Hi All

Apologies if this is too simple but its driving me mad.

I have a D class amp that I wish to connect with a bluetooth reciever module via its audio out. All works fine but when hooked togehter there is a lot of digital chatter noise on the amp---they are both 12v and running off same battery. (Separate batteries--no noise). In the finished project I want one battery so I get hold of a 12v DC DC convertor (QDC1S-1212S--data sheet here http://www.tme.eu/gb/Document/57f67002a9a9de08fda68ad242b570b4/qdc2s-2405s.pdf)...
So I think to isolate one power supply from the other and to stop digital chatter noise (its very loud) I can stick this in the supply to the bluetooth reciever module.....Sadly not got this far as confused by the pinning.

Could some one confirmt hat if I connect at 12 v batter to pins 1 and 2 (2 =Vin and 1-Gnd (-ve on battery) I should get 12V across pins 3 and 4 (3 0V 4-Vout)....Surely it is this simple or am I missing something? I guess I must as I have nothing across 3 and 4 when I supplying 12v across 1 and 2 pins.

Also any clues to what Omitted means on Pin Table details (see page 3 of pdf above)

Many thanks in anticipation of help

 

It seems like this part is pretty poorly documented relative to others I've come across. If you're set on using the one you've got, it does look like all you have to do is hook up 12V to Vin and the ground to ground. You can verify by safely connecting a low amperage 12V source to Vin and the ground to ground. On the other side of the IC, you'll get 13.2V according to the product sheet and a 0V that may be an isolated ground, I can't really be sure. The capacitors shown are important to include to ensure a stable and noise free output. It's also not clear to me what they mean by "Ommited" .

You're correct about how you would connect the battery.

Safely breadboard it first before you put it into your application

 

Hi Avshi
Many thanks for that.. Its really helpful.

I've been looking around trying to understand how to get the correct capacitors across inputs and outputs but I don't see any clues so far... Any advice also gratefully recieved.

Best wishes

 

Hi Avshi
Many thanks for that.. Its really helpful.

I've been looking around trying to understand how to get the correct capacitors across inputs and outputs but I don't see any clues so far... Any advice also gratefully recieved.

Best wishes

Actually just now looking at this...

https://www.google.co.uk/url?sa=t&s...gguMAA&usg=AFQjCNEwrbio17jaMMPpd1n4j02GUgedQA
. Seems useful and suggests about 10uF

Cheers

 

What output voltage are you aiming for?

 

What output voltage are you aiming for?

12v

Basically the same im putting in... I'm trying to use it to isolate one device from the other

 

It seems to me that you need to decouple your power supply and filter noise maybe. I don't know that a dc-dc regulator will fix that. Also, won't connecting a Bluetooth receiver to audio out not work anyway? Shouldn't it be connected to audio in?

 

Actually just now looking at this...

https://www.google.co.uk/url?sa=t&s...gguMAA&usg=AFQjCNEwrbio17jaMMPpd1n4j02GUgedQA
. Seems useful and suggests about 10uF

Cheers

I think that article is more about buck converters and the like rather than the isolated DC-DC converter you are considering. I have used DC-DC converters similar to the one linked in your OP and they work just fine, giving you an isolated supply. If you have QDC2S-1212S it should work OK in the pin configuration you describe.



Just had a thought....I assume you are correctly orienting the converter and therefore correctly identiying Pin 1? Additionally, the type I used (different manufacture) required a small load (I used a small resistor between the output +/- pins) before they would operate.