Datasheet

LPC2377_78 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 6.1 — 16 October 2013 39 of 69
NXP Semiconductors
LPC2377/78
Single-chip 16-bit/32-bit microcontrollers
9. Thermal characteristics
The average chip junction temperature, T
j
(C), can be calculated using the following
equation:
(1)
• T
amb
= ambient temperature (C)
• R
th(j-a)
= the package junction-to-ambient thermal resistance (C/W)
• P
D
= sum of internal and I/O power dissipation
The internal power dissipation is the product of I
DD
and V
DD
. The I/O power dissipation of
the I/O pins is often small and many times can be negligible. However it can be significant
in some applications.
T
j
T
amb
P
D
R
th j a–
+=
Table 5. Thermal characteristics
V
DD
= 3.0 V to 3.6 V; T
amb
=  40  C to +85  C unless otherwise specified
Symbol Parameter Conditions Min Typ Max Unit
T
j(max)
maximum junction
temperature
--125 C
Table 6. Thermal resistance value (C/W): ±15 %
V
DD
= 3.0 V to 3.6 V; T
amb
=  40  C to +85  C unless otherwise specified
LQFP144
ja
JEDEC (4.5 in  4 in)
0 m/s 31.5
1 m/s 28.1
2.5 m/s 26.2
Single-layer (4.5 in  3 in)
0 m/s 43.2
1 m/s 35.7
2.5 m/s 32.8
jc 7.8
jb 13.8