ADP1706/ADP1707/ADP1708

Rev. 0 | Page 15 of 20

PCB LAYOUT CONSIDERATIONS

Heat dissipation from the package can be improved by

increasing the amount of copper attached to the pins of the

ADP1706/ADP1707/ADP1708. However, as can be seen from

Table 5, a point of diminishing returns is eventually reached,

beyond which an increase in the copper size does not yield

significant heat dissipation benefits.

The ADP1706/ADP1707/ADP1708 feature an exposed pad on

the bottom of both the SOIC and LFCSP packages to improve

thermal performance. Because the exposed pad is electrically

connected to GND inside the package, it is recommended that

it also be connected to the ground plane on the PCB with a

sufficient amount of copper.

Here are a few general tips when designing PCBs:

•

Place the input capacitor as close as possible to the IN and

GND pins.

•

Place the output capacitor as close as possible to the OUT

and GND pins.

•

For the ADP1706, place the soft start capacitor as close as

possible to the SS pin.

•

Connect the load as close as possible to the OUT and

SENSE pins.

Use of 0402 or 0603 size capacitors and resistors achieves the

smallest possible footprint solution on boards where area is

limited.

GND

GND

GND

GND

EN

ADJ/TRK/SS

VIN

VOUT

J1

R2

R1

U1

C1

C2

C3

ADP1706/ADP1707/ADP1708

SOIC8

ANALOG

DEVICES

Figure 42. Example PCB Layout