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HMC939ALP4E Production
The HMC939ALP4E is a 5-bit digital attenuator with a 31 dB attenuation control range in 1 dB steps. The HMC939ALP4E offers optimum insertion loss, attenuation...
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HMC939ALP4E on Analog.com

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HMC941LP4 and HMC939ALP4E negative supply voltage range

		
	
				

			

									
					    Venkadesan21
					
							

            
            			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Sep 15, 2025 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
    
		      		            		        
    Category: Hardware
    
    		        		            		    
    Product Number:  HMC939ALP4E 
    
    		        		    		    
    
		    		    
		    			
    
			    
    In HMC941LP4 and HMC939ALP4E the Vss supply voltage specified at -5V.
    

    What would happen if the voltage drops to -4.5V with the Vdd at +5V. Is there any degradation in performance.
    

    Also what is the maximum current at the Vss pin. Is there any variation based on Vss or RF Power.
    
			
    
			
									
		                             
                        

    
    
                                            
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                 Digital Step Attenuators
                
                                                    
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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Sep 15, 2025 10:03 AM
            
            
						
			            		
      
		
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      Q1. What would happen if the voltage drops to -4.5V with the Vdd at +5V? Is there any degradation in performance?
      A1. The supply voltage balance is not critical. So a positive supply at 5V and a negative supply at -4.5V is not problematic. Also, for your information, the sequencing of the supplies relative to each other is not critical. 
       
      Q2. What is the maximum current at the Vss pin? Is there any variation based on Vss or RF Power?
      A2. The max currents at the Vss pins are specified in the datasheet, -7mA in both cases. I looked at some power sweep data and don't see any significant increase in current on either the positive or negative supplies as the RF power changes.  
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
				
				
				
				
		
		
      
			
		
      
	
      

      

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