More Information - Wireless Home - Application Notes and Tutorials - EV Kit Software - Technical Support   Abstract: The MAX2170/MAX2171 tuner plus demodulator IC reference design demonstrates a compact daughter board solution for DAB and T-DMB. The design converts VHF-III and L-Band signals to a MPEG-2 transport stream. Figure 1. The MAX2170/MAX2171 tuner plus demodulator reference design. Figure 2. System Block Diagram Lab Measurements Figure 3. The VHF sensitivity measures better than -100.9dBm for DAB and better than -101.3dBm for T-DMB. Figure 4. The L-Band sensitivity measures better than -100.6dBm for DAB and better than -100.7dBm for T-DMB. Figure 5. The Adjacent Channel Selectivity (ACS) is better than 46dBc at the N±1 adjacents for VHF, and improves by almost 2dB for L-band. With these ACS measurements, the desired signal is at -70dBm and 206.352MHz for VHF and 1471.792MHz for L-band. The channel spacing is 1.712MHz. Additional Measurements The maximum input level is 10dBm for DAB and T-DMB in both VHF and L-band. This input level is limited by the absolute maximum rating of the MAX2170/MAX2171 devices. DAB Parameter Conditions Measured Units Maximum Input VHF: 174.928, 206.352, 239.200MHz 10, 10, 10 dBm L-Band: 1452.960, 1471.792, 1490.624MHz 10, 10, 10 Far-Off Selectivity, VHF (Desired: -70dBm, 206.352MHz) N+5MHz FM Adj 66.7 dBc N-5MHz FM Adj 66.6 Far-Off Selectivity, L-Band (Desired: -70dBm, 1471.792MHz) N+5MHz FM Adj 67.0 dBc N-5MHz FM Adj 66.9 T-DMB Parameter Conditions Measured Units Maximum Input VHF: 174.928, 206.352, 239.200MHz 10, 10, 10 dBm L-Band: 1452.960, 1471.792, 1490.624MHz 10, 10, 10 Far-Off Selectivity, VHF (Desired: -70dBm, 206.352MHz) N+5MHz FM Adj 66.2 dBc N-5MHz FM Adj 66.9 Far-Off Selectivity, L-Band (Desired: -70dBm, 1471.792MHz) N+5MHz FM Adj 67.0 dBc N-5MHz FM Adj 66.9 DAB/T-DMB Frequency Plan Figure 6. The DAB/T-DMB RF signal is typically broadcast in the VHF-III band and L-band. The channel spacing is typically 1.712MHz with 1.536MHz signal bandwidth. Detailed Description The MAX2170/MAX2171 low-IF tuner is designed for Digital Audio Broadcast (DAB) and Terrestrial Digital Multimedia Broadcast (T-DMB) applications, covering an input frequency range of 168MHz to 240MHz (VHF-III) and 1452MHz to 1492MHz (L-band). The MAX2170/MAX2171 achieve a high level of component integration, thus allowing low-power, tuner-on-board designs. The low-IF architecture eliminates the need for an IF-SAW filter, while providing a balanced 2.048MHz center frequency baseband output to the demodulator. The MAX2170 provides a buffered reference clock at the crystal frequency, while the MAX2171 outputs a reference at 1/3rd of the crystal frequency. A sigma-delta fractional-N synthesizer is incorporated to optimize both close-in and wideband phase-noise performances for OFDM applications where sensitivity to both 1kHz phase noise and wideband phase noise related to strong adjacents can be a problem. 의견을 보내주세요! 위 내용이 도움이 되셨나요? 여러분의 의견을 기다립니다 — Maxim은 보내주신 정정이나 제안사항을 반영하고 있습니다. 이 페이지를 평가하고 의견을 보내주십시오. 자동 업데이트 관심있는 분야의 애플리케이션 노트가 나올 때 자동으로 업데이트 받고 싶으세요? 그렇다면 EE-Mail™을 신청하십시오. 추가 정보   APP 4154: Dec 20, 2007 MAX2170 디지털 오디오 방송을 위한 직접 변환 - Low-IF 튜너 MAX2171 디지털 오디오 방송을 위한 직접 변환 - Low-IF 튜너   다운로드, PDF 형식 (135kB)  AN4154, AN 4154, APP4154, Appnote4154, Appnote 4154