Step-Up/Step-Down DC-DC Converter for 1-Cell Lithium-Ion Batteries

Impala Linear Corporation

9

(408) 574-3939

www.impalalinear.com

Jan 1999

ILC6360 1.1

Layout And Grounding Considerations

High frequency switching and large peak currents means

PCB design for DC-DC converters requires careful consid-

eration. A general rule is to place the DC-DC converter cir-

cuitry well away from any sensitive RF or analog compo-

nents. The layout of the DC-DC converters and its external

components are also based on some simple rules to mini-

mize EMI and output voltage ripple.

Layout

1. Place all power components, ILC6360, inductor, input

capacitor and output capacitor as close together as possible.

2. Keep the output capacitor as close to the ILC6360 as

Typically it should be within 0.25 inches or 6mm.

3. Keep the traces for the power components wide, typically >

50mil or 1.25mm.

ILC6360, but away from the power components as far

as possible.

Grounding

1. Use a star grounding system with separate traces for the

power ground and the low power signals such as LBI/SD

supply enters the PCB.

2. On multilayer boards use component side copper for

grounding around the ILC6360 and connect back to a

quiet ground plane using vias.

100

µF

V

IN

15

µH

C

OUT

R1

R2

ILC6360CIR-ADJ

L

X

V

IN

LBI/SD

SYNC

GND

LBO

V

FB

V

OUT

V

OUT

1

2

3

4

8

7

6

5

C

IN

R3

R4

ON/OFF

Local "Quiet" Ground

Power Ground

L1

+

+

10µF 100µF