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Medical ECG low power/low distortion DIP Op amp



		

			

									
					    Hoagim2013
					
							

			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Feb 14, 2013 
				
			
			
		
    

				
		
    
		    		    
		    
		    	
			
    I have been having trouble choosing an appropriate op amp package that meets the criteria stated in the tittle of this thread. Most of the op amps recommended in the medical applications section of this website are SO packages and too small to use in prototyping breadboard. Any suggestions or advice on choosing a particular model ? The functions required are for the Right leg driver and filtering of the ECG. I already have an instrumentation amplifier 
    
								
    

				
				
		
    
			
						
									
									
						
						
			
			
			
			
		
    

        
        

					
    
			
    


    


	
    
		
	
    















    
	
    
	
    
					



			


				
	









	
      
	

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                on Feb 14, 2013 6:21 PM
            
            
					
        
	
        

		
		
        
					
        Have a look at the OP90 or the OP193, both available as DIP parts. I would also say that prototyping with SO parts really isn't that hard, and I gave up on DIP many years ago.
        
			
        

		
		
		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
				
						
						
				
				
		
		
        
			
		
        
	
        

        

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        •  Analog Employees  
        
            
			                            
                        
                on Feb 14, 2013 6:55 PM
            
            
					
        
	
        

		
		
        
					
        Hi, Hoagim2013.
        
 
        A right leg drive amplifier is purposely used for common-mode bias and for noise cancellation especially the 50/60Hz. A high CMRR and and low noise amplifier would suit this application. OP90 and OP193, which Oliver had suggested, are good choices since both are micropower amps, high CMRR and have low voltage noise. 
        
 
        You can also try OP97 and OP07 which have a noise voltage of more or less 0.5uVp-p and have higher typical CMRR of more or less 120dB. These two are also micropower amps but is more or less 400uA supply current. These are offered in your required package which is DIP and also in SOIC which cost cheaper. 
        
 
        If you are currently using SOIC part, you may want to use an SOIC to DIP adapters for breadboarding purposes. You may want to look at this link.   
        
 
        Hope this helps.
        
 
        Regards,
        
 
        Anna
        
			
        

		
		
		
		
	
        
	
        
		
        
			
		
        
	
        
	
        
		
						
						
				
						
				
				
		
		
        
			
		
        
	
        

        

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                on Feb 15, 2013 6:20 AM
            
            
					
          
	
          

		
		
          
					
          Thank you very much. I would have thought that SO chips would too small to put in breadboard. Is there any other way to prototype using SO chips. 
          
 
          Cheers!!
          
			
          

		
		
		
		
	
          
	
          
		
          
			
		
          
	
          
	
          
		
						
						
				
						
				
				
		
		
          
			
		
          
	
          

          

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                on Feb 18, 2013 4:54 PM
            
            
					
            
	
            

		
		
            
					
            Breadboards aren't really suitable for performance analogue works, so I usually get a quick and dirty 2 layer PCB made for prototyping. I get them for less than £100, which compares well for engineering time and you get results you can trust. It's easy to hand solder SOIC chips and 0805 passives, and with a bit of practice you can do 0.65mm lead pitch ICs and 0603 passives. I still find 0.5mm pitch packages and 0402 passives a bit tricky.
            
 
            The mindset that 'you can't prototype SMT' is probably your biggest stumbling block.
            
			
            

		
		
		
		
	
            
	
            
		
            
			
		
            
	
            
	
            
		
						
						
				
						
				
				
		
		
            
			
		
            
	
            

            

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