Data Sheet
FEATURES
Continuous output current: 3 A
Input voltage: 4.5 V to 36 V
Integrated MOSFETs: 98 mΩ/35 mΩ
Reference voltage: 0.6 V ± 1%
Fast minimum on time: 50 ns
Programmable switching frequency: 200 kHz to 1.8 MHz
Synchronizes to external clock: 200 kHz to 1.8 MHz
Precision enable and power good
Cycle-by-cycle current limit with hiccup protection
External compensation
Programmable soft start time
Startup into a precharged output
Supported by
ADIsimPower
design tool
3 A, 36 V, Synchronous Step-Down
DC-to-DC Regulator
ADP2443
TYPICAL APPLICATION CIRCUIT
ADP2443
V
IN
C
IN
R
RAMP
RAMP
PGOOD
RT/SYNC
R
T
C
VREG
VREG
GND
FB
COMP
SS
PGND
C
SS
R
C
R
BOT
C
C
14794-001
PVIN
EN
BST
SW
C
BST
L
V
OUT
R
TOP
C
OUT
Figure 1.
APPLICATIONS
Intermediate power rail conversion
Multicell battery powered systems
Process control and industrial automation
Healthcare and medical
Networking and servers
GENERAL DESCRIPTION
The
ADP2443
is synchronous step-down, dc-to-dc regulator
with an integrated 98 mΩ, high-side power metal oxide semicon-
ductor field effect transistor (MOSFET) and a 35 mΩ, synchronous
rectifier MOSFET to provide a high efficiency solution in a
compact 4 mm × 4 mm LFCSP package. The regulators operate
from an input voltage range of 4.5 V to 36 V. The output voltage
can be adjusted down to 0.6 V and deliver up to 3 A of
continuous current. The fast 50 ns minimum on time allows the
regulators convert high input voltage to low output voltage at high
frequency.
The
ADP2443
uses an emulated current mode, constant frequency
pulse-width modulation (PWM) control scheme for excellent
stability and transient response. The switching frequency of the
ADP2443
can be programmed from 200 kHz to 1.8 MHz. The
synchronization function allows the switching frequency be syn-
chronized with an external clock to minimize the system noise.
The
ADP2443
targets high performance applications that require
high efficiency and design flexibility. External compensation
and an adjustable soft start function provide design flexibility.
The power-good output and precision enable input provide
simple and reliable power sequencing.
Other key features include undervoltage lockout (UVLO),
overvoltage protection (OVP), overcurrent protection (OCP),
short-circuit protection (SCP), and thermal shutdown (TSD).
The
ADP2443
operates over the −40°C to +125°C operating
junction temperature range and is available in a 24-lead, 4 mm ×
4 mm LFCSP package.
100
95
90
85
EFFICIENCY (%)
80
75
70
65
60
55
14794-002
V
OUT
= 5V
V
OUT
= 3.3V
50
0
0.5
1.0
1.5
2.0
2.5
3.0
OUTPUT CURRENT (A)
Figure 2. Efficiency vs. Output Current, V
IN
= 24 V, f
SW
= 300 kHz
Rev. 0
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Trademarks and registered trademarks are the property of their respective owners.
ADP2443
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Typical Application Circuit ............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Functional Block Diagram .............................................................. 3
Specifications..................................................................................... 4
Absolute Maximum Ratings ............................................................ 6
Thermal Resistance ...................................................................... 6
ESD Caution .................................................................................. 6
Pin Configuration and Function Descriptions ............................. 7
Typical Performance Characteristics ............................................. 8
Theory of Operation ...................................................................... 13
Control Scheme .......................................................................... 13
Precision Enable/Shutdown ...................................................... 13
Internal Regulator (VREG) ....................................................... 13
Bootstrap Circuitry .................................................................... 13
Oscillator ..................................................................................... 13
Synchronization .......................................................................... 13
Soft Start ...................................................................................... 14
Power Good ................................................................................. 14
Peak Current-Limit and Short-Circuit Protection................. 14
Overvoltage Protection (OVP) ................................................. 14
Undervoltage Lockout (UVLO) ............................................... 14
Thermal Shutdown ..................................................................... 14
Data Sheet
Applications Information .............................................................. 15
Input Capacitor Selection .......................................................... 15
Output Voltage Setting .............................................................. 15
Voltage Conversion Limitations ............................................... 15
Inductor Selection ...................................................................... 15
Output Capacitor Selection....................................................... 17
Programming Input Voltage UVLO ........................................ 17
Slope Compensation Setting ..................................................... 17
Compensation Design ............................................................... 17
ADIsimPower Design Tool ....................................................... 18
Design Example .............................................................................. 19
Output Voltage Setting .............................................................. 19
Frequency Setting ....................................................................... 19
Inductor Selection ...................................................................... 19
Output Capacitor Selection....................................................... 20
Slope Compensation Setting ..................................................... 20
Compensation Components ..................................................... 20
Soft Start Time Program ........................................................... 20
Input Capacitor Selection .......................................................... 20
Recommended External Components .................................... 21
Printed Circuit Board Layout Recommendations ..................... 22
Typical Applications Circuits ........................................................ 23
Outline Dimensions ....................................................................... 24
Ordering Guide .......................................................................... 24
REVISION HISTORY
9/2016—Revision 0: Initial Version
Rev. 0 | Page 2 of 24
Data Sheet
FUNCTIONAL BLOCK DIAGRAM
VREG
4µA
ADP2443
ADP2443
EN
0.13µA
1.2V
EN_BUF
5V
REGULATOR
PVIN
PGOOD
UVLO
DEGLITCH
GND
0.66V
BOOST
REGULATOR
0.54V
0.7V
OVP
DRIVER
BST
NFET
FB
I
SS
SS
0.6V
AMP
AMP
CMP
CONTROL
LOGIC AND
MOSFET
DRIVER
WITH
ANTICROSS
PROTECTION
SW
VREG
NFET
DRIVER
PGND
COMP
RAMP
SLOPE
COMPENSATION
AND RAMP
GENERATOR
A
CS
HICCUP
MODE
RT/SYNC
OSC
CLK
OCP
I
NEG
NEGATIVE CURRENT CMP
OCP
14794-003
I
MAX
Figure 3.
Rev. 0 | Page 3 of 24
ADP2443
SPECIFICATIONS
Data Sheet
V
PVIN
= 12 V, T
J
= −40°C to +125°C for minimum/maximum specifications, T
A
= 25°C for typical specifications, unless otherwise noted.
Table 1.
Parameters
PVIN
PVIN Voltage Range
Quiescent Current
Shutdown Current
PVIN Undervoltage Lockout Threshold
FB
Regulation Voltage
Bias Current
ERROR AMPLIFIER (EA)
Transconductance
Source Current
Sink Current
INTERNAL REGULATOR (VREG)
VREG Voltage
Dropout Voltage
Regulator Current Limit
SW
High-Side On Resistance
1
Low-Side On Resistance
1
Low-Side Valley Current Limit
Low-Side Negative Current Limit
Leakage Current
SW Minimum On Time
SW Minimum Off Time
BST
Bootstrap Voltage
OSCILLATOR (RT/SYNC)
Switching Frequency
Switching Frequency Range
Synchronization Range
SYNC Minimum Pulse Width
SYNC Minimum Off Time
SYNC Input Voltage
High
Low
SS
SS Pin Pull-Up Current
PGOOD
Power-Good Range
FB Rising Threshold
FB Rising Hysteresis
FB Falling Threshold
FB Falling Hysteresis
Power-Good Deglitch Time
Power-Good Leakage Current
Power-Good Output Low Voltage
Symbol
V
PVIN
I
Q
I
SHDN
Test Conditions/Comments
Min
4.5
No switching, RAMP connected to PVIN
through a resistor
EN = GND
PVIN rising
PVIN falling
−40°C < T
J
< +125°C
0.868
28
4.3
3.9
0.6
0.05
515
50
50
5
320
100
98
35
4.7
2.5
1.5
50
200
5
600
Typ
Max
36
1.1
57
4.45
Unit
V
mA
µA
V
V
V
µA
µS
µA
µA
V
mV
mA
mΩ
mΩ
A
A
µA
ns
ns
V
kHz
kHz
kHz
ns
ns
V
V
µA
3.8
0.594
V
FB
I
FB
g
m
I
SOURCE
I
SINK
V
VREG
0.606
0.2
545
485
V
FB
= 0.45 V
V
FB
= 0.75 V
V
PVIN
= 12 V, I
VREG
= 10 mA
V
PVIN
= 12 V, I
VREG
= 30 mA
4.9
5.1
R
DSON_HS
R
DSON_LS
BST pin voltage (V
BST
) − V
SW
= 5 V
V
VREG
= 5 V
3.9
2
V
SW
= 0 V, EN = GND
t
MIN_ON
t
MIN_OFF
V
BOOT
f
SW
R
T
= 280 kΩ
4.65
540
200
200
100
100
1.3
147
58
5.1
3
7.9
65
235
5.2
660
1800
1800
0.4
I
SS
3.0
3.4
3.8
108
88
Both rising and falling
V
PGOOD
= 5 V
I
PGOOD
= 1 mA
Rev. 0 | Page 4 of 24
110
5
90
5
16
0.1
220
112
92
1
300
%
%
%
%
Clock cycles
µA
mV
Data Sheet
Parameters
EN
EN Rising Threshold
EN Input Hysteresis
EN Current
THERMAL SHUTDOWN
Threshold
Hysteresis
1
ADP2443
Symbol
Test Conditions/Comments
Min
1.16
EN voltage < 1.1 V, sink current
EN voltage > 1.2 V, source current
Typ
1.2
100
0.13
4
150
25
Max
1.24
Unit
V
mV
µA
µA
°C
°C
Pin to pin measurement.
Rev. 0 | Page 5 of 24
Microcontroller MCU
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