TPS73533建立时间长的问题如何解决？

用示波器测量LDO的输入跟输出波形对比一下看看。

Hi

    注意datasheet说明： For the fastest start-up, VIN should be applied first, then the enable pin (EN) driven high

Hi

    NR电容也要注意一下：

The NR pin is high impedance so a low-leakage CNR capacitor must be used. Most
ceramic capacitors are appropriate in this configuration. A high-quality, COG-type (NPO) dielectric ceramic
capacitor is recommended for CNR when used in environments where abrupt changes in temperature can occur.

I see，Thanks.

Hi
     是否可以解决问题？

板子当时设计时直接将EN和输入相连了，现在不好做更改。即使先给IN供电，然后再给EN供电，这个时间多长合适？这不同样引入延时了吗？后续划板子试一试

Hi

   The quick-start switch is closed for  approximately 135 μs. To ensure that CNR is fully charged during the quick-start time, use a capacitor with a
value of no more than 0.01 μF.

   从描述看是Vin启动后EN再启动，实际操作中，可以从Vin通过电阻接到EN, 然后在EN上增加一个电容来延长EN的启动。

试过从Vin串联一个10欧姆电阻到EN，EN端对地焊接560pF电容或者1120pF电容，观测启动时间，依然很慢......

Hi

    10ohm电阻太小，至少改到1kohm.

HI

    电容可以放大到1uF.