DVB-T Receiver Reference Desig

DVB-T Receiver Reference Design with the MAX3580

Abstract: The DVB-T reference design meets NDig 1.0.3 and MBR requirements. This NIM design includes the MAX3580 direct-conversion tuner and a DVB-T demodulator/decoder. A discre, ve loop-through with low power consumption and low cost is included. Target applations include digital televisions, digital terrestrial set-tops, laptop televisions, automotive televisions, and peripherals.




Figure 1. DVB-T receiver reference design features the .



Figure 2. System block diag

Lab Measurements

Figure 3. VHF sensitivity measures better than -97dBm for QPSK modulation with Code Rate 1/2.



Figure 4. UHF sensitivity measures better than -96dBm for QPSK modulation and Code Rate 1/2



Figure 5. The jacent channel selectivity (ACS) is better than 32dBc for N ±1 digital adjacents and better than 38.5dBc for N ±1 adjacents. These measurements show MBRAI compliance for category a/b1 requirements

Loop-Through Peormance Parameter Conditions Measured Units Min. Typ. Max. Frequency Range   47   862 MHz Return Loss at Loop-Through Out Antenna input terminated with 75Ω 10     dB Power Gain to Loop-Through Out   -1.2   2.7 dB Noise Figure to Loop-Through Ou     4.5 5.0 dB Loop-Through Out to RF In Isolation   31     dB Loop-Through Out to Tuner In Isolation   15     dB

DVB-T Terrestrial Frequency Plan in Europe

Figure 6. The DVB-T/PAL signal is broast in the VHF Low, VHF High, and UHF bands as shown above. Channel spacing is 7MHz in the VHF band and 8MHz in the UHF band.

Detai Description

The MAX3580 fully integrated, direct-conversion TV tuner is designed for digital video broadcasting-terrestrial (DVB-T) applications. The integrated tuner covers a 170MHz to 230MHz input frequency range for the VHF-III band and 470MHz to 878MHz for the UHF band.

The MAX3580 integrates an RF input switch and a multiband tracking filter, allowing low-power tuner-on-board applications without the cost and power-dissipation issues of dual-conve ion tuner solutions. The zero-IF architecture eliminates the need for SAW filters by providing baseband I and Q outputs directly to the demodulator. In addition, -offset cellation is implemented on-chip using a mixed-signal architecture to improve the second-order distortion performance and the dynamic range of the downstream digitizer and demodulator.

The MAX3580 communicates using a 2-wire serial bus. The device ty cally operates from a +3.3V power supply, dissipating 650mV. The MAX3580 is available in a small 32-pin thin QFN package (5mm x 5mm) with an exposed paddle. Electrical performance is guaranteed over extended -40°C to +85°C temperature range.