Peripheral operating requirements and behaviors
The average chip-junction temperature (TJ) in °C can be obtained from:
TJ = TA + (PD × θJA)
Where:
TA = Ambient temperature, °C
θJA = Package thermal resistance, junction-to-ambient, °C/W
PD = Pint + PI/O
Pint = IDD × VDD, Watts - chip internal power
PI/O = Power dissipation on input and output pins - user determined
For most applications, PI/O << Pint and can be neglected. An approximate relationship
between PD and TJ (if PI/O is neglected) is:
PD = K ÷ (TJ + 273 °C)
Solving the equations above for K gives:
K = PD × (TA + 273 °C) + θJA × (PD)2
where K is a constant pertaining to the particular part. K can be determined by measuring
PD (at equilibrium) for an known TA. Using this value of K, the values of PD and TJ can
be obtained by solving the above equations iteratively for any value of TA.
6 Peripheral operating requirements and behaviors
6.1 Core modules
6.1.1 SWD electricals
Table 9. SWD full voltage range electricals
Symbol
Description
Min.
Max.
Unit
Operating voltage
2.7
5.5
V
J1
SWD_CLK frequency of operation
• Serial wire debug
0
25
—
MHz
ns
J2
J3
SWD_CLK cycle period
1/J1
SWD_CLK clock pulse width
20
—
ns
Table continues on the next page...
KE02 Sub-Family Data Sheet, Rev3, 07/2013.
Freescale Semiconductor, Inc.
19
FREESCALE [ Freescale ]
