A high voltage generation circuit and DTOF ranging system

Abstract

The present invention discloses a high-voltage generation circuit and a DTOF ranging system, comprising a reference voltage generation module, a comparator, a charge pump circuit, a current sensing module, and a voltage-dividing resistor string. The current sensing module is used to generate an adaptive current based on the output current flowing through the voltage-dividing resistor string, and output the adaptive current to the charge pump circuit to adjust the load capacity of the charge pump circuit, wherein the magnitude of the adaptive current is negatively correlated with the magnitude of the output current, and the magnitude of the adaptive current is positively correlated with the magnitude of the load capacity of the charge pump circuit. Since the magnitude of the adaptive current can change with the magnitude of the load, the load capacity of the charge pump circuit can also be adaptively adjusted with the magnitude of the load, thereby being suitable for a variety of different application scenarios.

Description

Technical Field

[0001] The present invention relates to the field of circuit design, and in particular to a high-voltage generating circuit and a DTOF ranging system. Background Art

[0002] Currently, in DTOF (Direct Time Of Flight) ranging systems, the power supply for the SPAD array (Single Photon Avalanche Diode) includes a charge pump circuit that can generate a relatively high voltage (approximately 25V to 30V). In order to achieve the high voltage output of the charge pump circuit, the driving capability of the charge pump circuit is usually made very strong, but this also makes the power consumption loss of the charge pump circuit high. Especially when the SPAD array is not started or is in the waiting stage, which does not require the high voltage output for the SPAD array, that is, when the load capacity is weak, the power consumption loss caused by the excess driving capability of the charge pump circuit is particularly obvious. In addition, the driving capability of the charge pump circuit in the prior art is usually fixed, resulting in poor reusability of the charge pump circuit and its inability to be applied to a variety of application scenarios. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-voltage generation circuit and a DTOF ranging system, which can adjust the load capacity of the charge pump circuit according to the size of the load, thereby reducing losses when the load capacity is weak, and can be applicable to a variety of different application scenarios to improve reusability.

[0004] To solve the above technical problems, the present invention provides a high voltage generating circuit, comprising a reference voltage generating module, a comparator, a charge pump circuit, a current sensing module, and a voltage dividing resistor string comprising a plurality of voltage dividing resistors connected in series;

[0005] The reference voltage generating module is used to generate a reference voltage (VREF);

[0006] The comparator has a positive input terminal for inputting the reference voltage (VREF), a negative input terminal for inputting the feedback voltage (VFDBK), and an output terminal connected to the input terminal of the charge pump circuit, wherein the feedback voltage (VFDBK) is the voltage at the feedback voltage terminal of the voltage-dividing resistor string;

[0007] The charge pump circuit is configured to generate a high voltage output voltage (HVOUT) based on the output of the comparator, wherein the output terminal of the charge pump circuit is connected to a first terminal of the voltage-dividing resistor string and a first terminal of a load, and a second terminal of the load is grounded;

[0008] The feedback voltage terminal of the voltage-dividing resistor string is located between the first terminal of the voltage-dividing resistor string and the second terminal of the voltage-dividing resistor string, and the second terminal of the voltage-dividing resistor string is connected to the input terminal of the current sensing module;

[0009] The current sensing module is used to generate an adaptive current (IADAPT) based on the output current (I0) flowing through the voltage-dividing resistor string, and output the adaptive current (IADAPT) to the charge pump circuit to adjust the load capacity of the charge pump circuit, wherein the magnitude of the adaptive current (IADAPT) is negatively correlated with the magnitude of the output current (I0), and the magnitude of the adaptive current (IADAPT) is positively correlated with the magnitude of the load capacity of the charge pump circuit.

[0010] Preferably, the current sensing module includes a first current mirror unit, a second current mirror unit, a third current mirror unit and a current source;

[0011] The first current mirror unit is used to mirror the output current (I0) to obtain a first mirror current (I3);

[0012] The current source is used to generate a constant bias current (Ibias);

[0013] The second current mirror unit is used to mirror a difference current (I4) to obtain a second mirror current (I5), wherein the difference current (I4) is a current obtained by subtracting the first mirror current (I3) from the bias current (Ibias);

[0014] The third current mirror unit is used to mirror the second mirror current (I5) to obtain the adaptive current (IADAPT).

[0015] Preferably, the first current mirror unit includes a first NMOS (N1) and a second NMOS (N2), the second current mirror unit includes a third NMOS (N3) and a fourth NMOS (N4), the current source includes a first PMOS (P1), and the third current mirror unit includes a second PMOS (P2) and a third PMOS (P3);

[0016] The gate of the first PMOS (P1) is used to input a bias voltage, and the source is connected to a power supply;

[0017] The drain of the first NMOS (N1) is connected to the gate of the first NMOS (N1), the gate of the second NMOS (N2) and the second end of the voltage-dividing resistor string, the source of the first NMOS (N1) and the source of the second NMOS (N2) are both grounded, and the drain of the second NMOS (N2) is connected to the drain of the first PMOS (P1);

[0018] The drain of the third NMOS (N3) is connected to the drain of the first PMOS (P1) and the gate of the third NMOS (N3), the gate of the third NMOS (N3) is connected to the gate of the fourth NMOS (N4), and the source of the third NMOS (N3) and the source of the fourth NMOS (N4) are both grounded;

[0019] The drain of the second PMOS (P2) is connected to the drain of the fourth NMOS (N4) and the gate of the second PMOS (P2), the gate of the second PMOS (P2) is connected to the gate of the third PMOS (P3), the source of the second PMOS (P2) and the source of the third PMOS (P3) are both connected to a power supply, and the drain of the third PMOS (P3) is used to output the adaptive current (IADAPT).

[0020] Preferably, the current sensing module further includes a plurality of current mirror branches;

[0021] Each of the current mirror branches is used to mirror the second mirror current (I5) in a preset ratio to generate a third mirror current, and the adaptive current (IADAPT) is the sum of the second mirror current (I5) and each of the third mirror currents.

[0022] Preferably, each of the current mirror branches includes a mirror transistor PMOS (Pz1) and a switch transistor PMOS (Pz2);

[0023] The gate of the switch tube PMOS (Pz2) is connected to the output end of the external register, the source of the switch tube PMOS (Pz2) is connected to the power supply, and the external register is used to control the on and off of the switch tube PMOS (Pz2);

[0024] The source of the mirror tube PMOS (Pz1) is connected to the drain of the switch tube PMOS (Pz2), the gate of the mirror tube PMOS (Pz1) is connected to the gate of the second PMOS (P2), and the drain of the mirror tube PMOS (Pz1) is used to output the third mirror current.

[0025] Preferably, the third current mirror unit further includes a fourth PMOS (P4) and a fifth PMOS (P5);

[0026] The sources of the fourth PMOS (P4) and the fifth PMOS (P5) are both connected to a power supply, the gate of the fourth PMOS (P4) is connected to the gate of the fifth PMOS (P5), the drain of the fourth PMOS (P4) is connected to the source of the second PMOS (P2), and the drain of the fifth PMOS (P5) is connected to the source of the third PMOS (P3);

[0027] The fourth PMOS (P4), the fifth PMOS (P5), and each of the switch tubes PMOS (Pz2) have the same size.

[0028] Preferably, the charge pump circuit includes:

[0029] An oscillator circuit for generating an initial clock signal (CLKIN);

[0030] a driving circuit, configured to generate a clock signal (CLKBUF) with driving capability according to the initial clock signal (CLKIN), and adjust the driving capability of the clock signal according to the adaptive current (IADAPT);

[0031] The charge pump core unit is used to generate the high voltage output voltage (HVOUT) according to the clock signal with driving capability to adjust the load capacity of the charge pump circuit, and the load capacity of the charge pump circuit is positively correlated with the driving capability of the clock signal.

[0032] Preferably, the charge pump circuit includes:

[0033] an oscillation circuit, configured to generate an initial clock signal (CLKIN) according to the adaptive current (IADAPT), wherein a frequency of the initial clock signal (CLKIN) is positively correlated with a magnitude of the adaptive current (IADAPT);

[0034] A driving circuit, configured to generate a clock signal (CLKBUF) with driving capability according to the initial clock signal (CLKIN);

[0035] The charge pump core unit is used to generate the high voltage output voltage (HVOUT) according to the clock signal with driving capability to adjust the load capacity of the charge pump circuit, and the load capacity of the charge pump circuit is positively correlated with the frequency of the clock signal.

[0036] Preferably, the charge pump circuit includes:

[0037] an oscillation circuit, configured to generate an initial clock signal (CLKIN) according to the adaptive current (IADAPT), wherein a frequency of the initial clock signal (CLKIN) is positively correlated with a magnitude of the adaptive current (IADAPT);

[0038] a driving circuit, configured to generate a clock signal (CLKBUF) with driving capability according to the initial clock signal (CLKIN), and adjust the driving capability of the clock signal according to the adaptive current (IADAPT);

[0039] The charge pump core unit is used to generate the high voltage output voltage (HVOUT) according to the clock signal with driving capability to adjust the load capacity of the charge pump circuit. The load capacity of the charge pump circuit is positively correlated with the driving capability and frequency of the clock signal.

[0040] The present application also provides a DTOF ranging system, comprising the above-mentioned high-voltage generating circuit, and also comprising a SPAD array connected to the output end of the high-voltage generating circuit.

[0041] In summary, the present invention discloses a high-voltage generating circuit and a DTOF ranging system, comprising a reference voltage generating module, a comparator, a charge pump circuit, a current sensing module and a voltage-dividing resistor string, wherein the reference voltage generating module and the comparator maintain the voltage division of the high-voltage output voltage generated by the charge pump circuit as a reference voltage. In the default initial state, the charge pump circuit operates in a low-load capacity and low-power state. When the load connected to the output end of the charge pump circuit becomes larger and exceeds its load capacity, in a transient state, the output voltage of the charge pump circuit will temporarily drop, causing the output current flowing through the voltage-dividing resistor string to decrease, and the current sensing module increases the adaptive current generated based on the output current. After the current sensing module outputs the adaptive current to the charge pump circuit, the temporarily decreased output voltage will be pulled back to the original set value, so that the load capacity of the charge pump circuit is enhanced. It can be seen that the size of the adaptive current is positively correlated with the load capacity of the charge pump circuit. Since the size of the adaptive current can change with the size of the load, the load capacity of the charge pump circuit can also be adaptively adjusted with the size of the load, thereby being suitable for a variety of different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the prior art and the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 A schematic structural diagram of a high voltage generating circuit provided in this application;

[0044] Figure 2 A circuit diagram of a current sensing module in a high voltage generating circuit provided by the present application;

[0045] Figure 3 Another circuit diagram of a current sensing module in a high voltage generating circuit provided by the present application;

[0046] Figure 4 This is a schematic structural diagram of a first charge pump circuit in a high voltage generating circuit provided by the present application;

[0047] Figure 5 This is a schematic structural diagram of a second charge pump circuit in a high voltage generating circuit provided by the present application;

[0048] Figure 6 This is a schematic structural diagram of a third charge pump circuit in a high voltage generating circuit provided in this application. DETAILED DESCRIPTION

[0049] The core of the present invention is to provide a high-voltage generation circuit and a DTOF ranging system, which can adjust the driving capability of the charge pump circuit according to the size of the load, thereby reducing losses when the load capacity is weak, and can be applied to a variety of different application scenarios to improve reusability.

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0051] Please refer to Figure 1 , Figure 1 This is a schematic structural diagram of a high-voltage generating circuit provided by the present application, which includes a reference voltage generating module 1, a comparator 2, a charge pump circuit 3, a current sensing module 4, and a voltage-dividing resistor string 5 including a plurality of voltage-dividing resistors connected in series.

[0052] The reference voltage generating module 1 is used to generate a reference voltage VREF;

[0053] The comparator 2 has a positive input terminal for inputting a reference voltage VREF, a negative input terminal for inputting a feedback voltage VFDBK, and an output terminal connected to an input terminal of a charge pump circuit 3, wherein the feedback voltage VFDBK is the voltage at the feedback voltage terminal of the voltage divider resistor string 5;

[0054] The charge pump circuit 3 is used to generate a high-voltage output voltage HVOUT based on the output of the comparator 2. The output end of the charge pump circuit 3 is connected to the first end of the voltage-dividing resistor string 5 and the first end of the load, and the second end of the load is grounded.

[0055] The feedback voltage terminal of the voltage-dividing resistor string 5 is located between the first terminal of the voltage-dividing resistor string 5 and the second terminal of the voltage-dividing resistor string 5 , and the second terminal of the voltage-dividing resistor string 5 is connected to the input terminal of the current sensing module 4 ;

[0056] The current sensing module 4 is used to generate an adaptive current IADAPT based on the output current I0 flowing through the voltage-dividing resistor string 5, and output the adaptive current IADAPT to the charge pump circuit 3 to adjust the high-voltage output voltage HVOUT, wherein the magnitude of the adaptive current IADAPT is negatively correlated with the magnitude of the output current I0, and the magnitude of the adaptive current IADAPT is positively correlated with the magnitude of the high-voltage output voltage HVOUT.

[0057] The high-voltage generation circuits that currently power the SPAD arrays in DTOF ranging systems typically have strong drive capabilities. However, this approach increases power consumption, especially when the SPAD array is in a standby or inactive state, where the load capacity is low. The power loss from excess drive capability is particularly noticeable. Furthermore, the drive capability of existing high-voltage generation circuits cannot be adjusted, resulting in poor reusability.

[0058] To solve the above technical problems, the present application provides a high-voltage generation circuit, including a reference voltage generation module 1, a comparator 2, a charge pump circuit 3, a current sensing module 4, and a voltage-dividing resistor string 5. The reference voltage generation module 1 is used to generate a reference voltage VREF. The present application does not specifically limit the specific structure of the reference voltage generation module 1 and the specific value of the reference voltage VREF, which can be set according to actual conditions. The reference voltage VREF generated by the reference voltage generation module 1 is input to the positive input terminal of the comparator 2, and the negative input terminal of the comparator 2 inputs the feedback voltage VFDBK, that is, the voltage on the feedback voltage terminal of the voltage-dividing resistor string 5. The output terminal of the comparator 2 is connected to the input terminal of the charge pump circuit 3 so that the charge pump circuit 3 generates a high-voltage output voltage HVOUT based on the output of the comparator 2. It can be seen that the reference voltage generation module 1, the comparator 2 and the charge pump circuit form a feedback loop. The voltage at the feedback voltage terminal of the voltage-dividing resistor string 5 can be clamped to the reference voltage VREF through the reference voltage generation module 1 and the comparator 2, thereby indirectly clamping the high-voltage output voltage HVOUT output by the charge pump circuit 3.

[0059] The first end of the voltage-dividing resistor string 5 and the first end of the load are both connected to the output end of the charge pump circuit 3. Therefore, the output current I0 flowing through the voltage-dividing resistor string 5 will change as the load changes, thereby causing the adaptive current IADAPT generated by the current sensing module 4 based on the output current I0 of the voltage-dividing resistor string 5 to also change. The current sensing module 4 also outputs the adaptive current IADAPT to the charge pump circuit 3 to adjust the voltage value of the high-voltage output voltage HVOUT generated by the charge pump circuit 3. Furthermore, because the magnitude of the adaptive current IADAPT generated by the current sensing module 4 is negatively correlated with the magnitude of the output current I0, the load capacity of the high-voltage output voltage HVOUT is positively correlated with the magnitude of the adaptive current IADAPT. Therefore, when the load decreases, the output current I0 will increase, the adaptive current IADAPT will decrease, and the load capacity of the high-voltage output voltage HVOUT will also decrease, thereby reducing losses; when the load increases, the output current I0 will decrease, the adaptive current IADAPT will increase, and the load capacity of the high-voltage output voltage HVOUT will also increase. It can be seen that when the load size is different, the load capacity of the high-voltage output voltage HVOUT provided in this application is different, and it can be applied to various application scenarios and has strong reusability.

[0060] It should also be noted that the present application does not impose any particular limitation on the specific resistance values of the various voltage-dividing resistors included in the voltage-dividing resistor string 5 , and the resistance values can be selected according to actual conditions.

[0061] In summary, the present invention discloses a high-voltage generating circuit and a DTOF ranging system, comprising a reference voltage generating module, a comparator, a charge pump circuit, a current sensing module and a voltage-dividing resistor string, wherein the reference voltage generating module and the comparator maintain the voltage division of the high-voltage output voltage generated by the charge pump circuit as a reference voltage. In the default initial state, the charge pump circuit operates in a low-load capacity and low-power state. When the load connected to the output end of the charge pump circuit becomes larger and exceeds its load capacity, in a transient state, the output voltage of the charge pump circuit will temporarily drop, causing the output current flowing through the voltage-dividing resistor string to decrease, and the current sensing module increases the adaptive current generated based on the output current. After the current sensing module outputs the adaptive current to the charge pump circuit, the temporarily decreased output voltage will be pulled back to the original set value, so that the load capacity of the charge pump circuit is enhanced. It can be seen that the size of the adaptive current is positively correlated with the load capacity of the charge pump circuit. Since the size of the adaptive current can change with the size of the load, the load capacity of the charge pump circuit can also be adaptively adjusted with the size of the load, thereby being suitable for a variety of different application scenarios.

[0062] Based on the above embodiment:

[0063] As a preferred embodiment, the current sensing module 4 includes a first current mirror unit, a second current mirror unit, a third current mirror unit and a current source;

[0064] The first current mirror unit is used for mirroring the output current I0 to obtain a first mirror current I3;

[0065] The current source is used to generate a constant bias current Ibias;

[0066] The second current mirror unit is used for mirroring the difference current I4 to obtain a second mirror current I5, wherein the difference current I4 is a current obtained by subtracting the first mirror current I3 from the bias current Ibias;

[0067] The third current mirror unit is used for mirroring the second mirror current I5 to obtain the adaptive current IADAPT.

[0068] In this embodiment, a specific implementation structure of the current sensing module 4 is provided. The current sensing module 4 uses multiple sets of current mirrors to achieve the purpose of generating an adaptive current IADAPT based on the output current I0 of the voltage-dividing resistor string 5. When generating the adaptive current IADAPT through the current mirror, it is necessary to ensure that the magnitude of the adaptive current IADAPT is negatively correlated with the magnitude of the output current I0.

[0069] Please refer to Figure 2 , Figure 2 This is a circuit diagram of a current sensing module in a high-voltage generation circuit provided by the present application. Specifically, the current sensing module 4 includes a first current mirror unit, a second current mirror unit, a third current mirror unit, and a current source. The first current mirror unit is used to mirror the output current I0 to obtain a first mirror current I3. The magnitude of the first mirror current I3 is positively correlated with the magnitude of the output current I0. The present application does not specifically limit the ratio between the output current I0 and the first mirror current I3, which can be achieved by adjusting the size ratio of the current mirrors in the first current mirror unit. The second current mirror unit mirrors the difference current I4 obtained by subtracting the first mirror current I3 from the bias current Ibias generated by the current source to obtain a second mirror current I4. Since the magnitude of the difference current I4 is negatively correlated with the first mirror current I3 and the magnitude of the second mirror current I5 is positively correlated with the magnitude of the difference current I4, the second mirror current is negatively correlated with the output current I0. Similarly, the present application does not specifically limit the ratio between the difference current I4 and the second mirror current I4. Finally, the second mirror current I5 is mirrored by the third current mirror to obtain an adaptive current IADAPT that is convenient for output. The present application does not impose any particular limitation on the ratio between the second mirror current I5 and the adaptive current IADAPT.

[0070] If the ratios between the output current I0 and the first mirror current I3 , the difference current I4 and the second mirror current I5 , and the second mirror current I5 and the adaptive current IADAPT are all 1, then IADAPT=Ibias−I0 .

[0071] In summary, in this embodiment, the current sensing module 4 generates an adaptive current IADAPT based on the output current I0 flowing through the voltage-dividing resistor string 5 through the first current mirror unit, the second current mirror unit, the third current mirror unit, and the current source, and meets the requirement that the magnitude of the adaptive current IADAPT is negatively correlated with the magnitude of the output current I0. The overall structure is simple and easy to implement.

[0072] As a preferred embodiment, the first current mirror unit includes a first NMOS N1 and a second NMOS N2, the second current mirror unit includes a third NMOS N3 and a fourth NMOS N4, the current source includes a first PMOS P1, and the third current mirror unit includes a second PMOS P2 and a third PMOS P3;

[0073] The gate of the first PMOS P1 is used to input the bias voltage Vbp, and the source is connected to the power supply;

[0074] The drain of the first NMOS N1 is connected to the gate of the first NMOS N1, the gate of the second NMOS N2 and the second end of the voltage divider resistor string 5, the source of the first NMOS N1 and the source of the second NMOS N2 are both grounded, and the drain of the second NMOS N2 is connected to the drain of the first PMOS P1;

[0075] The drain of the third NMOS N3 is connected to the drain of the first PMOS P1 and the gate of the third NMOS N3, the gate of the third NMOS N3 is connected to the gate of the fourth NMOS N4, and the source of the third NMOS N3 and the source of the fourth NMOS N4 are both grounded;

[0076] The drain of the second PMOS P2 is connected to the drain of the fourth NMOS N4 and the gate of the second PMOS P2, the gate of the second PMOS P2 is connected to the gate of the third PMOS P3, the source of the second PMOS P2 and the source of the third PMOS P3 are both connected to the power supply, and the drain of the third PMOS P3 is used to output the adaptive current IADAPT.

[0077] Please refer to Figure 2 , Figure 2This is a circuit diagram of a current sensing module 4 in a high-voltage generation circuit provided by the present application. In this embodiment, the specific circuit structures of a first current mirror unit, a second current mirror unit, a third current mirror unit, and a current source are provided. The gate of the first NMOS N1 in the first current mirror unit is connected to the second end of the voltage-divider resistor string 5. Due to the presence of the first NMOS N1, the first current mirror unit can copy the output current I0 on the voltage-divider resistor string 5 to the second NMOS N2 in any proportion. The current output from the drain of the first PMOS P1 in the current source is the sum of the current flowing into the drain of the third NMOS N3 and the current flowing into the drain of the fourth NMOS N4 in the second current mirror unit. Therefore, the current on the drain of the fourth NMOS N4 in the second current mirror unit is negatively correlated with the output current I0 on the voltage-divider resistor string 5. The current output by the drain of the second PMOS P2 in the third current mirror unit is consistent with the current on the drain of the fourth NMOS N4. The second PMOS P2 and the third PMOS P3 form a current mirror. Therefore, the current output by the drain of the third PMOS P3 is also negatively correlated with the output current I0. This enables the current sensing module 4 to generate the adaptive current IADAPT based on the output current I0 flowing through the voltage-dividing resistor string 5, and meets the requirement that the magnitude of the adaptive current IADAPT is negatively correlated with the magnitude of the output current I0.

[0078] It should also be noted that the present application does not impose any particular limitation on the ratio of the current mirror groups included in the first current mirror unit, the second current mirror unit, and the third current mirror unit.

[0079] As a preferred embodiment, the current sensing module 4 further includes a plurality of current mirror branches;

[0080] Each current mirror branch is used to mirror the second mirror current I5 in a preset ratio to generate a third mirror current. The adaptive current IADAPT is the sum of the second mirror current I5 and each third mirror current.

[0081] Please refer to Figure 3 , Figure 3 This is another circuit diagram of the current sensing module 4 in the high-voltage generation circuit provided by the present application. Because the high-voltage output voltage HVOUT generated by the high-voltage generation circuit provided by the present application has load-adaptive capabilities and can meet different load capacity requirements, in this embodiment, multiple current mirror branches are added to the current sensing module 4 to enhance the adaptive capability. Each current mirror branch can output a third mirror current, thereby increasing the range of variation of the adaptive current IADAPT and raising the upper and lower limits of the load capacity applicable to the high-voltage generation circuit.

[0082] As a preferred embodiment, each current mirror branch includes a mirror transistor PMOS Pz1 and a switch transistor PMOS Pz2;

[0083] The gate of the switch tube PMOS Pz2 is connected to the output end of the external register, the source of the switch tube PMOS Pz2 is connected to the power supply, and the external register is used to control the on and off of the switch tube PMOS Pz2;

[0084] The source of the mirror transistor PMOS Pz1 is connected to the drain of the switch transistor PMOS Pz2 , the gate of the mirror transistor PMOS Pz1 is connected to the gate of the second PMOS P2 , and the drain of the mirror transistor PMOS Pz1 is used to output a third mirror current.

[0085] Please refer to Figure 3 , Figure 3 Another circuit diagram of a current sensing module in a high-voltage generation circuit provided by the present application. In this embodiment, the current mirror branch specifically includes a mirror transistor PMOS Pz1 that forms a current mirror with a second PMOS P2, and a switch transistor PMOS Pz2 for controlling the on / off of the mirror transistor PMOS Pz1. The source of the mirror transistor PMOS Pz1 is connected to the drain of the switch transistor PMOS Pz2, the gate of the mirror transistor PMOS Pz1 is connected to the gate of the second PMOS P2, and the drain of the mirror transistor PMOS Pz1 is used to output a third mirror current. That is, the mirror transistor PMOS Pz1 and the second PMOS P2 form a current mirror to achieve the purpose of mirroring the second mirror current I5 according to a preset ratio to generate a third mirror current. The present application does not specifically limit the size ratio between the second PMOS P2 and the mirror transistor PMOS Pz1.

[0086] The gate of the switch tube PMOS Pz2 is connected to the output end of the external register. The external register controls the on and off of the switch tube PMOS Pz2 by changing the voltage of the gate of the switch tube PMOS Pz2. When more switch tubes PMOS Pz2 are turned on, the high-voltage output circuit has a stronger load-carrying capacity.

[0087] As a preferred embodiment, the third current mirror unit further includes a fourth PMOS P4 and a fifth PMOS P5;

[0088] The sources of the fourth PMOS P4 and the fifth PMOS P5 are both connected to the power supply, the gate of the fourth PMOS P4 is connected to the gate of the fifth PMOS P5, the drain of the fourth PMOS P4 is connected to the source of the second PMOS P2, and the drain of the fifth PMOS P5 is connected to the source of the third PMOS P3;

[0089] The fourth PMOS P4, the fifth PMOS P5, and the sizes of the switch transistors PMOS Pz2 are the same.

[0090] Please refer to Figure 3 , Figure 3 Another circuit diagram of a current sensing module in a high-voltage generation circuit provided in the present application. In this embodiment, to further improve the stability of the adaptive current IADAPT output, a fourth PMOS P4 and a fifth PMOS P5 are additionally provided in the third current mirror unit. The fourth PMOS P4 and the fifth PMOS P5 also form a set of current mirrors, which can improve the matching and stability of the circuit. In addition, in this embodiment, the fourth PMOS P4, the fifth PMOS P5, the mirror transistors PMOS Pz1, and the switch transistors PMOS Pz2 are all of the same size, so that each mirror transistor PMOS Pz1 can better mirror the second mirror current I5 on the second PMOS P2, further improving the matching and stability of the circuit.

[0091] As a preferred embodiment, the charge pump circuit 3 includes:

[0092] An oscillator circuit, used for generating an initial clock signal CLKIN;

[0093] A driving circuit, configured to generate a clock signal CLKBUF with driving capability according to an initial clock signal CLKIN, and to adjust the driving capability of the clock signal CLKBUF according to an adaptive current IADAPT;

[0094] The charge pump core unit is used to generate a high-voltage output voltage HVOUT according to a clock signal CLKBUF with driving capability to adjust the load capacity of the charge pump circuit. The load capacity of the charge pump circuit is positively correlated with the driving capability of the clock signal CLKBUF.

[0095] Please refer to Figure 4 , Figure 4This is a schematic diagram of the structure of a first charge pump circuit 3 in a high-voltage generation circuit provided by the present application. In this embodiment, the charge pump circuit 3 includes an oscillator circuit, a driver circuit, and a charge pump core unit. The oscillator circuit generates an initial clock signal CLKIN required for the operation of the charge pump core unit; the driver circuit generates a clock signal CLKBUF with drive capability based on the initial clock signal CLKIN, and uses the clock signal CLKBUF to drive the charge pump core unit. When the drive capability of the clock signal CLKBUF with drive capability varies, the load capacity of the charge pump circuit varies. Furthermore, in this embodiment, the adaptive current IADAPT output by the current sensing module 4 is superimposed on the driver circuit. Therefore, the magnitude of the adaptive current IADAPT is positively correlated with the drive capability of the clock signal CLKBUF. Therefore, the drive capability of the clock signal CLKBUF is positively correlated with the load size, which can reduce power consumption when the load is very small.

[0096] As a preferred embodiment, the charge pump circuit 3 includes:

[0097] an oscillation circuit, configured to generate an initial clock signal CLKIN according to the adaptive current IADAPT, wherein the frequency of the initial clock signal CLKIN is positively correlated with the magnitude of the adaptive current IADAPT;

[0098] A driving circuit, configured to generate a clock signal CLKBUF with driving capability according to an initial clock signal CLKIN;

[0099] The charge pump core unit is used to generate a high-voltage output voltage HVOUT according to a clock signal CLKBUF with driving capability to adjust the load capacity of the charge pump circuit. The load capacity of the charge pump circuit is positively correlated with the frequency of the clock signal CLKBUF (within a specific range).

[0100] Please refer to Figure 5 , Figure 5This is a schematic diagram of the structure of a second charge pump circuit 3 in a high-voltage generation circuit provided by the present application. In this embodiment, the charge pump circuit 3 includes an oscillator circuit, a driver circuit, and a charge pump core unit. The oscillator circuit generates an initial clock signal CLKIN required for the operation of the charge pump core unit. The driver circuit generates a clock signal CLKBUF with drive capability based on the initial clock signal CLKIN, and uses the clock signal CLKBUF to drive the charge pump core unit. When the frequency of the initial clock signal CLKIN varies, the magnitude of the high-voltage output voltage HVOUT generated by the charge pump core unit varies. Furthermore, in this embodiment, the adaptive current IADAPT output by the current sensing module 4 is superimposed on the driver circuit. Therefore, the magnitude of the adaptive current IADAPT is positively correlated with the frequency of the initial clock signal CLKIN. Therefore, the frequency of the initial clock signal CLKIN is positively correlated with the magnitude of the load, which can reduce power consumption when the load is very small.

[0101] As a preferred embodiment, the charge pump circuit 3 includes:

[0102] an oscillation circuit, configured to generate an initial clock signal CLKIN according to the adaptive current IADAPT, wherein the frequency of the initial clock signal CLKIN is positively correlated with the magnitude of the adaptive current IADAPT;

[0103] A driving circuit, configured to generate a clock signal CLKBUF with driving capability according to an initial clock signal CLKIN, and to adjust the driving capability of the clock signal CLKBUF according to an adaptive current IADAPT;

[0104] The charge pump core unit is used to generate a high-voltage output voltage HVOUT according to a clock signal CLKBUF with driving capability to adjust the load capacity of the charge pump circuit. The load capacity of the charge pump circuit is positively correlated with the driving capability and frequency of the clock signal CLKBUF.

[0105] Please refer to Figure 6 , Figure 6This is a schematic diagram of the structure of a third charge pump circuit 3 in a high-voltage generation circuit provided by the present application. In this embodiment, the charge pump circuit 3 includes an oscillator circuit, a driver circuit, and a charge pump core unit. The oscillator circuit generates an initial clock signal CLKIN required for the operation of the charge pump core unit. The driver circuit generates a clock signal CLKBUF with drive capability based on the initial clock signal CLKIN, and uses the clock signal CLKBUF to drive the charge pump core unit. When the drive capability of the clock signal CLKBUF varies, the load capacity of the high-voltage output voltage HVOUT generated by the charge pump core unit varies. Furthermore, in this embodiment, the adaptive current IADAPT output by the current sensing module 4 is superimposed on the driver circuit. Therefore, the magnitude of the adaptive current IADAPT is positively correlated with the drive capability of the clock signal CLKBUF. Therefore, the drive capability of the clock signal CLKBUF is positively correlated with the load size, which can reduce power consumption when the load is very small. Furthermore, in this embodiment, the adaptive current IADAPT output by the current sensing module 4 is superimposed on the driving circuit. Therefore, the magnitude of the adaptive current IADAPT is positively correlated with the frequency of the initial clock signal CLKIN. Therefore, the frequency of the initial clock signal CLKIN is positively correlated with the magnitude of the load, which can reduce power consumption when the load is very small.

[0106] As can be seen, this embodiment combines the above two embodiments. The current sensing module 4 can output a lower adaptive current IADAPT under low load conditions, thereby reducing the driving capability of the clock signal CLKBUF in the charge pump circuit 3 and the frequency of the initial clock signal CLKIN. This reduces switching loss and feedthrough loss from two aspects, thereby reducing power consumption. Under high load conditions, the load capacity of the charge pump circuit can still be increased by increasing the adaptive current. In summary, this embodiment improves the flexibility and practicality of the high-voltage generation circuit by realizing the adaptive capability of the charge pump circuit 3.

[0107] The present application also provides a DTOF ranging system, which includes the above-mentioned high-voltage generating circuit and a SPAD array connected to the output end of the high-voltage generating circuit.

[0108] For the relevant introduction of a DTOF ranging system provided in this application, please refer to the above-mentioned embodiment of the high-voltage generating circuit, which will not be repeated here.

[0109] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referred to each other. It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "comprise a..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0110] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high voltage generating circuit, characterized in that: It includes a reference voltage generating module, a comparator, a charge pump circuit, a current sensing module and a voltage dividing resistor string including a plurality of voltage dividing resistors connected in series; The reference voltage generating module is used to generate a reference voltage; The comparator has a positive input terminal for inputting the reference voltage, a negative input terminal for inputting the feedback voltage, and an output terminal connected to the input terminal of the charge pump circuit, wherein the feedback voltage is the voltage at the feedback voltage terminal of the voltage-dividing resistor string; The charge pump circuit is used to generate a high-voltage output voltage based on the output of the comparator, the output end of the charge pump circuit is connected to the first end of the voltage-dividing resistor string and the first end of the load, and the second end of the load is grounded; The feedback voltage terminal of the voltage-dividing resistor string is located between the first terminal of the voltage-dividing resistor string and the second terminal of the voltage-dividing resistor string, and the second terminal of the voltage-dividing resistor string is connected to the input terminal of the current sensing module; The current sensing module is used to generate an adaptive current based on the output current flowing through the voltage-dividing resistor string, and output the adaptive current to the charge pump circuit to adjust the load capacity of the charge pump circuit, wherein the magnitude of the adaptive current is negatively correlated with the magnitude of the output current, and the magnitude of the adaptive current is positively correlated with the magnitude of the load capacity of the charge pump circuit.

2. The high voltage generating circuit according to claim 1, wherein: The current sensing module includes a first current mirror unit, a second current mirror unit, a third current mirror unit and a current source; The first current mirror unit is used to mirror the output current to obtain a first mirror current; The current source is used to generate a constant bias current; The second current mirror unit is used to mirror a difference current to obtain a second mirror current, wherein the difference current is a current obtained by subtracting the first mirror current from the bias current; The third current mirror unit is used for mirroring the second mirror current to obtain the adaptive current.

3. The high voltage generating circuit according to claim 2, wherein: The first current mirror unit includes a first NMOS (N1) and a second NMOS (N2), the second current mirror unit includes a third NMOS (N3) and a fourth NMOS (N4), the current source includes a first PMOS (P1), and the third current mirror unit includes a second PMOS (P2) and a third PMOS (P3); The gate of the first PMOS (P1) is used to input a bias voltage, and the source is connected to a power supply; The drain of the first NMOS (N1) is connected to the gate of the first NMOS (N1), the gate of the second NMOS (N2) and the second end of the voltage-dividing resistor string, the source of the first NMOS (N1) and the source of the second NMOS (N2) are both grounded, and the drain of the second NMOS (N2) is connected to the drain of the first PMOS (P1); The drain of the third NMOS (N3) is connected to the drain of the first PMOS (P1) and the gate of the third NMOS (N3), the gate of the third NMOS (N3) is connected to the gate of the fourth NMOS (N4), and the source of the third NMOS (N3) and the source of the fourth NMOS (N4) are both grounded; The drain of the second PMOS (P2) is connected to the drain of the fourth NMOS (N4) and the gate of the second PMOS (P2), the gate of the second PMOS (P2) is connected to the gate of the third PMOS (P3), the source of the second PMOS (P2) and the source of the third PMOS (P3) are both connected to a power supply, and the drain of the third PMOS (P3) is used to output the adaptive current.

4. The high voltage generating circuit according to claim 3, wherein: The current sensing module further includes a plurality of current mirror branches; Each of the current mirror branches is used to mirror the second mirror current in a preset ratio to generate a third mirror current, and the adaptive current is the sum of the second mirror current and each of the third mirror currents.

5. The high voltage generating circuit according to claim 4, wherein: Each of the current mirror branches includes a mirror transistor PMOS (Pz1) and a switch transistor PMOS (Pz2); The gate of the switch tube PMOS (Pz2) is connected to the output end of the external register, the source of the switch tube PMOS (Pz2) is connected to the power supply, and the external register is used to control the on and off of the switch tube PMOS (Pz2); The source of the mirror transistor PMOS (Pz1) is connected to the drain of the switch transistor PMOS (Pz2), the gate of the mirror transistor PMOS (Pz1) is connected to the gate of the second PMOS (P2), and the drain of the mirror transistor PMOS (Pz1) is used to output the third mirror current.

6. The high voltage generating circuit according to claim 5, wherein: The third current mirror unit further includes a fourth PMOS (P4) and a fifth PMOS (P5); The sources of the fourth PMOS (P4) and the fifth PMOS (P5) are both connected to a power supply, the gate of the fourth PMOS (P4) is connected to the gate of the fifth PMOS (P5), the drain of the fourth PMOS (P4) is connected to the source of the second PMOS (P2), and the drain of the fifth PMOS (P5) is connected to the source of the third PMOS (P3); The fourth PMOS (P4), the fifth PMOS (P5), and each of the switch tubes PMOS (Pz2) have the same size.

7. The high voltage generating circuit according to claim 1, wherein: The charge pump circuit comprises: an oscillator circuit for generating an initial clock signal; a driving circuit, configured to generate a clock signal with driving capability according to the initial clock signal, and adjust the driving capability of the clock signal according to the adaptive current; The charge pump core unit is used to generate the high-voltage output voltage according to the clock signal with driving capability to adjust the load capacity of the charge pump circuit. The load capacity of the charge pump circuit is positively correlated with the driving capability of the clock signal.

8. The high voltage generating circuit according to claim 1, wherein: The charge pump circuit comprises: an oscillation circuit, configured to generate an initial clock signal according to the adaptive current, wherein a frequency of the initial clock signal is positively correlated with a magnitude of the adaptive current; A driving circuit, configured to generate a clock signal with driving capability according to the initial clock signal; The charge pump core unit is used to generate the high-voltage output voltage according to the clock signal with driving capability to adjust the load capacity of the charge pump circuit, and the load capacity of the charge pump circuit is positively correlated with the frequency of the clock signal.

9. The high voltage generating circuit according to claim 1, wherein: The charge pump circuit comprises: an oscillation circuit, configured to generate an initial clock signal according to the adaptive current, wherein a frequency of the initial clock signal is positively correlated with a magnitude of the adaptive current; a driving circuit, configured to generate a clock signal with driving capability according to the initial clock signal, and adjust the driving capability of the clock signal according to the adaptive current; The charge pump core unit is used to generate the high-voltage output voltage according to the clock signal with driving capability to adjust the load capacity of the charge pump circuit. The load capacity of the charge pump circuit is positively correlated with the driving capability and frequency of the clock signal.

10. A DTOF ranging system, characterized in that: The method comprises the high voltage generating circuit according to any one of claims 1 to 9, and further comprises a SPAD array connected to the output terminal of the high voltage generating circuit.

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