MPC866 Freescale Semiconductor, MPC866 Datasheet - Page 14

• Manufacturer Part Number: MPC866
• Description: (MPC859 / MPC866) Hardware Specifications
• Manufacturer: Freescale Semiconductor

Power Supply and Power Sequencing
Power Supply and Power Sequencing
7.5
To determine the junction temperature of the device in the application after prototypes are available, the
thermal characterization parameter (Ψ
measurement of the temperature at the top center of the package case using the following equation:
where:
The thermal characterization parameter is measured per JESD51-2 specification published by JEDEC using
a 40 gauge type T thermocouple epoxied to the top center of the package case. The thermocouple should be
positioned so that the thermocouple junction rests on the package. A small amount of epoxy is placed over
the thermocouple junction and over about 1 mm of wire extending from the junction. The thermocouple wire
is placed flat against the package case to avoid measurement errors caused by cooling effects of the
thermocouple wire.
7.6
Semiconductor Equipment and Materials International
805 East Middlefield Rd.
Mountain View, CA 94043
MIL-SPEC and EIA/JESD (JEDEC) specifications
(Available from Global Engineering Documents)
JEDEC Specifications
1. C.E. Triplett and B. Joiner, “An Experimental Characterization of a 272 PBGA Within an Automotive
2. B. Joiner and V. Adams, “Measurement and Simulation of Junction to Board Thermal Resistance and Its
8
This section provides design considerations for the MPC866/859 power supply. The MPC866/859 has a
core voltage (VDDL) and PLL voltage (VDDSYN) that operates at a lower voltage than the I/O voltage
VDDH. The I/O section of the MPC866/859 is supplied with 3.3 V across VDDH and V
Signals PA[0:15], PB[14:31], PC[4:15], PD[3:15], TDI, TDO, TCK, TRST_B, TMS, MII_TXEN, and
MII_MDIO are 5-V tolerant. All inputs cannot be more than 2.5 V greater than VDDH. In addition, 5-V
tolerant pins cannot exceed 5.5 V and the remaining input pins cannot exceed 3.465 V. This restriction
applies to power up/down and normal operation.
One consequence of multiple power supplies is that when power is initially applied the voltage rails ramp
up at different rates. The rates depend on the nature of the power supply, the type of load on each power
supply, and the manner in which different voltages are derived. The following restrictions apply:
14
Engine Controller Module,” Proceedings of SemiTherm, San Diego, 1998, pp. 47-54.
Application in Thermal Modeling,” Proceedings of SemiTherm, San Diego, 1999, pp. 212-220.
•
•
T
VDDL must not exceed VDDH during power up and power down.
VDDL must not exceed 1.9 V and VDDH must not exceed 3.465 V.
J
Power Supply and Power Sequencing
= T
Experimental Determination
Ψ
T
P
References
D
T
JT
T
= thermocouple temperature on top of package
= power dissipation in package
+(Ψ
= thermal characterization parameter
JT
x P
D
Freescale Semiconductor, Inc.
)
For More Information On This Product,
MPC866/859 Hardware Specifications
Go to: www.freescale.com
JT
) can be used to determine the junction temperature with a
[phone]
800-854-7179 or
303-397-7956
http://www.jedec.org
SS
(GND).
MOTOROLA