XPC823VR81B2T Freescale Semiconductor, XPC823VR81B2T Datasheet - Page 3

• Manufacturer Part Number: XPC823VR81B2T
• Description: IC MPU POWERQUICC 81MHZ 256-PBGA
• Manufacturer: Freescale Semiconductor

Specifications of XPC823VR81B2T

• Processor Type: MPC8xx PowerQUICC 32-Bit
• Speed: 81MHz
• Voltage: 1.8V
• Mounting Type: Surface Mount
• Package / Case: 256-PBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

POWER CONSIDERATIONS
The average chip-junction temperature
where
For most applications P
relationship between P
Solving equations (1) and (2) for K gives
where K is a constant pertaining to the particular part. K can be determined from equation (3)
by measuring P
can be obtained by solving equations (1) and (2) iteratively for any value of T
Layout Practices
Each V
supply. Each GND pin should be provided with a low-impedance path to ground. The power
supply pins drive distinct groups of logic on chip. The V
ground using at least four 0.1 m F bypass capacitors located as close as possible to the four
sides of the package. The capacitor leads and associated printed circuit traces connecting to
chip V
board that employs two inner layers as V
All output pins on the MPC823 have fast rise and fall times. Printed circuit (PC) trace
interconnection length should be minimized in order to minimize undershoot and reflections
caused by these fast output switching times. This recommendation particularly applies to the
address and data busses. Maximum PC trace lengths of six inches are recommended.
Capacitance calculations should consider all device loads as well as parasitic capacitances
due to the PC traces. Attention to proper PCB layout and bypassing becomes especially critical
in systems with higher capacitive loads because these loads create higher transient currents
in the V
Special care should be taken to minimize the noise levels on the PLL supply pins.
CC
CC
CC
and GND should be kept to less than half an inch per capacitor lead. A four-layer
T
T
q
P
P
P
P
K =
pin on the MPC823 should be provided with a low-impedance path to the boardÕs
and GND circuits. Pull up all unused inputs or signals that will be inputs during reset.
JA
J
A
D
INT
I/O
D
= T
=
=
=
=
=
=
A
D
+ (P
(at equilibrium) for a known T
Ambient Temperature
Package Thermal Resistance
P
I
Power Dissipation on Input and Output PinsÑUser Determined
K Õ (T
P
DD
D
INT
D
D
¥
I/O
Freescale Semiconductor, Inc.
¥
x V
and T
q
+ P
(T
For More Information On This Product,
< 0.3
JA
DD
J
MPC823 ELECTRICAL SPECIFICATIONS
A
)
I/O
+ 273 ¥ C)
+ 273 ¥ C) + q
,
WattsÑChip Internal Power
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¥
is:
P
Go to: www.freescale.com
(1)
INT
and can be neglected. If P
,
T
(2)
CC
J
,
,
JA
in ° C can be obtained from
¥ C
and GND planes should be used.
¥ P
A
. Using this value of K
D
2
,
Junction to Ambient
CC
power supply should be bypassed to
(3)
I/O
is neglected
,
the values of P
,
¥ C/W
,
A
an approximate
.
D
and T
3
J