●Detailed Description and Projected Impact：
■Previous revisions of the PPC185 had an internal noise sensitivity which caused the internal PLL to lose synchronization, and immediately lock up. This PLL lock up generally leads to the host CPU generating a Machine Check Error, and the board on which the 185 is operating to lock up as well. To address this PLL errata, both the package and the silicon of the PPC185 were redesigned to eliminate noise sensitivity. The first silicon to incorporate these changes is the PPC185VFB。
■Initial testing determined that the PPC185VFB PLL no longer exhibited the PLL Lock Up errata, and the device was made available for customer orders. Recent testing has determined that the PPC185VFB's PLL is still affected by worst case switching noise, with the noise manifesting itself as PLL jitter. This jitter can be reduced by running the MPC185's PLL at 1.8v (the PLL has its own Vdd, APLL), however the PLL voltage must be tightly controlled(+/-2.5%) to minimize PLL noise sensitivity while meeting long term reliability requirements.
■With the higher PLL voltage, PLL jitter is reduced, but not eliminated, and because this jitter can have a positive or negative effect on timing on each clock edge, the worst case jitter can cause timing failures in boards not designed to account for it. The worst case jitter in 3.3V systems is 1.9 ns and in 2.5V systems is 0.85ns.
■As a consequence of the 185’s PLL jitter, Motorola is issuing the following revised 185 AC timings. These timings indicate a new maximum operating frequency of 66MHz in Power QUICC II systems. It is also recommended that for Power QUICC II systems,'PLL Range' - pin F15, should be connected to Ovdd, indicating that the PLL is operating in the 33-66MHz range.
■MPC185 users are requested to contact their Motorola sales/FAE organization to schedule calls with the 185 Product Team to discuss the impact of this errata on their programs.

Brand of Product：	NXP
Part#：	PPC185 、 MPC185 、 MPC107 、 PPC185VFB More Part#
Product Category：	More
Application：	More
Data Type：	PCN/EOL More
Safety & Environment Standards：	More
Operating Temperature：	Please see the document for details
Qualification Grade：	More
Qualification Approval：	More
Package：
Language：	English Chinese Chinese and English Japanese
Date of Creation：	04/2004
Version Number：	Rev 0.0 4/2004
Data Encoding：
Data Size：	188 KB