SAMD21J datasheet(43/59 Pages) MICROCHIP

43 / 59 page

Packaging Information

8.1

Thermal Considerations

Related Links

Junction Temperature

8.1.1

Thermal Resistance Data

The following Table summarizes the thermal resistance data depending on the package.

Table 8-1. Thermal Resistance Data

Package Type

θJA

θJC

32-pin TQFP

64.7°C/W

23.1°C/W

48-pin TQFP

63.6°C/W

12.2°C/W

64-pin TQFP

60.9°C/W

12.2°C/W

32-pin QFN

40.9°C/W

15.2°C/W

48-pin QFN

32.0°C/W

10.9°C/W

64-pin QFN

32.5°C/W

10.7°C/W

35-ball WLCSP

41.8°C/W

2.26°C/W

8.1.2

Junction Temperature

The average chip-junction temperature, TJ, in °C can be obtained from the following:

TJ = TA + (PD x θJA)

TJ = TA + (PD x (θHEATSINK + θJC))

where:

•

θJA = Package thermal resistance, Junction-to-ambient (°C/W), see Thermal Resistance Data

•

θJC = Package thermal resistance, Junction-to-case thermal resistance (°C/W), see Thermal

Resistance Data

•

θHEATSINK = Thermal resistance (°C/W) specification of the external cooling device

•

PD = Device power consumption (W)

•

TA = Ambient temperature (°C)

From the first equation, the user can derive the estimated lifetime of the chip and decide if a cooling

device is necessary or not. If a cooling device is to be fitted on the chip, the second equation should be

used to compute the resulting average chip-junction temperature TJ in °C.

SAMD21J Datasheet(PDF) 43 Page - Microchip Technology

SAMD21J Datasheet(HTML) 43 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59

Datasheet Download

Link URL