1.2 A, 20 V, 700 kHz/1.4 MHz,
Nonsynchronous Step-Down Regulator
ADP2300/ADP2301
FEATURES
1.2 A maximum load current
±2% output accuracy over temperature range
Wide input voltage range: 3.0 V to 20 V
700 kHz (ADP2300) or 1.4 MHz (ADP2301)
switching frequency options
High efficiency up to 91%
Current-mode control architecture
Output voltage from 0.8 V to 0.85 × V
IN
Automatic PFM/PWM mode switching
Precision enable pin with hysteresis
Integrated high-side MOSFET
Integrated bootstrap diode
Internal compensation and soft start
Minimum external components
Undervoltage lockout (UVLO)
Overcurrent protection (OCP) and thermal shutdown (TSD)
ADIsimPower™ online design tool
Available in ultrasmall, 6-lead TSOT package
TYPICAL APPLICATIONS CIRCUIT
3.0V TO 20V
BST
VIN
V
OUT
ADP2300/
ADP2301
ON
OFF
EN
GND
SW
FB
08342-001
Figure 1.
100
95
90
EFFICIENCY (%)
85
80
75
70
65
60
f
SW
= 1.4MHz
f
SW
= 700kHz
APPLICATIONS
LDO replacement for digital load applications
Intermediate power rail conversion
Communications and networking
Industrial and instrumentation
Healthcare and medical
Consumer
V
IN
= 12V
V
OUT
= 5.0V
0
0.2
0.4
0.6
I
OUT
(A)
0.8
1.0
1.2
08342-069
Figure 2. Efficiency vs. Output Current
GENERAL DESCRIPTION
The ADP2300/ADP2301 are compact, constant-frequency,
current-mode, step-down dc-to-dc regulators with integrated
power MOSFET. The ADP2300/ADP2301 devices run from
input voltages of 3.0 V to 20 V, making them suitable for a wide
range of applications. A precise, low voltage internal reference
makes these devices ideal for generating a regulated output
voltage as low as 0.8 V, with ±2% accuracy, for up to 1.2 A load
current.
There are two frequency options: the ADP2300 runs at 700 kHz,
and the ADP2301 runs at 1.4 MHz. These options allow users to
make decisions based on the trade-off between efficiency and
total solution size. Current-mode control provides fast and stable
line and load transient performance. The ADP2300/ADP2301
devices include internal soft start to prevent inrush current at
power-up. Other key safety features include short-circuit protec-
tion, thermal shutdown (TSD), and input undervoltage lockout
(UVLO). The precision enable pin threshold voltage allows the
ADP2300/ADP2301 to be easily sequenced from other input/
output supplies. It can also be used as a programmable UVLO
input by using a resistive divider.
The ADP2300/ADP2301 are available in a 6-lead TSOT package
and are rated for the −40°C to +125°C junction temperature range.
Rev. 0
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ADP2300/ADP2301
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Typical Applications Circuit............................................................ 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 4
Thermal Resistance ...................................................................... 4
ESD Caution .................................................................................. 4
Pin Configuration and Function Descriptions ............................. 5
Typical Performance Characteristics ............................................. 6
Functional Block Diagram ............................................................ 13
Theory of Operation ...................................................................... 14
Basic Operation .......................................................................... 14
PWM Mode ................................................................................. 14
Power Saving Mode .................................................................... 14
Bootstrap Circuitry .................................................................... 14
Precision Enable ......................................................................... 14
Integrated Soft Start ................................................................... 14
Current Limit .............................................................................. 14
Short-Circuit Protection ............................................................ 15
Undervoltage Lockout (UVLO) ............................................... 15
Thermal Shutdown .................................................................... 15
Control Loop............................................................................... 15
Applications Information .............................................................. 16
Programming the Output Voltage ........................................... 16
Voltage Conversion Limitations ............................................... 16
Low Input Voltage Considerations .......................................... 17
Programming the Precision Enable ......................................... 17
Inductor ....................................................................................... 18
Catch Diode ................................................................................ 19
Input Capacitor ........................................................................... 19
Output Capacitor........................................................................ 19
Thermal Considerations............................................................ 20
Design Example .............................................................................. 21
Switching Frequency Selection ................................................. 21
Catch Diode Selection ............................................................... 21
Inductor Selection ...................................................................... 21
Output Capacitor Selection....................................................... 21
Resistive Voltage Divider Selection.......................................... 22
Circuit Board Layout Recommendations ................................... 23
Typical Application Circuits ......................................................... 24
Outline Dimensions ....................................................................... 26
Ordering Guide .......................................................................... 26
REVISION HISTORY
2/10—Revision 0: Initial Version
Rev. 0 | Page 2 of 28
ADP2300/ADP2301
SPECIFICATIONS
V
IN
= 3.3 V, T
J
= −40°C to +125°C for minimum/maximum specifications, and T
A
= 25°C for typical specifications, unless otherwise noted.
Table 1.
Parameter
VIN
Voltage Range
Supply Current
Shutdown Current
Undervoltage Lockout Threshold
FB
Regulation Voltage
Bias Current
SW
On Resistance
1
Peak Current Limit
2
Minimum On Time
Minimum Off Time
OSCILLATOR FREQUENCY
SOFT START TIME
EN
Input Threshold
Input Hysteresis
Pull-Down Current
BOOTSTRAP VOLTAGE
THERMAL SHUTDOWN
Threshold
Hysteresis
1
2
Symbol
V
IN
I
VIN
I
SHDN
UVLO
Test Conditions
Min
3
Typ
Max
20
800
35
2.95
Unit
V
μA
μA
V
V
V
V
μA
mΩ
A
ns
ns
ns
MHz
MHz
μs
μs
V
mV
μA
V
°C
°C
No switching, V
IN
= 12 V
V
EN
= 0 V, V
IN
= 12 V
V
IN
rising
V
IN
falling
T
J
= 0°C to +125°C
T
J
= −40°C to +125°C
2.15
0.788
0.784
640
18
2.80
2.40
0.800
0.800
0.01
440
1.9
100
145
70
0.7
1.4
1460
730
1.2
100
1.2
5.0
140
15
V
FB
I
FB
0.812
0.816
0.1
700
2.5
135
190
120
0.9
1.75
V
BST
− V
SW
= 5 V, I
SW
= 150 mA
V
BST
− V
SW
= 5 V, V
IN
= 12 V
ADP2300
ADP2301
ADP2300
ADP2301
ADP2300
ADP2301
V
EN
1.5
0.5
1.0
1.13
1.27
V
BOOT
No switching, V
IN
= 12 V
Pin-to-pin measurements.
Guaranteed by design.
Rev. 0 | Page 3 of 28
ADP2300/ADP2301
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter
VIN, EN
SW
BST to SW
BST
FB
Operating Junction Temperature Range
Storage Temperature Range
Soldering Conditions
Rating
−0.3 V to +28 V
−1.0 V to +28 V
−0.6 V to +6 V
−0.3 V to +28 V
−0.3 V to +3.3 V
−40°C to +125°C
−65°C to +150°C
JEDEC J-STD-020
THERMAL RESISTANCE
θ
JA
is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Table 3. Thermal Resistance
1
Package Type
6-Lead TSOT
1
θ
JA
186.02
θ
JC
66.34
Unit
°C/W
θ
JA
and
θ
JC
are measured using natural convection on a JEDEC 4-layer board.
ESD CAUTION
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Absolute maximum ratings apply individually only, not in
combination. Unless otherwise specified, all voltages are
referenced to GND.
Rev. 0 | Page 4 of 28
ADP2300/ADP2301
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
BST
GND
FB
1
2
3
ADP2300/
ADP2301
TOP VIEW
(Not to Scale)
6
5
4
SW
VIN
EN
08342-002
Figure 3. Pin Configuration
Table 4. Pin Function Descriptions
Pin No.
1
2
3
4
5
6
Mnemonic
BST
GND
FB
EN
VIN
SW
Description
Boost Supply for the High-Side MOSFET Driver. A 0.1 μF capacitor is connected between the SW and BST pins
to form a floating supply to drive the gate of the MOSFET switch above the V
IN
supply voltage.
Ground. Connect this pin to the ground plane.
Feedback Voltage Sense Input. Connect this pin to a resistive divider from V
OUT
. Set the voltage to 0.8 V for a
desired V
OUT
.
Output Enable. Pull this pin high to enable the output. Pull this pin low to disable the output. This pin can
also be used as a programmable UVLO input. This pin has a 1.2 μA pull-down current to GND.
Power Input. Connect to the input power source with a ceramic bypass capacitor to GND directly from this pin.
Switch Node Output. Connect an inductor to V
OUT
and a catch diode to GND from this pin.
Rev. 0 | Page 5 of 28
