CN202103635U - PDM (Pulse Density Modulation) signal generating system - Google Patents

Abstract

The utility model discloses a PDM signal generating system, which comprises a PC (Personal Computer), a data signal acquisition and output module and an adapter plate, wherein the PC is electrically connected with the data signal acquisition and output module, the data signal acquisition and output module is connected with the adapter plate, and the data signal acquisition and output module is PXI 6534. Compared with the prior art, the PDM signal generating system is low in requirement on operation personnel, convenient in usage, low in cost, short in exploitation flow, and simple in hardware demand.

Description

PDM signal generation system

technical field

The utility model relates to a PDM signal generation system based on PXI6534.

Background technique

PDM (Pulse Density Modulation) is pulse density modulation, and PDM is a modulation method that provides analog signals in the digital field. At present, the generation of PDM signals is all generated by the signal source through FPGA modulation. The corresponding PDM signal generation system consists of a signal source (signal generator or Audio Precision), FPGA, and a test board. It first generates a standard sine wave or other signal through the signal source; the signal is input to the FPGA that has been burned with Verilg or VHDL program, and after compilation, the PDM signal can be obtained; the PDM signal passes through the test board, and then is generated by the signal source or crystal oscillator The clock can be used as the PDM transmission format of audio or other data.

However, there are some problems in the above PDM signal generation system:

First, this kind of modulation requires a signal source, requires knowledge of FPGA and Verilog logic language, and has high requirements for operators.

Second, the cost and requirements of the FPGA development board are too high and too complicated.

Third, the price of the signal source is high, which also causes the cost of the existing PDM signal generation system to be too high.

Fourth, every time the FPGA development board is used, the program needs to be burned in, and the operation is very cumbersome.

Fifth, the existing technology has a long development process and complex hardware requirements.

Utility model content

In order to overcome the defects of the prior art, the utility model discloses a PDM signal generating system, which has low requirements for operators, is convenient to use, low in cost, short in development process and simple in hardware requirements.

The technical scheme of the utility model is as follows:

A PDM signal generating system, comprising: a PC, a digital signal acquisition output module, an adapter plate; the PC is electrically connected to the digital signal acquisition output module; the digital signal acquisition output module is connected to the adapter plate Electrical connections.

Preferably, the digital signal acquisition and output module is PXI6534.

First, it generates digital PDM signals by using software programs programmed in the PC. Therefore, when debugging, it is no longer necessary to burn programs into the FPGA development board every time as in the prior art.

Second, PCs are very common, and the prices of PXI6534 and adapter boards are not expensive, which greatly reduces the cost.

Third, it can be directly generated by directly setting the sampling frequency, clock frequency, and output channel, which saves the trouble of Vrilog programming and importing FPGA to generate signals with Audio Precision, and is easy to use.

Fourth, the requirements for operators are not high, the development process is short, and the hardware requirements are relatively simple.

Description of drawings

Fig. 1 is a schematic structural view of an embodiment of the utility model.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

Example

As shown in Figure 1, a kind of PDM signal generating system 100 comprises: PC 11, digital signal acquisition output module 12, adapter plate 13; PC 11 is electrically connected with digital signal acquisition output module 12; digital signal acquisition output module 12 and The adapter board 13 is connected.

In this embodiment, the digital signal acquisition and output module 12 is a PXI6534.

The system of the utility model can not only generate PDM signals, but also conveniently change the sampling frequency and clock frequency, and can provide four-channel, 32-channel signals and an interactive clock.

The following describes its working process in detail:

S11: Programming a VI based on PXI6534 in the PC 11 through LabVIEW programming.

S12: The PC 11 generates a digital PDM signal and a clock according to the above procedure.

S13: PC 11 transmits the digital PDM signal and clock to PXI6534.

S14: PXI6534 is connected to the adapter board 13 through the adapter cable. In this embodiment, the adapter board 13 is a 68pin-connector, which is designed into the PCB board and undergoes data buffering and level conversion. Finally, it is connected to the output connector that provides signals and clocks to achieve the purpose of outputting PDM analog signals.

The utility model can directly generate the PDM analog signal by directly setting the sampling frequency, the clock frequency, and the output channel, which saves the trouble of Vrilog programming and importing FPGA to generate signals by means of Audio Precision, and is convenient to use.

Compared with the prior art, the beneficial effects of the utility model are as follows:

First, it generates digital PDM signals by using software programs programmed in the PC. Therefore, when debugging, it is no longer necessary to burn programs into the FPGA development board every time as in the prior art.

Second, PCs are very common, and the prices of PXI6534 and adapter boards are not expensive, which greatly reduces the cost.

Third, it can be directly generated by directly setting the sampling frequency, clock frequency, and output channel, which saves the trouble of Vrilog programming and importing FPGA with Audio Precision, and is easy to use.

Fourth, the requirements for operators are not high, the development process is short, and the hardware requirements are complex.

The preferred embodiments of the present invention are only used to help explain the present invention. The preferred embodiments do not exhaust all details, nor do they limit the utility model to the specific implementations described. Obviously, many modifications and variations can be made based on the contents of this specification. This description selects and specifically describes these embodiments in order to better explain the principle and practical application of the utility model, so that those skilled in the art can make good use of the utility model. The invention is to be limited only by the claims and their full scope and equivalents. The above disclosures are only a few specific embodiments of the present application, but the present application is not limited thereto, and any changes conceivable by those skilled in the art shall fall within the protection scope of the present application.

Claims (2)

1. A PDM signal generating system, characterized in that, comprising: A PC, a digital signal acquisition and output module, and an adapter board; the PC is electrically connected to the digital signal acquisition and output module; the digital signal acquisition and output module is electrically connected to the adapter board. 2. The PDM signal generation system according to claim 1, wherein the digital signal acquisition and output module is PXI6534.

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