ADP7182ACPZ-R7 datasheet(26/28 Pages) ANACHIP

26 / 28 page

ADP7182

Data Sheet

Rev. A | Page 26 of 28

Thermal Characterization Parameter, ΨJB

When the board temperature is known, use the thermal

characterization parameter, ΨJB, to estimate the junction

temperature rise (see Figure 93 and Figure 94). Maximum

junction temperature (TJ) is calculated from the board temperature

(TB) and power dissipation (PD) using the following formula:

TJ = TB + (PD × ΨJB)

(6)

The typical value of ΨJB is 18.2°C/W for the 8-lead LFCSP package

and 43°C/W for the 5 lead TSOT package.

140

120

100

TOTAL POWER DISSIPATION (W)

TB = 25°C

TB = 50°C

TB = 85°C

TJ MAX

Figure 93. Junction Temperature vs. Total Power Dissipation for the

8-Lead LFCSP, TA = 85°C

140

120

100

TOTAL POWER DISSIPATION (W)

TB = 25°C

TB = 50°C

TB = 85°C

TJ MAX

Figure 94. Junction Temperature vs. Total Power Dissipation for the

5-Lead TSOT, TA = 85°C

PCB LAYOUT CONSIDERATIONS

Place the input capacitor as close as possible to the VIN and GND

pins. Place the output capacitor as close as possible to the VOUT

and GND pins. Use of 1206 or 0805 size capacitors and resistors

achieves the smallest possible footprint solution on boards where

area is limited.

Figure 95. Example of the 8-Lead LFCSP PCB Layout

Figure 96. Example of the 5-Lead TSOT PCB Layout

ADP7182ACPZ-R7 Arkusz danych(PDF) 26 Page - Anachip Corp