Bus voltage converter
By converting the bus voltage of different external devices to a unified power supply voltage through a bus voltage converter, the problem of inconsistent voltage support on different external device ports of the I2C bus is solved, enabling normal communication of various bus devices and reducing costs.
Patent Information
- Application Number
- CN202520208784.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-10
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2035-02-10
AI Technical Summary
The existing I2C bus cannot communicate properly when different external device ports support inconsistent voltages, and an additional control module is required for isolation.
A bus voltage converter is used to convert the bus voltage of different external devices to a unified power supply voltage through a bus voltage conversion module. PMOS transistors and current detection modules are used to ensure normal data transmission. It supports simultaneous communication of devices with different open-drain bus voltages, such as I2C, PMBUS, and SMBUS.
Without altering the original equipment design, normal communication between different external devices was achieved, reducing communication costs.
Smart Images
Figure CN223712135U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of bus design, in particular to a bus voltage converter. BACKGROUND
[0002] The 12C bus is a kind of serial, half-duplex bus. The 12C bus has two bidirectional signal lines, one serial data line SDA for transmitting data, and one serial clock line SCL for synchronizing the clock of both parties. The 12C bus has simple hardware structure, simplifies PCB wiring, reduces system cost, improves system reliability, and is widely used in various fields.
[0003] To prevent the communication from being abnormal due to the voltage drop of the 12C bus, the related technology discloses a multi-channel cascaded 12C bus isolation circuit, as shown in Figure 1 The isolation circuit includes a first isolation circuit and a second isolation circuit for connecting devices and the 12C bus; the first isolation circuit includes at least a power supply, a first resistor and a second resistor; the second isolation circuit includes at least a switch module, an SCL pin, an SDA pin, an enable terminal and a total enable terminal; the isolation circuit is connected with an enable module for controlling the switch module to be turned on or turned off. One end of the enable module is connected with the total enable terminal, and the other end is connected with the enable terminal; the total enable terminal inputs a signal to the enable module to open or close the corresponding enable terminal of the switch module, so that the switch module is turned on or turned off, and the corresponding device is connected to or disconnected from the I2C bus.
[0004] However, in the above scheme, if the device voltage on the I2C bus is inconsistent with other devices, only isolation can be performed, and an additional control module is required for communication. Utility model content
[0005] Therefore, the present application provides a bus voltage converter to solve the problem of inconsistent communication of different external device port support voltages.
[0006] The bus voltage converter provided by the present application includes: a plurality of bus voltage conversion modules independently connected to a bus, one end of each bus voltage conversion module is respectively connected to a serial data line SDA and a serial clock line SCL of the bus, and the other end of each bus voltage conversion module is respectively connected to a corresponding external device, for converting the bus voltage of a plurality of external devices to a unified power supply voltage.
[0007] Preferably, the plurality of external devices are respectively connected to corresponding bus voltages through resistors, and the bus voltages corresponding to each external device are different from each other.
[0008] Preferably, each bus voltage conversion module is connected to a corresponding external device through an SCL pin and an SDA pin.
[0009] Preferably, the bus voltage conversion module comprises a first PMOS tube and a second PMOS tube, the sources of the first PMOS tube and the second PMOS tube are grounded, the bus voltage conversion module further comprises a first current detection module and a second current detection module, the gate of the first PMOS tube is connected to the serial clock line SCL or the serial data line SDA of the master device and the slave device through the first current detection module, the gate of the second PMOS tube is connected to the serial clock line SCL or the serial data line SDA of the master device and the slave device through the second current detection module, the drains of the first PMOS tube and the second PMOS tube are connected to the bus voltage of the slave device and the bus voltage of the master device respectively.
[0010] Preferably, the bus voltage conversion module comprises a third resistance and a fourth resistance, the third resistance is connected between the drain of the first PMOS tube and the bus voltage of the slave device, and the fourth resistance is connected between the drain of the second PMOS tube and the bus voltage of the master device.
[0011] Preferably, the drain of the first PMOS tube is connected to the serial clock line SCL or the serial data line SDA of the slave device, and the drain of the second PMOS tube is connected to the serial clock line SCL or the serial data line SDA of the master device.
[0012] Preferably, the bus voltage conversion module comprises a third PMOS tube and a fourth PMOS tube, the sources of the third PMOS tube and the fourth PMOS tube are connected to the bus voltage of the master device and the bus voltage of the slave device respectively, the drain and the gate of the third PMOS tube are connected between the drain of the first PMOS tube and the second current detection module, and the drain and the gate of the fourth PMOS tube are connected between the drain of the second PMOS tube and the first current detection module.
[0013] Preferably, the bus is an I2C bus, an I3C bus, a power management bus PMBUS or a system management bus SMBUS.
[0014] It can be seen that the bus voltage converter of the present application supports the simultaneous communication of different open-drain bus voltage I2C, power management bus PMBUS and system management bus SMBUS devices without changing the original device design, thereby reducing the communication cost. BRIEF DESCRIPTION OF DRAWINGS
[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the accompanying drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.
[0016] Figure 1 For the multi-channel cascaded I2C bus isolation circuit diagram according to the related art.
[0017] Figure 2 For the overall schematic diagram of the bus voltage converter according to the present application.
[0018] Figure 3 For the detailed structure diagram of one embodiment of the bus voltage conversion module according to the present application.
[0019] Figure 4 For the detailed structure diagram of another embodiment of the bus voltage conversion module according to the present application. DETAILED DESCRIPTION
[0020] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the accompanying drawings of the specification and specific embodiments.
[0021] It should be clear that the described embodiments are only some embodiments of the present application, not all embodiments. In order to more clearly illustrate the present application, numerous technical details are described in the following specific embodiments, and those skilled in the art should understand that the present application can also be implemented without some of the details. In addition, in order to highlight the main idea of the present application, some methods, means, parts and their applications known to those skilled in the art are not described in detail, but this does not affect the implementation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0022] As the process node continues to move forward, the voltage resistance of the device is also lower and lower. In order to support different I2C bus voltages, the present application provides an open-drain bus voltage converter to solve the communication problem of inconsistent support voltage of different external device ports, and reduce the manufacturing and design cost.
[0023] As Figure 2As shown, when n 12C peripherals (n>1) are connected on the bus, due to different process nodes of different devices, the supported I2C bus voltage is also different. If the bus pull-up resistance power supply is directly connected to the power supply voltage of a certain I2C device, it will cause communication errors and chip damage. The bus voltage converter of the application includes n bus voltage conversion modules, which are connected to the bus of each peripheral, that is, the bus voltage conversion module corresponds to the I2C peripheral one by one, and each bus voltage conversion module is connected to the corresponding external device through the SCL pin and the SDA pin, so as to convert the bus voltage of different peripherals to a unified power supply voltage, and ensure normal communication.
[0024] As shown in Figure 3 , VDD1 is the bus voltage of the master device, VDD2 is the bus voltage of the slave device, VDD1 and VDD2 are not equal, bus open-drain Levelshift is a bus voltage conversion module, including a first current detection module and a second current detection module. The bus voltage of two ends can be converted to the bus voltage supported by the other party to ensure normal transmission of data without changing the original I2C device design.
[0025] Specifically, bus open-drain Levelshift includes a first PMOS tube and a second PMOS tube, the gates of the first PMOS tube and the second PMOS tube are respectively connected to the serial clock line SCL of the master device and the slave device through the first current detection module and the second current detection module, the sources of the first PMOS tube and the second PMOS tube are grounded, and the drains of the first PMOS tube and the second PMOS tube are respectively connected to the bus voltage of the slave device and the bus voltage of the master device. The first current detection module and the second current detection module are respectively used for detecting the input current of the master device and the slave device.
[0026] The bus voltage conversion module includes a third resistor and a fourth resistor, the third resistor is connected between the drain of the first PMOS tube and the bus voltage of the slave device, and the fourth resistor is connected between the drain of the second PMOS tube and the bus voltage of the master device.
[0027] Specifically, referring to Figure 3 , the first current detection module and the second current detection module are used for detecting whether there is a continuous pull-down current on the bus, and the output signal net3 is combined with the lower end signal net1 of the pull-up resistance to output a signal, when a continuous pull-down current is detected and net1 is 0, net3 outputs 0, otherwise net3 outputs 1; the generation logic of net4 is the same as that of net3.
[0028] The current detection module can be implemented with a small resistance, and the voltage across the detection resistance is used to determine whether there is a continuous pull-down current.
[0029] The application scenarios are as follows: as long as any one of SCL_IN0 or SCL_IN1 is 1, SCL0 / SCL1 will be pulled to 0.
[0030] Scenario 1: SCL_IN0: 0->0, SCL_IN1: 0->0, SCL0=VDD1, SCL1=VDD2;
[0031] Scenario 2: SCL_IN0: 0->0, SCL_IN1: 1->1, SCL0=0, SCL1=0;
[0032] Scenario 3: SCL_IN0: 0->0, SCL_IN1: 0->1, SCL0=0, SCL1=0;
[0033] Scenario 4: SCL_IN0: 0->0, SCL_IN1: 1->0, SCL0=VDD1, SCL1=VDD2;
[0034] Scenario 5: SCL_IN0: 1->1, SCL_IN1: 0->0, SCL0=0, SCL1=0;
[0035] Scenario 6: SCL_IN0: 1->1, SCL_IN1: 1->1, SCL0=0, SCL1=0;
[0036] Scenario 7: SCL_IN0: 1->1, SCL_IN1: 0->1, SCL0=0, SCL1=0;
[0037] Scenario 8: SCL_IN0: 1->1, SCL_IN1: 1->0, SCL0=0, SCL1=0;
[0038] Scenario 9: SCL_IN0: 0->1, SCL_IN1: 0->1, SCL0=0, SCL1=0;
[0039] Scenario 10: SCL_IN0: 0->1, SCL_IN1: 1->0, SCL0=0, SCL1=0;
[0040] Scenario 11: SCL_IN0: 1->0, SCL_IN1: 0->1, SCL0=0, SCL1=0;
[0041] Scenario 12: SCL_IN0: 1->0, SCL_IN1: 1->0, SCL0=VDD1, SCL1=VDD2.
[0042] Although Figure 3 The connection method of the serial clock line SCL is shown, and those skilled in the art should understand that the same connection method can be used for the serial data line SDA.
[0043] In Figure 4 In the further optional embodiment shown, on the basis of comprising the first current detection module and the second current detection module, different from Figure 3 The bus voltage conversion module comprises a third PMOS tube and a fourth PMOS tube, the sources of the third PMOS tube and the fourth PMOS tube are connected to the voltages VDD1 and VDD2 respectively, the drain and the gate of the third PMOS tube are connected between the drain of the first PMOS tube and the second current detection module, and the drain and the gate of the fourth PMOS tube are connected between the drain of the second PMOS tube and the first current detection module.
[0044] In the optional embodiment, the structure can be used for all buses of bidirectional open-drain communication structure, including I3C communication, in addition to I2C communication. The voltage converter structure can also be used for communication between the device of output Push-Pull structure and the device of output Open-Drain structure.
[0045] It can be seen that the above technical solutions of the present application support simultaneous communication of different open-drain bus voltage I2C, power management bus PMBUS, and system management bus SMBUS devices without changing the original device design, thereby reducing the communication cost.
[0046] The above describes a plurality of embodiment schemes provided by the embodiments of the present application, and each optional mode introduced by each embodiment scheme can be combined, cross-referenced in the case of no conflict, thereby extending a plurality of possible embodiment schemes, which can be considered as the embodiment schemes disclosed and disclosed by the embodiments of the present application.
[0047] Although the embodiments of the present application are disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be subject to the scope defined by the claims.
Claims
1. A bus voltage converter, characterized by The bus voltage conversion module comprises a plurality of bus voltage conversion modules connected to the bus independently, one end of each bus voltage conversion module is connected to a serial data line SDA and a serial clock line SCL of the bus respectively, and the other end of each bus voltage conversion module is connected to a corresponding external device, for converting the bus voltage of the plurality of external devices to a unified power supply voltage.
2. The bus voltage converter of claim 1, wherein, The plurality of external devices are connected to corresponding bus voltages through resistors respectively, and the corresponding bus voltages of each external device are different from each other.
3. The bus voltage converter of claim 1, wherein, Each bus voltage conversion module is connected to a corresponding external device through an SCL pin and an SDA pin respectively.
4. The bus voltage converter of claim 1, wherein, The bus voltage conversion module comprises a first PMOS tube and a second PMOS tube, the sources of the first PMOS tube and the second PMOS tube are grounded, the bus voltage conversion module further comprises a first current detection module and a second current detection module, the gate of the first PMOS tube is connected to a serial clock line SCL or a serial data line SDA of a master device and a slave device through the first current detection module, the gate of the second PMOS tube is connected to the serial clock line SCL or the serial data line SDA of the master device and the slave device through the second current detection module, and the drains of the first PMOS tube and the second PMOS tube are connected to the bus voltage of the slave device and the bus voltage of the master device respectively.
5. The bus voltage converter of claim 4, wherein, The bus voltage conversion module comprises a third resistor and a fourth resistor, the third resistor is connected between the drain of the first PMOS tube and the bus voltage of the slave device, and the fourth resistor is connected between the drain of the second PMOS tube and the bus voltage of the master device.
6. The bus voltage converter of claim 5, wherein, The drain of the first PMOS tube is connected to the serial clock line SCL or the serial data line SDA of the slave device, and the drain of the second PMOS tube is connected to the serial clock line SCL or the serial data line SDA of the master device.
7. The bus voltage converter of claim 5, wherein, The bus voltage conversion module comprises a third PMOS tube and a fourth PMOS tube, the sources of the third PMOS tube and the fourth PMOS tube are connected to the bus voltage of the master device and the bus voltage of the slave device respectively, the drain and the gate of the third PMOS tube are connected between the drain of the first PMOS tube and the second current detection module, and the drain and the gate of the fourth PMOS tube are connected between the drain of the second PMOS tube and the first current detection module.
8. The bus voltage converter of claim 1, wherein, The bus is a 12C bus, a 13C bus, a power management bus PMBUS or a system management bus SMBUS.