mpc880 Freescale Semiconductor, Inc, mpc880 Datasheet - Page 12

• Manufacturer Part Number: mpc880
• Description: Mpc885 Powerquicc Integrated Communications Processor
• Manufacturer: Freescale Semiconductor, Inc

Thermal Calculation and Measurement
1
2
3
4
5
6
7
For the following discussions, P
drivers.
7.1
An estimation of the chip junction temperature, T
where:
The junction-to-ambient thermal resistance is an industry standard value that provides a quick and easy
estimation of thermal performance. However, the answer is only an estimate; test cases have demonstrated
that errors of a factor of two (in the quantity T
12
Output high voltage, I
Output low voltage
I
I
I
I
I
OL
OL
OL
OL
OL
The difference between V
The signals PA[0:15], PB[14:31], PC[4:15], PD[3:15], PE(14:31), TDI, TDO, TCK, TRST, TMS, MII1_TXEN, MII_MDIO are 5-V
tolerant. The minimum voltage is still 2.0 V.
V
Input capacitance is periodically sampled.
A(0:31), TSIZ0/REG, TSIZ1, D(0:31), IRQ(2:4), IRQ6, RD/WR, BURST, IP_B(3:7), PA(0:11), PA13, PA15, PB(14:31),
PC(4:15), PD(3:15), PE(14:31), MII1_CRS, MII_MDIO, MII1_TXEN, and MII1_COL.
BDIP/GPL_B(5), BR, BG, FRZ/IRQ6, CS(0:7), WE(0:3), BS_A(0:3), GPL_A0/GPL_B0, OE/GPL_A1/GPL_B1,
GPL_A(2:3)/GPL_B(2:3)/CS(2:3), UPWAITA/GPL_A4, UPWAITB/GPL_B4, GPL_A5, ALE_A, CE1_A, CE2_A, OP(0:3), and
BADDR(28:30).
IL
= 2.0 mA (CLKOUT)
= 3.2 mA
= 5.3 mA
= 7.0 mA (TXD1/PA14, TXD2/PA12)
= 8.9 mA (TS, TA, TEA, BI, BB, HRESET, SRESET)
(max) for the I
Thermal Calculation and Measurement
T
R
P
A
D
θJA
Estimation with Junction-to-Ambient Thermal Resistance
= ambient temperature (ºC)
= power dissipation in package
5
6
= package junction-to-ambient thermal resistance (ºC/W)
T
J
2
C interface is 0.8 V rather than the 1.5 V as specified in the I
= T
OH
A
= –2.0 mA, except XTAL and open-drain pins
+ (R
DDL
MPC885/MPC880 PowerQUICC™ Hardware Specifications, Rev. 4
Characteristic
and V
θJA
Table 6. DC Electrical Specifications (continued)
The V
× P
DDSYN
D
= (V
D
)
DDSYN
cannot be more than 100 mV.
DDL
×
power dissipation is negligible.
I
DDL
J
– T
J
) + PI/O, where PI/O is the power dissipation of the I/O
NOTE
, in °C can be obtained from the following equation:
A
) are possible.
Symbol
2
V
V
C standard.
OH
OL
Min
2.4
—
Freescale Semiconductor
Max
0.5
—
Unit
V
V