MPQ4560

– 2A, 2MHz, 55V, STEP-DOWN CONVERTER

MPQ4560 Rev. 1.1

www.MonolithicPower.com

18

5/24/2016

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2016 MPS. All Rights Reserved.

PCB LAYOUT GUIDE

PCB

layout

is

very

important

for

stable

operation. Try to duplicate the EVB layout for

optimum performance.

For changes, please follow these guidelines

and use Figure 5 as reference.

1)

Place the input decoupling capacitor and

the catch diode as close to the MPQ4560

(VIN pin, SW pin and PGND) as possible,

with traces that are very short and fairly

wide. This can help to greatly reduce the

voltage spike on SW node, and the EMI

noise.

2)

Ensure all feedback connections are short

and direct. Place the feedback resistors

and compensation components as close to

the chip as possible. Try to run the

feedback trace as far from the inductor and

noisy power traces as possible. Run the

feedback trace on the side of the PCB

opposite of the inductor with a ground

plane separating the two.

3)

Route SW away from sensitive analog

areas such as FB.

4)

Connect IN, SW, and especially GND to

large copper surfaces to cool the chip to

improve thermal performance and long-

term reliability.

5)

Place the compensation components close

to

the

MPQ4560.

Avoid

placing

the

compensation components close to or

under high dv/dt SW node, or inside the

high di/dt power loop. If necessary, add a

ground plane to isolate the loops.

6)

Switching

loss

increases

at

higher

frequencies.

To

improve

thermal

conduction, add a grid of thermal vias

under the exposed pad. Use small vias

(15mil barrel diameter) so that the hole fills

during the plating process: larger vias can

cause solder-wicking during the reflow

process. The pitch (distance between the

centers) between these thermal vias is

typically 40mil.

MPQ4560 Typical Application Circuit