Low-cost 4g module power supply circuit

Abstract

The utility model discloses a low -cost 4G module power supply circuit relates to 4G module power supply technical field, including DCDC power supply circuit, diode voltage reducing circuit, filter voltage stabilizing circuit and 4G module power supply circuit, DCDC power supply circuit is used for converting 5V for 12V input voltage, diode voltage reducing circuit is constituted by two series diodes, and 5V voltage falls to 3.8V, filter voltage stabilizing circuit is used for filtering voltage noise, and 4G module power supply circuit is used for providing electrostatic protection and secondary filtering. The utility model discloses through utilizing the 12V of having in equipment to 5V power, through the simple diode voltage reducing mode replacement special 3.8V DCDC conversion circuit, reaches the beneficial effect of reducing hardware cost, reducing energy loss, and simplifying circuit structure saves the PCB space.

Description

Technical Field

[0001] This utility model relates to the field of 4G module power supply technology, specifically a low-cost 4G module power supply circuit. Background Technology

[0002] With the widespread application of 4G communication technology, 4G modules have become core communication components for various smart devices. The standard power supply voltage for 4G modules on the market is 3.8V, but the power supply voltage commonly used on the motherboards of existing devices is 12V, 5V or 3.3V, lacking a directly matched 3.8V voltage output.

[0003] In existing technologies, a separate DC-DC converter circuit is typically required to convert the motherboard voltage to 3.8V to meet the power supply requirements of the 4G module. While this solution is feasible, it has significant drawbacks: First, adding a separate DC-DC converter circuit directly increases the number of components and procurement costs, leading to an increase in the overall hardware cost of the device. Second, each additional DC-DC converter circuit introduces its inherent switching losses and static power consumption, resulting in a decrease in the overall power supply efficiency from the power supply to the module. Finally, the dedicated DC-DC circuit structure is relatively complex, requiring a large PCB area, which is not conducive to the miniaturization design of the device.

[0004] In response, we propose a low-cost 4G module power supply circuit. Utility Model Content

[0005] The purpose of this invention is to provide a low-cost 4G module power supply circuit to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: including a DC-DC power supply circuit, a diode step-down circuit, a filter and voltage regulator circuit, and a 4G module power supply circuit;

[0007] The DC-DC power supply circuit has a 12V DC input and a 5V DC output. The diode step-down circuit has an input connected to the output of the DC-DC power supply circuit and outputs a 3.8V DC output. The filter and voltage regulator circuit has an input connected to the output of the diode step-down module to filter out interference signals in the voltage. The 4G module power supply circuit has an input connected to the output of the filter and voltage regulator module and an output connected to the power supply pin of the 4G module.

[0008] Preferably, the DC-DC power supply circuit includes chip U8, inductor L2, resistor R1 and resistor R2;

[0009] The inductor L2 is connected between the SW pin of the chip U8 and the 5V output terminal, and the resistors R1 and R2 are connected in series between the 5V output terminal and ground, with their voltage divider node connected to the FB pin of the chip U8.

[0010] Preferably, the DC-DC power supply circuit further includes capacitor C109, capacitor C106, capacitor C110, and resistor R64;

[0011] The capacitor C109 is connected in parallel between the 12V DC power supply and ground. The capacitor C106 is connected between the BST pin and the SW pin of the chip U8. The capacitor C110 is connected in parallel between the 5V output terminal and ground. The resistor R64 is connected between the 12V DC power supply and the EN pin of the chip U8.

[0012] Preferably, the diode step-down circuit includes capacitor C269, diode D43, and diode D44;

[0013] One end of capacitor C269 is connected to the 5V output terminal, and the other end is grounded. The anode of diode D43 is connected to the 5V output terminal, and the cathode is connected to the anode of diode D44. The cathode of diode D44 is connected to the 3.8V output terminal.

[0014] Preferably, the filter and voltage regulator circuit includes capacitors C270, C271, C272, and C273, and a ferrite bead FB8.

[0015] One end of capacitors C272 and C273 is connected to 3.8V, and the other end is grounded. One end of the 3.8V side of the ferrite bead FB8 is connected to the common node, and the other end is connected to the common node on the 4G_3V8 side. One end of capacitors C270 and C271 is connected to 4G_3V8, and the other end is grounded.

[0016] Preferably, the 4G module power supply circuit includes capacitor C168, capacitor C169, capacitor C170, capacitor C171 and diode D21;

[0017] One end of capacitors C188, C189, C190, and C191 is connected to the 4G_3V8 power supply terminal, and the other end is grounded; diode D21 is connected in parallel between the 4G module power supply 4G_3V8 voltage node and ground.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] This invention utilizes an existing 12V to 5V DC-DC converter circuit, connecting two ordinary diodes in series at its output for voltage reduction. This allows the 5V voltage to be stably reduced to the 3.8V required by the 4G module, eliminating the need for an additional dedicated 3.8V DC-DC converter circuit and reducing hardware costs. Reducing the number of DC-DC conversion stages avoids the switching losses and static power consumption inherent in this stage, thereby reducing energy loss throughout the power supply path and improving the overall power supply efficiency from the power supply to the 4G module. The circuit structure is simple; this invention uses only common and low-cost components such as diodes and capacitors to achieve voltage reduction and filtering regulation, saving space on the motherboard. Attached Figure Description

[0020] Figure 1 A schematic diagram of a low-cost 4G module power supply circuit.

[0021] Figure 2 Circuit diagram for powering a DC-DC converter;

[0022] Figure 3 This is a diagram of a diode step-down circuit.

[0023] Figure 4 This is a diagram of a filter and voltage regulator circuit.

[0024] Figure 5 Circuit diagram for power supply to 4G module. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] In the description of this utility model, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] Example 1

[0028] Please see Figure 1-5 One embodiment of this utility model includes a DC-DC power supply circuit, a diode step-down circuit, a filter and voltage regulator circuit, and a 4G module power supply circuit.

[0029] The DC-DC power supply circuit has a 12V DC input and a 5V DC output. The diode step-down circuit has its input connected to the output of the DC-DC power supply circuit and outputs a 3.8V DC voltage. The filter and voltage regulator circuit has its input connected to the output of the diode step-down module to filter out interference signals in the voltage. The 4G module power supply circuit has its input connected to the output of the filter and voltage regulator module and its output connected to the power supply pin of the 4G module.

[0030] The DC-DC power supply circuit converts the external 12V input voltage into a stable 5V DC voltage. The diode step-down circuit uses the fixed voltage drop characteristic of the diode to reduce the 5V voltage to the 3.8V required by the 4G module. The filter and voltage regulation circuit filters out high and low frequency noise in the voltage. The 4G module power supply circuit realizes electrostatic protection and secondary filtering, and finally provides a clean and stable 3.8V power supply for the 4G module.

[0031] Furthermore, the DC-DC power supply circuit includes chip U8, inductor L2, resistor R1, and resistor R2;

[0032] Inductor L2 is connected between the SW pin of chip U8 and the 5V output terminal. Resistors R1 and R2 are connected in series between the 5V output terminal and ground, and their voltage divider node is connected to the FB pin of chip U8.

[0033] The output voltage of chip U8 is calculated as follows: Vout = 0.8V × [1 + (R1 / R2)], where 0.8V is the reference voltage of the internal voltage comparator of chip U8.

[0034] Specifically, inductor L2, in conjunction with the internal circuitry of chip U8, enables energy storage and release, and completes voltage conversion. Resistors R1 and R2 are connected in series between the 5V output node and ground, and their voltage divider signal is fed back to the FB pin of chip U8. The output voltage accuracy is adjusted by the formula Vout=0.8V×[1+(R1 / R2)] to ensure stable 5V output.

[0035] Furthermore, the DC-DC power supply circuit also includes capacitors C109, C106, C110, and resistor R64.

[0036] Capacitor C109 is connected in parallel between the 12V DC power supply and ground. Capacitor C106 is connected between the BST pin and the SW pin of chip U8. Capacitor C110 is connected in parallel between the 5V output terminal and ground. Resistor R64 is connected between the 12V DC power supply and the EN pin of chip U8.

[0037] Among them, capacitor C109 is connected in parallel between the 12V input voltage and ground to filter out low-frequency noise in the input voltage and stabilize the power supply. The EN pin of chip U8 is connected to the 12V voltage through resistor R64 to ensure that chip U8 starts working automatically after power-on. Capacitor C106 provides the drive voltage for the internal MOSFET of chip U8 to ensure efficient conversion of the chip. Capacitor C110 is connected in parallel between the 5V output node and ground to filter out high-frequency noise after conversion.

[0038] Furthermore, the diode step-down circuit includes capacitor C269, diode D43, and diode D44;

[0039] One end of capacitor C269 is connected to the 5V output terminal, and the other end is grounded. The anode of diode D43 is connected to the 5V output terminal, and the cathode is connected to the anode of D44. The cathode of diode D44 is connected to the 3.8V output terminal.

[0040] Among them, diodes D43 and D44 are both of the 1N4148W model. The fixed voltage drop of this model diode when forward conduction is 0.6V. After the two are connected in series, the total voltage drop is 1.2V. The 5V voltage is output as 3.8V after passing through the series diodes, which just matches the standard power supply voltage of the 4G module. The capacitor C269 is connected in parallel between the 3.8V output node and ground to filter out the voltage fluctuations generated during the diode voltage drop process and initially stabilize the 3.8V voltage.

[0041] Furthermore, the filter and voltage regulator circuit includes capacitors C270, C271, C272, and C273, and a ferrite bead FB8.

[0042] One end of capacitors C272 and C273 is connected to 3.8V, and the other end is grounded. One end of ferrite bead FB8 is connected to the common node on the 3.8V side, and the other end is connected to the common node on the 4G_3V8 side. One end of capacitors C270 and C271 is connected to 4G_3V8, and the other end is grounded.

[0043] Among them, the FB8 ferrite bead is used to suppress high-frequency electromagnetic interference in the 100MHz band and prevent noise from being conducted from the power supply to the 4G module; capacitors C270 and C271 are responsible for filtering out low-frequency ripple in the 3.8V voltage; capacitors C272 and C273 are responsible for filtering out high-frequency noise. Through their synergistic effect, they achieve wide-band noise filtering and ensure the purity of power supply.

[0044] Furthermore, the 4G module power supply circuit includes capacitors C168, C169, C170, C171, and diode D21.

[0045] One end of capacitors C188, C189, C190, and C191 is connected to the 4G_3V8 power supply terminal, and the other end is grounded. Diode D21 is connected in parallel between the 4G module power supply 4G_3V8 voltage node and ground.

[0046] Among them, diode D21 plays an anti-static protection role to prevent external electrostatic shock from damaging the 4G module. Capacitors C168, C169, C170 and C171 further filter residual noise in different frequency bands, while optimizing the transient response speed of voltage to ensure stable power supply to the 4G module during communication and avoid communication interruption due to voltage fluctuations.

[0047] In summary, when an external 12V DC power supply is input, the DC-DC power supply circuit first efficiently converts it into a stable 5V DC voltage. This 5V voltage then enters the diode buck circuit, where two series diodes generate a fixed voltage drop of 1.2V, thereby accurately outputting the 3.8V voltage required by the 4G module. This voltage then passes through a filter and voltage regulator circuit, where a ferrite bead FB8 suppresses high-frequency interference, and multiple sets of capacitors work together to filter out high and low-frequency noise, ensuring voltage purity. Finally, the 4G module power supply circuit provides a stable and reliable 3.8V power supply to the 4G module through an anti-static diode and further filtering.

[0048] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0049] Finally, it should be noted that the above-described embodiments are merely specific implementations of this utility model, used to illustrate the technical solution of this utility model, and not to limit it. The protection scope of this utility model is not limited thereto. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this utility model. These modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A low-cost 4G module power supply circuit, characterized in that, Includes DC-DC power supply circuit, diode step-down circuit, filter and voltage regulator circuit and 4G module power supply circuit; The DC-DC power supply circuit has a 12V DC input and a 5V DC output. The diode step-down circuit has an input connected to the output of the DC-DC power supply circuit and outputs a 3.8V DC output. The filter and voltage regulator circuit has an input connected to the output of the diode step-down module to filter out interference signals in the voltage. The 4G module power supply circuit has an input connected to the output of the filter and voltage regulator module and an output connected to the power supply pin of the 4G module.

2. The low-cost 4G module power supply circuit according to claim 1, characterized in that, The DC-DC power supply circuit includes chip U8, inductor L2, resistor R1 and resistor R2; The inductor L2 is connected between the SW pin of the chip U8 and the 5V output terminal, and the resistors R1 and R2 are connected in series between the 5V output terminal and ground, with their voltage divider node connected to the FB pin of the chip U8.

3. The low-cost 4G module power supply circuit according to claim 2, characterized in that, The DC-DC power supply circuit also includes capacitors C109, C106, and C110, and resistor R64. The capacitor C109 is connected in parallel between the 12V DC power supply and ground. The capacitor C106 is connected between the BST pin and the SW pin of the chip U8. The capacitor C110 is connected in parallel between the 5V output terminal and ground. The resistor R64 is connected between the 12V DC power supply and the EN pin of the chip U8.

4. The low-cost 4G module power supply circuit according to claim 1, characterized in that, The diode step-down circuit includes capacitor C269, diode D43, and diode D44; One end of capacitor C269 is connected to the 5V output terminal, and the other end is grounded. The anode of diode D43 is connected to the 5V output terminal, and the cathode is connected to the anode of diode D44. The cathode of diode D44 is connected to the 3.8V output terminal.

5. The low-cost 4G module power supply circuit according to claim 1, characterized in that, The filter and voltage regulator circuit includes capacitors C270, C271, C272, and C273, and a ferrite bead FB8. One end of capacitors C272 and C273 is connected to 3.8V, and the other end is grounded. One end of the 3.8V side of the ferrite bead FB8 is connected to the common node, and the other end is connected to the common node on the 4G_3V8 side. One end of capacitors C270 and C271 is connected to 4G_3V8, and the other end is grounded.

6. The low-cost 4G module power supply circuit according to claim 1, characterized in that, The 4G module power supply circuit includes capacitors C168, C169, C170, C171, and diode D21. One end of capacitors C188, C189, C190, and C191 is connected to the 4G_3V8 power supply terminal, and the other end is grounded. Diode D21 is connected in parallel between the 4G module power supply 4G_3V8 voltage node and ground.

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