Data Sheet

ADPL42002

analog.com

Rev. 1

7 of 22

Maximum TJ is calculated from the TA and PD using the formula.

TJ = TA + (PD × θJA)

(1)

θJA of the package is based on modeling and calculation using a 4-layer board. The θJA is highly dependent on the

application and board layout. In applications where high maximum power dissipation exists, close attention to

thermal board design is required. The value of θJA may vary depending on PCB material, layout, and environmental

conditions. The specified values of θJA are based on a 4-layer, 4 inches x 3 inches circuit board. See JESD51-7 and

JESD51-9 for detailed information on the board construction.

ΨJB is the junction-to-board thermal characterization parameter with units of °C/W. The ΨJB of the package is based

on modeling and calculation using a 4-layer board. The JESD51-12, Guidelines for Reporting and Using Electronic

Package Thermal Information, states that thermal characterization parameters are not the same as thermal

resistances. ΨJB measures the component power flowing through multiple thermal paths rather than a single path,

as in thermal resistance (θJB). Therefore, ΨJB thermal paths include convection from the top of the package as well

as radiation from the package, factors that make ΨJB more useful in real-world applications. Maximum TJis

calculated from the board temperature (TB) and PD using the formula.

TJ = TB + (PD × ΨJB)

(2)

See JESD51-8 and JESD51-12 for more detailed information about ΨJB.

Thermal Resistance

θJA, θJC, and ΨJB are specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-

mount packages.

Table 4. Thermal Resistance

Package Type

θJA

θJC

ΨJB

UNIT

6-Lead LFCSP

72.1

42.3

47.1

°C/W

8-Lead SOIC

52.7

41.5

32.7

°C/W

ESD Caution

ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can

discharge without detection. Although this product features patented or proprietary

protection circuitry, damage may occur on devices subjected to high energy ESD. Therefore,

proper ESD precautions should be taken to avoid performance degradation or loss of

functionality.