MCP1662 BOOST CONV评估板

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MCP1662设备是一个紧凑，空间效率高的， 固定频率，非同步升压转换器优化，从双或三节碱性电池或锂劲量，或者镍氢/镍镉电池，或者一节锂离子或锂聚合物电池驱动一个LED串具有恒流。The MCP1662 is a boost device with PWM-only functionality that operates at a fixed 500 kHz switching frequency. The device has an operating input voltage range from 2.4V to 5.5V (with a typical undervoltage of 2.3V to start and 1.85V to stop). Compared to its counterpart, the MCP1661, the reference voltage is only 300 mV in order to minimize the losses on the sense resistor and increase the overall efficiency of the application.The LED can be turned on and off with a variable duty cycle applied to the EN pin for applications that require current dimming (variable lighting). Compared to its counterpart, the MCP1661, which is designed to be a voltage source, the start-up time for the MCP1662 has been decreased in order to obtain higher dimming frequencies.The MCP1662 can supply up to 100 mA of current for a string of four white LEDs (LED forward voltage of 3.2V) from a 3V or higher input voltage source. More detailed information regarding the current capabilities of the MCP1662 are available in the data sheet.Features

       

•  36V, 800m Integrated Switch       
  
•  Up to 92% Efficiency       
  
• Drive LED Strings in Constant Current       
  
•  1.3A Peak Input Current Limit:
  
         
  
  •  ILED up to 200 mA @ 5.0V VIN, 4 White LEDs       
    
  •  ILED up to 125 mA @ 3.3V VIN, 4 White LEDs       
    
  •  ILED up to 100 mA @ 4.2V VIN, 8 White LEDs
    
         
  
•   Input Voltage Range: 2.4V to 5.5V       
  
•   Feedback Voltage Reference: VFB = 300 mV       
  
•  Undervoltage Lockout (UVLO):
  
         
  
  •  UVLO@VIN Rising: 2.3V, typical       
    
  •  UVLO@VIN Falling: 1.85V, typical
    
         
  
•  Sleep Mode with 20 nA Typical Quiescent Current       
  
•  PWM Operation: 500 kHz Switching Frequency       
  
•  Cycle-by-Cycle Current Limiting       
  
•  Internal Compensation       
  
•  Open Load Protection (OLP) in the Event of:
  
         
  
  •  Feedback pin shorted to GND (prevent excessive current into LEDs)       
    
  •  Disconnected LED string (prevent overvoltage to the converter’s Output and SW pin)