Linear LTC3810-5 60V同步降压电源转换解决方案


  Linear公司的LTC3810-5 是60V电流模式同步开关稳压电源控制器,工作电压高达60V,集成了1欧姆栅极驱动器,不需要电流检测电阻,双N-MOSFET同步驱动,具有极快的瞬态响应,基准电压±0.5% 0.8V,可编程输出电压跟踪/软起动,主要用在48V通信和基站电源,网络设备和服务器,汽车和工业控制系统.本文介绍了LTC3810-5主要特性,方框图, 高效高压降压转换器和多种应用电路, DC1168A - LTC3810EUH-5评估板技术指标,电路图.

  LTC3810-5: 60V Current Mode Synchronous Switching Regulator Controller

  The LTC3810-5 is a synchronous step-down switching regulator controller that can directly step-down voltages from up to 60V, making it ideal for telecom and automotive applications. The LTC3810-5 uses a constant on-time valley current control architecture to deliver very low duty cycles with accurate cycle-by-cycle current limit, without requiring a sense resistor.

  A precise internal reference provides 0.5% DC accuracy. A high bandwidth (25MHz) error amplifier provides very fast line and load transient response. Large 1Ω gate drivers allow the LTC3810-5 to drive multiple MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in VIN and can also be synchronized to an external clock for switching-noise sensitive applications. A shutdown pin allows the LTC3810-5 to be turned off, reducing the supply current to 240μA.

  Integrated bias control generates gate drive power from the input supply during start-up or when an output shortcircuit occurs, with the addition of a small external SOT23 MOSFET. When in regulation, power is derived from the output for higher efficiency.


  High Voltage Operation: Up to 60V

  Large 1Ω Gate Drivers

  No Current Sense Resistor Required

  Dual N-Channel MOSFET Synchronous Drive

  Extremely Fast Transient Response

  ±0.5% 0.8V Voltage Reference

  Programmable Output Voltage Tracking/Soft-Start

  Generates 5.5V Driver Supply from Input Supply

  Synchronizable to External Clock

  Selectable Pulse Skip Mode Operation

  Power Good Output Voltage Monitor

  Adjustable On-Time/Frequency: tON(MIN) <100ns

  Adjustable Cycle-by-Cycle Current Limit

  Programmable Undervoltage Lockout

  Output Overvoltage Protection

  5mmx ?5mm QFN Package


  48V Telecom and Base Station Power Supplies

  Networking Equipment, Servers

  Automotive and Industrial Control Systems



图3.LTC3810-5输入12-60V输出5V/6A 250kHz同步转换器



  DC1168A - LTC3810EUH-5评估板

  DC1168A - LTC3810EUH-5 Evaluation Kit Demonstration circuit 1168 is a current mode ynchronous switching regulator featuring the LTC3810-5. The circuit is configured as a synchronous step-down regulator operating at 250kHz switching frequency. Output voltage is 12V at 10A maximum load. The input voltage range is 14V –60V.

  The operating mode can be selected with jumper JP1. Depending on the position of this jumper, at low load the circuit will operate in forced continuous mode (for best load transient response at low current) or in pulse skip mode (for best efficiency at low current).A Power Good output is provided. The PGOOD output is normally high, with a pull up resistor to VLOGIC. If the output voltage is not within ± 10% of nominal value the PGOOD signal will go low.

  The switching frequency can be synchronized to an external clock signal.

  DC1168A - LTC3810EUH-5评估板技术指标:

图6.DC1168A - LTC3810EUH-5评估板电路图