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ADV7343 Not Recommended for New Designs
The ADV7342/ADV7343 are high speed, digital-to-analog video encoders in a 64-lead LQFP package. Six high speed, 3.3 V, 11-bit video DACs provide support...
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ADV7343 on Analog.com

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Abnormal failure condition for ADV7343

		
	
				

			

									
					    ZOEYANG
					
							

            
            			
				
									
											
			
			
				
  •  Analog Employees  

			
			
			    	
			                    
                
				                on Jun 4, 2025 
				
			
			
		

		
		                    	    

        	    
Thread Summary

                The user experienced failures in three ADV7343 chips, with one showing burn marks, another having abnormal VAA pin impedance, and the third failing after a month of use. The final answer suggests verifying the PCB layout recommendations, using proper decoupling capacitors, adding a ferrite bead on VCC, ensuring clean and stable power supply, and protecting the board from ESD to prevent Electrical Overstress (EOS) on Pin 41 (Vcc).
                        	    

                
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Category: Hardware

    		        		            		    
Product Number:  ADV7343  

    		        		    		    

		    		    
		    			

			    
Hi team,


We recently had 3 ADV7343 chip damage failures. 


    

  1. Chip1 even had burn marks on its surface. 
    2. 

  2. Chip2 had its 41-pin VAA connected to a 3.3V power supply, and the test found that the impedance to ground was abnormal, only more than 40 ohms. 
    3. 

  3. Chip4 gradually became unstable in video output after more than a month of use, and eventually had no output at all. There was no abnormality in the 41-pin VAA 3.3V power supply impedance.
    4. 



After removing the chip and testing the resistance value with a multimeter, it was found that the power PIN pin was abnormal to the ground. No abnormality was found in other pins. Pin44 (DAC1), Pin43 (DAC2), Pin42 (DAC3) are designed for VGA interface, Pin39 (DAC4) is used for Video, Pin38 (DAC5), Pin37 (DAC6) is used for SVideo. However, the client did not use the VGA interface, only Video and SVideo, but the VGA interface, Pin44 (DAC1), Pin43 (DAC2), Pin42 (DAC3) were damaged.


Below are failed IC ground resistance value and corresponding abnormal scenario.  


 


 


Attached is the datasheet provided by customer. Do you have any other suggestions on this issue if any challenges might cause this EOS on PIN41? 


PDF


Looking forward to your reply! 

			

			
									
		                             
                        

    

                                            
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    •  Analog Employees  
    •  Super User  
    
            
						
                            
            
            				
            
                on Jun 6, 2025 6:00 AM
            
            
						
			            		
    
		
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    Hi,
    

       Please let us know, Are you following "PRINTED CIRCUIT BOARD (PCB) LAYOUT(Page 73)" recommendation from the datasheet. Kindly crosscheck. 
    

       Few suggestions to prevent EOS:
        1. Use Proper decoupling capacitors
        2. Add a Ferrite bead on VCC input
              There are a number of good ways to implement the power rail filters. The goal is to keep the power rails clean and isolated from each other.
              The reference design uses Murata NFE61PT472C1H9L as part of the Pi EMI filter network
              You can use ferrite beads such as Murata BLM15EG221SN1D.
              I prefer Murata NFM21PC105B1A3D style filters.
        3. Follow proper power sequencing and grounding and check clean & stable power supply.
        4. Protect the board from ESD
    

      Kindly note that, To prevent Electrical Overstress (EOS) on Pin 41 (Vcc) of the ADV7343, you need to protect the power rail from voltage spikes, transients, ESD, and inrush currents. Since Vcc is the main power supply pin, damage here can lead to chip failure. 
    

    

    Thanks,
    

    Poornima
    
			
    

		
			
	      

		
		
	
    
	
    
		
    
			
		
    
	
    
	
    
		
						
						
						
						
				
				
		
		
    
			
		
    
	
    

    

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