200 kHz, 1 A High Voltage
Step-Down Switching Regulator
Data Sheet
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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
g
m
1.2V
CMP
R
S Q
DRIVER
SWITCH
IN
COMP
+
ADP3050
3
6
7
4
5
1
2
8
00125-001
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.
