A start-up power supply module

Abstract

The utility model provides a kind of starting power supply module, it includes depletion mode NMOS tube, control module and power supply capacitor, the drain of depletion mode NMOS tube is connected with input voltage VIN, the grid of depletion mode NMOS tube is signal 203, signal 203 is accessed in control module, the source of depletion mode NMOS tube is signal 204, signal 204 is accessed in control module, the control module output signal VCC, signal VCC is connected with one end of power supply capacitor, the other end of power supply capacitor is grounded.The utility model includes depletion mode NMOS tube, because depletion mode NMOS tube has negative opening threshold, so it has lower starting and power supply voltage.

Description

Technical Field

[0001] This utility model belongs to the field of integrated circuit technology, and specifically relates to a startup power supply module. Background Technology

[0002] Traditional startup power supply circuits, such as Figure 1 As shown, it includes: a start-up resistor 100, an enhancement-mode NMOS transistor 101, a control module 102, and a power supply capacitor 103. The control module 102 controls the gate of the enhancement-mode NMOS transistor 101 to charge the power supply capacitor 103, thereby completing the start-up and power supply functions.

[0003] In recent years, with the development of related electronic devices, the requirements for chip startup and power supply have become increasingly stringent, thus necessitating the design of startup and power supply circuits that meet these requirements.

[0004] Because enhancement-mode NMOS transistors have a positive turn-on threshold.

[0005] Figure 1 middle: (Equation 1) Equation 2 is derived from Equation 1: (Equation 2).

[0006] Assuming VCC is the target startup and power supply voltage, the input voltage VIN in a traditional startup power supply circuit must be greater than VCC and the turn-on threshold voltage of the enhancement-mode NMOS transistor in order to complete startup and power supply.

[0007] Therefore, a circuit that can complete startup and power supply with a lower input voltage is needed. Utility Model Content The purpose of this invention is to provide a new startup power supply module; the module includes a depletion-type NMOS transistor, which has a negative turn-on threshold and therefore a lower startup and supply voltage.

[0008] To achieve the above objectives, this utility model provides a startup power supply module, which includes a depletion-type NMOS transistor, a control module, and a power supply capacitor. The drain terminal of the depletion-type NMOS transistor is connected to the input voltage VIN, the gate terminal of the depletion-type NMOS transistor is signal 203, and signal 203 is connected to the control module. The source terminal of the depletion-type NMOS transistor is signal 204, and signal 204 is connected to the control module. The control module outputs signal VCC, which is connected to one end of the power supply capacitor, and the other end of the power supply capacitor is grounded. Preferably, the control module includes a resistor, a PMOS transistor, a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, a diode, and a hysteresis comparator. One end of the resistor is connected to a signal, the drain of the second NMOS transistor, and the drain of the third NMOS transistor, respectively. The other end of the resistor is connected to the signal, one end of the resistor, and the source of the PMOS transistor. The gate of the PMOS transistor is connected to the other end of the resistor and the P-terminus of the diode. The drain of the PMOS transistor is connected to the drain of the first NMOS transistor, the gate of the first NMOS transistor, and the gate of the second NMOS transistor. The N-terminus of the diode is connected to the signal VCC and also to the positive input of the hysteresis comparator. The negative input of the hysteresis comparator is connected to the reference voltage VREF, and the output of the hysteresis comparator is connected to the gate of the third NMOS transistor. The sources of the second and third NMOS transistors are grounded. The first and second NMOS transistors are mirror images of each other.

[0009] Preferably, the two ends of the resistor are connected to signal 203 and signal 204 respectively. When the power is first turned on, the Vgs of the depletion-type NMOS transistor is 0V, which is greater than its negative turn-on threshold. The voltage at the drain of the depletion-type NMOS transistor and signal 204 begins to rise, charging the power supply capacitor through the resistor and diode.

[0010] Preferably, when the voltage drop across the resistor caused by the charging current is greater than the turn-on threshold of the PMOS transistor, the PMOS transistor turns on and flows through the first NMOS transistor. Because the first and second NMOS transistors are mirror images of each other, current will flow through the resistor and into the drain of the second NMOS transistor. The voltage across the resistor caused by the current flowing through the resistor makes the Vgs of the depletion-type NMOS transistor less than the negative turn-on threshold, and the depletion-type NMOS transistor turns off, forming a closed-loop feedback charging method.

[0011] Preferably, assuming the input hysteresis voltage of the hysteresis comparator is Δ, due to the charging relationship between the current and the power supply capacitor, the VCC voltage gradually increases, and the hysteresis comparator detects that the VCC voltage is greater than Δ. When the hysteresis comparator outputs a high level, the third NMOS transistor turns on, increasing the current flowing through the resistor. This causes the Vgs of the depletion-type NMOS transistor to fall below the negative turn-on threshold, turning it off. As the VCC voltage gradually decreases, the hysteresis comparator detects that the VCC voltage is less than... When the hysteresis comparator outputs a low level, the third NMOS transistor is turned off, and the current flowing through the resistor decreases to 0. This causes the Vgs of the depletion-type NMOS transistor to be greater than the negative turn-on threshold, and the depletion-type NMOS transistor turns on, starting to charge the power supply capacitor.

[0012] Preferably, a depletion-type NMOS transistor can be replaced by a field-effect transistor.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The startup power supply module disclosed in this utility model includes a depletion-type NMOS transistor. Because the depletion-type NMOS transistor has a negative turn-on threshold, the startup power supply module provided by this utility model has a lower startup and supply voltage compared to traditional circuits. Attached Figure Description

[0014] Figure 1 A schematic diagram of a conventional startup power supply circuit in the background art is shown; Figure 2 A schematic diagram of the startup power supply circuit in this utility model is shown; Figure 3 A circuit diagram of the control module in this utility model is shown. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings.

[0016] like Figure 2 and Figure 3 As shown, this utility model discloses a startup power supply module, which includes a depletion-type NMOS transistor 200, a control module 201, and a power supply capacitor 202. The drain terminal of the depletion-type NMOS transistor 200 is connected to the input voltage VIN, the gate terminal of the depletion-type NMOS transistor 200 is signal 203, and signal 203 is connected to the control module 201. The source terminal of the depletion-type NMOS transistor 200 is signal 204, and signal 204 is connected to the control module 201. The control module 201 outputs signal VCC, which is connected to one end of the power supply capacitor 202, and the other end of the power supply capacitor 202 is grounded. The startup power supply module provided by this utility model has a lower startup and power supply voltage.

[0017] The control module 201 includes resistors 300 and 301, a PMOS transistor 302, a first NMOS transistor 304, a second NMOS transistor 305, a third NMOS transistor 306, a diode 303, and a hysteresis comparator 307. One end of resistor 300 is connected to signal 203, the drain of the second NMOS transistor 305, and the drain of the third NMOS transistor 306, respectively. The other end of resistor 300 is connected to signal 204, one end of resistor 301, and the source of PMOS transistor 302. The gate of PMOS transistor 302 is connected to the other end of resistor 301 and the P-terminal of diode 303. The drain of PMOS transistor 302 is connected to the drain of first NMOS transistor 304, the gate of first NMOS transistor 304, and the gate of second NMOS transistor 305; the N-terminal of diode 303 is connected to signal VCC and also to the positive input of hysteresis comparator 307; the negative input of hysteresis comparator 307 is connected to reference voltage VREF, and the output of hysteresis comparator 307 is connected to the gate of third NMOS transistor 306; the sources of second NMOS transistor 305 and third NMOS transistor 306 are grounded; first NMOS transistor 304 and second NMOS transistor 305 are mirror images of each other.

[0018] The two ends of resistor 300 are connected to signal 203 and signal 204 respectively. When the power is first turned on, the Vgs of the depletion-type NMOS transistor 200 is 0V, which is greater than its negative turn-on threshold. The voltage at the drain of the depletion-type NMOS transistor 200 and signal 204 begins to rise, charging the power supply capacitor 202 through resistor 301 and diode 303.

[0019] When the voltage drop across resistor 301 caused by the charging current exceeds the turn-on threshold of PMOS transistor 302, PMOS transistor 302 turns on and flows through the first NMOS transistor 304. Because of the mirror relationship between the first NMOS transistor 304 and the second NMOS transistor 305, current flows through resistor 300 and into the drain of the second NMOS transistor 305. The voltage across resistor 300 caused by the current flowing through resistor 300 makes the Vgs of the depletion-type NMOS transistor 200 less than the negative turn-on threshold, and the depletion-type NMOS transistor 200 turns off, forming a closed-loop feedback charging method.

[0020] Assuming the charging current of capacitor 202 is I1, the resistance of resistor 301 is R1, and the threshold voltage of PMOS transistor 302 is Vth1, then we will get: .

[0021] Assuming the input hysteresis voltage of the hysteresis comparator 307 is Δ, due to the charging relationship of the power supply capacitor 202, the VCC voltage gradually increases. The hysteresis comparator 307 detects that the VCC voltage is greater than Δ. When the hysteresis comparator 307 outputs a high level, the third NMOS transistor 306 is turned on, increasing the current flowing through resistor 300. This causes the Vgs of the depletion-type NMOS transistor 200 to fall below the negative turn-on threshold, turning off the depletion-type NMOS transistor 200. As the VCC voltage gradually decreases, the hysteresis comparator 307 detects that the VCC voltage is less than... When the hysteresis comparator 307 outputs a low level, the third NMOS transistor 306 is turned off, the current flowing through the resistor 300 is reduced to 0, the Vgs of the depletion-type NMOS transistor 200 is greater than the negative turn-on threshold, the depletion-type NMOS transistor 200 is turned on, and the power supply capacitor 202 begins to charge.

[0022] The depletion-type NMOS transistor 200 can be replaced by a field-effect transistor, and the specific connection method can also refer to the connection method disclosed in this utility model.

[0023] In the startup power supply module z disclosed in this utility model, because the depletion-type NMOS transistor has a negative turn-on threshold, the startup power supply module provided by this utility model has a lower startup and supply voltage compared with the traditional circuit.

[0024] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A startup power supply module, characterized in that, The system includes a depletion-type NMOS transistor (200), a control module (201), and a power supply capacitor (202). The drain of the depletion-type NMOS transistor (200) is connected to the input voltage VIN. The gate of the depletion-type NMOS transistor (200) is a signal (203), which is connected to the control module (201). The source of the depletion-type NMOS transistor (200) is a signal (204), which is connected to the control module (201). The control module (201) outputs a signal VCC, which is connected to one end of the power supply capacitor (202). The other end of the power supply capacitor (202) is grounded.

2. The startup power supply module according to claim 1, characterized in that, The control module (201) includes a resistor (300), a PMOS transistor (302), a first NMOS transistor (304), a second NMOS transistor (305), a third NMOS transistor (306), a diode (303), and a hysteresis comparator (307). One end of the resistor (300) is connected to the signal (203), the drain of the second NMOS transistor (305), and the drain of the third NMOS transistor (306), respectively. The other end of the resistor (300) is connected to the signal (204), one end of the resistor (301), and the source of the PMOS transistor (302). The gate of the PMOS transistor (302) is connected to the other end of the resistor (301) and the diode (307). 3) The P terminal is connected, the drain terminal of the PMOS transistor (302) is connected to the drain terminal of the first NMOS transistor (304), the gate terminal of the first NMOS transistor (304), and the gate terminal of the second NMOS transistor (305); the N terminal of the diode (303) is connected to the signal VCC and also to the positive input terminal of the hysteresis comparator (307); the negative input terminal of the hysteresis comparator (307) is connected to the reference voltage VREF, and the output terminal of the hysteresis comparator (307) is connected to the gate terminal of the third NMOS transistor (306); the source terminals of the second NMOS transistor (305) and the third NMOS transistor (306) are grounded; the first NMOS transistor (304) and the second NMOS transistor (305) are mirror images of each other.

3. A startup power supply module according to claim 2, characterized in that, The two ends of the resistor (300) are connected to the signal (203) and the signal (204) respectively. When the power is turned on, the Vgs of the depletion-type NMOS transistor (200) is 0V, which is greater than its negative turn-on threshold. The voltage of the drain of the depletion-type NMOS transistor (200) and the signal (204) begins to rise, and the power supply capacitor (202) is charged through the resistor (301) and the diode (303).

4. A startup power supply module according to claim 3, characterized in that, When the voltage drop across the resistor (301) caused by the charging current is greater than the turn-on threshold of the PMOS transistor (302), the PMOS transistor (302) turns on and flows through the first NMOS transistor (304). Because of the mirror relationship between the first NMOS transistor (304) and the second NMOS transistor (305), current will flow through the resistor (300) and into the drain of the second NMOS transistor (305). The voltage formed on the resistor (300) by the current flowing through the resistor (300) makes the Vgs of the depletion-type NMOS transistor (200) less than the negative turn-on threshold, and the depletion-type NMOS transistor (200) turns off, forming a closed-loop feedback charging method.

5. A startup power supply module according to claim 4, characterized in that, Assuming the input hysteresis voltage of the hysteresis comparator (307) is Δ, due to the charging relationship of the current to the power supply capacitor (202), the VCC voltage gradually increases, and the hysteresis comparator (307) detects that the VCC voltage is greater than Δ. When the hysteresis comparator (307) outputs a high level, the third NMOS transistor (306) is turned on, and the current flowing through the resistor (300) increases, causing the Vgs of the depletion-type NMOS transistor (200) to be less than the negative turn-on threshold, and the depletion-type NMOS transistor (200) is turned off; when the VCC voltage gradually decreases, the hysteresis comparator (307) detects that the VCC voltage is less than When the hysteresis comparator (307) outputs a low level, the third NMOS transistor (306) is turned off, the current flowing through the resistor (300) will decrease to 0, the Vgs of the depletion-type NMOS transistor (200) will be greater than the negative turn-on threshold, the depletion-type NMOS transistor (200) will turn on, and start charging the power supply capacitor (202).

6. A startup power supply module according to claim 5, characterized in that, The depletion-type NMOS transistor (200) is replaced by a field-effect transistor.

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