MPC8572CLPXARLD FREESCALE [Freescale Semiconductor, Inc], MPC8572CLPXARLD Datasheet - Page 126

• Manufacturer Part Number: MPC8572CLPXARLD
• Description: MPC8572E PowerQUICC III Integrated Processor Hardware Specifications
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

System Design Information
Figure 62
The AV
of the internal clock, the power supplied to the PLL is filtered using a circuit similar to the one shown in
following figure. For maximum effectiveness, the filter circuit is placed as closely as possible to the
AV
the AV
capacitors, and finally the 1 Ω resistor to the board supply plane. The capacitors are connected from
AV
frequency. All traces should be kept short, wide and direct.
Note the following:
21.3
Due to large address and data buses, and high operating frequencies, the device can generate transient
power surges and high frequency noise in its power supply, especially while driving large capacitive loads.
This noise must be prevented from reaching other components in the MPC8572E system, and the device
itself requires a clean, tightly regulated source of power. Therefore, it is recommended that the system
designer place at least one decoupling capacitor at each V
126
DD
DD
•
•
_SRDSn ball to ensure it filters out as much noise as possible. The ground connection should be near
_SRDSn to the ground plane. Use ceramic chip capacitors with the highest possible self-resonant
DD
AV
Signals on the SerDesn interface are fed from the XV
DD
Decoupling Recommendations
_SRDSn ball. The 0.003-µF capacitor is closest to the ball, followed by the two 2.2 µF
shows the PLL power supply filter circuits.
_SRDSn signal provides power for the analog portions of the SerDesn PLL. To ensure stability
DD
_SRDSn should be a filtered version of SV
It is recommended to have the minimum number of vias in the AV
for board layout. For example, zero vias might be possible if the AV
is placed on the component side. One via might be possible if it is placed on
the opposite of the component side. Additionally, all traces for AV
the filter components should be low impedance, 10 to 15 mils wide and
short. This includes traces going to GND and the supply rails they are
filtering.
SV
MPC8572E PowerQUICC III Integrated Processor Hardware Specifications, Rev. 4
DD_SRDSn
V
DD
1. An 0805 sized capacitor is recommended for system initial bring-up.
Figure 63. SerDes PLL Power Supply Filter
10 Ω
Figure 62. PLL Power Supply Filter Circuit
1.0 Ω
2.2 µF
2.2 µF
GND
NOTE
1
GND
Low ESL Surface Mount Capacitors
2.2 µF
DD
DD
2.2 µF
, TV
_SRDSn.
DD
1
_SRDSn power plane.
DD
, BV
AV
DD
0.003 µF
DD
, OV
AV
DD
DD
DD
DD
DD
, GV
_SRDSn
Freescale Semiconductor
trace
filter
and
DD
, and LV
DD
pin