Datasheet
LPC1759_58_56_54_52_51 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 8.5 — 24 June 2014 39 of 80
NXP Semiconductors
LPC1759/58/56/54/52/51
32-bit ARM Cortex-M3 microcontroller
10. Thermal characteristics
10.1 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.
Table 6. Thermal resistance (15 %)
Symbol Parameter Conditions Max/Min Unit
LQFP80
R
th(j-a)
thermal resistance from
junction to ambient
JEDEC (4.5 in 4 in); still air 39.46 C/W
Single-layer (4.5 in 3 in); still air 59.39 C/W
R
th(j-c)
thermal resistance from
junction to case
6.769 C/W
T
J
T
amb
P
D
R
th j a–
+=