SCI7638 查看數據表（PDF） - Seiko Epson Corp

零件编号

产品描述 (功能)

生产厂家

SCI7638

POWER SUPPLY IC - DC/DC Switching Regulators

Seiko Epson Corp 

SCI7630 Series

Powering up

Ensure that VO is at least the minimum operating volt-

age (0.9V) before switching on the booster circuit. One

way to do this is to connect a capacitor between PS and

GND so that the chip connects VO to VI when the power

is applied for the first time.

Battery

VI2

PS

C SCI7633M

TYPICAL APPLICATIONS

Example Circuits

The output current, IO, and power conversion efficiency

Peff, of a particular device in the series depends on fac-

tors such as the switching frequency, type of coil, and

the size and type of other external components.

SCI7633 series

L

D

VSW

VI

VO

SCI7633M

GND

C1

Crystal

CG

CD

PS CLO

Notes

s 100µH ≤ L ≤ 1mH, C ≤ 10µF, D: Schottky diode

s SCI7633MBA

• Peff = 70% when L = 220µH (leadless inductor),

VI1 = 1.5V, fCLK = 32kHz, IO = 8mA

• Peff = 75% when L = 220µH (drum coil),

VI1 = 1.5V, fCLK = 32kHz, IO = 9mA

• Peff = 80% when L = 300µH (toroidal coil),

VI1 = 1.5V, fCLK = 32kHz, IO = 10mA

External Components

The performance characteristics of switching regulators

depend greatly on the choice of external components.

Observing the following guidelines will ensure high

performance and maximum efficiency.

Inductor

Use an inductor with low direct-current resistance and

low losses.

Leadless

Pre-wound, leadless inductors using surface-mount

technology are the most suitable for portable equipment

and other space-critical applications.

Drum coll

Avoid drum coils because their magnetic field can in-

duce noise.

Toroidal coil

Use a toroidal coil to virtually eliminate magnetic field

leakage, reduce losses and improve performance.

SCI7000 Series

Technical Manual

EPSON

4–27

Share Link: