LPC2420_60 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 6.2 — 16 October 2013 49 of 87
NXP Semiconductors
LPC2420/2460
Flashless 16-bit/32-bit microcontroller
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 7. 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 8. 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;
LQFP208 TFBGA208
ja ja
JEDEC (4.5 in 4 in) JEDEC (4.5 in 4 in)
0 m/s 27.4 0 m/s 41
1 m/s 25.7 1 m/s 35
2.5 m/s 24.4 2.5 m/s 31
Single-layer (4.5 in 3 in) 8-layer (4.5 in 3 in)
0 m/s 35.4 0 m/s 34.9
1 m/s 31.2 1 m/s 30.9
2.5 m/s 29.2 2.5 m/s 28
jc 8.8 jc 8.3
jb 15.4 jb 13.6