an N-type MOS tube, that is, Figure 3 Of course, in other embodiments, the first switch unit 120 may also be other power semiconductor devices, such as an IGBT insulated gate bipolar transistor, a thyristor, etc.

[0034] In addition, in this exemplary embodiment, the energy storage unit 110 can be an inductor GL20, which is a conventional electrical component. The embodiment of the present application uses conventional electrical components to build a boost circuit, which has the advantages of simple circuit structure, easy implementation and replacement, and low cost.

[0035] like Figure 3 As shown, in an exemplary embodiment, the charging unit 130 may include a capacitor. As an example, the charging unit 130 may specifically include a sixth capacitor C6 and a seventh capacitor C7. The sixth capacitor C6 and the seventh capacitor C7 are arranged in parallel, and one end of the two is connected to the second node N2, and the other end is connected to the ground.

[0036] Among them, the sixth capacitor C6 and the seventh capacitor C7 constitute a charge pump. As described above, under the control signal CTR output by the control unit 10, the first switch unit 120 is turned on or off, so that the energy storage unit 110 can be charged and stored or discharge the first node N1. And the first switch unit 120 can adjust the charging time of the energy storage unit 110 as the duty cycle of the control signal CTR changes. It should be understood that the longer the energy storage charging time of the energy storage unit 110, the shorter the discharge time to the first node N1, and accordingly, the shorter the charging time of the charging unit 130; the shorter the energy storage charging time of the energy storage unit 110, the longer the discharge time to the first node N1, and accordingly, the longer the charging time of the charging unit 130.

[0037] In this exemplary embodiment, when the first switch unit 120 is turned on, the energy storage unit 110 performs energy storage charging, the potential of the first node N1 is maintained, and correspondingly, the potential of the second node N2 is maintained, and the sixth capacitor C6 and the seventh capacitor C7 maintain the potential of the previous stage; when the first switch unit 120 is turned off, the energy storage unit 110 discharges the first node N1, the potential of the first node N1 is raised, and correspondingly, the potential of the second node N2 is raised, and the sixth capacitor C6 and the seventh capacitor C7 are charged, so that the voltage value of the output voltage terminal Vout is raised, and a boosted output is achieved.

[0038] like Figure 3 As shown, in an exemplary embodiment, the anti-reverse unit 140 may include a Schottky diode GD2, the anode of the Schottky diode GD2 is connected to the first node N1, and the cathode is connected to the second node N2. Among them, the Schottky diode GD2 is a metal-semiconductor junction diode formed by the contact between metal and semiconductor, also known as a metal-semiconductor diode or a surface barrier diode. The Schottky diode GD2 has a small forward conduction voltage drop, no reverse recovery charge, low power consumption on the Schottky diode GD2, small parasitic capacitance, high switching frequency, and sufficient avalanche breakdown capability, so that the voltage value of the output voltage VOUT can be increased, thereby improving the boost efficiency of the boost circuit.

[0039] Continue to refer Figure 3 In an exemplary embodiment, the first filtering unit 150 may include a first capacitor C3, a second capacitor C4 and a third capacitor C5, wherein a first end of the first capacitor C3 is connected to a voltage input terminal Vin, and a second end is grounded, a first end of the second capacitor C4 is connected to a voltage input terminal Vin, and a second end is grounded, and a first end of the third capacitor C5 is connected to a voltage input terminal Vin, and a second end is grounded. The first capacitor, the second capacitor and the third capacitor constitute a three-stage filtering network to filter out interference signals of different frequency components, so that after the input voltage is filtered by three different capacitors in the first capacitor C3, the second capacitor C4 and the third capacitor C5, a 3.3V power supply with a small ripple can be obtained.

[0040] For further information, please refer to Figure 2 In an exemplary embodiment, the boost circuit may further include a protection unit 160, one end of the protection unit 160 is connected to the second node N2, the other end is connected to the ground end, and the control end is connected to the signal feedback end FB (the signal feedback end FB is the signal feedback end FB of the feedback unit described in the subsequent embodiments, and the signal feedback end FB is connected to the signal feedback pin of the control unit). The protection unit 160 can be used to respond to the feedback signal of the signal feedback end FB to connect the second node N2 and the ground end to release the overvoltage of the boost signal of the second node N2.

[0041] Specifically, one end of the protection unit 160 is connected to the second node N2, and the other end is grounded. The protection unit 160 conducts the second node N2 and the ground end according to the feedback voltage signal of the control end, thereby realizing overvoltage release of the boost signal of the second node N2 to avoid outputting an overvoltage signal with an amplitude exceeding the standard, thereby protecting the load.

[0042] As described above, there is a preset voltage ratio between the feedback signal of the signal feedback terminal FB and the output signal of the output voltage terminal Vout, so that the protection unit 160 can dynamically adjust the output voltage of the boost circuit according to the size of the extracted feedback signal. Exemplarily, when the voltage value of the second node N2 exceeds the set value, the feedback signal also exceeds the threshold value accordingly, then the protection unit 160 is started, and a path is formed between the second node N2 and the ground terminal, and the overvoltage signal of the second node N2 is released to the ground, so that the boost circuit can still output the set voltage value. On the contrary, if the voltage value of the second node N2 does not exceed the set value, the feedback signal cannot start the protection unit 160, so that the protection unit 160 is turned off, and the circuit between the second node N2 and the ground terminal is open, so that the voltage of the second node N2 can be ensured to continue to rise.

[0043] refer to Figure 3 In an exemplary embodiment, the protection unit 160 may include a second resistor R2, a second switch unit GQ6, a first diode GD1 and a fifth resistor R5, wherein one end of the second resistor R2 is connected to the second node N2, and the other end is connected to the first end of the second switch unit GQ6, the other end of the second switch unit GQ6 is connected to the anode of the first diode GD1, and the control end of the second switch unit GQ6 is connected to one end of the fifth resistor R5 as the control end of the protection unit 160; the cathode of the first diode GD1 is connected to the ground end, and the other end of the fifth resistor R5 is connected to the signal feedback end FB; wherein the second switch unit GQ6 turns on the second node N2 and the ground end in response to the voltage signal of the signal feedback end FB.

[0044] Specifically, the second resistor R2 and the fifth resistor R5 play a current limiting role. When the voltage of the second node N2 is higher than the set value, the voltage value of the feedback signal extracted by the protection unit 160 reaches the threshold value. At this time, under the action of the feedback signal, the second switch unit GQ6 is turned on, so that the second node N2 is connected to the ground terminal via the second resistor R2, the second switch unit GQ6 and the first diode GD1, forming a path to the ground, and the overvoltage release of the second node N2 can be performed. On the contrary, when the voltage of the second node N2 does not reach the set value, the feedback signal is also correspondingly less than the threshold value, then the second switch unit GQ6 is turned off, and the protection unit 160 forms a circuit break between the second node N2 and the ground terminal, so as not to affect the voltage rise of the second node N2.

[0045] Further, the polarity of the conduction level of the second switch unit GQ6 in this exemplary embodiment is the same as the voltage polarity of the second node N2. Exemplarily, in this embodiment, because the voltage of the second node N2 is a positive voltage, the second switch unit GQ6 can be an N-type MOS tube. For example, if the voltage of the feedback signal of the signal feedback terminal FB is less than 1.2V, the two ends of the second switch unit GQ6 are in a closed state, and the second node N2 is disconnected to the ground; if the voltage of the feedback signal is greater than 1.2V, the two ends of the second switch unit GQ6 are in a conducting state, and the voltage signal of the second node N2 flows to the ground terminal via the second resistor R2, the second switch unit GQ6 and the first diode GD1, thereby performing overvoltage discharge. It should be understood that the proportionality coefficient between the feedback signal and the voltage signal of the second node N2 can be determined according to the threshold voltage of the second switch unit GQ6, which will not be described in detail here.

[0046] Continue to refer Figure 2 In an exemplary embodiment, the boost circuit may further include a feedback unit 170, the feedback unit 170 having a signal feedback terminal FB, one end of the feedback unit 170 being connected to the second node N2, and the other end being grounded, the feedback unit 170 being used to extract a voltage signal of the second node N2 and output a feedback signal through the signal feedback terminal FB.

[0047] Specifically, the feedback unit 170 determines the magnitude of the feedback signal by extracting the voltage signal of the second node N2. When the voltage of the second node N2 increases, the voltage value extracted by the feedback unit 170 also increases accordingly, that is, the feedback signal output by the signal feedback terminal FB also increases accordingly; conversely, when the voltage of the second node N2 decreases, the voltage value of the feedback signal extracted by the feedback unit 170 also decreases accordingly, that is, the feedback signal output by the signal feedback terminal FB also decreases accordingly. In this way, the voltage signal of the second node N2 is extracted by the feedback unit 170 and the voltage of the second node N2 is dynamically adjusted through the protection unit 160 to ensure that the final output meets the required set voltage value.

[0048] As described above, there is a preset voltage ratio between the voltage signal of the signal feedback terminal FB and the voltage signal of the second node N2. In an exemplary embodiment, the feedback unit 170 can be implemented by a voltage dividing module. Figure 3 The feedback unit 170 may include a third resistor R3 and a fourth resistor R4, one end of the third resistor R3 is connected to the second node N2, the other end of the third resistor R3 is connected to one end of the fourth resistor R4 to form a signal feedback end FB of the feedback unit 170, and the other end of the fourth resistor R4 is connected to the ground end.

[0049] The third resistor R3 and the fourth resistor R4 form a voltage divider circuit, and a voltage divider signal (i.e., feedback signal) is output at the connection end of the third resistor R3 and the fourth resistor R4. The output / input ratio of the feedback unit 170 can be determined by adjusting the resistance value of the third resistor R3 and the resistance value of the fourth resistor R4, that is, the preset voltage ratio mentioned above can be determined.

[0050] When the voltage value of the feedback signal is less than 1.2V, the feedback signal is sent to the control unit 10 (i.e., the BOB driving module). The BOB driving module increases / decreases the duty cycle of the PWM signal through software, thereby adjusting the voltage of the energy storage unit 110 at the first node N1, thereby achieving the effect of adjusting the voltage of the output voltage terminal Vout.

[0051] like Figure 3 As shown, in this exemplary embodiment, when the voltage value of the second node N2 is higher than the set value, a feedback signal exceeding the threshold value is outputted through the voltage division effect of the third resistor R3 and the fourth resistor R4. At this time, the control unit 10 increases the duty cycle of the high-level signal in the output PWM signal (i.e., the duty cycle of the adjustment signal) based on the feedback signal, so that the conduction time of the first switch unit 120 is increased. When the first switch unit 120 is turned on, the potential of the first node N1 is pulled down, and the energy storage unit 110 is charged. In this way, when the duty cycle of the high level in the PWM signal increases, the charging time of the energy storage unit 110 is increased, so that the energy storage unit 110 is charged. 0 reduces the charging time of the subsequent charging unit 130, thereby reducing the voltage value of the output voltage terminal Vout; conversely, when the voltage value of the second node N2 is lower than the set value, the third resistor R3 and the fourth resistor R4 output a feedback signal less than the threshold value. At this time, the control unit 10 reduces the duty cycle of the high-level signal in the output PWM signal based on the feedback signal, so that the conduction time of the first switch unit 120 is reduced, and the charging time of the energy storage unit 110 is increased, so that the time for the energy storage unit 110 to discharge the subsequent charging unit 130 is increased, thereby raising the voltage value of the output voltage terminal Vout.

[0052] Continue to refer Figure 3 In an exemplary embodiment, the boost circuit may further include a sixth resistor R6, one end of which is connected to the control end of the first switch unit 120, and the other end is grounded; wherein the sixth resistor R6 can provide a residual power discharge path for the control signal CTR pin of the control module.

[0053] like Figure 2As shown, in an embodiment of the present application, the boost circuit may further include a current limiting unit 180 and a second filtering unit 190, one end of the current limiting unit 180 is connected to the second node N2; one end of the second filtering unit 190 is connected to the other end of the current limiting unit 180, and the other end of the second filtering unit 190 is connected to the output voltage terminal Vout, and the second filtering unit 190 can be used to filter the voltage signal of the second node N2 and provide a ripple-filtered boost signal to the output voltage terminal Vout.

[0054] Specifically, the first end of the current limiting unit 180 is connected to the second node N2, and the second end is connected to the output voltage terminal Vout through the second filtering unit 190. The current limiting unit 180 can prevent the load current from being too large, and the voltage drop of the current limiting unit 180 is very small, and its influence on the output voltage can be ignored.

[0055] For further reference, Figure 3 In an exemplary embodiment, the current limiting unit 180 may include a current limiting resistor R7; the second filtering unit 190 may be a magnetic bead GL1. Specifically, the voltage drop of the current limiting resistor R7 is very small and can be ignored. The magnetic bead GL1 is a ferrite bead, which is an inductive EMI noise suppression filter, mainly used to suppress high-frequency noise and spike interference. The magnetic bead is usually made of ferrite material with high resistivity and magnetic permeability, which makes the magnetic bead GL1 present a higher impedance at high frequency, thereby effectively converting the high-frequency current into heat and dissipating it.

[0056] In summary, the embodiment of the present application uses conventional separated electronic devices to build a boost circuit to achieve the boost function, avoiding the use of power chips. Not only are there fewer devices and a simple circuit structure, but also because they are all commonly used components, when a circuit fails, it is easy to repair and easy to find replacement devices. It has the advantage of strong substitutability and is no longer subject to chip model constraints, and has better practicality. In addition, the boost circuit provided in the embodiment of the present application also has a feedback function, which can adjust the output voltage and can meet the boost requirements of different models and products. Further, the boost circuit provided in the embodiment of the present application has an overvoltage protection function. When the output voltage is too high, it will immediately reduce the output to about 1V, and it can return to normal after the fault is resolved, thereby achieving load protection.

[0057] Based on the above embodiments, the present application further provides a modem, which may include the boost circuit described in any of the above embodiments, and accordingly, also has the beneficial effects described in any of the above embodiments.

[0058] Figure 4 FIG. 1 is a schematic block diagram of an internal circuit of a modem according to an embodiment of the present application. Figure 4As shown, in this exemplary embodiment, the modem 200 may include a WiFi module 201, a voice module 202, a BOB driver module 203, a BOSA module 204, and a CPU module 205. The WiFi module 201 is used to provide 2.4G and 5G wireless signal connections for other devices, the voice module 202 is used to connect voice devices via wired / wireless, and the BOB driver module 203 and the BOSA module 204 are used to connect OLT devices via optical fibers. Among them, the BOSA module 204 is the data flow upstream and downstream ports of the entire product, and the CPU module 205 is used for data conversion and is the core of the entire product.

[0059] Furthermore, the WiFi module 201 is bidirectionally connected to the CPU module 205 through the PCE-E channel. The WiFi module 201 of the modem 200 can be configured and managed through a web interface or a dedicated APP, and the operation is simple and convenient. The voice module 202 is bidirectionally connected to the CPU module 205. The voice module 202 enables the modem 200 to provide not only high-speed data services, but also traditional telephone services to meet the diverse communication needs of users. With the development of technology, the voice modules of some modems may also support more advanced communication services, such as HD Voice. The BOSA module 204 is bidirectionally connected to the CPU module 205 using SerDes technology. SerDes (Serializer / Deserializer) is a high-speed serial data transmission technology that converts parallel data into serial data at the transmitting end and restores serial data to parallel data at the receiving end. This technology is widely used in point-to-point transmission scenarios between chips, boards or chassis. SerDes technology can reduce the number of lines and reduce the length of lines, thereby providing high-speed and reliable data transmission. The BOSA module 204 is also bidirectionally connected to the BOB driver module 203. BOB (BOSA on Board) is a technical solution integrated on an optical module, which is used to realize the photoelectric signal conversion in a single-fiber bidirectional optical communication system. The BOB driver module 203 is responsible for driving the BOSA module 204. BOSA is a Bi-Directional Optical Sub-Assembly, which is an integrated optical transmitting and receiving component and can be applied to a single-fiber bidirectional optical module. The integration of the BOSA module 204 helps to reduce the size of the terminal and facilitate home installation. It is one of the important signs of the rapid development of FTTH terminals. The BOSA module 204 is also communicatively connected to the boost circuit in any of the above embodiments. The BOB driver module 203 sends a PWM wave to the boost circuit according to the instruction of the CPU module 205, controls the boost circuit to output a boost voltage, and provides a reverse boost voltage to the avalanche photodiode of the BOSA module 204, so that it is in an avalanche multiplication state, thereby increasing the sensitivity of the photoelectric conversion. As described in the background technology section, the boost chip used in modem products is relatively special. Not only are there fewer available boost chips but they are also relatively expensive, the embodiments of the present application perfectly replace the function of this special boost chip by using the boost circuit built by separate electronic devices provided by the above embodiments, thereby solving the problems of few boost chip suppliers and high costs faced by current modem products, thereby improving the maintainability of modem products, reducing the cost of using modem products, and further enhancing the market competitiveness of modem products.

[0060] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A boost circuit, characterized in that: The boost circuit is connected to a control unit, and the control unit has a signal adjustment pin; the boost circuit includes: An energy storage unit connected to the voltage input terminal and the first node; A first switch unit, a first end of which is connected to the first node, a second end of which is connected to a ground end, and a control end of which receives a control signal; a charging unit, connected to the first node and the output voltage terminal; Wherein, the control unit is used to output the control signal through the signal adjustment pin; The first switch unit is used for connecting the first node to the ground terminal or disconnecting the first node from the ground terminal in response to the control signal; The energy storage unit is used to charge the first node when a path is formed between the first node and the ground terminal, or to discharge the first node when a circuit is broken between the first node and the ground terminal; The charging unit is used for performing voltage bootstrapping using the discharge signal of the first node to provide a boosted voltage signal to the output voltage terminal.

2. The boost circuit according to claim 1, characterized in that: The boost circuit further includes: an anti-reverse unit, connected in series between the first node and the charging unit, wherein a connection end of the anti-reverse unit and the charging unit forms a second node, and the anti-reverse unit is used to transmit a voltage signal of the first node to the second node; The first filtering unit is connected in series between the first node and the voltage input terminal, and is used for filtering the voltage signal of the voltage input terminal and providing the energy storage unit with a voltage signal after ripple filtering.

3. The boost circuit according to claim 2, characterized in that: The control unit also has a feedback signal pin; The control unit is further configured to receive a feedback signal through the feedback signal pin, and adjust the control signal based on the feedback signal, wherein a preset voltage ratio exists between the feedback signal and the voltage signal outputted by the output voltage terminal; The first switch unit is further used for adjusting the on-off duration between the first node and the ground terminal in response to the control signal; The charging unit is further configured to adjust the magnitude of the boost voltage signal output to the output voltage terminal in response to the charging duration of the first node.

4. The boost circuit according to claim 2, characterized in that: The boost circuit further includes: A protection unit, one end of which is connected to the second node, the other end of which is connected to the ground end, and a control end of which is connected to the signal feedback end. The protection unit is used to respond to the feedback signal of the signal feedback end to connect the second node and the ground end to release the overvoltage of the boost signal of the second node.

5. The boost circuit according to claim 2, characterized in that: The boost circuit further includes: A feedback unit has a signal feedback end, one end of the feedback unit is connected to the second node, and the other end is grounded, and the feedback unit is used to extract the voltage signal of the second node and output a feedback signal through the signal feedback end.

6. The boost circuit according to claim 4, characterized in that: The protection unit includes a second resistor, a second switch unit, a first diode and a fifth resistor; One end of the second resistor is connected to the second node, and the other end is connected to the first end of the second switch unit, the other end of the second switch unit is connected to the anode of the first diode, and the control end of the second switch unit is connected to one end of the fifth resistor as the control end of the protection unit; The cathode of the first diode is connected to the ground terminal, and the other end of the fifth resistor is connected to the signal feedback terminal; The second switch unit conducts the second node and the ground terminal in response to the voltage signal at the signal feedback terminal.

7. The boost circuit according to claim 6, characterized in that: The boost circuit further includes: a sixth resistor, one end of which is connected to the control end of the first switch unit, and the other end of which is grounded; Wherein, the energy storage unit is an inductor, and the first switch unit and the second switch unit are both N-type transistors.

8. The voltage boost circuit according to claim 5, characterized in that: The feedback unit includes a third resistor and a fourth resistor; One end of the third resistor is connected to the second node, and the other end is connected to one end of the fourth resistor to form a signal feedback end of the feedback unit. The other end of the fourth resistor is grounded.

9. The boost circuit according to claim 2, characterized in that: The boost circuit further includes: a current limiting unit, one end of which is connected to the second node; A second filtering unit has one end connected to the other end of the current limiting unit and the other end connected to the output voltage end. The second filtering unit is used to filter the voltage signal of the second node and then provide a ripple-filtered boost signal to the output voltage end.

10. A modem, characterized in that: include: The boost circuit according to any one of claims 1 to 9.

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