Mechanical Design Guidelines
Page 107
... circuit current) VIL = 0.8 V RPM must be demonstrated to a minimum useful lifetime of the functional mechanical elements (ball bearing, shaft, and tower assembly) must be within spec for specified duty cycle In addition to passing the environmental reliability tests described in Sections 5.2 and 6.3, the fan must demonstrate adequate performance after 7,500 on...
... circuit current) VIL = 0.8 V RPM must be demonstrated to a minimum useful lifetime of the functional mechanical elements (ball bearing, shaft, and tower assembly) must be within spec for specified duty cycle In addition to passing the environmental reliability tests described in Sections 5.2 and 6.3, the fan must demonstrate adequate performance after 7,500 on...