Datasheet

 2005-2015 Microchip Technology Inc. DS40001262F-page 233
PIC16F631/677/685/687/689/690
17.5 Thermal Considerations
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C  T
A  +125°C
Param
No.
Sym. Characteristic Typ. Units Conditions
TH01 
JA Thermal Resistance
Junction to Ambient
62.4 C/W 20-pin PDIP package
85.2 C/W 20-pin SOIC package
108.1 C/W 20-pin SSOP package
40 C/W 20-pin QFN 4x4mm package
TH02 
JC Thermal Resistance
Junction to Case
28.1 C/W 20-pin PDIP package
24.2 C/W 20-pin SOIC package
32.2 C/W 20-pin SSOP package
2.5 C/W 20-pin QFN 4x4mm package
TH03 T
DIE Die Temperature 150 C For derated power calculations
TH04 PD Power Dissipation — W PD = P
INTERNAL + PI/O
TH05 PINTERNAL Internal Power Dissipation — W PINTERNAL = IDD x VDD
(Note 1)
TH06 P
I/O I/O Power Dissipation — W PI/O =  (IOL * VOL) +  (IOH * (VDD - VOH))
TH07 PDER Derated Power — W PDER = PDMAX (TDIE - TA)/JA
(Note 2, 3)
Note 1: IDD is current to run the chip alone without driving any load on the output pins.
2: TA = Ambient Temperature.
3: Maximum allowable power dissipation is the lower value of either the absolute maximum total power
dissipation or derated power.