A delay detection circuit and driving circuit of a DTOF driving circuit

Abstract

The present invention provides a delay detection circuit of a DTOF driving circuit and a DTOF driving circuit. The delay detection circuit is used to detect the target delay of the DTOF driving circuit, and includes a first feedforward module, a second feedforward module, a feedback module and a delay control module; the first feedforward module receives a detection input signal and generates a first delay feedback signal; the second feedforward module outputs a delay compensation signal; the feedback module outputs a second delay feedback signal; the delay between the detection input signal and the delay compensation signal is recorded as the compensation delay; the delay between the detection input signal and the second delay feedback signal is recorded as the feedback delay; the delay difference between the feedback delay and the compensation delay is equal to the target delay; the first feedforward module adjusts its own delay time under the delay control signal generated by the delay control module so that the delay difference is equal to the reference delay.

Description

Technical Field

[0001] The present invention relates to the field of driving circuits, and in particular to a delay detection circuit and a driving circuit of a DTOF driving circuit. Background Art

[0002] A DTOF system measures distance based on the delay between sending and receiving a light signal. For a DTOF drive system, the delay from the input control signal to the output light signal must be stable and independent of changes in power supply voltage, temperature, or process technology. Therefore, delay control is necessary within the DTOF drive system.

[0003] When performing delay control on a DTOF drive system, it is necessary to detect the time delay from the input signal to the drive output signal on-chip. A common approach in practice is to perform closed-loop control on this delay time and compare the actual detected delay time with a reference time. Since the delay time of the signal input module itself is difficult to obtain directly on-chip, excluding this delay time from the delay control will result in significant system errors. Furthermore, while detecting the drive output signal, the delay time introduced by the detection circuit will also introduce system errors into the delay control. Therefore, accurately detecting the delay time of the drive system is a key issue in DTOF systems. Summary of the Invention

[0004] The present invention provides a delay detection circuit of a DTOF driving circuit and a DTOF driving circuit, so as to solve the problem that it is difficult to accurately detect the system delay time in the DTOF driving circuit.

[0005] According to a first aspect of the present invention, a delay detection circuit for a DTOF driver circuit is provided, for detecting a target delay of the DTOF driver circuit, wherein the DTOF driver circuit is configured to output an output signal to drive a laser diode. The delay detection circuit comprises: a first feedforward module, a second feedforward module, a feedback module, and a delay control module; wherein:

[0006] The first feedforward module is used to receive the detection input signal and generate a first delayed feedback signal;

[0007] The first feedforward module includes a first input differential signal detection unit and a delay adjustment unit; the input end of the first input differential signal detection unit receives the detection input signal, and the output end of the first input differential signal detection unit outputs the first delayed feedback signal; the first delayed feedback signal is input into the DTOF driving circuit after passing through the delay adjustment unit, and the DTOF driving circuit generates the output signal;

[0008] The second feedforward module includes a delay unit, wherein the input end of the delay unit is connected to the output end of the first input differential signal detection unit to receive the first delayed feedback signal; the output end of the delay unit outputs a delay compensation signal; the delay between the detection input signal and the delay compensation signal is recorded as the compensation delay;

[0009] The input end of the feedback module receives the output signal output by the DTOF driving circuit, and the output end thereof outputs a second delayed feedback signal; the delay between the detection input signal and the second delayed feedback signal is recorded as feedback delay;

[0010] The delay control module is used to generate a delay control signal based on the delay difference between the feedback delay and the compensation delay and the reference delay; the delay adjustment unit is used to adjust its own delay time under the delay control signal so that the delay difference is equal to the reference delay; wherein the delay difference between the feedback delay and the compensation delay is equal to the target delay; the target delay represents the circuit delay from the detection input signal to the output signal.

[0011] Optionally, the feedback module includes a second input differential signal detection unit and an inverter; the first input end and the second input end of the second input differential signal detection unit respectively receive the output signal and the inverted output signal output by the inverter; the output end of the second input differential signal detection unit outputs a second delayed feedback signal.

[0012] Optionally, the delay control module includes a trigger unit and a delay control unit; a first input end of the trigger unit is connected to the output end of the second feedforward module for receiving the delay compensation signal, a second input end of the trigger unit is connected to the output end of the feedback module for receiving the second delayed feedback signal, and an output end of the trigger unit is connected to the delay control unit to output a difference signal representing the delay difference to the delay control unit;

[0013] The first input end of the delay control unit receives the delay difference, and the second input end of the delay control unit receives the reference delay; the output end of the delay control unit is connected to the delay adjustment unit; the delay control unit is used to compare the difference signal with the reference delay and output a delay control signal to the delay adjustment unit.

[0014] Optionally, the trigger unit includes an RS trigger; the S end of the RS trigger is connected to the output end of the second feedforward module to receive the delay compensation signal; the R end of the RS trigger is connected to the output end of the feedback module to receive the second delayed feedback signal; the output end of the RS trigger is connected to the delay control unit to output the delay difference.

[0015] Optionally, the circuit delay of the delay unit in the second feedforward module is the same as the circuit delay of the inverter.

[0016] Optionally, the feedback module further includes a first level shifting unit and a second level shifting unit;

[0017] The input end of the first level shift unit is connected to the output end of the inverter; the output end of the first level shift unit is connected to the first input end of the second input differential signal detection unit;

[0018] The input end of the second level shifting unit is connected to the output end of the DTOF driving circuit to receive the output signal output by the DTOF driving circuit; the output end of the second level shifting unit is connected to the second input end of the second input differential signal detection unit.

[0019] Optionally, the second feedforward module includes a third level shifting unit;

[0020] An input end of the third level shift unit is connected to an output end of the first input differential signal detection unit; and an output end of the third level shift unit is connected to the delay unit.

[0021] Optionally, the circuit delays of the first level shifting unit, the second level shifting unit, and the third level shifting unit are the same.

[0022] Optionally, the feedforward module further includes a fourth level transfer unit; the input end of the fourth level transfer unit is connected to the output end of the delay adjustment unit; and the output end of the fourth level transfer unit is connected to the DTOF driving circuit.

[0023] Optionally, the DTOF driving circuit includes a driving amplifier unit and a switching tube; the input end of the driving amplifier unit is connected to the output end of the feedforward module; the output end of the driving amplifier unit is connected to the control end of the switching tube; the first end of the switching tube is connected to the laser diode; and the second end of the switching tube is grounded or connected to a power supply.

[0024] Optionally, the switching tube is a MOSFET.

[0025] According to a second aspect of the present invention, a DTOF driving circuit with closed-loop delay control is provided, comprising the delay detection circuit of the DTOF driving circuit described in the first aspect of the present invention and the DTOF driving circuit described.

[0026] The present invention provides a delay detection circuit and a DTOF driving circuit of a DTOF driving circuit, wherein the delay detection circuit is used to detect a target delay of the DTOF driving circuit, wherein the target delay represents the circuit delay from the detection input signal to the output signal; the delay detection circuit obtains a compensation delay based on a first delay feedback signal generated by the first feedforward module and a delay compensation signal generated by the second feedforward module; the feedback delay is obtained based on a second delay feedback signal output by the feedback module; the delay control module generates a delay control signal based on a delay difference between the feedback delay and the compensation delay and a reference delay; and the delay adjustment unit in the first feedforward module adjusts its own delay time under the delay control signal so that the delay difference is equal to the reference delay.

[0027] The delay detection circuit of the DTOF driving circuit provided by the present invention makes the delay difference between the feedback delay and the compensation delay equal to the target delay through the delay compensation circuit in the second feedforward module, and adjusts the delay difference to be the same as the reference delay through the delay adjustment unit, thereby achieving control of the target delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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.

[0029] Figure 1 This is a circuit structure diagram of a delay detection circuit of a common closed-loop controlled DTOF drive circuit;

[0030] Figure 2 1 is a schematic diagram of a circuit structure of a delay detection circuit of a DTOF driving circuit provided in an exemplary embodiment;

[0031] Figure 3 2 is a circuit structure diagram of a delay detection circuit of a DTOF driving circuit provided in another exemplary embodiment. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 are within the scope of protection of the present invention.

[0033] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way are interchangeable where appropriate, so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0034] The following specific embodiments are used to describe the technical solution of the present invention in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0035] DTOF, or Direct TOF, directly measures the time of flight, that is, the time interval between the transmitted pulse and the received pulse. When performing delay control on the DTOF drive system, it is necessary to detect the time delay from the input signal to the drive output signal on the chip. In practice, a common method is to perform closed-loop control on the delay time and compare the actual detected delay time with the reference time. Figure 1 As shown, a common closed-loop control circuit compares the delay difference between the output signal X1 of the feedforward module and the output signal X3 of the feedback circuit with the reference time. However, since the detection point x1 of the feedforward module is after the input differential signal detection unit LVDS circuit, the circuit delay time of the LVDS itself is not included in the delay time obtained by detection; while in the feedback branch, the delay time of the circuit that detects the driving output voltage is included in the delay time obtained by detection. In this way, there will be an error between the delay time obtained by detection and the actual delay. In order to eliminate this error, the delay detection circuit of the DTOF drive circuit provided by the present invention is based on the principle of error cancellation. Through the compensation circuit in the second feedforward module and the feedback module, the delay difference between the feedback delay and the compensation delay is equal to the target delay. The delay adjustment unit adjusts the delay difference to be the same as the reference delay, thereby more accurately achieving control of the target delay.

[0036] Figure 2 A delay detection circuit of a DTOF driving circuit provided in an embodiment of the present invention is used to detect a target delay tdly_target of the DTOF driving circuit, wherein the DTOF driving circuit is used to output an output signal to drive a laser diode. The delay detection circuit includes: a first feedforward module 10, a second feedforward module 20, a feedback module 30, and a delay control module 40; wherein:

[0037] The first feedforward module 10 is used to receive the detection input signal and generate a first delayed feedback signal X1;

[0038] The first feedforward module 10 includes a first input differential signal detection unit 11 and a delay adjustment unit 12; the input end of the first input differential signal detection unit 11 receives the detection input signal, and the output end of the first input differential signal detection unit 11 outputs the first delayed feedback signal X1; the first delayed feedback signal X1 is input into the DTOF driving circuit after passing through the delay adjustment unit 12, and the DTOF driving circuit generates the output signal X2;

[0039] The detection input signal is a set of differential signals DATA / XDATA; the first input differential signal detection unit is a low voltage differential signal detection circuit LVDS, which converts a set of differential input signals DATA / XDATA into a single-ended digital signal, namely the first delayed feedback signal X1;

[0040] The second feedforward module 20 includes a delay unit 21, the input end of the delay unit is connected to the output end of the first input differential signal detection unit 11 to receive the first delayed feedback signal X1; the output end of the delay unit 21 outputs a delay compensation signal X1a; the delay between the detected input signal DATA / XDATA and the delay compensation signal X1a is recorded as the compensation delay tdly_X1a;

[0041] The input end of the feedback module 30 receives the output signal X2 output by the DTOF driving circuit, and the output end thereof outputs a second delayed feedback signal X3a; the delay between the detection input signal and the second delayed feedback signal X3a is recorded as feedback delay tdly_X3a;

[0042] In one embodiment, the feedback module 30 includes a second input differential signal detection unit 31 and an inverter 32; the first input end and the second input end of the second input differential signal detection unit 31 respectively receive the output signal X2 and the inverted output signal X3 output by the inverter 32; the output end of the second input differential signal detection unit 31 outputs a second delayed feedback signal X3a.

[0043] The delay control module 40 is used to generate a delay control signal dly_ctrl based on the delay difference tdly_det between the feedback delay tdly_X3a and the compensation delay tdly_X1a and the reference delay Time_Ref; the delay adjustment unit 12 is used to adjust its own delay time under the delay control signal dly_ctrl so that the delay difference tdly_det is equal to the reference delay Time_Ref; wherein, the delay difference between the feedback delay tdly_X3a and the compensation delay tdly_X1a is equal to the target delay tdly_target; the target delay tdly_target represents the circuit delay from the detection input signal to the output signal.

[0044] In one embodiment, the delay control module 40 includes a trigger unit 41 and a delay control unit 42; a first input end of the trigger unit 40 is connected to the output end of the second feedforward module 20 for receiving the delay compensation signal X1a, a second input end of the trigger unit 41 is connected to the output end of the feedback module 30 for receiving the second delayed feedback signal X3a, and an output end of the trigger unit 41 is connected to the delay control unit 42 to output the delay difference tdly_det to the delay control unit 42; wherein tdly_det=tdly_X3a-tdly_X1a;

[0045] In one embodiment, the trigger unit 41 includes an RS trigger; the S terminal of the RS trigger is connected to the output terminal of the second feedforward module 20 to receive the delay compensation signal X1a; the R terminal of the RS trigger is connected to the output terminal of the feedback module 30 to receive the second delayed feedback signal X3a; the output terminal of the RS trigger is connected to the delay control unit 12 to output a difference signal dly_det representing the delay difference tdly_det. The RS trigger compares the delay between X1a and X3a to generate the difference signal dly_det. The output signal dly_det is a pulse signal whose pulse width is equal to the delay difference tdly_det.

[0046] Of course, it should be realized that the RS trigger is only an example of the present invention. The trigger unit of the present invention is not limited to the RS trigger, and any circuit that performs time domain comparison on two signals, such as a phase frequency detector (PFD), etc. can also be used.

[0047] The first input terminal of the delay control unit 42 receives the delay difference, and the second input terminal of the delay control unit 42 receives the reference delay Time_Ref. The output terminal of the delay control unit 42 is connected to the delay unit 21. The delay control unit 42 is configured to compare the delay difference tdly_det with the reference delay Time_Ref and output a delay control signal dly_ctrl to the delay adjustment unit 12. The delay control signal dly_ctrl is configured to control the delay adjustment unit 12. The delay adjustment unit adjusts its own delay so that the pulse width of the output signal dly_det representing the delay difference tdly_det is equal to the reference delay Time_Ref, thereby achieving closed-loop control of the delay difference between the feedback delay tdly_X3a and the compensation delay tdly_X1a.

[0048] In one embodiment, the circuit delay of the delay unit 21 in the second feedforward module is the same as the circuit delay of the inverter 32. In this way, the second feedforward module 20 can output the delay compensation signal X1a to compensate for the circuit delay caused by the inverter 32 in the feedback module 30. In this way, the delay difference tdly_det between the feedback delay tdly_X3a and the compensation delay tdly_X1a can be more accurately equal to the target delay tdly_target.

[0049] The delay detection circuit of the DTOF driving circuit provided by the present invention is based on the principle of error cancellation, and adds a second feedforward module 20. Through the delay compensation circuit in the second feedforward module 20, the influence of the corresponding circuit in the feedback branch is offset, and the delay compensation signal is output. In addition, an input differential signal detection unit LVDS is added to the feedback module 30 to offset the circuit delay of the LVDS in the feedforward module 20. Through the compensation circuit in the second feedforward module and the feedback module, the delay difference between the feedback delay and the compensation delay is equal to the target delay. The delay adjustment unit adjusts the delay difference to be the same as the reference delay, thereby realizing control of the target delay and obtaining a more accurate driving delay.

[0050] In one embodiment, the feedback module 30 further includes a first level shifter 33 and a second level shifter 34; the input of the first level shifter 33 is connected to the output of the inverter 32; the output of the first level shifter 33 is connected to the first input of the second input differential signal detection unit 31; the input of the second level shifter 34 is connected to the output of the DTOF driver circuit to receive the output signal of the DTOF driver circuit; the output of the second level shifter 34 is connected to the second input of the second input differential signal detection unit 31. The second feedforward module includes a third level shifter 22; the input of the third level shifter 22 is connected to the output of the first input differential signal detection unit 11; and the output of the third level shifter 22 is connected to the delay unit 21.

[0051] The circuit delays of the first level shifting unit 33 , the second level shifting unit 34 and the third level shifting unit 22 are the same.

[0052] In one embodiment, the feedforward module 10 further includes a fourth level shifting unit 13; the input end of the fourth level shifting unit 13 is connected to the output end of the delay adjustment unit 12; and the output end of the fourth level shifting unit 13 is connected to the DTOF driving circuit.

[0053] In one embodiment, Figure 3 As shown, the DTOF drive circuit includes a drive amplifier unit 51 and a switch tube 52. The input end of the drive amplifier unit is connected to the output end of the feedforward module; the output end of the drive amplifier unit is connected to the control end of the switch tube; the first end of the switch tube is connected to the laser diode; and the second end of the switch tube is grounded or connected to a power supply. The switch tube is a MOSFET.

[0054] Of course, it should be appreciated that the switch tube of the present invention is not limited to MOSFET, and bipolar transistors or other types of switch tubes are all within the protection scope of the present invention.

[0055] The present invention also provides a DTOF driving circuit with closed-loop delay control, comprising the delay detection circuit of the DTOF driving circuit of the present invention and the DTOF driving circuit.

[0056] In order to illustrate the detection of the target delay tdly_target of the DTOF driving circuit, the circuit delay of each unit in each module is represented by tdly (unit number), such as the circuit delay of the first input differential signal detection unit 11 is represented as tdly(11).

[0057] The target delay tdly_target represents the circuit delay from the detection input signal to the output signal, that is, the circuit delay from the input signal DATA / XDATA to the output signal X2. tdly_target can be expressed as:

[0058] tdly_target=tdly(11)+tdly(12)+tdly(13)+tdly(51)+tdly(52)

[0059] The delay detection circuit of the DTOF driving circuit using the delay matching closed-loop control proposed by the present invention actually controls the delay difference between the feedback delay tdly_X3a and the compensation delay tdly_X1a.

[0060] The compensation delay tdly_X1a is the delay between the detection input signal DATA / XDATA and the delay compensation signal X1a. tdly_X1a can be expressed as:

[0061] tdly_X1a=tdly(11)+tdly(21)+tdly(22)

[0062] The feedback delay tdly_X3a is the delay between the detection input signal DATA / XDATA and the second delayed feedback signal X3a, that is, from the detection input signal DATA / XDATA to the output signal X2, and then to the second delayed feedback signal X3a. tdly_X3a can be expressed as:

[0063] tdly_X3a=tdly_target+tdly(31)+tdly(32)+tdly(33)

[0064] Since the circuit delay of the delay unit 21 in the second feedforward module is the same as the circuit delay of the inverter 32, that is, tdly(21)=tdly(32); the circuit delay of the first level transfer unit 33 is the same as that of the third level transfer unit 22, that is, tdly(22)=tdly(33); the circuit delay of the first input differential signal detection unit 11 is the same as that of the second input differential signal detection unit 31, that is, dly(31)=tdly(11).

[0065] Therefore, the delay difference tdly_det = tdly_X3a - tdly_X1a = tdly_target, that is, the delay difference tdly_det between the feedback delay tdly_X3a and the compensation delay tdly_X1a is equal to the target delay tdly_target. In the delay matching solution provided by the present invention, the delay difference tdly_det is controlled to be the same as the time reference Time_Ref through closed-loop control, thereby achieving control of the target delay.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A delay detection circuit for a DTOF driving circuit, for detecting a target delay of the DTOF driving circuit, wherein: The DTOF driving circuit is used to output an output signal to drive the laser diode, and is characterized in that the delay detection circuit includes: a first feedforward module, a second feedforward module, a feedback module and a delay control module; wherein: The first feedforward module is used to receive a detection input signal and generate a first delayed feedback signal; The first feedforward module includes a first input differential signal detection unit and a delay adjustment unit; the input end of the first input differential signal detection unit receives the detection input signal, and the output end of the first input differential signal detection unit outputs the first delayed feedback signal; the first delayed feedback signal is input into the DTOF driving circuit after passing through the delay adjustment unit, and the DTOF driving circuit generates the output signal; The second feedforward module includes a delay unit, wherein the input end of the delay unit is connected to the output end of the first input differential signal detection unit to receive the first delayed feedback signal; the output end of the delay unit outputs a delay compensation signal; the delay between the detection input signal and the delay compensation signal is recorded as the compensation delay; The input end of the feedback module receives the output signal output by the DTOF driving circuit, and the output end thereof outputs a second delayed feedback signal; the delay between the detection input signal and the second delayed feedback signal is recorded as feedback delay; The delay control module is used to generate a delay control signal based on the delay difference between the feedback delay and the compensation delay and the reference delay; the delay adjustment unit is used to adjust its own delay time under the delay control signal so that the delay difference between the feedback delay and the compensation delay is equal to the reference delay; wherein the delay difference between the feedback delay and the compensation delay is equal to the target delay; the target delay represents the circuit delay from the detection input signal to the output signal.

2. The delay detection circuit of the DTOF driving circuit according to claim 1, characterized in that: The feedback module includes a second input differential signal detection unit and an inverter; the first input end and the second input end of the second input differential signal detection unit respectively receive the output signal and the inverted output signal output by the inverter; the output end of the second input differential signal detection unit outputs a second delayed feedback signal.

3. The delay detection circuit of the DTOF driving circuit according to claim 2, characterized in that: The delay control module includes a trigger unit and a delay control unit; a first input end of the trigger unit is connected to the output end of the second feedforward module for receiving the delay compensation signal, a second input end of the trigger unit is connected to the output end of the feedback module for receiving the second delayed feedback signal, and an output end of the trigger unit is connected to the delay control unit to output a difference signal representing the delay difference to the delay control unit; The first input terminal of the delay control unit receives the delay difference, and the second input terminal of the delay control unit receives the reference delay; The output end of the delay control unit is connected to the delay adjustment unit; The delay control unit is used to compare the difference signal with the reference delay and output a delay control signal to the delay adjustment unit.

4. The delay detection circuit of the DTOF driving circuit according to claim 3, characterized in that: The trigger unit includes an RS trigger; the S end of the RS trigger is connected to the output end of the second feedforward module to receive the delay compensation signal; the R end of the RS trigger is connected to the output end of the feedback module to receive the second delayed feedback signal; the output end of the RS trigger is connected to the delay control unit to output the delay difference.

5. The delay detection circuit of the DTOF driving circuit according to claim 2, characterized in that: The circuit delay of the delay unit in the second feedforward module is the same as the circuit delay of the inverter.

6. The delay detection circuit of the DTOF driving circuit according to claim 2, characterized in that: The feedback module further includes a first level shifting unit and a second level shifting unit; The input end of the first level shift unit is connected to the output end of the inverter; The output end of the first level shifting unit is connected to the first input end of the second input differential signal detection unit; The input end of the second level shifting unit is connected to the output end of the DTOF driving circuit to receive the output signal output by the DTOF driving circuit; the output end of the second level shifting unit is connected to the second input end of the second input differential signal detection unit.

7. The delay detection circuit of the DTOF driving circuit according to claim 6, characterized in that: The second feedforward module includes a third level shifting unit; An input end of the third level shifting unit is connected to an output end of the first input differential signal detecting unit; An output end of the third level shift unit is connected to the delay unit.

8. The delay detection circuit of the DTOF driving circuit according to claim 7, characterized in that: The circuit delays of the first level shifting unit, the second level shifting unit, and the third level shifting unit are the same.

9. The delay detection circuit of the DTOF driving circuit according to claim 2, characterized in that: The feedforward module further includes a fourth level shifting unit; an input end of the fourth level shifting unit is connected to an output end of the delay adjustment unit; and an output end of the fourth level shifting unit is connected to the DTOF driving circuit.

10. The delay detection circuit of the DTOF driving circuit according to claim 1, characterized in that: The DTOF driving circuit includes a driving amplifier unit and a switching tube; the input end of the driving amplifier unit is connected to the output end of the first feedforward module; the output end of the driving amplifier unit is connected to the control end of the switching tube; the first end of the switching tube is connected to the laser diode; and the second end of the switching tube is grounded or connected to a power supply.

11. The delay detection circuit of the DTOF driving circuit according to claim 10, characterized in that: The switch tube is a MOSFET.

12. A DTOF driving circuit with closed-loop delay control, characterized in that: A delay detection circuit comprising the DTOF driving circuit according to any one of claims 1 to 11 and the DTOF driving circuit.

Images