Single-chip multi-mode digital television tuner

Abstract

The invention discloses a system structure of a single-chip multi-mode digital television tuner compatible with various domestic and foreign digital television standards such as DVB-T / C / H, DMB-T / H, CMMB, and the like. By adopting a double low-middle frequency conversion way, the structure realizes the inception and the amplification of multi-standard digital television signals with different frequencies through two low noise amplifiers respectively working at frequency bands of 50-860MHz and 2.5GHz and finally obtains the needed middle frequency signals through modules such as an up-conversion mixer, an orthogonal down-conversion mixer, a preliminary amplifier, a filter, a variable gain amplifier, and the like, thereby achieving the function of signal tune. The invention mainly aims to achieve a single-chip fully integrated digital television tuner compatible with the internationally universal DVB-T / C / H standard and homemade DMB-T / H, CMMB standard; in addition, the area and the power consumption of a chip are reduced due to the sharing of the modules.

Description

technical field [0001] The invention relates to a radio frequency receiver, in particular to a single-chip multi-mode digital TV tuner, which belongs to the technical field of radio frequency integrated circuits. Background technique [0002] The TV tuner is a key circuit for TV signal reception. Its function is to select a desired frequency band signal from the received TV signal and move its frequency to a low frequency, which is the frequency range that the demodulator can handle. , and then send the signal to a digital circuit for processing. [0003] A traditional TV tuner is made up of discrete components interconnected by a printed circuit board and looks like a tin box. Each internal area implements different functions, and each area is isolated by metal to prevent crosstalk between signals. Such tuners suffer from several intractable flaws: [0004] 1. Unstable performance. Each device has independent electrical and temperature characteristics, so the overall pe...

AI Technical Summary

Problems solved by technology

Each device has independent electrical and temperature characteristics, so the overall performance of the tuner can vary widely over time and with changes in the external environment, resulting in changes in image quality

[0005] 2. Larger volume

[0006] 3. Higher cost

[0008] However, in different regions and different application methods, the digital TV standards adopted are not the same. The standards widely used in the world include DVB-T / C / H (Digital Video Broadcasting-Terrestrial / Cable / Handheld, digital TV broadcasting- —Terrestrial / Cable / Handheld), etc. China’s terrestrial broadcasting adopts the DMB-T / H (Digital Multimedia Broadcast-Terrestrial / Handheld, Digital Multimedia Broadcasting-Terrestrial / Handheld) standard, while China Mobile’s digital TV adopts the CMMB (China Multimedia Mobile Broadcasting , China Multimedia Mobile Broadcasting) standard, so the tuner chip for a single standard has great limitations, and cannot meet the requirements of cross-regional and multi-purpose reception of digital TV signals

If we simply integrate several chips for various standards into one chip, there is no doubt that the area of ​​the chip will be greatly increased, and the cost will also increase accordingly, which will inevitably lead us to a disadvantage in market competition.

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