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TPA3245EVM: TPA3245EVM 2 x BTL x 2pcs

user357205584
Intellectual 345 points
Part Number: TPA3245EVM
Other Parts Discussed in Thread: TPA3245

I am considering an audio amplifier of BTL x 4 ch using two TPA3245EVM.

In order to synchronize these two amplifiers, make fpwm common.

At this time, OSC_IOP of MASTER board and OSC_IOM of SLAVE board are connected.

Then, the output was intermittent like the attached waveform.(LED of CLIP_OTW is lights up.)

Do you know the cause of this event?

When OSC_IOP and OSC_IOM were not connected and both were MASTER, it worked without any problem.

How do I select SLAVE 1 and SLAVE 2?

EVM SETTING

J21:open

J5:short

J6:short

J16:No1.Master mode,No.2 Slave mode

J3:SE input

J4:SE

J26:short(INA=INC)

J27:short(INB=IND)

J7:open

J8:open

No.1.tif

No.2.tif

  • 0
    TI__Expert 6195 points

    Hi,

    I think I see what may be the issue here.  OSC_IOP and OSC_IOM have to be connected on both boards. You can either use with the same polarity for slave mode 1 (OSC_IOP master to OSC_IOP slave and OSC_IOM master to OSC_IOM slave) or with inverse polarity for slave mode 2 (OSC_IOP master to OSC_IOM slave and OSC_IOM master to OSC_IOP slave) .  This information can be found in the second paragraph of 1.2 TPA3245EVM Frequency Adjust in the EVM user guide or in 10.2.1.2.4 Oscillator in the TPA3245 datasheet. 

    I tried attaching just OSC_IOP master to OSC_IOM slave on some EVMs in the lab and leaving the rest unattached and I got similar results to what you found.

    Best Regards,

    Dan

  • 0 in reply to Dan Kisling
    Intellectual 345 points
    Hi,thank you for your reply.
    I connected OSC_IOP MASTER (10pin) and OSC_IOP SLAVE (10pin), and connected OSC_IOM MASETR (9pin) and OSC_IOM SLAVE (9pin).
    EVM -BOARD worked normally in this state, so, is there a problem?

    ･Question
    1.　Is OSC-IOP "+" polarity ? Is OSC_IOM "-" polarity?
    2.　Which pin does OSC_ION show?

    Best regards.
  • 0 in reply to user357205584
    TI__Expert 6195 points

    Hi,

    Glad to hear the EVM is working now. No there is no problem, this is expected behavior. OSC_I/O pins as inputs need to be slaved from an external differential clock.

    1. Yes, OSC_IOP for "+" and OSC_IOM for "-".

    2. That was my mistake. OSC_ION is not the name for that pin. I was thinking OSC_IOP for positive and OSC_ION for negative. You are correct: it is OSC_IOP for "plus" and OSC_IOM for "minus". I have edited my above response so hopefully it does not confuse others.

    Best Regards,

    Dan

  • 0 in reply to Dan Kisling
    Intellectual 345 points

    Hi, Dan

    Thank you for your nice support! I understood. 

    Please let me question if there is any doubt.

    Okaz

    

    
			
    

		
		
		
		
	
    
	
    
		
    
			
		
    
	
    

	            
                	
	
    
				
		                
                
                
                
                
                
                
        		
		
				
    
			
		
    
		
		 
		
		
     
    
	
    

    
			
    
			
    
		
    

		
    
	
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