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LTC7000 Recommended for New Designs
The LTC7000/LTC7000-1 is a fast high side N-channel MOSFET gate driver that operates from input voltages up to 135V. It contains an internal charge pump...
Datasheet
LTC7000 on Analog.com

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LTC7000 Timer calculation

		
	
				

			

									
					    dheeraj_harikant
					
							


			
				
									
											
			
			
				
    
			
			
			    	
			                    
                
				                on Apr 6, 2022 
				
			
			
		
    
		
		                     
				
        		
    
		    
		    		    
		    			
    
			    
    Hello,
    

    I'm using LTC7000 for H-bridge application.
    

    When I have connected Resistor at timer pin to 100K, cutoff current is 9.5 Amps as designed.
    

    Capacitor value at timer pin is 100nF.
    

    If I decrease the value of resistor to 17.4K, LTC7000 not cutting off till 12 Amps (Since the current capacity of PCB tracks are limited to 10 Amps not tested for more than 12 Amps).
    

    What is the calculation behind Selecting 100kohm at Timer pin.
    

     
    

    Regards,
    

    Dheeraj
    
			
    
			
									
		                             
                        

    
    
                                            
                 High-Side Switches and MOSFET Drivers
                
                                                    
                 ltc7000
                
                                                    
                 ltc7000A
                
                                                    
                 Power Monitor  Control  and Protection
                
                                                    
                 LTC7000-1
                
                                
            
    
    
    
		
    

				
				        
        		
    
			
						
									
												
			
			
                        
                                    
                        
                                                    
                        
            
			            
						
						
			
			
			
			
		
    

        
        
        
    
					
    
			
    


    
















    
	
    
	
    
					



			


				
	









	
      
	

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      •  Analog Employees  
      
            
						
                            
            
            				
            
                on Apr 6, 2022 8:59 PM
            
            
						
			            		
      
		
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      Yes, to defeat the automatic retry, place a 100kΩ resistor in parallel with the TIMER capacitor. Use only a 100k (Data Sheet does not mention adjusting the value) or omit the 100k resistor. To adjust the timer period, change the value of the timer capacitor. To adjust the current limit, adjust the value of the sense resistor. Then, if you are seeing a change in peak current limit when Timer capacitor is adjusted, the current may be ramping (changing) during the Timer period.
      
			
      

		
			
	      

		
		
	
      
	
      
		
      
			
		
      
	
      
	
      
		
						
						
						
				
				
				
		
		
      
			
		
      
	
      

      

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