ILC6382 Просмотр технического описания (PDF) - Impala Linear Corporation

Номер в каталоге

Компоненты Описание

производитель

ILC6382

1-Cell to 3-Cell Boost with True Load Disconnect, 3.3V, 5V or Adjustable Output

Impala Linear Corporation 

1-Cell to 3-Cell Boost with True Load Disconnect, 3.3V, 5V, or Adjustable Output

External Component Selection

Inductors

The ILC6382 is designed to work with a 15µH inductor in

most applications. There are several vendors who supply

standard surface mount inductors to this value. Suggested

suppliers are shown in table 1. Higher values of inductance

will improve efficiency, but will reduce peak inductor current

and consequently ripple and noise, but will also limit output

current.

Vendor

Coilcraft

muRata

Sumida

TDK

Part No

DO3308P-153

D03316P-153

D01608C-153

LQH4N150K

LQH3C150K

CDR74B-150MC

CD43-150

CD54-150

NLC453232T-150K

Contact

(847) 639 6400

(814) 237 1431

(847) 956 0666

(847) 390 4373

Capacitors

Input Capacitor

The input capacitor is necessary to minimize the peak cur-

rent drawn from the battery. Typically a 10µF tantalum

capacitor is recommended. Low equivalent series resist-

ance ( ESR ) capacitors will help to minimize battery voltage

ripple.

Output Capacitor

Low ESR capacitors should be used at the output of the

ILC6382 to minimize output ripple. The high switching

speeds and fast changes in the output capacitor current,

mean that the equivalent series impedance of the capacitor

can contribute greatly to the output ripple. In order to mini-

mize these effects choose an output capacitor with less

than 10nH of equivalent series inductance (ESL) and less

than 100mΩ of equivalent series resistance (ESR).

Typically these characteristics are met with ceramic capac-

itors, but may also be met with certain types of tantalum

capacitors. Suitable vendors are shown in table 2.

Description

T495 series tantalum

595D series tantalum

TAJ, TPS series tantalum

X7R Ceramic

Vendor

Kemet

Sprague

AVX

TDK

AVX

Contact

(864) 963 6300

(603) 224 1961

(803) 946 0690

(847) 390 4373

(803) 946 0690

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 exter-

nal components are also based on some simple rules to

minimise EMI and output voltage ripple.

Layout

1. Place all power components, ILC6382, inductor,

input capacitor and output capacitor as close together

as possible.

2. Keep the output capacitor as close to the ILC6382 as

possible with very short traces to the VOUT and GND

pins. Typically it should be within 0.25 inches or 6mm.

3. Keep the traces for the power components wide, typi-

cally >50mil or 1.25mm.

4. Place the external networks for LBI and VFB close to

the ILC6382, 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 and VFB. The star should radiate from where the

power supply enters the PCB.

2. On multilayer boards use component side copper for

grounding around the ILC6382 and connect back to a

quiet ground plane using vias.

CIN

10µF

VIN

L1

15µH

ON/OFF

R4

ILC6382

1

LX

2 VIN

VOUT 8

+

COUT

10µF

GND 7

R1

3 LBI/SD LBO 6

4 SYNC

VFB

5

R2

Local "Quiet" Ground

Power Ground

VOUT

R3

Recommended application circuit schematic for ILC6382CIR-ADJ

Impala Linear Corporation

ILC6382 1.5

(408) 574-3939 www.impalalinear.com

Oct 1999 9

Share Link: