POWER MANAGEMENT



28V 2A Step-Down Switching Regulator

SC4524E

Typical Application Circuit

Features

Wide Input Voltage Range: 3V to 28V

2A 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

Fully RoHS and WEEE Compliant

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

step-down switching regulator capable of producing 2A

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

switching frequency of the SC4524E can be programmed

up to 2MHz for component miniaturization or it can be

set at lower frequencies to accommodate high step-down

ratios. The SC4524E is suitable for next generation XDSL

modems, high-definition TVs and various point of load

applications.

Peak current-mode PWM control employed in the

SC4524E 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 SC4524E is available in SOIC-8 EDP package.

Figure 1. 1MHz 10V-28V to 5V/2A Step-down Converter

Efficiency

40

45

50

55

60

65

70

75

80

85

90

0

0.5

1

1.5

2

Load Current (A)

SS270 REV 4

Fig.1 Efficiency of the 1M Hz 10V-28V to 5V/2A Step-Down Converter (Front Page)

SC4524E

G ND

IN

SW

BST

L1

8.2mH

C 1

0.33mF

SS/EN

CO M P

FB

D2

20BQ030

10.5k

R6

42.2k

10nF

C 8

22pF

C 5

2.2nF

L1: Coiltronics DR 73-8R 2

O UT

5V/2A

D 1

1N4148

10V – 28V

RO SC

C 2: M urata G RM 31CR 60J226K

C 4

2.2mF

C 4: M urata G RM 31CR 71H 225K

V IN

C2

22mF

C 7

R4

15.8k

R5

28.0k

R7

Rev. 2.0