Digital TV Tuner Auto Test System Design

Along with the flourish development of digital television broadcast in our country, the requirements for the instruments of this domain are going up at very fast speed, so as to the development of measurement equipment.Digital TV Tuner Test System is the specialist among them. It is designed to auto test the quality of the tuner using in the extensive product line. The tuner is used in the DVB-C or DVB-T Set-Top Box which could change the RF signal to IF, then demodulate it to the base-band transmit stream. It is the mostly part of Set-Top Box, and influences the receiver's quality.Now, tuner manufacturer control the quality of tuner by using it in Set-Top Box to see the decode screen. This method is inefficient and subjective; and it is difficult to control the coherence. The design of this object composes of transmit stream output, DVB-C/T modulator, noise added, tuner power-supply, I2C control and transmit input, analyze and display. This method is effective, impersonal, and it makes great improve of productive efficiency.This measure system includes hardware power supply, RF attenuator, embedded software design and windows application software etc. Equip with TS player and receiver, DVB-C or DVB-T modulator, it achieves the auto-test measure instrument. The embedded hardware uses 51 series Single Chip System, and uses FPGA to realize more complex logical control. The 51 software finishes I2C control to make tuner work accurately. Windows software uses Visual C++ and DirectShow to offer user interface. Now the system has been used normally in many domestic tuner manufacturers.