Data Sheet

ADP1761

APPLICATIONS INFORMATION

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Rev. D | 18 of 21

TJ=TB+ PD×ΨJB

(7)

Figure 40 through Figure 43 show the junction temperature calcula-

tions for the different board temperatures, load currents, VIN to VOUT

differentials, and areas of PCB copper.

Figure 40. 500 mm2 of PCB Copper, TB = 25°C

Figure 41. 500 mm2 of PCB Copper, TB = 50°C

Figure 42. 1000 mm2 of PCB Copper, TB = 25°C

Figure 43. 1000 mm2 of PCB Copper, TB = 50°C

PCB LAYOUT CONSIDERATIONS

Heat dissipation from the package can be improved by increasing

the amount of copper attached to the pins of the ADP1761. Howev-

er, as shown in Table 7, a point of diminishing returns is eventually

reached, beyond which an increase in the copper size does not

yield significant heat dissipation benefits.

Use the following recommendations when designing PCBs:

►

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.

►

Place the soft start capacitor (CSS) as close as possible to the

SS pin.

►

Place the reference capacitor (CREF) and regulator capacitor

(CREG) as close as possible to the REFCAP pin and the

VREG pin, respectively.

►

Connect the load as close as possible to the VOUT and SENSE

pins.

Use of 0603 or 0805 size capacitors and resistors achieves the

smallest possible footprint solution on boards where area is limited.

Figure 44. Evaluation Board