在实际应用中一般驱动路数不止一路，用上图的分立电路体积大，很多场合用现成的集成电路作为多路驱动。常用的小型步进电机驱动电路可以用ULN2003或ULN2803。本书配套实验板上用的是ULN2003。ULN2003是高压大电流达林顿晶体管阵列系列产品，具有电流增益高、工作电压高、温度范围宽、带负载能力强等特点，适应于各类要求高速大功率驱动的系统。ULN2003A由7组达林顿晶体管阵列和相应的电阻网络以及钳位二极管网络构成，具有同时驱动7组负载的能力，为单片双极型大功率高速集成电路。ULN2003内部结构及等效电路-In practice, more than large ones usually drive all the way, with the use of discrete circuit bulky figure, ready to use on many occasions as a multi-channel driver IC. Commonly used in small stepper motor drive circuit can ULN2003 or ULN2803. This book is a complete test board with ULN2003. ULN2003 is high-voltage high-current Darlington transistor array series, with high current gain, high voltage, wide temperature range, with load capacity and other characteristics to meet various requirements in high-speed high-power drive system. ULN2003A Darlington transistor from the array of seven groups and the corresponding resistor network and the network of clamp diodes,