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ADV7393 Recommended for New Designs
The ADV7390 / ADV7391 / ADV7392 / ADV7393 are a family of high speed, digital-to-analog video encoders on single monolithic chips. Three 2.7 V/3...
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ADV7393 on Analog.com

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ADV7393 RESET pin connection and I²C configuration for reliable device detection

		
	
				

			

									
					    Loga
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Nov 13, 2025 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
    
		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:  ADV7393  
    
    		        		    		    
    
		    		    
		    			
    
			    
    Hello ADI team,
    

    I’m designing with the ADV7393 video encoder, and I’d like to confirm the correct hardware connection for the RESET pin and how to ensure the device is properly recognized on the I²C bus after power-up.
    

    From the datasheet:
    

      

    • 

      RESET is described as an active-low input.
      

      • 

    • 

      It must go through a high-to-low transition to trigger a hardware reset.
      

      • 

    • 

      There’s mention of using an RC network if no MCU reset control is used.
      

      • 

    

    My setup:
    

      

    • I have left RESET* pin as NC in my circuit.
      • 

    

    Questions:
    

      

    1. 

      Is connecting RESET to 3.3 V via a pull-up resistor correct when DVDDIO = 3.3 V?
      

      2. 

    2. 

      How long should RESET be held low after power-up to guarantee proper initialization?
      

      3. 

    3. 

      Are there any required delays between RESET release and the first I²C transaction to ensure the ADV7393 responds correctly?
      

      4. 

    4. 

      Is any additional hardware (like an RC delay) recommended to ensure reliable I²C detection after reset?
      

      5. 

    

    Thanks for your help!
    
			
    
			
									
		                             
                        

    
    
                                            
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      •  Analog Employees  
      •  Super User  
      
            
						
                            
            
            				
            
                on Nov 13, 2025 6:43 AM
            
            
						
			            		
      
		
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      Hi,
      

         Regarding RESET release, Normally we give 5ms after reset goes high.
      

         After setting the Chip RESET bit (or initiating a reset via the pin), the part returns to the default mode of operation with respect to its primary mode of operation, and so on. All I2C bits will be loaded with their default value, which makes this bit self-clearing.
      

      • Executing a software reset takes approximately 2ms. However, it is recommended to wait 5ms before any further I2C writes are performed.
      

      • The I2C master controller will receive a no acknowledge condition on the ninth clock cycle  when Chip Reset is implemented.
      

      • It is recommended to wait 5ms after the low pulse before an I2C write is performed.
      

      Note: Setting the Chip RESET bit is equivalent to controlling the Reset pin on the ADV739x and will issue a full chip reset. All I2C registers will be reset to their default values. After the reset sequence, the part will immediately start to acquire the incoming video signal.
      

       According to the datasheet specification, A hardware reset is necessary after power-up for correct device operation. If no hardware reset functionality is required by the application, the RESET pin can be connected to an RC network to provide the hardware reset necessary after power-up. After power-up, the time constant of the RC network holds the RESET pin low long enough to cause a reset to take place. All subsequent resets can be done via software.
      

      

      Please refer  ADV739x Hardware Reset 
      

      

      

      Thanks,
      

      Poornima
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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