MP8712 – 18V, 12A, SYNCHRONOUS STEP-DOWN CONVERTER

MP8712 Rev. 1.2

MonolithicPower.com

21

3/19/2021

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PCB Layout Guidelines (8)

Efficient PCB layout is critical for stable

operation. A four-layer layout is strongly

recommended

to

achieve

better

thermal

performance. For best results, refer to Figure 7

and follow the guidelines below.

1. Place the high current paths (PGND, VIN,

and SW) very close to the device with short,

direct, and wide traces.

2. Keep the VIN and PGND pads connected

with large coppers.

3. Use at least two layers for the VIN and

PGND trace to achieve better thermal

performance.

4. Add several vias close to the VIN and

PGND pads to help with thermal dissipation.

Place m than one via adjacent to the inner

edge of PGND pad which connects to

AGND pad through low impedance routing

or ground plane.

5. Place the input capacitors as close to VIN

and PGND as possible.

6. Place the decoupling capacitor as close to

VCC and AGND as possible.

7. Add several vias close the the AGND pad,

and connect to PGND plane with Kelvin

connection.

8. Place the external feedback resistors next

to FB.

9. Ensure that there is no via on the FB trace.

10. Keep the switching node (SW) short and

away from the feedback network.

11. Keep the BST voltage path (BST, C3, and

SW) as short as possible.

NOTE:

8)

The recommended layout is based on the Typical

Application Circuits on page 22 to page 25.

Figure 7: Recommended Layout

Design Example

Table 2 is a design example following the

application guidelines for the specifications.

Table 2: Design Example

VIN

12V, 3V

VOUT

1V

IOUT

12A

The detailed application schematics are shown

in Figure 8 through Figure 17. The typical

performance and circuit waveforms are shown

in the Typical Performance Characteristics

section. For more device applications, please

refer to the related evaluation board datasheets.