tr/tf

Question

根据手册定义，tr/tf的典型值为16n，现实中即使忽略MOS的Rdson，当外接3.9o的电阻和2nF的电容，激励给理想的阶跃，Vout算出来约17n，请问这个数据你们确认没问题吗？ 
 峰值电流4.61A 在实际测试中如何测得？需要外接多大的电容？

jeco · Accepted Answer

Hi wwwd , 
 The actual test board has these 3.9ohm RG and 2x 1nF capacitors for the rise and fall time specifications. This mean that there are some tolerances and derating in these components that affect the rise and fall time results that is why we have 16ns (typ) in the specs which is lower than the 17ns calculated rise and fall time. 
 For the 4.61A output current, this was tested using a higher value capacitance, you can us 100nF or more. As the capacitance is increased, you will see a plateau in the current graph - that is the maximum current. 
 Thanks, 
 Jefferson)