SparkFun Forums

[helltone]

I'm building an alarm clock and with the AR1010 FM receiver module. This module characteristics are:

Audio output voltage: 100mV rms
Output load resistance: 10k ohm
Output load capacitance: 10pF

I know nothing about analog electronics, so it would be nice if someone could explain what exactly I need in order to connect this module to two small, common speakers. I don't need very loud audio, just audible enough to wake up in the morning .

My supply voltage is 5v.

[riden]

Yes you will need an amplifier. An LM386 based amplifier should provide a low cost solution for you.

[helltone]

Is there any equivalent to the LM386 that can handle stereo? I would like to keep parts to a minimum.

[riden]

STMMicroelectronics use to make 1 to 2 watt single chip stereo amplifiers, but I don't know what is currently available.

[leon_heller]

NXP makes the TDA1517 - 2 x 6W. It doesn't use many parts.

[helltone]

Any equivalent made by TI?

[leon_heller]

What's wrong with the NXP part?

[helltone]

Nothing, just that I can find TI parts easier. By the way, I've just found out about the LM4880, its a stereo amp with minimal parts. I'm almost sure it suits me, but it seems to be hard to find.

[leon_heller]

Mouser, Farnell and RS stock the TDA1517.

[helltone]

I've just found out that the TDA1517 requires a 6v supply ;(.

[leon_heller]

That's usually the case with that type of amplifier.

[riden]

Perhaps a stereo headphone chip that delivers 80-150 mw per channel driving 16 or 32 ohm speakers would work if you don't need huge amounts of volume. The chips are pretty cheap and can be powered from 1.8v on up depending upon the chip. National, STMElectronics, and Maxim are three manufacturers that make the chips.

[helltone]

Ok, so I think I will use the LM4880 chip, I have a friend who has one of these and can spare it (datasheet:http://www-inst.eecs.berkeley.edu/~ee10 ... LM4880.pdf).

There is some schematics in the datasheet:


I wonder if Ri and Ci can be omitted if I connect it directly to the FM module, because its datasheet says it has already a resistor and capacitor.

Output load resistance: 10k ohm
Output load capacitance: 10pF

[a_rod_h]

Somewhat of a thread necro but would a TDA2822 be more of a better fit for this use.

[bcgrown]

Check out the T-Amps like this: http://www.parts-express.com/pe/showdet ... er=300-385 or the ones from these guys: http://www.41hz.com/shop/.