Linear公司的 LT3757是宽输入电压电流模式DC/DC转换控制器,能产生正或负向电压.LT3757的输入电压从表面上看2.9V到40V,用外接电阻可编程工作频率从100kHz到1Mz,能和外接时钟同步,输出电压保护,关断电流小于1uA ,内部有7.2V低压降稳压器,可编程输入欠压锁定和软起动,主要用于汽车电子和工业,通信电源和手提设备电源.
The LT3757 is a wide input range, current mode, DC/DC controller which is capable of generating either positive or negative output voltages. It can be configured as either a boost, flyback, SEPIC or inverting converter. The LT3757 drives a low side external N-channel power MOSFET from an internal regulated 7.2V supply. The fi xed frequency,current-mode architecture results in stable operation over a wide range of supply and output voltages.
The operating frequency of LT3757 can be set with an external resistor over a 100kHz to 1MHz range, and can be synchronized to an external clock using the SYNC pin.
A low minimum operating supply voltage of 2.9V, and a low shutdown quiescent current of less than 1μA, make the LT3757 ideally suited for battery-operated systems.
The LT3757 features soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit.
The device is available in a small 10-lead DFN (3mmx ?3mm) or MSOP package.
LT3757主要特性:
Wide Input Voltage Range: 2.9V to 40V
Positive or Negative Output Voltage Programming with a Single Feedback Pin
Current Mode Control Provides Excellent Transient Response
Programmable Operating Frequency (100kHz-1MHz) with One External Resistor
Synchronizable to an External Clock
Output Overvoltage Protection
Low Shutdown Current < 1μA
Internal 7.2V Low Dropout Voltage Regulator
Programmable Input Undervoltage Lockout with Hysteresis
Programmable Soft-Start
Small 10-Lead DFN (3mm x?3mm) and Thermally Enhanced 10-Pin MSOP Packages
LT3757应用:
Automotive and Industrial Boost, Flyback, SEPIC and Inverting Converters
Telecom Power Supplies
Portable Electronic Equipment