![](http://datasheet.mmic.net.cn/290000/XPC801ZP25_datasheet_16187868/XPC801ZP25_489.png)
Electrical Characteristics
20-2
MPC801 USER’S MANUAL
MOTOROLA
20
This device contains circuitry that protects against damage from high static voltage or
electrical fields. However, it is advised that precautions be taken to avoid application of any
voltages higher than the maximum-rated voltages to this high-impedance circuit. Reliability
of operation is enhanced if unused inputs are tied to an appropriate logic voltage level (either
GND or V
CC
).
20.2 THERMAL CHARACTERISTICS
20.3 POWER CONSIDERATIONS
The average chip-junction temperature
,
T
J
,
in
°
C can be obtained from
T
J
= T
A
+ (P
D
q
JA
)
(1)
where
T
A
=
Ambient Temperature
,
∞
C
q
JA
=
Package Thermal Resistance
,
Junction to Ambient
,
∞
C/W
P
D
=
P
INT
+ P
I/O
P
INT
=
I
DD
Power Dissipation on Input and Output Pins—User Determined
x V
DD
,
Watts—Chip Internal Power
P
I/O
=
For most applications P
approximate relationship between P
< 0.3
P
INT
D
and can be neglected. If P
and T
J
is:
I/O
is neglected
,
an
P
D
=
K
∏
(T
J
+ 273
∞
C)
(2)
CHARACTERISTIC
SYMBOL
VALUE
UNIT
Thermal Resistance for BGA
θ
JC
-30
1
°
C/W
θ
JA
30
2
°
C/W
θ
JA
15
3
°
C/W
NOTES:
1.
Assumes natural convection, a multilayer board with thermal vias, 1 watt MPC801
dissipation, and a board temperature rise of 20
°
C above ambient.
2.
Assumes natural convection, a multilayer board with thermal vias,1 watt MPC801
dissipation, and a board temperature rise of 10
°
C above ambient.
For more information on the design of thermal vias on multilayer boards and BGA
layout considerations in general, refer to AN-1231/D,
Application Note
available from your local Motorola sales office.
Plastic Ball Grid Array
T
J
= T
P
A
= (V
+ (P
D
θ
I
JA
DD
)
D
DD
) + P
I/O
where:
P
I/O
is the power dissipation on pins.