200 kHz, 1 A High Voltage

Step-Down Switching Regulator

Data Sheet

ADP3050

Rev. C

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FEATURES

Wide input voltage range: 3.6 V to 30 V

Adjustable and fixed (3.3 V, 5 V) output options

Integrated 1 A power switch

Uses small surface-mount components

Cycle-by-cycle current limiting

Peak input voltage (100 ms): 60 V

Configurable as a buck, buck-boost, and SEPIC

regulator

Available in 8-lead SOIC package

Supported by ADIsimPower™ design tool

APPLICATIONS

Industrial power systems

PC peripheral power systems

Preregulator for linear regulators

Distributed power systems

Automotive systems

Battery chargers

FUNCTIONAL BLOCK DIAGRAM

200kHz

OSCILLATOR

FREQUENCY

AND CURRENT LIMIT

FOLDBACK

2.50V

REGULATOR

CURRENT SENSE

AMPLIFIER

BOOST

FB

SD

GND

BIAS

CURRENT

LIMIT

gm

1.2V

CMP

R

S

Q

DRIVER

SWITCH

IN

COMP

+

ADP3050

3

6

7

4

5

1

2

8

Figure 1.

GENERAL DESCRIPTION

The ADP3050 is a current mode monolithic buck (step down)

PWM switching regulator that contains a high current 1 A power

switch and all control, logic, and protection functions. It uses a

unique compensation scheme allowing the use of any type of

output capacitor (tantalum, ceramic, electrolytic, OS-CON).

Unlike some buck regulators, the design is not restricted to using

a specific type of output capacitor or ESR value.

A special boosted drive stage is used to saturate the NPN power

switch, providing a system efficiency higher than conventional

bipolar buck switchers. Further efficiency improvements are

obtained by using the low voltage regulated output to provide

the internal operating current of the device. A high switching

frequency allows the use of small external surface-mount compo-

nents. A wide variety of standard off-the-shelf devices can be

used, providing a great deal of design flexibility. A complete

regulator design requires only a few external components.

The ADP3050 includes a shutdown input that places the device

in a low power mode, reducing the total supply current to under

20 µA. Internal protection features include thermal shutdown

circuitry and a cycle-by-cycle current limit for the power switch

to provide complete device protection under fault conditions.

The ADP3050 provides excellent line and load regulation,

maintaining typically less than ±3% output voltage accuracy

over temperature and under all input voltage and output

current conditions.

The ADP3050 is specified over the industrial temperature range

of −40°C to +85°C and is available in a thermally enhanced 8-lead

(not Pb-free only) SOIC package and a standard 8-lead (Pb-free

only) RoHS-compliant SOIC package.