TPA3255: MASTER SLAVE configuration for 3 devices (TPA3255)

JULIAN DE ROSS

Part Number: TPA3255

RELATED QUESTION. MASTER/SLAVE mode. (3 x 3255)

I've had a look at the information in http://www.ti.com/lit/an/slaa787/slaa787.pdf

but cannot quite work out how to connect my 3 devices as Master and 2 slaves.
Can I simply connect the OSC-IOM of each device together? and also the OSC-IOP's to each other?

The attached image shows that in a 5 device system, sometimes the OSC IOM is connected to the OSC-IOP and

in other devices it goes to the OSC-IOM.

(of course also setting the master freq with the resistor)

Regards

Julian

over 4 years ago

0 Matthew Miao over 4 years ago

TI__Expert 6720 points

Hi Julian,

Robert will follow up TPA3255 related questions soon.

Rdgs,
Matthew

0 Robert Clifton56 over 4 years ago in reply to Matthew Miao

TI__Mastermind 20770 points

Hi Julian,

Yes you can tie the OSC-IOM and the OSC-IOP together. I remember we actually created an board for internal testing on tying multiple TPA3255 devices together with one being the master. We did use a buffer gate between the master and slaves to ensure that the master was able to drive the slave devices.

Best Regards,
Robert Clifton

0 JULIAN DE ROSS over 4 years ago in reply to Robert Clifton56

Intellectual 450 points

Hi Rob

I can't find the original response to my questions about wire or-ing Reset, but I sent a reply that went into the 'noreply' bin it seems.

My OR cct is attached for the FAULT and CLIP outputs. Regarding RESET? I'm still a bit foggy on that.. I'll look at ways of doing it today.

I've got a couple of issues needing guidance.

INDUCTORS Am trying to get away from the huge inductors generally found with these Amps. (big toroids).. I came across an amp being offered from Sure Electronics, which shows they used some 'SAGAMI' inductors. This company makes dedicated smd chokes for Class D amps.. and the size is quite good.
However, I've also come across one of those "Seems too good to be true" items on the TDK website.
Can you have a look at this and advise me on how you think it might go as the main output chokes?

https://product.tdk.com/en/search/inductor/inductor/smd/info?part_no=SPM10040T-100M-HZ This unit has a 6.5amp current, 10uh L and is very compact.
Can you see problems in using this? (I can't believe it's so small!)

This is just about the end of my questions, so thanks very much for the help offered thus far.
Regards

Julian

0 Robert Clifton56 over 4 years ago in reply to JULIAN DE ROSS

TI__Mastermind 20770 points

Hi Julian,

Just as I mentioned in your other post, we usually choose inductors that retain most of their inductance till it reaches saturation. AKA flat inductance vs current curve till the saturation point.

Best Regards,
Robert Clifton

0 JULIAN DE ROSS over 4 years ago in reply to Robert Clifton56

Intellectual 450 points

Thanks Robert.
J

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TPA3255: MASTER SLAVE configuration for 3 devices (TPA3255)