Should be concerned CLR# Pin of LTC2642 at power ON?

Hi EZ Team,

We are using the LTC2642. We face one issue that some times LTC2642 not turned ON even we have given all Supply, reference and kept SPI lines as default. 

While debugging process we found that the CLR# Pin should be concerned. But in datasheet, the timing diagram not mentioned any points for CLR$ signal, the timing diagram speaks upto t8 only, it excluded t9.

We included t9 = 15ns = LOW at first power ON in our design and tested the device and it works for all number of iterations with power ON/OFF. [t9=15ns (Datasheet Page No.5)]

Can you please confirm that should we consider the CLR# for every Power ON?

Expecting quick and favorable reply

Thanks and Regards,

Venkatesh P.