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MAX14913 Not Recommended for New Designs
The MAX14912/MAX14913 have eight 640mA smart high-side switches that can also be configured as push-pull drivers for high-speed switching. The propagation...
Datasheet
MAX14913 on Analog.com

MAX14912 Production
The MAX14912/MAX14913 have eight 640mA smart high-side switches that can also be configured as push-pull drivers for high-speed switching. The propagation...
Datasheet
MAX14912 on Analog.com

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Does MAX14912/MAX14912 joinDW/joinUP feature require external tie?

		
	
				

			

									
					    cscott
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Jun 19, 2023 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
    
		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:  MAX14912 
    
    		        		        		        
    Software Version: n/a
    
    		    		    
    
		    		    
		    			
    
			    
    Do I need to externally tie the OUT pins together when using the joinDW/joinUP feature on the MAX14912/MAX14913?
    

    The datasheet says "When joinDW = 1, OUT1 and OUT2 are connected together" and "The above configuration can be used without any additional external zener clamping" and contrasts it with a different setup: "Besides pairing of drivers through internal configuration, multiple OUTs can be operated in parallel by tying the OUT_ together and driving the inputs simultaneously."  So it would seem like externally tying the pins together isn't necessary.
    

    But on the other hand, when I set up the MAX14912 this way, connect my load only to (say) OUT1 and turn on the Open Load Detect feature, the MAX14912 reports that OUT2 is an open load, which I wouldn't expect it to be if OUT1 and OUT2 were indeed tied together.
    

    Can you clarify what the connection to the load should look like when joinDW/joinUP are used?  Thanks!
    
			
    
			
									
		                             
                        

    
    
                                            
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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Jun 20, 2023 2:13 PM
            
            
						
			            		
      
		
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      The respective OUT_ MUST be tied together when using either joinDW or joinUP bits. When the joinDW (or/and joinUP) bit is set, you need to update just IN1(IN5) and IN3(IN7) bits respectively. The IN2(IN6) and IN4(IN8) bits are neglected, i.e., have no effect on the outputs. If you don't use joinDW or joinUP bits, you still need to tie any paralleling outputs together. For example, you need to parallelize two channels and it is convenient to use OUT2 and OUT3. In this case, you cannot use the joinDW bit and have to drive IN2 and IN3 as independent inputs.
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
						
				
				
		
		
      
			
		
      
	
      

      

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                on Jun 23, 2023 3:14 PM
            
            
												
						in reply to YuriyK1
					
										
			            		
        
		
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        Thank you!  It seems the datasheet really ought to say "When joinDW = 1, IN1 and IN2 are connected together" rather than saying that "OUT1 and OUT2 are connected together". 
        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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        •  Analog Employees  
        
            
						
                            
            
            				
            
                on Jun 27, 2023 1:38 PM
            
            
												
						in reply to cscott
					
										
			            		
        
		
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        The datasheet describes the condition of paralleling two channels, 
        

        "The devices support paralleling of channels in high-side mode to provide higher current. The channels can be paired (1-2, 3-4, 5-6, and 7-8) by setting two bits of the SPI register 3: joinUP and joinDW (see Table 6).
        

        When joinDW = 1, OUT1 and OUT2 are connected together, and OUT3 and OUT4 are connected together, and:
        

        ● Input signals related to channels 2 and 4 are neglected;
        

        ● Output status is determined by inputs 1 and 3;
        

        ● Push-pull mode is disabled."
        

        joinDW = 1, OUT1 and OUT2 are connected together, and OUT3 and OUT4 are connected together are the conditions.
        

        We will add clarification that OUT1 and OUT2 as well as OUT3 and OUT4 must be connected together externally.
        

        
			
        

		
			
	      

		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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