rsdio writes: I’d rather find a DTV modulator chip than a tuner, but maybe some day…
MAX3544
Multiband Digital Television TunerAchieves Highest Performance with Spur-Free, Easy Design-In Architecture Addressing Worldwide Digital Standards
- Offers robust picture and increased receiving range to require much less engineering effort to implement
- Provides one single pin out and board layout for all worldwide standards and TV designs
- Saves space and cost with easy-to-design tuner layout
LC bandpass filter is just a block, any idea what the actual implementation looks like?
I have been eying the max3543 for a while now, as it could make a decent front end to a low end VHF-UHF scanner radio as the MAX3543 also has an analog section. All other homebrew scanner radio’s use the huge TV tuner modules.
I have not found any info on this one section, otherwise I would have sampled months ago.
Take a look at the schematic of the evaluation board http://datasheets.maxim-ic.com/en/ds/MAX3543EVKIT.pdf for an example of the bandpass. Above that, marked FL1, is a ceramic filter which can be used as an alternative. These filters are only in the signal path if you use the differential output (DTVOUT) which has it’s own intermediate frequency amplifier. If you use the single ended output (IFOUT2) you should also filter it before applying it to your demodulator.
AFAIK the IF used in these tuners is always in the 30-40MHz range, so you have to design your demodulator with this in mind.
Interesting timing, i was just about to start (try) designing a VHF/UHF to HF down-converter :)
This might come in handy if i give up on a frequency mixer + programmable LO approach.
Looks like it’d be a good building block for making up an open source HT.