POWER MANAGEMENT



SC4525E

Typical Application Circuit

Features

3A Output Current

200kHz to 2MHz Programmable Frequency

Precision V Feedback Voltage

Peak Current-Mode Control

Cycle-by-Cycle Current Limiting

Hiccup Overload Protection with Frequency Foldback

Soft-Start and Enable

Thermal Shutdown

Thermally Enhanced 8-pin SOIC Package

Applications

XDSL and Cable Modems

Set Top Boxes

Point of Load Applications

CPE Equipment

DSP Power Supplies

LCD and Plasma TVs

Automotive Car Audio

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Description

The SC4525E is a constant frequency peak current-mode

step-down switching regulator capable of producing 3A

output current from an input ranging from 3V to 28V. The

switching frequency of the SC4525E can be programmed

up to 2MHz for component miniaturization or it can be

set at lower frequencies to accommodate high step-down

ratios. The SC4525E is suitable for next generation XDSL

modems, high-definition TVs and various point of load

applications.

Peak current-mode PWM control employed in the

SC4525E achieves fast transient response with simple loop

compensation. Cycle-by-cycle current limiting and hiccup

overload protection reduces power dissipation during

output overload. Soft-start function reduces input start-

up current and prevents the output from overshooting

during power-up.

The SC4525E is available in SOIC-8 EDP package.

Figure 1. 1MHz 10V -28V to 5V/3A Step-down Converter

Efficiency of the 1M Hz 10V-28V to 5V/3A Step-Down Converter (Front Page)

Efficiency

40

50

60

70

80

90

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Load Current (A)

SC 4525A

SC4525E

G ND

IN

SW

BST

L1

5.2mH

C 1

0.33 mF

SS/EN

CO M P

FB

D2

20BQ030

8.25k

R 6

33.2k

22nF

C8

22pF

C5

2.2nF

L1: Coiltronics CD 1- 5R 2

O UT

5V/3A

D 1

1N4148

10V – 28V

RO SC

C 2: M urata G RM 31CR 60J106K

C4

4.7mF

C4: M urata G RM 32ER71H475K

V IN

C 2

10 mFX3

C7

R 4

15.8k

R5

12.7k

R7

Rev. 2.