SD card circuit based on foresight all-in-one machine

Abstract

The utility model belongs to the technical field of SD (Secure Digital) card circuits, and particularly relates to an SD card circuit based on a foresight all-in-one machine, which comprises a power supply circuit comprising a step-down circuit, and the step-down circuit converts 12V voltage into 3.3 V voltage and outputs the 3.3 V voltage; the input end of the load switch circuit is connected with the output end of the step-down circuit; and the SD card circuit comprises a card slot for plugging an SD card, the card slot is connected with the output end of the load switch circuit, and the output end of the SD card circuit is connected with the GPIO of the foresight all-in-one machine SOC. According to the SD card circuit based on the foresight all-in-one machine, the stability and the anti-interference capability of SD card data transmission are improved, the SOC chip communicated with the SD card can be effectively protected, and the increased cost caused by abnormal damage of the SD card can be saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of SD card circuits, and in particular relates to an SD card circuit based on a front-view integrated machine. Background Art

[0002] SD cards have the characteristics of light weight, small size, large capacity, high flexibility and high security.

[0003] SD cards have serial and random read capabilities, can be accessed through a speed-optimized serial interface, and have reliable data transmission. SD cards are widely used in daily life and have become a more common data storage card. The reason why they are so widely used is that they are not only low-priced, have large storage capacity, but are also easy to use and highly secure.

[0004] Currently, the interface of electronic devices with SD cards on the market is not built-in in the CPU. The use of SD cards is achieved through the USB to MMC interface. If used frequently, it will lead to abnormal reading and writing or slow reading and writing speeds. In addition, the back-end chip will be damaged due to weak anti-interference ability, thereby increasing the corresponding cost. Utility Model Content

[0005] The purpose of the utility model is to provide an SD card circuit with anti-interference, so as to solve the technical problem that the SD card in the prior art is prone to abnormal reading and writing or damage to the SD card. In order to solve the above problems, the utility model provides an SD card circuit with anti-interference, improves the stability and anti-interference ability of SD card data transmission, can effectively protect the SOC chip communicating with it, and can also save the increased cost caused by abnormal damage to the SD card.

[0006] The utility model provides an SD card circuit based on a front-view integrated machine, which communicates with the SOC of the front-view integrated machine, including:

[0007] A power supply circuit, the power supply circuit comprising a step-down circuit, the step-down circuit converts a 12V voltage into a 3.3V voltage output;

[0008] A load switch circuit, wherein an input end of the load switch circuit is connected to an output end of the step-down circuit;

[0009] An SD card circuit, wherein the SD card circuit comprises a card slot for inserting an SD card, wherein the card slot is connected to the output end of the load switch circuit, and the output end of the SD card circuit is connected to the GPIO of the front-view integrated machine SOC.

[0010] Furthermore, the load switch circuit includes a load chip U1, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4 and a diode D1. The first pin of the load chip U1 is connected to the output voltage of the step-down circuit, one end of the capacitor C1 and the capacitor C2 are both connected to the first pin of the load chip U1, one end of the capacitor C1 and the capacitor C2 are both grounded, the second pin of the load chip U1 is grounded, and the third pin of the load chip U1 is connected to the enable signal SD_EN, so that the load switch circuit provides 3V3_SD power supply for the SD card circuit, the fourth pin of the load chip U1 is connected to one end of the capacitor C3, and the other end of the capacitor C3 is grounded, the sixth pin of the load chip U1 is connected to the positive electrode of the diode D1, the negative electrode of the diode D1 is connected to the capacitor C4, the other end of the capacitor C4 is grounded, and the negative electrode of the diode D1 outputs the 3V3_SD power supply connected to the SD card circuit.

[0011] Furthermore, the load chip U1 is of model TPS22810.

[0012] Furthermore, the card slot of the SD card includes a clock signal SD_CLK, a data signal SD_DATA, a command signal SD_CMD, and a card insertion detection signal SD_DET.

[0013] Furthermore, the data signal SD_DATA includes: a data signal SD_DATA0, a data signal SD_DATA1, a data signal SD_DATA2, a data signal SD_DATA3, and a data signal SD_DATA4.

[0014] Furthermore, the SD card circuit also includes: resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7 and capacitor C5, capacitor C6, the fourth pin of the SD card slot is connected to the 3V3_SD power supply, capacitor C5 and capacitor C6 are both connected to the fourth pin of the SD card slot, the other ends of capacitor C5 and capacitor C6 are both grounded, one end of resistor R2 is connected to the first pin of the SD card slot, the other end of resistor R2 is connected to the receiving end of the data signal SD_DATA2, one end of resistor R3 is connected to the second pin of the SD card slot, and the other end of resistor R3 is connected to the data signal SD_DA The receiving end of TA3, one end of the resistor R4 is connected to the third pin of the SD card slot, the other end of the resistor R4 is connected to the receiving end of the command signal SD_CMD, one end of the resistor R5 is connected to the fifth pin of the SD card slot, the other end of the resistor R5 is connected to the receiving end of the clock signal SD_CLK, the sixth pin of the SD card slot is grounded, one end of the resistor R6 is connected to the seventh pin of the SD card slot, the other end of the resistor R6 is connected to the receiving end of the data signal SD_DATA0, one end of the resistor R7 is connected to the eighth pin of the SD card slot, and the other end of the resistor R7 is connected to the receiving end of the data signal SD_DATA1.

[0015] Furthermore, the SD card circuit also includes: a resistor R1, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13 and a TVS tube D2, a TVS tube D3, a TVS tube D4, a TVS tube D5, a TVS tube D6 and a TVS tube D7. One ends of the resistors R1, R8, R9, R10, R11, R12 and R13 are all connected to a power supply 3V3_SD, the other end of the resistor R1 is connected to a card insertion detection signal SD_DET, the other end of the resistor R8 is respectively connected to a receiving end of a data signal SD_DATA2 and a first pin of the TVS tube D2, the second pin of the TVS tube D2 is grounded, and the other end of the resistor R9 is respectively connected to a data signal SD_DATA3. The receiving end of the resistor R10 is respectively connected to the receiving end of the command signal SD_CMD and the first pin of the TVS tube D4, and the second pin of the TVS tube D4 is grounded. The other end of the resistor R11 is respectively connected to the receiving end of the clock signal SD_CLK and the first pin of the TVS tube D5, and the second pin of the TVS tube D5 is grounded. The other end of the resistor R12 is respectively connected to the receiving end of the data signal SD_DATA0 and the first pin of the TVS tube D6, and the second pin of the TVS tube D6 is grounded. The other end of the resistor R13 is respectively connected to the receiving end of the data signal SD_DATA1 and the first pin of the TVS tube D7, and the second pin of the TVS tube D7 is grounded.

[0016] Furthermore, the models of TVS tube D2, TVS tube D3, TVS tube D4, TVS tube D5, TVS tube D6, and TVS tube D7 are all TPD1E05U06QDPYRQ1.

[0017] The beneficial effects of the utility model are:

[0018] The SD card circuit based on the front-view integrated machine of the utility model mainly communicates with the SOC of the front-view integrated machine and is used to store sampled data. By adding matching resistors and TVS tubes at the SD card signal end, the stability and anti-interference ability of the SD card data transmission are improved, the SOC chip communicating with it can be effectively protected, and the increased cost caused by abnormal damage to the SD card can be saved.

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is a schematic diagram of the power supply framework of the SD card circuit based on the front-view integrated machine of the utility model;

[0022] Figure 2 It is a signal transmission schematic diagram of the SD card circuit based on the front-view integrated machine of the utility model;

[0023] Figure 3 This is a load switch circuit diagram of the SD card circuit based on the front-view integrated machine of the utility model;

[0024] Figure 4 The utility model is an SD card circuit diagram of the SD card circuit based on the front-view integrated machine.

[0025] In the figure:

[0026] 1. Power supply circuit; 2. Load switch circuit; 3. SD card circuit. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] like Figures 1 to 4 As shown, it is the best embodiment of the utility model, an SD card circuit based on the front-view integrated machine, communicating with the SOC of the front-view integrated machine, including:

[0029] The power supply circuit 1 includes a step-down circuit, which converts a 12V voltage into a 3.3V voltage output;

[0030] A load switch circuit 2, wherein an input end of the load switch circuit 2 is connected to an output end of the step-down circuit;

[0031] SD card circuit 3, SD card circuit 3 includes a card slot for inserting an SD card, the card slot is connected to the output end of the load switch circuit 2, and the output end of the SD card circuit 3 is connected to the GPIO of the front-view integrated machine SOC.

[0032] like Figure 3 As shown, the load switch circuit 2 includes a load chip U1, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4 and a diode D1. The first pin of the load chip U1 is connected to the output voltage of the buck circuit, one end of the capacitor C1 and the capacitor C2 are connected to the first pin of the load chip U1, one end of the capacitor C1 and the capacitor C2 are grounded, the second pin of the load chip U1 is grounded, and the third pin of the load chip U1 is connected to the enable signal SD_EN, so that the load switch circuit 2 provides 3V3_SD power supply for the SD card circuit 3. When the SD_EN signal is high, the load switch is turned on, and when the SD_EN signal is low, the load switch is turned off, and the SD card circuit is not powered, thereby improving the safety of the circuit. The fourth pin of the load chip U1 is connected to one end of the capacitor C3, and the other end of the capacitor C3 is grounded. The sixth pin of the load chip U1 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to the capacitor C4, and the other end of the capacitor C4 is grounded. The negative electrode of the diode D1 outputs the 3V3_SD power supply connected to the SD card circuit 3. The model of the load chip U1 is TPS22810.

[0033] like Figure 4As shown, the card slot of the SD card includes a clock signal SD_CLK, a data signal SD_DATA, a command signal SD_CMD, and a card insertion detection signal SD_DET. The data signal SD_DATA includes: data signal SD_DATA0, data signal SD_DATA1, data signal SD_DATA2, data signal SD_DATA3, and data signal SD_DATA4.

[0034] SD card circuit 3 also includes: resistor R2, resistor R3, resistor R4, resistor R5, resistor R6, resistor R7 and capacitor C5, capacitor C6, the fourth pin of the SD card slot is connected to the power supply of 3V3_SD, capacitor C5 and capacitor C6 are both connected to the fourth pin of the SD card slot, the other ends of capacitor C5 and capacitor C6 are both grounded, the function of the capacitor is to filter and make the output stable, one end of resistor R2 is connected to the first pin of the SD card slot, the other end of resistor R2 is connected to the receiving end of data signal SD_DATA2, one end of resistor R3 is connected to the second pin of the SD card slot, the other end of resistor R3 is connected to the receiving end of data signal SD_DATA3, one end of resistor R4 is connected to the third pin of the SD card slot, and the other end of resistor R4 is connected to the command The receiving end of the signal SD_CMD, one end of the resistor R5 is connected to the fifth pin of the SD card slot, the other end of the resistor R5 is connected to the receiving end of the clock signal SD_CLK, the sixth pin of the SD card slot is grounded, one end of the resistor R6 is connected to the seventh pin of the SD card slot, the other end of the resistor R6 is connected to the receiving end of the data signal SD_DATA0, one end of the resistor R7 is connected to the eighth pin of the SD card slot, the other end of the resistor R7 is connected to the receiving end of the data signal SD_DATA1, resistors R2, R3, R4, R5, R6, and R7 are signal matching resistors with a resistance of 33Ω, which can not only improve the quality of signal transmission and avoid oscillation, but also reduce high-frequency noise and overshoot, thereby ensuring stable data transmission.

[0035] The SD card circuit 3 also includes: a resistor R1, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13 and a TVS tube D2, a TVS tube D3, a TVS tube D4, a TVS tube D5, a TVS tube D6, and a TVS tube D7. One end of the resistor R1, the resistor R8, the resistor R9, the resistor R10, the resistor R11, the resistor R12, and the resistor R13 are all connected to the power supply 3V3_SD, and the other end of the resistor R1 is connected to the card insertion detection signal SD_DET. The card insertion detection signal SD_DET detects whether an SD card is inserted. When the signal of SD_DET is in a low level state, it indicates that the SD card is inserted, the other end of the resistor R8 is respectively connected to the receiving end of the data signal SD_DATA2 and the first pin of the TVS tube D2, and the second pin of the TVS tube D2 is grounded, the other end of the resistor R9 is respectively connected to the receiving end of the data signal SD_DATA3 and the first pin of the TVS tube D3, and the second pin of the TVS tube D3 is grounded, the other end of the resistor R10 is respectively connected to the receiving end of the command signal SD_CMD and the first pin of the TVS tube D4, and the second pin of the TVS tube D4 is grounded, the other end of the resistor R11 is respectively connected to the receiving end of the clock signal SD_CLK and the first pin of the TVS tube D5, and the second pin of the TVS tube D5 is grounded, the other end of the resistor R12 is respectively connected to the receiving end of the data signal SD_DATA0 and the first pin of the TVS tube D6, and the second pin of the TVS tube D6 is grounded, the other end of the resistor R13 is respectively connected to the receiving end of the data signal SD_DATA1 and the first pin of the TVS tube D7, and the second pin of the TVS tube D7 is grounded, the resistor R1, the resistor R8, the resistor R9, the resistor Resistor R10, resistor R11, resistor R12, and resistor R13 are all pull-up resistors of the SD card circuit, and the resistance value is 47K. The models of TVS tube D2, TVS tube D3, TVS tube D4, TVS tube D5, TVS tube D6, and TVS tube D7 are all TPD1E05U06QDPYRQ1. The purpose of adding TVS tubes at the signal end is to prevent the circuit from being damaged by the subsequent circuit due to instantaneous voltage shock, and to improve the anti-interference ability, so that the back-end circuit can be effectively protected at a lower cost to avoid damage to the SOC of the all-in-one machine.

[0036] In the SD card circuit based on the front-view integrated machine of the utility model, the pull-up resistor of the relevant signal end of the SD card slot is set to 47K, and the matching resistor of the interface end is set to 33Ω, which can greatly improve the stability of data transmission, and the addition of a TVS tube can greatly improve the anti-interference ability and anti-static ability. In addition, the utility model also uses a load switch to enable the control of the SD card circuit and provide power for it. When the SD_EN signal is at a high level, the load switch is turned on to avoid damage caused by short circuit or overload in the circuit.

[0037] In summary, the SD card circuit based on the front-view integrated machine of the utility model improves the stability and anti-interference ability of SD card data transmission by adding matching resistors and TVS tubes at the SD card signal end. When communicating with the SOC of the front-view integrated machine, it can effectively protect the SOC chip communicating with it, and can also save the increased cost caused by abnormal damage to the SD card.

[0038] The various devices selected in the present invention are all universal standard parts or parts known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0039] In the description of the embodiments of the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An SD card circuit based on a front-view integrated machine, communicating with the SOC of the front-view integrated machine, characterized in that: include: A power supply circuit (1), the power supply circuit (1) comprising a step-down circuit, the step-down circuit converting a 12V voltage into a 3.3V voltage output; A load switch circuit (2), wherein an input end of the load switch circuit (2) is connected to an output end of the step-down circuit; An SD card circuit (3), the SD card circuit (3) comprising a card slot for inserting an SD card, the card slot being connected to an output end of the load switch circuit (2), and the output end of the SD card circuit (3) being connected to a GPIO of a front-view integrated machine SOC.

2. The SD card circuit based on the front-view integrated machine as claimed in claim 1, characterized in that: The load switch circuit (2) comprises a load chip U1, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4 and a diode D1. The first pin of the load chip U1 is connected to the output voltage of the step-down circuit. One end of the capacitor C1 and the capacitor C2 are both connected to the first pin of the load chip U1. One end of the capacitor C1 and the capacitor C2 are both grounded. The second pin of the load chip U1 is grounded. The third pin of the load chip U1 is connected to an enable signal SD_EN, so that the load switch circuit (2) provides 3V3_SD power supply for the SD card circuit (3). The fourth pin of the load chip U1 is connected to one end of the capacitor C3. The other end of the capacitor C3 is grounded. The sixth pin of the load chip U1 is connected to the positive electrode of the diode D1. The negative electrode of the diode D1 is connected to the capacitor C4. The other end of the capacitor C4 is grounded. The negative electrode of the diode D1 outputs the 3V3_SD power supply connected to the SD card circuit (3).

3. The SD card circuit based on the front-view integrated machine as claimed in claim 2, characterized in that: The load chip U1 is TPS22810.

4. The SD card circuit based on the front-view integrated machine as claimed in claim 3, characterized in that: The card slot of the SD card includes a clock signal SD_CLK, a data signal SD_DATA, a command signal SD_CMD, and a card insertion detection signal SD_DET.

5. The SD card circuit based on the front-view integrated machine as claimed in claim 4, characterized in that: The data signal SD_DATA includes: a data signal SD_DATA0, a data signal SD_DATA1, a data signal SD_DATA2, a data signal SD_DATA3, and a data signal SD_DATA4.

6. The SD card circuit based on the front-view integrated machine as claimed in claim 5, characterized in that: The SD card circuit (3) further comprises: a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, and a capacitor C5 and a capacitor C6; the fourth pin of the SD card slot is connected to the power supply of 3V3_SD; the capacitors C5 and C6 are both connected to the fourth pin of the SD card slot; the other ends of the capacitors C5 and C6 are both grounded; one end of the resistor R2 is connected to the first pin of the SD card slot; the other end of the resistor R2 is connected to the receiving end of the data signal SD_DATA2; one end of the resistor R3 is connected to the second pin of the SD card slot; the other end of the resistor R3 is connected to the data signal SD_DAT A receiving end of A3, one end of resistor R4 is connected to the third pin of the SD card slot, the other end of resistor R4 is connected to the receiving end of the command signal SD_CMD, one end of resistor R5 is connected to the fifth pin of the SD card slot, the other end of resistor R5 is connected to the receiving end of the clock signal SD_CLK, the sixth pin of the SD card slot is grounded, one end of resistor R6 is connected to the seventh pin of the SD card slot, the other end of resistor R6 is connected to the receiving end of the data signal SD_DATA0, one end of resistor R7 is connected to the eighth pin of the SD card slot, and the other end of resistor R7 is connected to the receiving end of the data signal SD_DATA1.

7. The SD card circuit based on the front-view integrated machine as claimed in claim 6, characterized in that: The SD card circuit (3) further comprises: a resistor R1, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13 and a TVS tube D2, a TVS tube D3, a TVS tube D4, a TVS tube D5, a TVS tube D6 and a TVS tube D7. One end of the resistor R1, the resistor R8, the resistor R9, the resistor R10, the resistor R11, the resistor R12 and the resistor R13 are all connected to a power supply 3V3_SD. The other end of the resistor R1 is connected to a card insertion detection signal SD_DET. The other end of the resistor R8 is respectively connected to a receiving end of a data signal SD_DATA2 and a first pin of the TVS tube D2. The second pin of the TVS tube D2 is grounded. The other end of the resistor R9 is respectively connected to a receiving end of the data signal SD_DATA3 and a first pin of the TVS tube D2. The receiving end and the first pin of the TVS tube D3, the second pin of the TVS tube D3 is grounded, the other end of the resistor R10 is respectively connected to the receiving end of the command signal SD_CMD and the first pin of the TVS tube D4, the second pin of the TVS tube D4 is grounded, the other end of the resistor R11 is respectively connected to the receiving end of the clock signal SD_CLK and the first pin of the TVS tube D5, the second pin of the TVS tube D5 is grounded, the other end of the resistor R12 is respectively connected to the receiving end of the data signal SD_DATA0 and the first pin of the TVS tube D6, the second pin of the TVS tube D6 is grounded, the other end of the resistor R13 is respectively connected to the receiving end of the data signal SD_DATA1 and the first pin of the TVS tube D7, the second pin of the TVS tube D7 is grounded.

8. The SD card circuit based on the front-view integrated machine as claimed in claim 7, characterized in that: The models of TVS tube D2, TVS tube D3, TVS tube D4, TVS tube D5, TVS tube D6 and TVS tube D7 are all TPD1E05U06QDPYRQ1.

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