An ultra-low input voltage DC / DC boost device

Abstract

An ultra-low input voltage DC / DC boost device includes a first transistor Q1, a second transistor Q2, an inductor L1, an internal power supply module, a PWM generation module and a low-voltage startup control module. When the power supply voltage V3 does not reach the corresponding voltage threshold, the low-voltage startup control module outputs a rising and periodic voltage signal CLKN to drive the second transistor Q2 to turn on and off according to the received reverse POK signal, so that the power supply voltage V3 rises until the power OK submodule detects that the power supply voltage V3 reaches the predetermined threshold, and then turns off the low-voltage startup control module. Therefore, the present invention can effectively solve the limitation of the boost device on the input power supply voltage V1, that is, the input power supply voltage V1 can also ensure that the DC / DC boost device starts and works normally under ultra-low voltage conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of direct current boost circuit design and relates to an ultra-low input voltage DC / DC boost device. Background Art

[0002] At present, input voltage DC / DC direct current boost devices are increasingly widely used. For example, they are often used in scenarios where direct current boost is required, such as direct current alkaline batteries, nickel-metal hydride rechargeable batteries, lithium-manganese batteries or lithium-ion rechargeable batteries.

[0003] See also Figure 1 , Figure 1 The figure shows a schematic diagram of an ultra-low input voltage DC / DC boost device in the prior art. The DC / DC boost device is used to process the input power supply voltage V1 and output an output power supply voltage V2 that is equal to or higher than the input power supply voltage V1.

[0004] like Figure 1 As shown, it includes a power switching control module (Power Switch), a logic inverter (INV), an error amplifier module (EAMP), a PWM comparator module (CMP), a logic control module (PWM Control Logic), a drive module (DRVIER), a reference voltage source module (VREF), an oscillator module (OSC), a slope compensation module (Slopecompensation), feedback resistors (RFB1, RFB2, RFB3, RFB4), a power OK module (PowerOK), P-type transistors (Q1, Q3, Q4), an N-type transistor (Q2), an inductor (L1) and a capacitor (C1, C2) and other components.

[0005] The power supply of the internal module of the above-mentioned startup control circuit is the power supply voltage V3, which is connected to one end of the P-type transistors Q3 and Q4 respectively, and the other ends of the P-type transistors Q3 and Q4 are connected to the input power supply voltage V1 and the output power supply voltage V2 respectively. The power switching module outputs a judgment signal to control the opening or closing of the P-type transistors Q3 and Q4 by judging the magnitude of the input power supply voltage V1 and the output power supply voltage V2, thereby determining whether the power supply voltage V3 is provided to the internal module by the input power supply voltage V1 or the output power supply voltage V2. When the input power supply voltage V1 is greater than the output power supply voltage V2, the power supply V3 of the internal module comes from the input power supply voltage V1, and when the output power supply voltage V2 is greater than the input power supply voltage V1, the power supply V3 of the internal module is switched to come from the output power supply voltage V2.

[0006] That is to say, the power switching control module is used to switch the power supply of the internal module. When the output power voltage V2 is greater than the input power voltage V1, the P-type transistor Q4 is turned on and the P-type transistor Q3 is turned off; when the output power voltage V2 is less than the input power voltage V1, the P-type transistor Q3 is turned on and the P-type transistor Q4 is turned off.

[0007] In addition, the normal operation of the internal modules in the above control device requires that the power supply voltage V3 reaches a certain voltage value before it can start working normally. When the power supply voltage V3 meets the starting voltage requirement, the reference voltage module starts working first, and the output reference reference voltage VREF is used for the operation of the error amplifier, oscillator and comparator CMP comparison module. When the power OK module determines that the V3 voltage is normal, it outputs a POK signal to the logic control module to control all modules in the device to start working; at this time, the output power supply voltage V2 is low, and the FB signal obtained by the voltage division of RFB1 and RFB2 is at a low value. The FB signal and the VREF signal are processed by the error amplifier module to output the COMP signal, which is sent to one end of the PWM comparator module for input, and compared with the periodic RAMP signal output by the oscillator module and the slope compensation module at the other end of the PWM comparator module to obtain a PWM square wave signal. After being processed by the logic control module, the output DR signal is provided to the drive module. The drive module outputs the signal CLKN to turn on the N-type transistor Q2, and a loop is formed between the input power supply voltage V1 and the ground terminal GND. At this time, the energy storage inductor L 1 is charged into the energy storage, and then the driving module turns off the N-type transistor Q2 and turns on the P-type transistor Q1, forming a loop between the input power supply voltages V1 and V2. At this time, there is current on the energy storage inductor L1, and the current of the inductor L1 cannot change suddenly. At this time, the voltage VL formed at both ends of the inductor L1 and the input power supply voltage V1 simultaneously transmit energy to the output power supply voltage V2, causing the V2 voltage to rise. The FB signal obtained by the voltage division of the resistor RFB1 and the resistor RFB2 is greater than VREF. At this time, the error amplifier module and the PWM comparator module no longer output the PWM square wave signal, and the N-type transistor Q2 cannot be turned on until the FB signal is less than VREF, and then the N-type transistor Q2 will be turned on again to charge the energy storage inductor L1, and the output power supply voltage V2 will be guaranteed to output a stable voltage. When the power supply voltage V3 is detected by the power OK module and its voltage is lower than VREF, that is, the power supply voltage is too low, the reverse signal of POK will be output to the control logic module to shut down all modules in the device.

[0008] However, see Figure 2 , the above startup control circuit has the following defects:

[0009] If you want the boost device to work properly at startup, you need to limit the input power supply voltage V1. Too low an input power supply voltage V1 will cause the modules in the circuit to not work properly, limiting the application range of the boost device for the input power supply voltage V1. Summary of the invention

[0010] In order to solve the above technical problems, the present invention proposes an ultra-low input voltage DC / DC boost device, and its technical solution is as follows:

[0011] An ultra-low input voltage DC / DC boost device, used for boosting an input DC power supply voltage V1 into a DC power supply voltage V2; comprising:

[0012] A first transistor Q1, a second transistor Q2 and an inductor L1; the inductor L1 is connected between the input end of the DC power supply voltage V1 and the drain connection point SW of the first transistor Q1 and the second transistor Q2; the source of the first transistor Q1 is grounded, and the source of the second transistor Q2 is connected to the output end of the DC power supply voltage V2; an internal power supply module is used to generate a power supply voltage V3 for each module in the DC / DC boost device according to the power supply voltage V1 and the power supply voltage V2, and to judge the power supply threshold of the power supply voltage V3; it includes a power supply OK submodule, the power supply OK submodule is used to judge whether the power supply voltage V3 is greater than or equal to a predetermined threshold, if so, output a positive POK signal, otherwise, output a reverse POK signal;

[0013] PWM generation module, generating a PWM square wave signal;

[0014] The boost system driving control module controls the gates of the first transistor Q1 and the second transistor Q2 according to the PWM square wave signal and the POK signal received, if the received POK signal is a positive POK, according to the PWM square wave signal output signal corresponding to CLKP and CLKN to control the gates of the first transistor Q1 and the second transistor Q2; when CLKN controls the second transistor Q2 to turn on, and CLKP controls the first transistor to turn off, a loop is formed between the power supply voltage V1 and the ground terminal GND, at this time, the inductor L1 is charged to store energy; when CLKN controls the second transistor Q2 to turn off, and controls the first transistor Q1 to turn on, a loop is formed between the power supply voltages V1 and V2, and at this time, there is current in the inductor L1, because the current of the inductor L1 cannot suddenly change, the voltage difference VL formed at both ends of the inductor L1, and the input power supply voltage V1 simultaneously transmits energy to the output power supply voltage V2, so that the voltage of V2 rises;

[0015] The low-voltage startup control module outputs a rising and periodic voltage signal CLKN to drive the second transistor Q2 to turn on and off according to the received reverse POK signal when the power supply voltage V3 does not reach the corresponding voltage threshold, so that the power supply voltage V3 rises until the power OK submodule detects that the power supply voltage V3 reaches the predetermined threshold, and then the low-voltage startup control module is turned off.

[0016] Furthermore, the low-voltage startup control module includes a detection control module, a charge pump module and a charge pump oscillator module; when the detection control module receives the reverse POK signal to control the start-up of the oscillator and the charge pump, the charge pump oscillator module is used to generate a periodic square wave signal to output to the charge pump module to output a raised and periodic voltage signal CLKN, and when the detection control module receives the forward POK signal to control the shutdown of the oscillator and the charge pump.

[0017] Furthermore, the low-voltage startup control module also includes a level conversion module connected between the detection control module and the charge pump oscillator module, for converting logic signals between different power supply voltages output from the detection control module.

[0018] Furthermore, the internal power supply module also includes a power switching sub-module, which will switch to using the power supply voltage V1 to power the internal power supply voltage V3 when the power supply voltage V1 is greater than the power supply voltage V2; when the power supply voltage V2 is greater than the power supply voltage V1, it will switch to using the power supply voltage V2 to power the power supply voltage V3.

[0019] Furthermore, the boost system drive control module includes a logic control module LOGIC and a drive module DRIVER. The logic control module LOGIC receives the POK signal and the PWM square wave signal output. If the received POK signal is a positive POK, a drive signal DR1 is generated to the drive module DRIVER. The drive module DRIVER outputs a signal CLKP and a signal CLKN.

[0020] Furthermore, the internal power supply module also includes a third transistor Q3 and a fourth transistor Q4; the source of the third transistor Q3 is connected to the voltage V1, the source of the fourth transistor Q4 is connected to the voltage V2, and the drains of the third transistor Q3 and the fourth transistor Q4 output the power supply voltage V3; when the voltage V2 is greater than the voltage V1, the power switching submodule controls turning on the fourth transistor Q4 and turning off the third transistor Q3; when the voltage V2 is less than the voltage V1, the power switching submodule controls turning on the third transistor Q3 and turning off the fourth transistor Q4; the power OK submodule outputs the forward POK signal or the reverse POK signal according to the power supply voltage V3.

[0021] Furthermore, the PWM generation module includes an error amplifier module EAMP, a slope compensation module, a reference voltage source module VREF, a PWM comparator module and an oscillator OSC; the reference voltage source module is used to generate a constant voltage reference signal; the slope compensation module processes the periodic square wave signal into a RAMP signal; the oscillator module is used to generate a periodic square wave signal; the error amplifier module amplifies the difference between VREF and the feedback signal FB of V2, and outputs a COMP signal; the PWM comparator module compares the COMP signal with the RAMP signal, and outputs a PWM square wave signal.

[0022] Furthermore, the PWM generating module also includes a first resistor RFB1 and a second resistor RFB2, and the first resistor RFB1 and the second resistor RFB2 are connected in series between the power supply voltage V2 and the ground terminal GND; the connection point of the first resistor RFB1 and the second resistor RFB2 is the negative input terminal of the error amplifier module EAMP, and the positive input terminal of the error amplifier module EAMP is connected to the VREF signal generated by the reference voltage source module.

[0023] Furthermore, the ultra-low input voltage DC / DC boost device also includes a first capacitor C1 and a second capacitor C2, the first capacitor C1 is connected in parallel between the DC power supply voltage V1 input terminal and the ground terminal GND; the second capacitor C2 is connected in parallel between the DC power supply voltage V2 output terminal and the ground terminal GND.

[0024] It can be seen from the above technical solutions that the ultra-low input voltage DC / DC boost device in the present invention can effectively solve the limitation of the boost device on the input power supply voltage V1, that is, the input power supply voltage V1 can also ensure that the DC / DC boost device starts and works normally under ultra-low voltage conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure shows a schematic diagram of an ultra-low input voltage DC / DC boost device in the prior art.

[0026] Figure 2 Schematic diagram of the waveforms of the power supply voltage V1 and the power supply voltage V2 in the prior art and the embodiment of the present invention

[0027] Figure 3 FIG. 1 is a schematic diagram of an ultra-low input voltage DC / DC boost device according to an embodiment of the present invention.

[0028] Figure 4 The circuit diagram of the detection control module in the embodiment of the present invention is shown as follows

[0029] Figure 5FIG. 1 is a schematic diagram showing another preferred embodiment of the ultra-low input voltage DC / DC boost device of the present invention. DETAILED DESCRIPTION

[0030] The following is combined with Figure 2-5 , the specific implementation modes of the present invention are further described in detail.

[0031] It should be noted that the biggest difference between the present invention and the prior art is that in the startup control circuit of the low input voltage DC / DC boost device of the present invention, the input DC power supply voltage V1 is boosted to a DC power supply voltage V2, and a startup control module is added to achieve startup with an ultra-low V1 voltage. In other words, when the system operates under the condition of ultra-low input power supply voltage V1, the DC / DC boost device can also be guaranteed to start normally and work normally. Therefore, the present invention can effectively solve the limitation of the boost device on the input power supply voltage V1.

[0032] Example 1

[0033] See also Figure 3 , Figure 3 FIG. 2 is a schematic diagram of a preferred embodiment of an ultra-low input voltage DC / DC boost device of the present invention. Figure 3 As shown, the low input voltage DC / DC boost device includes a first voltage-dividing resistor RFB1, a second voltage-dividing resistor RFB2, a voltage-stabilizing capacitor C1 for a power supply voltage V1, a voltage-stabilizing capacitor C2 for a power supply voltage V2, an inductor L1, a first transistor Q1, a second transistor Q2, an internal power supply module, a PWM generation module, a boost system drive control module, and a low-voltage startup control module; the power supply voltage V1 is a voltage signal at the input end of the control circuit, and the power supply voltage V2 is a voltage signal at the output end of the control circuit, and the voltage V1 is usually less than the voltage V2.

[0034] Specifically, in the following embodiments of the present invention, the inductor L1 is connected between the input terminal of the DC power supply voltage V1 and the drain connection point SW of the first transistor Q1 and the second transistor Q2; the source of the first transistor Q1 is grounded, and the source of the second transistor Q2 is connected to the output terminal of the DC power supply voltage V2. The first capacitor C1 is connected in parallel between the input terminal of the DC power supply voltage V1 and the ground terminal GND; the second capacitor C2 is connected in parallel between the output terminal of the DC power supply voltage V2 and the ground terminal GND.

[0035] The internal power supply module is used to generate a power supply voltage V3 for powering each module in the DC / DC boost device according to the power supply voltage V1 and the power supply voltage V2. The internal power supply module may include a third transistor Q3, a fourth transistor Q4, a power OK submodule, and a power switching submodule. In an embodiment of the present invention, the source of the fourth transistor Q4 is connected to the voltage V2, and the drains of the third transistor Q3 and the fourth transistor Q4 output the power supply voltage V3.

[0036] Specifically, when the power supply voltage V2 is greater than the power supply voltage V1, the power supply voltage V2 is used to supply power to the power supply voltage V3; the power switching submodule controls turning on the fourth transistor Q4 and turning off the third transistor Q3.

[0037] When the power supply voltage V2 is less than the power supply voltage V1, the power switching submodule will switch to use the power supply voltage V1 to power the internal power supply voltage V3 and charge the inductor L1 when the power supply voltage V1 is greater than the power supply voltage V2. That is, the power switching submodule controls the opening of the third transistor Q3 and the closing of the fourth transistor Q4; the power OK submodule outputs the forward POK signal or the reverse POK signal according to the power supply voltage V3. In other words, the power OK submodule is used to determine whether the power supply voltage V3 is greater than or equal to a predetermined threshold, and if so, outputs a forward POK signal, otherwise, outputs a reverse POK signal.

[0038] The PWM generation module includes an error amplifier module EAMP, a slope compensation module, a reference voltage source module VREF, a first resistor RFB1, a second resistor RFB2, a PWM comparator module and an oscillator OSC; the first resistor RFB1 and the second resistor RFB2 are connected in series between a power supply voltage V2 and a ground terminal GND; the connection point of the first resistor RFB1 and the second resistor RFB2 is the negative input terminal of the error amplifier module EAMP, and the positive input terminal of the error amplifier module EAMP is connected to the VREF signal generated by the reference voltage source module.

[0039] The reference voltage source module is used to generate a constant voltage reference signal; the slope compensation module processes the periodic square wave signal into a RAMP signal; the oscillator module OSC is used to generate a periodic square wave signal; the error amplifier module amplifies the difference between VREF and the feedback signal FB of V2 and outputs a COMP signal; the PWM comparator module compares the COMP signal with the RAMP signal and outputs a PWM square wave signal.

[0040] The boost system drive control module includes a logic control module LOGIC and a drive module DRIVER. The logic control module LOGIC receives the POK signal and the PWM square wave signal output. If the received POK signal is a positive POK, a drive signal DR1 is generated to the drive module DRIVER. The drive module DRIVER outputs a signal CLKP and a signal CLKN.

[0041] In an embodiment of the present invention, the newly added low-voltage startup control module can output a rising and periodic voltage signal CLKN to drive the second transistor Q2 to turn on and off according to the received reverse POK signal when the power supply voltage V3 does not reach the corresponding voltage threshold, thereby increasing the power supply voltage V3 until the power OK sub-module detects that the power supply voltage V3 reaches the predetermined threshold, and then turns off the low-voltage startup control module.

[0042] like Figure 3 As shown, the low-voltage startup control module includes a detection control module (Sense Control), a charge pump module (Charge Pump) and a charge pump oscillator module (OSC Pump).

[0043] When the detection control module receives the reverse POK signal to control the start of the charge pump oscillator module and the charge pump, the charge pump oscillator module is used to generate a periodic square wave signal output to the charge pump module to output a rising and periodic voltage signal CLKN. When the detection control module receives the forward POK signal to control the shutdown of the oscillator OSC and the charge pump module.

[0044] Please combine Figure 3 See also Figure 4 , Figure 4 FIG. 1 is a circuit diagram of a detection control module in an embodiment of the present invention. Figure 4 As shown, when the boost device is started, the power supply voltage V2 is less than the power supply voltage V1, and the power switching module switches the internal power supply V3 from the power supply voltage V1. At this time, the feedback signal of the internal power supply V3 is not enough to make the boost device system work normally after being judged by the PWM comparator module. The detection control module outputs the ENPUMP signal to make the charge pump oscillator module and the charge pump module start working. The charge pump oscillator outputs a periodic square wave signal to make the charge pump module work, and outputs a raised voltage signal CLKN to drive the second transistor Q2 (an N-type transistor shown in the figure) to turn on, forming a current loop between the power supply voltage V1 and the ground terminal, and charging the energy storage inductor L1. At this time, the current detected by the third transistor Q3 (an N-type transistor shown in the figure) in the detection control module is in a certain proportion to the current of the second transistor Q2. By combining the current detected by the third transistor with a constant current source Ibias A comparison is made to determine whether the current of the third transistor Q3 reaches the set value.

[0045] When the set current value is reached, the reverse signal of ENPUMP is output to turn off the charge pump oscillator module OSC and the charge pump module, and the CLKN signal turns off the second transistor Q2 and turns on the first transistor Q1. At this time, there is current on the energy storage inductor L1, and the current of the inductor L1 cannot change suddenly, forming a current loop between the power supply voltage V1 and the power supply voltage V2. The voltage VL formed at both ends of the inductor L1, the voltage VL and the power supply voltage V1 simultaneously transmit energy to the power supply voltage V2, so that the power supply voltage V2 rises. When the power supply voltage V2 is greater than the power supply voltage V1, the power switching module will switch the internal power supply V3 from the power supply voltage V2. Then, if the feedback signal of the internal power supply V3 is still insufficient to allow the boost device system to work normally after being judged by the PWM comparator module, the detection control module will continue to output the ENPUMP signal to let the charge pump oscillator and the charge pump start working again, until the power OK module determines that the voltage of the internal power supply V3 is normal and outputs the POK signal that can make the boost device work normally, and then turns off the detection control module, the charge pump oscillator module and the charge pump module, and the energy saving effect can also be achieved.

[0046] Example 2

[0047] Based on the above-mentioned embodiment 1, the startup of the DC / DC boost device at an ultra-low voltage V1 has been achieved. However, since the detection control module consumes a large amount of current, when V1 is at an ultra-low voltage, the third transistor Q3 (P-type transistor shown in the figure) will be in a critically turned-on state to form a large resistance. At this time, the current flows from the power supply voltage V1 through the third transistor Q3 to the power supply voltage V3, forming a large voltage drop on the power supply voltage V3. The excessively low power supply voltage V3 causes the detection and judgment module and other modules to work abnormally, resulting in functional failures.

[0048] Therefore, in an embodiment of the present invention, the power supply voltage V1 is introduced to power the detection and judgment module so that it can output the judgment signal normally, and then the processed ENPUMP signal is output to the charge pump oscillator and charge pump via the level shift module to make it work.

[0049] See also Figure 5 , Figure 5 FIG. 2 is a schematic diagram of another preferred embodiment of the ultra-low input voltage DC / DC boost device of the present invention. Figure 5As shown, the low voltage startup control module includes a detection control module (Sense Control), a level conversion module (Level Shift), a charge pump module (Charge Pump) and a charge pump oscillator module (OSC Pump) to achieve startup of an ultra-low power supply voltage V1.

[0050] Among them, the charge pump oscillator module generates a periodic square wave signal and outputs it to the charge pump module; the charge pump module is used to output a boosted overvoltage drive signal; the detection control module is used to control the switch of the oscillator and the charge pump; and the level conversion module is used to convert logic signals between different power supply voltages.

[0051] Similarly, other specific circuits in Embodiment 1 can also be referred to in Embodiment 2, and will not be described in detail here.

[0052] Please refer to Figure 2 The boost device of the prior art has certain requirements for the minimum V1 voltage when starting, but the invention can break through the limitation of the current technology on the minimum power supply voltage V1, and can ensure the normal startup of the boost device at a lower power supply voltage V1.

[0053] The above-described embodiments are only preferred embodiments of the present invention, and the embodiments are not intended to limit the patent protection scope of the present invention. Therefore, any equivalent structural changes made using the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. An ultra-low input voltage DC / DC boost device, used to boost an input DC power supply voltage V1 into a DC power supply voltage V2; characterized in that: include: A first transistor Q1, a second transistor Q2 and an inductor L1; the inductor L1 is connected between the input end of the DC power supply voltage V1 and a drain connection point SW of the first transistor Q1 and the second transistor Q2; the source of the first transistor Q1 is grounded, and the source of the second transistor Q2 is connected to the output end of the DC power supply voltage V2; An internal power supply module, used to generate a power supply voltage V3 for each module in the DC / DC boost device according to the power supply voltage V1 and the power supply voltage V2, and to judge the power supply threshold of the power supply voltage V3; it includes a power supply OK submodule, the power supply OK submodule is used to judge whether the power supply voltage V3 is greater than or equal to a predetermined threshold, if so, output a positive POK signal, otherwise, output a reverse POK signal; PWM generation module, generating a PWM square wave signal; The boost system driving control module controls the gates of the first transistor Q1 and the second transistor Q2 according to the PWM square wave signal and the POK signal received, if the received POK signal is a positive POK, according to the PWM square wave signal output signal corresponding to CLKP and CLKN to control the gates of the first transistor Q1 and the second transistor Q2; when CLKN controls the second transistor Q2 to turn on, and CLKP controls the first transistor to turn off, a loop is formed between the power supply voltage V1 and the ground terminal GND, at this time, the inductor L1 is charged to store energy; when CLKN controls the second transistor Q2 to turn off, and controls the first transistor Q1 to turn on, a loop is formed between the power supply voltages V1 and V2, and at this time, there is current in the inductor L1, because the current of the inductor L1 cannot suddenly change, the voltage difference VL formed at both ends of the inductor L1, and the input power supply voltage V1 simultaneously transmits energy to the output power supply voltage V2, so that the voltage of V2 rises; The low-voltage startup control module outputs a rising and periodic voltage signal CLKN to drive the second transistor Q2 to turn on and off according to the received reverse POK signal when the power supply voltage V3 does not reach the corresponding voltage threshold, so that the power supply voltage V3 rises until the power OK submodule detects that the power supply voltage V3 reaches the predetermined threshold, and then turns off the low-voltage startup control module; The low-voltage startup control module includes a detection control module, a charge pump module and a charge pump oscillator module; When the detection control module receives the reverse POK signal to control the start of the oscillator and the charge pump, the charge pump oscillator module is used to generate a periodic square wave signal and output it to the charge pump module to output a raised and periodic voltage signal CLKN, and when the detection control module receives the forward POK signal to control the shut down of the oscillator and the charge pump; The boost system drive control module includes a logic control module LOGIC and a drive module DRIVER; the logic control module LOGIC receives the POK signal and the PWM square wave signal output, and if the received POK signal is a positive POK, a drive signal DR1 is generated to the drive module DRIVER, and the drive module DRIVER outputs a signal CLKP and a signal CLKN.

2. The ultra-low input voltage DC / DC boost device according to claim 1, characterized in that: The low-voltage startup control module further includes a level conversion module connected between the detection control module and the charge pump oscillator module, for converting logic signals between different power supply voltages output from the detection control module.

3. The ultra-low input voltage DC / DC boost device according to claim 1, characterized in that: The internal power supply module also includes a power switching submodule, which switches to using the power supply voltage V1 to power the internal power supply voltage V3 when the power supply voltage V1 is greater than the power supply voltage V2; and switches to using the power supply voltage V2 to power the power supply voltage V3 when the power supply voltage V2 is greater than the power supply voltage V1.

4. The ultra-low input voltage DC / DC boost device according to claim 1, characterized in that: The internal power supply module also includes a third transistor Q3 and a fourth transistor Q4; the source of the third transistor Q3 is connected to the voltage V1, the source of the fourth transistor Q4 is connected to the voltage V2, and the drains of the third transistor Q3 and the fourth transistor Q4 output the power supply voltage V3; when the voltage V2 is greater than the voltage V1, the power switching submodule controls turning on the fourth transistor Q4 and turning off the third transistor Q3; when the voltage V2 is less than the voltage V1, the power switching submodule controls turning on the third transistor Q3 and turning off the fourth transistor Q4; the power OK submodule outputs the forward POK signal or the reverse POK signal according to the power supply voltage V3.

5. The ultra-low input voltage DC / DC boost device according to claim 1, characterized in that: The PWM generation module includes an error amplifier module EAMP, a slope compensation module, a reference voltage source module VREF, a PWM comparator module and an oscillator OSC; the reference voltage source module is used to generate a constant voltage reference signal; the slope compensation module processes the periodic square wave signal into a RAMP signal; The oscillator module is used to generate a periodic square wave signal; The error amplifier module amplifies the difference between VREF and the feedback signal FB of V2 and outputs a COMP signal; the PWM comparator module compares the COMP signal with the RAMP signal and outputs a PWM square wave signal.

6. The ultra-low input voltage DC / DC boost device according to claim 5, characterized in that: The PWM generation module also includes a first resistor RFB1 and a second resistor RFB2, which are connected in series between a power supply voltage V2 and a ground terminal GND; a connection point between the first resistor RFB1 and the second resistor RFB2 is a negative input terminal of the error amplifier module EAMP, and a positive input terminal of the error amplifier module EAMP is connected to a VREF signal generated by the reference voltage source module.

7. The ultra-low input voltage DC / DC boost device according to claim 1, characterized in that: It also includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 is connected in parallel between the DC power supply voltage V1 input terminal and the ground terminal GND; the second capacitor C2 is connected in parallel between the DC power supply voltage V2 output terminal and the ground terminal GND.

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