一种高速恒流输出驱动电路的设计

Design of a High Speed Constant Current Output Driver Circuit

提出了一种新型的恒流输出驱动电路,该电路保持了传统电路的低负载电压调整率,同时,采用瞬间增强运放驱动的方式,提升了电路的开启速度。基于0.25μm BCD工艺,完成HSPICE仿真。结果表明,电路的负载电压调整率近似为0;输出电流为30mA时,电路的开启时间仅为10.3ns;在不同输出电流下,电路开启时间的差异较小。该电路可应用于开关电源、手机充电器及LED显示屏等电路芯片中。

A new type of constant-current output driver circuit was proposed,which enhanced turn-on speed of the circuit by boosting op-amp driver instantly,while maintaining low load voltage regulation of the traditional circuit.The circuit was simulated with HSPICE based on 0.25 μm BCD process.Results showed that the circuit had an approximate zero load voltage regulation,and a turn-on time of only 10.3 ns for an output current of 30 mA,which had little difference for different output currents.The circuit is applicable for switching power supply,handset charger and LED display driver IC＇s.