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ADP2105_15 [ADI]

1 Amp/1.5 Amp/2 Amp Synchronous, Step-Down DC-to-DC Converters;
ADP2105_15
型号： ADP2105_15
厂家： ADI    ADI
描述：

1 Amp/1.5 Amp/2 Amp Synchronous, Step-Down DC-to-DC Converters
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1 Amp/1.5 Amp/2 Amp Synchronous,  
Step-Down DC-to-DC Converters  
Data Sheet  
ADP2105/ADP2106/ADP2107  
FEATURES  
GENERAL DESCRIPTION  
Extremely high 97% efficiency  
Ultralow quiescent current: 20 μA  
1.2 MHz switching frequency  
0.1 μA shutdown supply current  
Maximum load current  
ADP2105: 1 A  
ADP2106: 1.5 A  
ADP2107: 2 A  
Input voltage: 2.7 V to 5.5 V  
Output voltage: 0.8 V to VIN  
Maximum duty cycle: 100%  
Smoothly transitions into low dropout (LDO) mode  
Internal synchronous rectifier  
Small 16-lead 4 mm × 4 mm LFCSP_VQ package  
Optimized for small ceramic output capacitors  
Enable/shutdown logic input  
Undervoltage lockout  
The ADP2105/ADP2106/ADP2107 are low quiescent current,  
synchronous, step-down dc-to-dc converters in a compact 4 mm ×  
4 mm LFCSP_VQ package. At medium to high load currents,  
these devices use a current mode, constant frequency pulse-  
width modulation (PWM) control scheme for excellent stability  
and transient response. To ensure the longest battery life in portable  
applications, the ADP2105/ADP2106/ADP2107 use a pulse  
frequency modulation (PFM) control scheme under light load  
conditions that reduces switching frequency to save power.  
The ADP2105/ADP2106/ADP2107 run from input voltages of  
2.7 V to 5.5 V, allowing single Li+/Li− polymer cell, multiple  
alkaline/NiMH cells, PCMCIA, and other standard power sources.  
The output voltage of ADP2105/ADP2106/ADP2107 is adjustable  
from 0.8 V to the input voltage (indicated by ADJ), whereas the  
ADP2105/ADP2106/ADP2107 are available in preset output  
voltage options of 3.3 V, 1.8 V, 1.5 V, and 1.2 V (indicated by x.x V).  
Each of these variations is available in three maximum current  
levels: 1 A (ADP2105), 1.5 A (ADP2106), and 2 A (ADP2107). The  
power switch and synchronous rectifier are integrated for minimal  
external part count and high efficiency. During logic controlled  
shutdown, the input is disconnected from the output, and it  
draws less than 0.1 µA from the input source. Other key features  
include undervoltage lockout to prevent deep battery discharge  
and programmable soft start to limit inrush current at startup.  
Soft start  
Supported by ADIsimPower™ design tool  
APPLICATIONS  
Mobile handsets  
PDAs and palmtop computers  
Telecommunication/networking equipment  
Set top boxes  
Audio/video consumer electronics  
TYPICAL OPERATING CIRCUIT  
0.1μF  
V
INPUT VOLTAGE = 2.7V TO 5.5V  
10Ω  
IN  
100  
10μF  
V
= 2.5V  
OUT  
V
= 3.6V  
IN  
FB  
16  
V
= 3.3V  
IN  
15  
14  
IN PWIN1  
LX2  
13  
95  
90  
85  
80  
75  
FB GND  
ON  
OUTPUT VOLTAGE = 2.5V  
1
2
3
4
12  
EN  
OFF  
2μH  
PGND  
11  
10  
9
GND  
GND  
GND  
10μF 4.7μF  
85kΩ  
V
= 5V  
IN  
ADP2107-ADJ  
LX1  
FB  
V
IN  
40kΩ  
PWIN2  
LOAD  
COMP SS AGND NC  
5
0A TO 2A  
10μF  
6
7
8
1nF  
70kΩ  
120pF  
0
200 400 600 800 1000 1200 1400 1600 1800 2000  
LOAD CURRENT (mA)  
NC = NO CONNECT  
Figure 2. Efficiency vs. Load Current for the ADP2107 with VOUT = 2.5 V  
Figure 1. Circuit Configuration of ADP2107 with VOUT = 2.5 V  
Rev. D  
Information furnished by Analog Devices is believed to be accurate and reliable. However, no  
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other  
rightsof third parties that may result fromits use. Specifications subject to change without notice. No  
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.  
Trademarks andregisteredtrademarks are the property of their respective owners.  
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.  
Tel: 781.329.4700  
www.analog.com  
Fax: 781.461.3113 ©2006–2012 Analog Devices, Inc. All rights reserved.  
 
 
 
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
TABLE OF CONTENTS  
Features .............................................................................................. 1  
External Component Selection ................................................ 16  
Setting the Output Voltage........................................................ 16  
Inductor Selection ...................................................................... 17  
Output Capacitor Selection....................................................... 18  
Input Capacitor Selection.......................................................... 19  
Input Filter................................................................................... 19  
Soft Start Period.......................................................................... 19  
Loop Compensation .................................................................. 19  
Bode Plots.................................................................................... 20  
Load Transient Response .......................................................... 21  
Efficiency Considerations ......................................................... 22  
Thermal Considerations............................................................ 22  
Design Example.............................................................................. 24  
External Component Recommendations.................................... 25  
Circuit Board Layout Recommendations ................................... 27  
Evaluation Board ............................................................................ 28  
Evaluation Board Schematic for ADP2107 (1.8 V) ............... 28  
Applications....................................................................................... 1  
General Description ......................................................................... 1  
Typical Operating Circuit................................................................ 1  
Revision History ............................................................................... 2  
Functional Block Diagram .............................................................. 3  
Specifications..................................................................................... 4  
Absolute Maximum Ratings............................................................ 6  
Thermal Resistance ...................................................................... 6  
Boundary Condition.................................................................... 6  
ESD Caution.................................................................................. 6  
Pin Configuration and Function Descriptions............................. 7  
Typical Performance Characteristics ............................................. 8  
Theory of Operation ...................................................................... 14  
Control Scheme .......................................................................... 14  
PWM Mode Operation.............................................................. 14  
PFM Mode Operation................................................................ 14  
Pulse-Skipping Threshold ......................................................... 14  
100% Duty Cycle Operation (LDO Mode)............................. 14  
Slope Compensation .................................................................. 15  
Design Features........................................................................... 15  
Applications Information .............................................................. 16  
Recommended PCB Board Layout (Evaluation Board  
Layout)......................................................................................... 28  
Application Circuits ....................................................................... 30  
Outline Dimensions....................................................................... 33  
Ordering Guide .......................................................................... 33  
Changes to Slope Compensation Section.................................... 15  
Changes to Setting the Output Voltage Section ........................ 16  
Changes to Figure 37...................................................................... 16  
Changes to Inductor Selection Section........................................ 17  
Changes to Input Capacitor Selection Section ........................... 18  
Changes to Figure 47 through Figure 52..................................... 21  
Changes to Transition Losses Section and Thermal  
Considerations Section.................................................................. 22  
Changes to Table 11 ....................................................................... 25  
Changes to Circuit Board Layout Recommendations Section..27  
Changes to Table 12 ....................................................................... 26  
Changes to Figure 53...................................................................... 28  
Changes to Figure 56 Through Figure 57.................................... 30  
Changes to Figure 58 Through Figure 59.................................... 31  
Changes to Outline Dimensions .................................................. 33  
3/07—Rev. 0 to Rev. A  
Updated Format..................................................................Universal  
Changes to Output Characteristics and  
LX (Switch Node) Characteristics Sections ...................................3  
Changes to Typical Performance Characteristics Section ...........7  
Changes to Load Transient Response Section............................ 21  
REVISION HISTORY  
8/12—Rev. C to Rev. D  
Change to Features Section ............................................................. 1  
Added Exposed Pad Notation to Pin Configuration and  
Function Description Section......................................................... 7  
Added ADIsimPower Design Tool Section................................. 16  
Updated Outline Dimensions....................................................... 33  
9/08—Rev. B to Rev. C  
Changes to Table Summary Statement .......................................... 4  
Changes to LX Minimum On-Time Parameter, Table 1............. 5  
7/08—Rev. A to Rev. B  
Changes to General Description Section ...................................... 1  
Changes to Figure 3.......................................................................... 3  
Changes to Table 1 ............................................................................ 4  
Changes to Table 2 ............................................................................ 6  
Changes to Figure 4.......................................................................... 7  
Changes to Table 4 ............................................................................ 7  
Changes to Figure 26...................................................................... 11  
Changes to Figure 31 Through Figure 34.................................... 12  
Changes to Figure 35...................................................................... 13  
Changes to PMW Mode Operation Section and Pulse Skipping  
Threshold Section........................................................................... 14  
7/06—Revision 0: Initial Version  
Rev. D | Page 2 of 36  
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
FUNCTIONAL BLOCK DIAGRAM  
5
6
14  
COMP  
SS  
IN  
9
PWIN2  
PWIN1  
SOFT  
START  
REFERENCE  
0.8V  
CURRENT SENSE  
AMPLIFIER  
13  
16  
16  
7
FB  
FB  
GM ERROR  
AMP  
CURRENT  
LIMIT  
PWM/  
PFM  
CONTROL  
AGND  
FOR PRESET  
VOLTAGE  
OPTIONS ONLY  
DRIVER  
AND  
ANTI-  
2
3
GND  
GND  
GND  
NC  
10  
12  
LX1  
LX2  
SHOOT  
THROUGH  
SLOPE  
COMPENSATION  
4
8
15  
GND  
OSCILLATOR  
ZERO CROSS  
COMPARATOR  
11  
PGND  
THERMAL  
SHUTDOWN  
1
EN  
Figure 3.  
Rev. D | Page 3 of 36  
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
SPECIFICATIONS  
VIN = 3.6 V @ TA = 25°C, unless otherwise noted.1  
Table 1.  
Parameter  
Min  
2.7  
2.2  
2.0  
Typ  
Max  
5.5  
Unit  
Conditions  
INPUT CHARACTERISTICS  
Input Voltage Range  
Undervoltage Lockout Threshold  
V
V
V
V
V
mV  
−40°C ≤ TJ ≤ +125°C  
VIN rising  
VIN rising, −40°C ≤ TJ ≤ +125°C  
VIN falling  
VIN falling, −40°C ≤ TJ ≤ +125°C  
VIN falling  
2.4  
2.2  
200  
2.6  
2.5  
Undervoltage Lockout Hysteresis2  
OUTPUT CHARACTERISTICS  
Output Regulation Voltage  
3.267 3.3  
3.3  
3.201  
3.333  
V
V
V
3.3 V, load = 10 mA  
3.3 V, VIN = 3.6 V to 5.5 V, no load to full load  
3.3 V, VIN = 3.6 V to 5.5 V, no load to full load,  
−40°C ≤ TJ ≤ +125°C  
1.8 V, load = 10 mA  
1.8 V, VIN = 2.7 V to 5.5 V, no load to full load  
1.8 V, VIN = 2.7 V to 5.5 V, no load to full load,  
−40°C ≤ TJ ≤ +125°C  
1.5, load = 10 mA  
ADP210x-1.5 V, VIN = 2.7 V to 5.5 V, no load to full load  
ADP210x-1.5 V, VIN = 2.7 V to 5.5 V, no load to full load,  
−40°C ≤ TJ ≤ +125°C  
1.2 V, load = 10 mA  
1.2 V, VIN = 2.7 V to 5.5 V, no load to full load  
1.2 V, VIN = 2.7 V to 5.5 V, no load to full load,  
−40°C ≤ TJ ≤ +125°C  
3.399  
1.818  
1.782 1.8  
1.8  
1.746  
V
V
V
1.854  
1.515  
1.485 1.5  
1.5  
1.455  
V
V
V
1.545  
1.212  
1.188 1.2  
1.2  
1.164  
V
V
V
1.236  
Load Regulation  
Line Regulation3  
0.4  
0.5  
0.6  
0.1  
%/A  
%/A  
%/A  
%/V  
%/V  
V
ADP2105  
ADP2106  
ADP2107  
0.33  
0.3  
VIN  
ADP2105, measured in servo loop  
ADP2106 and ADP2107, measured in servo loop  
ADJ  
0.1  
0.8  
Output Voltage Range  
FEEDBACK CHARACTERISTICS  
FB Regulation Voltage  
0.8  
V
ADJ  
0.784  
−0.1  
3
0.816  
+0.1  
V
ADJ, −40°C ≤ TJ ≤ +125°C  
ADJ, −40°C ≤ TJ ≤ +125°C  
1.2 V output voltage  
1.2 V output voltage, −40°C ≤ TJ ≤ +125°C  
1.5 V output voltage  
1.5 V output voltage, −40°C ≤ TJ ≤ +125°C  
1.8 V output voltage  
1.8 V output voltage, −40°C ≤ TJ ≤ +125°C  
3.3 V output voltage  
FB Bias Current  
µA  
µA  
µA  
µA  
µA  
µA  
µA  
µA  
µA  
6
4
8
5
10  
20  
10  
3.3 V output voltage, −40°C ≤ TJ ≤ +125°C  
Rev. D | Page 4 of 36  
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
Parameter  
Min  
Typ  
20  
Max  
Unit  
Conditions  
INPUT CURRENT CHARACTERISTICS  
IN Operating Current  
µA  
µA  
µA  
ADP210x(ADJ), VFB = 0.9 V  
ADP210x(ADJ), VFB = 0.9 V, −40°C ≤ TJ ≤ +125°C  
ADP210x(x.x V) output voltage 10% above regulation  
voltage  
30  
20  
30  
1
µA  
µA  
ADP210x(x.x V) output voltage 10% above regulation  
voltage, −40°C ≤ TJ ≤ +125°C  
VEN = 0 V  
IN Shutdown Current4  
LX (SWITCH) NODE CHARACTERISTICS  
LX On Resistance4  
0.1  
190  
100  
mΩ  
mΩ  
mΩ  
mΩ  
P-channel switch, ADP2105  
P-channel switch, ADP2105, −40°C ≤ TJ ≤ +125°C  
P-channel switch, ADP2106 and ADP2107  
P-channel switch, ADP2106 and ADP2107,  
−40°C ≤ TJ ≤ +125°C  
270  
165  
160  
90  
mΩ  
mΩ  
N-channel synchronous rectifier, ADP2105  
N-channel synchronous rectifier, ADP2105,  
−40°C ≤ TJ ≤ +125°C  
N-channel synchronous rectifier, ADP2106 and ADP2107  
N-channel synchronous rectifier, ADP2106 and ADP2107,  
−40°C ≤ TJ ≤ +125°C  
230  
mΩ  
mΩ  
140  
1
LX Leakage Current4, 5  
LX Peak Current Limit5  
0.1  
2.9  
µA  
A
VIN = 5.5 V, VLX = 0 V, 5.5 V  
P-channel switch, ADP2107  
2.6  
2.0  
1.3  
3.3  
2.6  
A
A
A
A
A
ns  
P-channel switch, ADP2107, −40°C ≤ TJ ≤ +125°C  
P-channel switch, ADP2106  
P-channel switch, ADP2106, −40°C ≤ TJ ≤ +125°C  
P-channel switch, ADP2105  
P-channel switch, ADP2105, −40°C ≤ TJ ≤ +125°C  
In PWM mode of operation, −40°C ≤ TJ ≤ +125°C  
2.25  
1.5  
1.8  
110  
LX Minimum On-Time  
ENABLE CHARACTERISTICS  
EN Input High Voltage  
EN Input Low Voltage  
2
V
V
VIN = 2.7 V to 5.5 V, −40°C ≤ TJ ≤ +125°C  
VIN = 2.7 V to 5.5 V, −40°C ≤ TJ ≤ +125°C  
VIN = 5.5 V, VEN = 0 V, 5.5 V  
VIN = 5.5 V, VEN = 0 V, 5.5 V, −40°C ≤ TJ ≤ +125°C  
VIN = 2.7 V to 5.5 V  
0.4  
+1  
EN Input Leakage Current  
−0.1  
1.2  
µA  
µA  
MHz  
MHz  
µs  
−1  
OSCILLATOR FREQUENCY  
1
1.4  
VIN = 2.7 V to 5.5 V, −40°C ≤ TJ ≤ +125°C  
CSS = 1 nF  
SOFT START PERIOD  
750  
1000  
1200  
THERMAL CHARACTERISTICS  
Thermal Shutdown Threshold  
Thermal Shutdown Hysteresis  
140  
40  
°C  
°C  
COMPENSATOR  
50  
µA/V  
TRANSCONDUCTANCE (gm)  
CURRENT SENSE AMPLIFIER GAIN (GCS)2  
1.875  
2.8125  
3.625  
A/V  
A/V  
A/V  
ADP2105  
ADP2106  
ADP2107  
1 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC). Typical values are at TA = 25°C.  
2 Guaranteed by design.  
3 The ADP2105/ADP2106/ADP2107 line regulation was measured in a servo loop on the automated test equipment that adjusts the feedback voltage to achieve a  
specific COMP voltage.  
4 All LX (switch) node characteristics are guaranteed only when the LX1 pin and LX2 pin are tied together.  
5 These specifications are guaranteed from −40°C to +85°C.  
Rev. D | Page 5 of 36  
 
 
 
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
ABSOLUTE MAXIMUM RATINGS  
THERMAL RESISTANCE  
Table 2.  
θJA is specified for the worst-case conditions, that is, a device  
soldered in a circuit board for surface-mount packages.  
Parameter  
Rating  
IN, EN, SS, COMP, FB to AGND  
LX1, LX2 to PGND  
PWIN1, PWIN2 to PGND  
PGND to AGND  
GND to AGND  
PWIN1, PWIN2 to IN  
−0.3 V to +6 V  
−0.3 V to (VIN + 0.3 V)  
−0.3 V to +6 V  
−0.3 V to +0.3 V  
−0.3 V to +0.3 V  
−0.3 V to +0.3 V  
Table 3. Thermal Resistance  
Package Type  
θJA  
40  
1
Unit  
°C/W  
W
16-Lead LFCSP_VQ/QFN  
Maximum Power Dissipation  
Operating Junction Temperature Range −40°C to +125°C  
BOUNDARY CONDITION  
Storage Temperature Range  
Soldering Conditions  
−65°C to +150°C  
JEDEC J-STD-020  
Natural convection, 4-layer board, exposed pad soldered to the PCB.  
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.  
Rev. D | Page 6 of 36  
 
 
 
 
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS  
PIN 1  
INDICATOR  
EN 1  
GND 2  
GND 3  
GND 4  
12 LX2  
ADP2105/  
ADP2106/  
ADP2107  
11 PGND  
10 LX1  
TOP VIEW  
(Not to Scale)  
9
PWIN2  
NOTES  
1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN.  
2. THE EXPOSED PAD SHOULD BE SOLDERED TO AN  
EXTERNAL GROUND PLANE UNDERNEATH THE IC FOR  
THERMAL DISSIPATION.  
Figure 4. Pin Configuration  
Table 4. Pin Function Descriptions  
Pin No.  
Mnemonic Description  
1
EN  
Enable Input. Drive EN high to turn on the device. Drive EN low to turn off the device and reduce the input  
current to 0.1 µA.  
2, 3, 4, 15 GND  
Test Pins. These pins are used for internal testing and are not ground return pins. These pins are to be tied to the  
AGND plane as close as possible to the ADP2105/ADP2106/ADP2107.  
5
6
7
COMP  
SS  
Feedback Loop Compensation Node. COMP is the output of the internal transconductance error amplifier. Place  
a series RC network from COMP to AGND to compensate the converter. See the Loop Compensation section.  
Soft Start Input. Place a capacitor from SS to AGND to set the soft start period. A 1 nF capacitor sets a 1 ms soft  
start period.  
Analog Ground. Connect the ground of the compensation components, the soft start capacitor, and the voltage  
divider on the FB pin to the AGND pin as close as possible to the ADP2105/ ADP2106/ADP2107. The AGND is  
also to be connected to the exposed pad of ADP2105/ADP2106/ADP2107.  
AGND  
8
NC  
No Connect. This is not internally connected and can be connected to other pins or left unconnected.  
9, 13  
PWIN2,  
PWIN1  
Power Source Inputs. The source of the PFET high-side switch. Bypass each PWIN pin to the nearest PGND plane with a  
4.7 µF or greater capacitor as close as possible to the ADP2105/ADP2106/ ADP2107. See the Input Capacitor  
Selection section.  
10, 12  
11  
LX1, LX2  
PGND  
Switch Outputs. The drain of the P-channel power switch and N-channel synchronous rectifier. These pins are to  
be tied together and connected to the output LC filter between LX and the output voltage.  
Power Ground. Connect the ground return of all input and output capacitors to the PGND pin using a power  
ground plane as close as possible to the ADP2105/ADP2106/ADP2107. The PGND is then to be connected to the  
exposed pad of the ADP2105/ADP2106/ADP2107.  
14  
16  
IN  
FB  
EP  
Power Input. The power source for the ADP2105/ADP2106/ADP2107 internal circuitry. Connect IN and PWIN1  
with a 10 Ω resistor as close as possible to the ADP2105/ADP2106/ADP2107. Bypass IN to AGND with a 0.1 µF or  
greater capacitor. See the Input Filter section.  
Output Voltage Sense or Feedback Input. For fixed output versions, connect to the output voltage. For  
adjustable versions, FB is the input to the error amplifier. Drive FB through a resistive voltage divider to set the  
output voltage. The FB regulation voltage is 0.8 V.  
Exposed Pad. The exposed pad should be soldered to an external ground plane underneath the IC for thermal  
dissipation.  
Rev. D | Page 7 of 36  
 
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
TYPICAL PERFORMANCE CHARACTERISTICS  
100  
100  
95  
95  
V
= 2.7V  
IN  
V
= 3.6V  
IN  
90  
85  
80  
V
= 3.6V  
IN  
90  
V
= 2.7V  
IN  
85  
80  
V
= 4.2V  
IN  
V
= 5.5V  
V
= 4.2V  
IN  
IN  
75  
70  
V
= 5.5V  
IN  
75  
70  
65  
65  
60  
INDUCTOR: SD14, 2.5µH  
INDUCTOR: SD3814, 3.3µH  
DCR: 93mΩ  
DCR: 60mΩ  
T
= 25°C  
T
= 25°C  
100  
A
A
1
1
1
10  
100  
1000  
1
1
1
1000  
10  
LOAD CURRENT (mA)  
LOAD CURRENT (mA)  
Figure 5. Efficiency—ADP2105 (1.2 V Output)  
Figure 8. Efficiency—ADP2105 (1.8 V Output)  
100  
95  
90  
85  
80  
75  
70  
65  
60  
55  
50  
100  
95  
90  
85  
80  
75  
70  
65  
60  
V
= 3.6V  
IN  
V
= 2.7V  
IN  
V
= 3.6V  
IN  
V
= 5.5V  
IN  
V
= 4.2V  
IN  
V
= 4.2V  
IN  
V
= 5.5V  
IN  
INDUCTOR: D62LCB, 2µH  
DCR: 28mΩ  
= 25°C  
INDUCTOR: CDRH5D18, 4.1μH  
DCR: 43mΩ  
T
T
= 25°C  
A
A
10  
100  
LOAD CURRENT (mA)  
1k  
10k  
1000  
10  
100  
LOAD CURRENT (mA)  
Figure 6. Efficiency—ADP2105 (3.3 V Output)  
Figure 9. Efficiency—ADP2106 (1.2 V Output)  
100  
95  
90  
85  
80  
75  
70  
65  
60  
55  
50  
100  
95  
90  
85  
80  
75  
70  
65  
60  
55  
50  
V
= 3.6V  
IN  
V
= 2.7V  
IN  
V
= 5.5V  
IN  
V
= 4.2V  
IN  
V
= 4.2V  
IN  
V
= 5.5V  
IN  
V
= 3.6V  
10  
IN  
INDUCTOR: D62LCB, 2µH  
INDUCTOR: D62LCB, 3.3µH  
DCR: 28mΩ  
DCR: 47mΩ  
T
= 25°C  
T = 25°C  
A
A
10k  
10k  
10  
100  
LOAD CURRENT (mA)  
1k  
100  
LOAD CURRENT (mA)  
1k  
Figure 7. Efficiency—ADP2106 (1.8 V Output)  
Figure 10. Efficiency—ADP2106 (3.3 V Output)  
Rev. D | Page 8 of 36  
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
100  
100  
95  
90  
85  
80  
75  
70  
65  
60  
55  
50  
V
= 3.6V  
IN  
95  
V
= 2.7V  
IN  
90  
V
= 2.7V  
IN  
V
= 3.6V  
IN  
85  
80  
75  
70  
65  
60  
55  
50  
V
= 4.2V  
IN  
V
= 5.5V  
IN  
V
= 4.2V  
IN  
V
= 5.5V  
IN  
INDUCTOR: SD12, 1.2µH  
DCR: 37mΩ  
= 25°C  
INDUCTOR: D62LCB, 1.5µH  
DCR: 21mΩ  
T
T
= 25°C  
A
A
1
10  
100  
LOAD CURRENT (mA)  
1k  
10k  
1
10k  
10k  
10k  
10  
100  
LOAD CURRENT (mA)  
1k  
Figure 11. Efficiency—ADP2107 (1.2 V)  
Figure 14. Efficiency—ADP2107 (1.8 V)  
100  
95  
90  
85  
80  
75  
70  
65  
60  
55  
50  
1.23  
1.22  
1.21  
1.20  
1.19  
1.18  
1.17  
2.7V, –40°C  
3.6V, –40°C  
5.5V, –40°C  
2.7V, +25°C  
3.6V, +25°C  
5.5V, +25°C  
2.7V, +125°C  
3.6V, +125°C  
5.5V, +125°C  
V
= 5.5V  
IN  
V
= 4.2V  
IN  
V
= 3.6V  
IN  
INDUCTOR: CDRH5D28, 2.5µH  
DCR: 13mΩ  
A
T
= 25°C  
1
10k  
0.01  
0.1  
1
10  
100  
1k  
10  
100  
1k  
LOAD CURRENT (mA)  
LOAD CURRENT (mA)  
Figure 12. Efficiency—ADP2107 (3.3 V)  
Figure 15. Output Voltage Accuracy—ADP2107 (1.2 V)  
1.85  
1.83  
1.81  
1.79  
1.77  
1.75  
3.38  
3.36  
3.34  
3.32  
3.30  
3.28  
3.26  
3.24  
3.22  
3.6V, –40°C  
5.5V, –40°C  
3.6V, +25°C  
5.5V, +25°C  
3.6V, +125°C  
5.5V, +125°C  
2.7V, –40°C  
3.6V, –40°C  
5.5V, –40°C  
2.7V, +25°C  
3.6V, +25°C  
5.5V, +25°C  
2.7V, +125°C  
3.6V, +125°C  
5.5V, +125°C  
0.1  
1
10  
100  
1k  
10k  
0.01  
0.1  
1
10  
100  
1k  
LOAD CURRENT (mA)  
LOAD CURRENT (mA)  
Figure 13. Output Voltage Accuracy—ADP2107 (1.8 V)  
Figure 16. Output Voltage Accuracy—ADP2107 (3.3 V)  
Rev. D | Page 9 of 36  
ADP2105/ADP2106/ADP2107  
Data Sheet  
10k  
190  
180  
170  
160  
1k  
PMOS POWER SWITCH  
+25°C  
150  
140  
130  
–40°C  
100  
NMOS SYNCHRONOUS RECTIFIER  
10  
120  
110  
100  
+125°C  
1
2.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2  
INPUT VOLTAGE (V)  
INPUT VOLTAGE (V)  
Figure 17. Quiescent Current vs. Input Voltage  
Figure 20. Switch On Resistance vs. Input Voltage—ADP2105  
120  
0.802  
PMOS POWER SWITCH  
100  
0.801  
0.800  
0.799  
0.798  
0.797  
0.796  
0.795  
80  
NMOS SYNCHRONOUS RECTIFIER  
60  
40  
20  
0
T
= 25°C  
A
2.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
–40  
–20  
0
20  
40  
60  
80  
100  
120125  
INPUT VOLTAGE (V)  
TEMPERATURE (°C)  
Figure 21. Switch On Resistance vs. Input Voltage—ADP2106 and ADP2107  
Figure 18. Feedback Voltage vs. Temperature  
1260  
1.75  
1.70  
1.65  
1.60  
1.55  
1.50  
1.45  
1.40  
1.35  
1.30  
1.25  
1250  
1240  
1230  
ADP2105 (1A)  
+125°C  
1220  
+25°C  
–40°C  
1210  
1200  
1190  
T
= 25°C  
A
2.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
2.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
5.7  
INPUT VOLTAGE (V)  
INPUT VOLTAGE (V)  
Figure 22. Switching Frequency vs. Input Voltage  
Figure 19. Peak Current Limit of ADP2105  
Rev. D | Page 10 of 36  
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
2.35  
2.30  
2.25  
2.20  
2.15  
2.10  
2.05  
2.00  
1.95  
1.90  
1.85  
LX (SWITCH) NODE  
3
ADP2106 (1.5A)  
INDUCTOR CURRENT  
Δ: 260mV  
@: 3.26V  
1
4
OUTPUT VOLTAGE  
T
= 25°C  
A
CH1 1V  
CH3 5V  
M
T
10µs  
45.8%  
A
CH1  
1.78V  
2.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
5.7  
CH4 1AΩ  
INPUT VOLTAGE (V)  
Figure 23. Peak Current Limit of ADP2106  
Figure 26. Short -Circuit Response at Output  
3.00  
135  
2.95  
2.90  
2.85  
2.80  
2.75  
2.70  
2.65  
2.60  
2.55  
2.50  
120  
105  
90  
75  
60  
45  
30  
15  
0
ADP2107 (2A)  
V
= 1.2V  
OUT  
V
= 1.8V  
OUT  
V
= 2.5V  
OUT  
T
= 25°C  
T
= 25°C  
A
A
2.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
5.7  
2.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
5.7  
INPUT VOLTAGE (V)  
INPUT VOLTAGE (V)  
Figure 27. Pulse-Skipping Threshold vs. Input Voltage for ADP2105  
Figure 24. Peak Current Limit of ADP2107  
195  
180  
150  
135  
120  
105  
90  
V
= 1.2V  
165  
150  
135  
120  
105  
90  
OUT  
V
= 1.8V  
= 2.5V  
OUT  
OUT  
V
= 1.2V  
OUT  
75  
V
60  
75  
V
= 2.5V  
OUT  
V
= 1.8V  
OUT  
60  
45  
45  
30  
30  
15  
15  
T
= 25°C  
T
= 25°C  
A
A
0
2.7  
0
2.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
5.7  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
5.7  
INPUT VOLTAGE (V)  
INPUT VOLTAGE (V)  
Figure 28. Pulse-Skipping Threshold vs. Input Voltage for ADP2107  
Figure 25. Pulse-Skipping Threshold vs. Input Voltage for ADP2106  
Rev. D | Page 11 of 36  
 
 
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
190  
180  
170  
160  
3
1
PMOS POWER SWITCH  
150  
LX (SWITCH) NODE  
140  
130  
OUTPUT VOLTAGE (AC-COUPLED)  
NMOS SYNCHRONOUS RECTIFIER  
120  
4
110  
INDUCTOR CURRENT  
100  
2.7  
CH1 50mV  
CH3 2V  
M
T
400ns  
17.4%  
A
CH3  
3.88V  
3.0  
3.3  
3.6  
3.9  
4.2  
4.5  
4.8  
5.1  
5.4  
CH4 200mAΩ  
INPUT VOLTAGE (V)  
Figure 32. DCM Mode of Operation at Light Load (100 mA)  
Figure 29. Switch On Resistance vs. Temperature—ADP2105  
140  
LX (SWITCH) NODE  
120  
PMOS POWER SWITCH  
100  
3
1
80  
NMOS SYNCHRONOUS RECTIFIER  
60  
OUTPUT VOLTAGE (AC-COUPLED)  
INDUCTOR CURRENT  
40  
20  
0
4
CH1 20mV  
CH3 2V  
M
T
2µs  
13.4%  
A
CH3  
1.84V  
–40  
–20  
0
20  
40  
60  
80  
100  
120  
CH4 1AΩ  
JUNCTION TEMPERATURE (°C)  
Figure 30. Switch On Resistance vs. Temperature—ADP2106 and ADP2107  
Figure 33. Minimum Off Time Control at Dropout  
LX (SWITCH) NODE  
LX (SWITCH)  
NODE  
3
3
1
1
OUTPUT VOLTAGE (AC-COUPLED)  
OUTPUT VOLTAGE (AC-COUPLED)  
INDUCTOR CURRENT  
4
INDUCTOR CURRENT  
4
CH1 50mV  
CH3 2V  
M
T
2µs  
6%  
A
CH3  
3.88V  
CH1 20mV  
CH3 2V  
M
T
1µs  
17.4%  
A
CH3  
3.88V  
CH4 200mAΩ  
CH4 1AΩ  
Figure 31. PFM Mode of Operation at Very Light Load (10 mA)  
Figure 34. PWM Mode of Operation at Medium/Heavy Load (1.5 A)  
Rev. D | Page 12 of 36  
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
LX (SWITCH) NODE  
ENABLE VOLTAGE  
3
3
OUTPUT VOLTAGE  
CHANNEL 3  
FREQUENCY  
= 336.6kHz  
Δ: 2.86A  
@: 2.86A  
1
4
INDUCTOR CURRENT  
OUTPUT VOLTAGE  
INDUCTOR CURRENT  
1
4
CH1 1V  
CH3 5V  
M
T
4µs  
45%  
A
CH3  
1.8V  
CH1 1V  
CH3 5V  
M
T
400µs  
20.2%  
A
CH1  
1.84V  
CH4 1AΩ  
CH4 500mAΩ  
Figure 35. Current Limit Behavior of ADP2107 (Frequency Foldback)  
Figure 36. Startup and Shutdown Waveform (CSS = 1 nF → SS Time = 1 ms)  
Rev. D | Page 13 of 36  
ADP2105/ADP2106/ADP2107  
Data Sheet  
THEORY OF OPERATION  
The ADP2105/ADP2106/ADP2107 are step-down, dc-to-dc  
converters that use a fixed frequency, peak current mode archi-  
tecture with an integrated high-side switch and low-side synchron-  
ous rectifier. The high 1.2 MHz switching frequency and tiny  
16-lead, 4 mm × 4 mm LFCSP_VQ package allow for a small step-  
down dc-to-dc converter solution. The integrated high-side switch  
(P-channel MOSFET) and synchronous rectifier (N-channel  
MOSFET) yield high efficiency at medium to heavy loads. Light  
load efficiency is improved by smoothly transitioning to variable  
frequency PFM mode.  
PFM MODE OPERATION  
The ADP2105/ADP2106/ADP2107 smoothly transition to the  
variable frequency PFM mode of operation when the load current  
decreases below the pulse skipping threshold current, switching  
only as necessary to maintain the output voltage within regulation.  
When the output voltage dips below regulation, the ADP2105/  
ADP2106/ADP2107 enter PWM mode for a few oscillator cycles  
to increase the output voltage back to regulation. During the wait  
time between bursts, both power switches are off, and the output  
capacitor supplies all the load current. Because the output voltage  
dips and recovers occasionally, the output voltage ripple in this  
mode is larger than the ripple in the PWM mode of operation.  
The ADP2105/ADP2106/ADP2107 (ADJ) operate with an input  
voltage from 2.7 V to 5.5 V and regulate an output voltage down  
to 0.8 V. The ADP2105/ADP2106/ADP2107 are also available with  
preset output voltage options of 3.3 V, 1.8 V, 1.5 V, and 1.2 V.  
PULSE-SKIPPING THRESHOLD  
The output current at which the ADP2105/ADP2106/ADP2107  
transition from variable frequency PFM control to fixed frequency  
PWM control is called the pulse-skipping threshold. The pulse-  
skipping threshold is optimized for excellent efficiency over all  
load currents. The variation of pulse-skipping threshold with  
input voltage and output voltage is shown in Figure 25, Figure 27,  
and Figure 28.  
CONTROL SCHEME  
The ADP2105/ADP2106/ADP2107 operate with a fixed frequency,  
peak current mode PWM control architecture at medium to high  
loads for high efficiency, but shift to a variable frequency PFM  
control scheme at light loads for lower quiescent current. When  
operating in fixed frequency PWM mode, the duty cycle of the  
integrated switches is adjusted to regulate the output voltage, but  
when operating in PFM mode at light loads, the switching  
frequency is adjusted to regulate the output voltage.  
100% DUTY CYCLE OPERATION (LDO MODE)  
As the input voltage drops, approaching the output voltage, the  
ADP2105/ADP2106/ADP2107 smoothly transition to 100%  
duty cycle, maintaining the P-channel MOSFET switch-on conti-  
nuously. This allows the ADP2105/ADP2106/ADP2107 to regulate  
the output voltage until the drop in input voltage forces the P-  
channel MOSFET switch to enter dropout, as shown in the  
following equation:  
The ADP2105/ADP2106/ADP2107 operate in the PWM mode  
only when the load current is greater than the pulse-skipping  
threshold current. At load currents below this value, the converter  
smoothly transitions to the PFM mode of operation.  
PWM MODE OPERATION  
In PWM mode, the ADP2105/ADP2106/ADP2107 operate at a  
fixed frequency of 1.2 MHz set by an internal oscillator. At the  
start of each oscillator cycle, the P-channel MOSFET switch is  
turned on, putting a positive voltage across the inductor. Current  
in the inductor increases until the current sense signal crosses  
the peak inductor current level that turns off the P-channel  
MOSFET switch and turns on the N-channel MOSFET synchro-  
nous rectifier. This puts a negative voltage across the inductor,  
causing the inductor current to decrease. The synchronous  
rectifier stays on for the remainder of the cycle, unless the  
inductor current reaches zero, which causes the zero-crossing  
comparator to turn off the N-channel MOSFET. The peak  
inductor current is set by the voltage on the COMP pin. The  
COMP pin is the output of a transconductance error amplifier that  
compares the feedback voltage with an internal 0.8 V reference.  
V
IN(MIN) = IOUT × (RDS(ON) − P + DCRIND) + VOUT(NOM)  
The ADP2105/ADP2106/ADP2107 achieve 100% duty cycle  
operation by stretching the P-channel MOSFET switch-on time  
if the inductor current does not reach the peak inductor current  
level by the end of the clock cycle. When this happens, the oscil-  
lator remains off until the inductor current reaches the peak  
inductor current level, at which time the switch is turned off and  
the synchronous rectifier is turned on for a fixed off time. At  
the end of the fixed off time, another cycle is initiated. As the  
ADP2105/ADP2106/ADP2107 approach dropout, the switching  
frequency decreases gradually to smoothly transition to 100%  
duty cycle operation.  
Rev. D | Page 14 of 36  
 
 
 
 
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
Short-Circuit Protection  
SLOPE COMPENSATION  
The ADP2105/ADP2106/ADP2107 include frequency foldback  
to prevent output current runaway on a hard short. When the  
voltage at the feedback pin falls below 0.3 V, indicating the possi-  
bility of a hard short at the output, the switching frequency is  
reduced to 1/4 of the internal oscillator frequency. The reduction  
in the switching frequency results in more time for the inductor to  
discharge, preventing a runaway of output current.  
Slope compensation stabilizes the internal current control loop  
of the ADP2105/ADP2106/ADP2107 when operating beyond  
50% duty cycle to prevent subharmonic oscillations. It is imple-  
mented by summing a fixed, scaled voltage ramp to the current  
sense signal during the on-time of the P-channel MOSFET switch.  
The slope compensation ramp value determines the minimum  
inductor that can be used to prevent subharmonic oscillations  
at a given output voltage. For slope compensation ramp values,  
see Table 5. For more information see the Inductor Selection  
section.  
Undervoltage Lockout (UVLO)  
To protect against deep battery discharge, UVLO circuitry is  
integrated on the ADP2105/ADP2106/ADP2107. If the  
input voltage drops below the 2.2 V UVLO threshold, the  
ADP2105/ADP2106/ADP2107 shut down, and both the power  
switch and synchronous rectifier turn off. When the voltage  
again rises above the UVLO threshold, the soft start period is  
initiated, and the part is enabled.  
Table 5. Slope Compensation Ramp Values  
Part  
Slope Compensation Ramp Values  
ADP2105  
ADP2106  
ADP2107  
0.72 A/µs  
1.07 A/µs  
1.38 A/µs  
Thermal Protection  
DESIGN FEATURES  
In the event that the ADP2105/ADP2106/ADP2107 junction  
temperatures rise above 140°C, the thermal shutdown circuit turns  
off the converter. Extreme junction temperatures can be the  
result of high current operation, poor circuit board design, and/or  
high ambient temperature. A 40°C hysteresis is included so that  
when thermal shutdown occurs, the ADP2105/ADP2106/  
ADP2107 do not return to operation until the on-chip tempera-  
ture drops below 100°C. When coming out of thermal shutdown,  
soft start is initiated.  
Enable/Shutdown  
Drive EN high to turn on the ADP2105/ADP2106/ADP2107.  
Drive EN low to turn off the ADP2105/ADP2106/ADP2107,  
reducing the input current below 0.1 µA. To force the  
ADP2105/ADP2106/ADP2107 to automatically start when  
input power is applied, connect EN to IN. When shut down, the  
ADP2105/ADP2106/ADP2107 discharge the soft start capacitor,  
causing a new soft start cycle every time they are re-enabled.  
Synchronous Rectification  
Soft Start  
In addition to the P-channel MOSFET switch, the ADP2105/  
ADP2106/ADP2107 include an integrated N-channel MOSFET  
synchronous rectifier. The synchronous rectifier improves effi-  
ciency, especially at low output voltage, and reduces cost and  
board space by eliminating the need for an external rectifier.  
The ADP2105/ADP2106/ADP2107 include soft start circuitry  
to limit the output voltage rise time to reduce inrush current at  
startup. To set the soft start period, connect the soft start capacitor  
(CSS) from SS to AGND. When the ADP2105/ADP2106/ADP2107  
are disabled, or if the input voltage is below the undervoltage  
lockout threshold, CSS is internally discharged. When the  
ADP2105/ADP2106/ADP2107 are enabled, CSS is charged through  
an internal 0.8 µA current source, causing the voltage at SS to rise  
linearly. The output voltage rises linearly with the voltage at SS.  
Current Limit  
The ADP2105/ADP2106/ADP2107 have protection circuitry to  
limit the direction and amount of current flowing through the  
power switch and synchronous rectifier. The positive current  
limit on the power switch limits the amount of current that can  
flow from the input to the output, and the negative current limit  
on the synchronous rectifier prevents the inductor current from  
reversing direction and flowing out of the load.  
Rev. D | Page 15 of 36  
 
 
 
ADP2105/ADP2106/ADP2107  
APPLICATIONS INFORMATION  
Data Sheet  
ADIsimPower DESIGN TOOL  
SETTING THE OUTPUT VOLTAGE  
The ADP2105/ADP2106/ADP2107 is supported by  
ADIsimPower design tool set. ADIsimPower is a collection  
of tools that produce complete power designs optimized for a  
specific design goal. The tools enable the user to generate a  
full schematic, bill of materials, and calculate performance in  
minutes. ADIsimPower can optimize designs for cost, area,  
efficiency, and parts count while taking into consideration  
the operating conditions and limitations of the IC and all  
real external components. For more information about  
ADIsimPower design tools, refer to www.analog.com/  
ADIsimPower. The tool set is available from this website, and  
users can also request an unpopulated board through the tool.  
The output voltage of ADP2105/ADP2106/ADP2107(ADJ) is  
externally set by a resistive voltage divider from the output  
voltage to FB. The ratio of the resistive voltage divider sets the  
output voltage, and the absolute value of those resistors sets the  
divider string current. For lower divider string currents, the  
small 10 nA (0.1 μA maximum) FB bias current is to be taken  
into account when calculating resistor values. The FB bias  
current can be ignored for a higher divider string current, but  
this degrades efficiency at very light loads.  
To limit output voltage accuracy degradation due to FB bias  
current to less than 0.05% (0.5% maximum), ensure that the  
divider string current is greater than 20 μA. To calculate the  
desired resistor values, first determine the value of the bottom  
divider string resistor (RBOT) using the following equation:  
EXTERNAL COMPONENT SELECTION  
The external component selection for the ADP2105/ADP2106/  
ADP2107 application circuits shown in Figure 37 and Figure 38  
depend on input voltage, output voltage, and load current  
requirements. Additionally, trade-offs between performance  
parameters like efficiency and transient response can be made  
by varying the choice of external components.  
VFB  
ISTRING  
RBOT  
=
where:  
FB = 0.8 V, the internal reference.  
STRING is the resistor divider string current.  
V
I
0.1μF  
V
INPUT VOLTAGE = 2.7V TO 5.5V  
10Ω  
IN  
C
IN1  
V
OUT  
16  
15  
GND IN PWIN1  
LX2  
14  
13  
FB  
ON  
1
2
3
4
12  
EN  
OFF  
OUTPUT VOLTAGE = 1.2V, 1.5V, 1.8V, 3.3V  
L
V
OUT  
GND  
GND  
GND  
PGND  
LX1  
11  
10  
9
ADP2105/  
ADP2106/  
ADP2107  
C
OUT  
LOAD  
V
IN  
PWIN2  
C
IN2  
COMP SS AGND NC  
5
6
7
8
C
SS  
R
COMP  
C
COMP  
NC = NO CONNECT  
Figure 37. Typical Applications Circuit for Fixed Output Voltage Options of ADP2105/ADP2106/ADP2107(x.x V)  
Rev. D | Page 16 of 36  
 
 
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
0.1μF  
V
INPUT VOLTAGE = 2.7V TO 5.5V  
C
10Ω  
IN  
IN1  
FB  
16  
15  
14  
IN PWIN1  
LX2  
13  
FB GND  
ON  
1
2
3
4
12  
EN  
OFF  
OUTPUT VOLTAGE  
L
= 0.8V TO V  
IN  
GND  
GND  
GND  
PGND  
LX1  
11  
10  
9
ADP2105/  
ADP2106/  
ADP2107  
C
OUT  
R
R
TOP  
LOAD  
V
FB  
IN  
PWIN2  
C
IN2  
BOT  
COMP SS AGND NC  
5
6
7
8
C
SS  
R
COMP  
C
COMP  
NC = NO CONNECT  
Figure 38. Typical Applications Circuit for Adjustable Output Voltage Option of ADP2105/ADP2106/ADP2107(ADJ)  
When RBOT is determined, calculate the value of the top resistor  
(RTOP) by using the following equation:  
For the ADP2106  
L > (0.83 µH/V) × VOUT  
For the ADP2107  
L > (0.66 µH/V) × VOUT  
VOUT −V  
RTOP = RBOT  
FB   
VFB  
The ADP2105/ADP2106/ADP2107(x.x V) include the resistive  
voltage divider internally, reducing the external circuitry required.  
For improved load regulation, connect the FB to the output  
voltage as close as possible to the load.  
Inductors 4.7 µH or larger are not recommended because they  
may cause instability in discontinuous conduction mode under  
light load conditions. It is also important that the inductor be  
capable of handling the maximum peak inductor current (IPK)  
determined by the following equation:  
INDUCTOR SELECTION  
∆I  
2
The high switching frequency of ADP2105/ADP2106/ADP2107  
allows for minimal output voltage ripple even with small inductors.  
The sizing of the inductor is a trade-off between efficiency and  
transient response. A small inductor leads to larger inductor  
current ripple that provides excellent transient response but  
degrades efficiency. Due to the high switching frequency of  
ADP2105/ADP2106/ADP2107, shielded ferrite core inductors  
are recommended for their low core losses and low electromagnetic  
interference (EMI).  
As a guideline, the inductor peak-to-peak current ripple (ΔIL) is  
typically set to 1/3 of the maximum load current for optimal  
transient response and efficiency, as shown in the following  
equations:  
L
IPK = ILOAD(MAX)  
+
Table 6. Minimum Inductor Value for Common Output  
Voltage Options for the ADP2105 (1 A)  
VIN  
VOUT  
1.2 V  
1.5 V  
1.8 V  
2.5 V  
3.3 V  
2.7 V  
3.6 V  
4.2 V  
5.5 V  
1.67 µH  
1.68 µH  
2.02 µH  
2.80 µH  
3.70 µH  
2.00 µH  
2.19 µH  
2.25 µH  
2.80 µH  
3.70 µH  
2.14 µH  
2.41 µH  
2.57 µH  
2.80 µH  
3.70 µH  
2.35 µH  
2.73 µH  
3.03 µH  
3.41 µH  
3.70 µH  
Table 7. Minimum Inductor Value for Common Output  
Voltage Options for the ADP2106 (1.5 A)  
ILOAD(MAX)  
VOUT ×(VIN −VOUT  
VIN × fSW × L  
)
∆IL  
=
≈
3
VIN  
VOUT  
1.2 V  
1.5 V  
1.8 V  
2.5 V  
3.3 V  
2.7 V  
3.6 V  
4.2 V  
5.5 V  
2.5×VOUT ×(VIN −VOUT  
)
⇒ LIDEAL  
=
μH  
1.11 µH  
1.25 µH  
1.49 µH  
2.08 µH  
2.74 µH  
2.33 µH  
1.46 µH  
1.50 µH  
2.08 µH  
2.74 µH  
2.43 µH  
1.61 µH  
1.71 µH  
2.08 µH  
2.74 µH  
1.56 µH  
1.82 µH  
2.02 µH  
2.27 µH  
2.74 µH  
VIN × ILOAD  
(MAX)  
where fSW is the switching frequency (1.2 MHz).  
The ADP2105/ADP2106/ADP2107 use slope compensation in  
the current control loop to prevent subharmonic oscillations  
when operating beyond 50% duty cycle. The fixed slope compen-  
sation limits the minimum inductor value as a function of  
output voltage.  
For the ADP2105  
L > (1.12 µH/V) × VOUT  
Rev. D | Page 17 of 36  
 
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
18  
17  
16  
15  
14  
13  
12  
11  
10  
9
8
7
6
5
4
3
Table 8. Minimum Inductor Value for Common Output  
Voltage Options for the ADP2107 (2 A)  
VIN  
VOUT  
1.2 V  
1.5 V  
1.8 V  
2.5 V  
3.3 V  
2.7 V  
3.6 V  
4.2 V  
5.5 V  
0.83 µH  
0.99 µH  
1.19 µH  
1.65 µH  
2.18 µH  
1.00 µH  
1.09 µH  
1.19 µH  
1.65 µH  
2.18 µH  
1.07 µH  
1.21 µH  
1.29 µH  
1.65 µH  
2.18 µH  
1.17 µH  
1.36 µH  
1.51 µH  
1.70 µH  
2.18 µH  
2
1
0
15  
Table 9. Inductor Recommendations for the ADP2105/  
ADP2106/ADP2107  
20  
25  
30  
35  
40  
45  
50  
55  
60  
65  
70  
Small-Sized Inductors Large-Sized Inductors  
OUTPUT CAPACITOR × OUTPUT VOLTAGE (μC)  
Vendor  
(< 5 mm × 5 mm)  
(> 5 mm × 5 mm)  
Figure 39. Percentage Overshoot for a 1 A Load Transient Response vs.  
Output Capacitor × Output Voltage  
Sumida  
CDRH2D14, 3D16,  
3D28  
CDRH4D18, 4D22,  
4D28, 5D18, 6D12  
For example, if the desired 1 A load transient response (overshoot)  
is 5% for an output voltage of 2.5 V, the n f rom Figure 39  
Toko  
1069AS-DB3018,  
1098AS-DE2812,  
1070AS-DB3020  
LPS3015, LPS4012,  
DO3314  
SD3110, SD3112,  
SD3114, SD3118,  
SD3812, SD3814  
D52LC, D518LC,  
D62LCB  
Output Capacitor × Output Voltage = 50 μC  
Coilcraft  
DO1605T  
50 μC  
2.5  
⇒ Output Capacitor =  
≈ 20 μF  
Cooper  
Bussmann  
SD10, SD12, SD14, SD52  
The ADP2105/ADP2106/ADP2107 have been designed for  
operation with small ceramic output capacitors that have low  
ESR and ESL. Therefore, they are comfortably able to meet tight  
output voltage ripple specifications. X5R or X7R dielectrics are  
recommended with a voltage rating of 6.3 V or 10 V. Y5V and Z5U  
dielectrics are not recommended, due to their poor temperature  
and dc bias characteristics. Table 10 shows a list of recommended  
MLCC capacitors from Murata and Taiyo Yuden.  
OUTPUT CAPACITOR SELECTION  
The output capacitor selection affects both the output voltage ripple  
and the loop dynamics of the converter. For a given loop crossover  
frequency (the frequency at which the loop gain drops to 0 dB), the  
maximum voltage transient excursion (overshoot) is inversely  
proportional to the value of the output capacitor. Therefore, larger  
output capacitors result in improved load transient response. To  
minimize the effects of the dc-to-dc converter switching, the cross-  
over frequency of the compensation loop should be less than 1/10  
of the switching frequency. Higher crossover frequency leads to  
faster settling time for a load transient response, but it can also  
cause ringing due to poor phase margin. Lower crossover  
frequency helps to provide stable operation but needs large output  
capacitors to achieve competitive overshoot specifications.  
Therefore, the optimal crossover frequency for the control loop of  
ADP2105/ADP2106/ADP2107 is 80 kHz, 1/15 of the switching  
frequency. For a crossover frequency of 80 kHz, Figure 39 shows  
the maximum output voltage excursion during a 1 A load transient,  
as the product of the output voltage and the output capacitor is  
varied. Choose the output capacitor based on the desired load  
transient response and target output voltage.  
When choosing output capacitors, it is also important to  
account for the loss of capacitance due to output voltage dc bias.  
Figure 40 shows the loss of capacitance due to output voltage dc  
bias for three X5R MLCC capacitors from Murata.  
20  
0
–20  
1
–40  
2
3
–60  
–80  
1
4.7µF 0805 X5R MURATA GRM21BR61A475K  
2
10µF 0805 X5R MURATA GRM21BR61A106K  
3
22µF 0805 X5R MURATA GRM21BR60J226M  
–100  
0
2
4
6
VOLTAGE (V  
DC  
)
Figure 40. Percentage Drop-In Capacitance vs. DC Bias for Ceramic  
Capacitors (Information Provided by Murata Corporation)  
For example, to get 20 µF output capacitance at an output voltage  
of 2.5 V, based on Figure 40, as well as to give some margin for  
temperature variance, a 22 μF and a 10 μF capacitor are to be  
Rev. D | Page 18 of 36  
 
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
used in parallel to ensure that the output capacitance is sufficient  
under all conditions for stable behavior.  
LOOP COMPENSATION  
The ADP2105/ADP2106/ADP2107 utilize a transconductance  
error amplifier to compensate the external voltage loop. The  
open loop transfer function at angular frequency (s) is given by  
Table 10. Recommended Input and Output Capacitor  
Selection for the ADP2105/ADP2106/ADP2107  
Vendor  
CS   
  
Z
sCOUT  
COMP (s) VREF  
  
  
H(s) = GmG  
Capacitor  
Murata  
Taiyo Yuden  
VOUT  
  
4.7 µF, 10 V  
X5R 0805  
GRM21BR61A475K  
LMK212BJ475KG  
where:  
10 μF, 10 V  
X5R 0805  
22 μF, 6.3 V  
X5R 0805  
GRM21BR61A106K  
GRM21BR60J226M  
LMK212BJ106KG  
JMK212BJ226MG  
V
V
REF is the internal reference voltage (0.8 V).  
OUT is the nominal output voltage.  
Z
COMP(s) is the impedance of the compensation network at the  
angular frequency.  
OUT is the output capacitor.  
INPUT CAPACITOR SELECTION  
C
gm is the transconductance of the error amplifier (50 μA/V  
nominal).  
The input capacitor reduces input voltage ripple caused by the  
switch currents on the PWIN pins. Place the input capacitors as  
close as possible to the PWIN pins. Select an input capacitor  
capable of withstanding the rms input current for the maximum  
load current in your application.  
G
CS is the effective transconductance of the current loop.  
G
G
G
CS = 1.875 A/V for the ADP2105.  
CS = 2.8125 A/V for the ADP2106.  
CS = 3.625 A/V for the ADP2107.  
For the ADP2105, it is recommended that each PWIN pin be  
bypassed with a 4.7 μF or larger input capacitor. For the ADP2106,  
bypass each PWIN pin with a 10 μF and a 4.7 μF capacitor, and  
for the ADP2107, bypass each PWIN pin with a 10 μF capacitor.  
The transconductance error amplifier drives the compensation  
network that consists of a resistor (RCOMP) and capacitor (CCOMP  
connected in series to form a pole and a zero, as shown in the  
following equation:  
)
As with the output capacitor, a low ESR ceramic capacitor is  
recommended to minimize input voltage ripple. X5R or X7R  
dielectrics are recommended, with a voltage rating of 6.3 V or  
10 V. Y5V and Z5U dielectrics are not recommended due to  
their poor temperature and dc bias characteristics. Refer to  
Table 10 for input capacitor recommendations.  
1 + sRCOMPCCOMP  
1
Z
COMP (s) = RCOMP  
+
=
sCCOMP  
sCCOMP  
At the crossover frequency, the gain of the open loop transfer  
function is unity. For the compensation network impedance at  
the crossover frequency, this yields the following equation:  
INPUT FILTER  
(2π)F  
GmGCS  
COUTVOUT  
VREF  
CROSS   
The IN pin is the power source for the ADP2105/ADP2106/  
ADP2107 internal circuitry, including the voltage reference and  
current sense amplifier that are sensitive to power supply noise.  
To prevent high frequency switching noise on the PWIN pins from  
corrupting the internal circuitry of the ADP2105/ADP2106/  
ADP2107, a low-pass RC filter should be placed between the IN  
pin and the PWIN1 pin. The suggested input filter consists of  
a small 0.1 μF ceramic capacitor placed between IN and AGND  
and a 10 Ω resistor placed between IN and PWIN1. This forms a  
150 kHz low-pass filter between PWIN1 and IN that prevents any  
high frequency noise on PWIN1 from coupling into the IN pin.  
Z
COMP (FCROSS ) =  
where:  
F
CROSS = 80 kHz, the crossover frequency of the loop.  
COUTVOUT is determined from the Output Capacitor Selection  
section.  
To ensure that there is sufficient phase margin at the crossover  
frequency, place the compensator zero at 1/4 of the crossover  
frequency, as shown in the following equation:  
F
CROSS   
(2π)  
RCOMPCCOMP = 1  
4
SOFT START PERIOD  
To set the soft start period, connect a soft start capacitor (CSS) from  
SS to AGND. The soft start period varies linearly with the size  
of the soft start capacitor, as shown in the following equation:  
Solving the three equations in this section simultaneously yields  
the value for the compensation resistor and compensation  
capacitor, as shown in the following equation:  
T
SS = CSS × 109 ms  
  
CROSS   
  
(2π)F  
GmGCS  
COUTVOUT  
VREF  
RCOMP = 0.8  
For a soft start period of 1 ms, a 1 nF capacitor must be  
connected between SS and AGND.  
  
2
CCOMP  
=
πFCROSSRCOMP  
Rev. D | Page 19 of 36  
 
 
 
 
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
BODE PLOTS  
60  
50  
ADP2105  
60  
ADP2106  
50  
40  
40  
0
LOOP GAIN  
LOOP GAIN  
0
30  
45  
30  
45  
90  
135  
180  
PHASE  
MARGIN = 49°  
20  
90  
PHASE  
20  
MARGIN = 48°  
LOOP PHASE  
10  
135  
180  
10  
LOOP PHASE  
0
0
CROSSOVER  
FREQUENCY = 79kHz  
OUTPUT VOLTAGE = 1.2V  
INPUT VOLTAGE = 5.5V  
LOAD CURRENT = 1A  
–10  
–20  
–30  
–40  
CROSSOVER  
FREQUENCY = 87kHz  
OUTPUT VOLTAGE = 1.8V  
INPUT VOLTAGE = 5.5V  
LOAD CURRENT = 1A  
–10  
–20  
–30  
–40  
INDUCTOR = 3.3µH (SD3814)  
INDUCTOR = 2.2µH (LPS4012)  
OUTPUT CAPACITOR = 22µF + 22µF + 4.7µF  
COMPENSATION RESISTOR = 267kΩ  
COMPENSATION CAPACITOR = 39pF  
OUTPUT CAPACITOR = 22µF + 22µF  
COMPENSATION RESISTOR = 180kΩ  
COMPENSATION CAPACITOR = 56pF  
1
10  
100  
300  
FREQUENCY (kHz)  
1
10  
100  
300  
FREQUENCY (kHz)  
NOTES  
NOTES  
1. EXTERNAL COMPONENTS WERE CHOSEN FOR A  
5% OVERSHOOT FOR A 1A LOAD TRANSIENT.  
1. EXTERNAL COMPONENTS WERE CHOSEN FOR A  
5% OVERSHOOT FOR A 1A LOAD TRANSIENT.  
Figure 44. ADP2105 Bode Plot at VIN = 5.5 V, VOUT = 1.2 V and Load = 1 A  
Figure 41. ADP2106 Bode Plot at VIN = 5.5 V, VOUT = 1.8 V and Load = 1 A  
60  
ADP2107  
60  
ADP2106  
50  
50  
40  
30  
0
LOOP GAIN  
40  
30  
0
LOOP GAIN  
45  
90  
135  
180  
PHASE  
45  
90  
135  
180  
MARGIN = 65°  
20  
PHASE  
20  
MARGIN = 52°  
LOOP PHASE  
10  
10  
LOOP PHASE  
0
0
CROSSOVER  
FREQUENCY = 76kHz  
OUTPUT VOLTAGE = 2.5V  
INPUT VOLTAGE = 5V  
LOAD CURRENT = 1A  
–10  
–20  
–30  
–40  
CROSSOVER  
FREQUENCY = 83kHz  
OUTPUT VOLTAGE = 1.8V  
INPUT VOLTAGE = 3.6V  
LOAD CURRENT = 1A  
–10  
–20  
–30  
–40  
INDUCTOR = 2µH (D62LCB)  
INDUCTOR = 2.2µH (LPS4012)  
OUTPUT CAPACITOR = 10µF + 4.7µF  
COMPENSATION RESISTOR = 70kΩ  
COMPENSATION CAPACITOR = 120pF  
OUTPUT CAPACITOR = 22µF + 22µF  
COMPENSATION RESISTOR = 180kΩ  
COMPENSATION CAPACITOR = 56pF  
1
10  
100  
300  
FREQUENCY (kHz)  
1
10  
100  
300  
FREQUENCY (kHz)  
NOTES  
NOTES  
1. EXTERNAL COMPONENTS WERE CHOSEN FOR A  
10% OVERSHOOT FOR A 1A LOAD TRANSIENT.  
1. EXTERNAL COMPONENTS WERE CHOSEN FOR A  
5% OVERSHOOT FOR A 1A LOAD TRANSIENT.  
Figure 45. ADP2107 Bode Plot at VIN = 5 V, VOUT = 2.5 V and Load = 1 A  
Figure 42. ADP2106 Bode Plot at VIN = 3.6 V, VOUT = 1.8 V, and Load = 1 A  
60  
60  
ADP2107  
ADP2105  
50  
50  
LOOP GAIN  
40  
30  
0
40  
30  
0
LOOP GAIN  
45  
90  
135  
180  
45  
90  
135  
180  
PHASE  
MARGIN = 70°  
20  
PHASE  
MARGIN = 51°  
20  
LOOP PHASE  
10  
10  
LOOP PHASE  
0
0
CROSSOVER  
FREQUENCY = 71kHz  
CROSSOVER  
FREQUENCY = 67kHz  
OUTPUT VOLTAGE = 3.3V  
INPUT VOLTAGE = 5V  
LOAD CURRENT = 1A  
OUTPUT VOLTAGE = 1.2V  
INPUT VOLTAGE = 3.6V  
LOAD CURRENT = 1A  
–10  
–20  
–30  
–40  
–10  
–20  
–30  
–40  
INDUCTOR = 2.5µH (CDRH5D28)  
INDUCTOR = 3.3µH (SD3814)  
OUTPUT CAPACITOR = 10µF + 4.7µF  
COMPENSATION RESISTOR = 70kΩ  
COMPENSATION CAPACITOR = 120pF  
OUTPUT CAPACITOR = 22µF + 22µF + 4.7µF  
COMPENSATION RESISTOR = 267kΩ  
COMPENSATION CAPACITOR = 39pF  
1
10  
100  
300  
1
10  
100  
300  
FREQUENCY (kHz)  
FREQUENCY (kHz)  
NOTES  
NOTES  
1. EXTERNAL COMPONENTS WERE CHOSEN FOR A  
10% OVERSHOOT FOR A 1A LOAD TRANSIENT.  
1. EXTERNAL COMPONENTS WERE CHOSEN FOR A  
5% OVERSHOOT FOR A 1A LOAD TRANSIENT.  
Figure 46. ADP2107 Bode Plot at VIN = 5 V, VOUT = 3.3 V, and Load = 1 A  
Figure 43. ADP2105 Bode Plot at VIN = 3.6 V, VOUT = 1.2 V, and Load = 1 A  
Rev. D | Page 20 of 36  
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
LOAD TRANSIENT RESPONSE  
T
T
OUTPUT CURRENT  
OUTPUT CURRENT  
3
2
3
OUTPUT VOLTAGE (AC-COUPLED)  
OUTPUT VOLTAGE (AC-COUPLED)  
2
1
1
LX NODE (SWITCH NODE)  
LX NODE (SWITCH NODE)  
CH1 2.00V  
CH3 1.00A Ω  
CH2 100mV~  
M 20.0µs  
10.00%  
A
CH3  
700mA  
CH1 2.00V  
CH3 1.00A Ω  
CH2 100mV~  
M 20.0µs  
10.00%  
A
CH3  
700mA  
T
T
OUTPUT CAPACITOR: 22µF + 4.7µF  
INDUCTOR: SD14, 2.5µH  
COMPENSATION RESISTOR: 135kΩ  
COMPENSATION CAPACITOR: 82pF  
OUTPUT CAPACITOR: 22µF + 22µF + 4.7µF  
INDUCTOR: SD14, 2.5µH  
COMPENSATION RESISTOR: 270kΩ  
COMPENSATION CAPACITOR: 39pF  
Figure 50. 1 A Load Transient Response for ADP2105-1.2  
with External Components Chosen for 10% Overshoot  
Figure 47. 1 A Load Transient Response for ADP2105-1.2  
with External Components Chosen for 5% Overshoot  
T
T
OUTPUT CURRENT  
OUTPUT CURRENT  
3
2
3
2
OUTPUT VOLTAGE (AC-COUPLED)  
OUTPUT VOLTAGE (AC-COUPLED)  
1
1
LX NODE (SWITCH NODE)  
LX NODE (SWITCH NODE)  
CH1 2.00V  
CH3 1.00A Ω  
CH2 100mV~  
M 20.0µs  
10.00%  
A
CH3  
700mA  
CH1 2.00V  
CH3 1.00A Ω  
CH2 100mV~  
M 20.0µs  
10.00%  
A
CH3  
700mA  
T
T
OUTPUT CAPACITOR: 10µF + 10µF  
INDUCTOR: SD3814, 3.3µH  
COMPENSATION RESISTOR: 135kΩ  
COMPENSATION CAPACITOR: 82pF  
OUTPUT CAPACITOR: 22µF + 22µF  
INDUCTOR: SD3814, 3.3µH  
COMPENSATION RESISTOR: 270kΩ  
COMPENSATION CAPACITOR: 39pF  
Figure 51. 1 A Load Transient Response for ADP2105-1.8  
with External Components Chosen for 10% Overshoot  
Figure 48. 1 A Load Transient Response for ADP2105-1.8  
with External Components Chosen for 5% Overshoot  
T
T
OUTPUT CURRENT  
OUTPUT CURRENT  
3
2
3
2
OUTPUT VOLTAGE (AC-COUPLED)  
OUTPUT VOLTAGE (AC-COUPLED)  
1
1
LX NODE (SWITCH NODE)  
LX NODE (SWITCH NODE)  
CH2 200mV~ M 20.0µs  
10.00%  
CH1 2.00V  
CH3 1.00A Ω  
CH2 200mV~  
M 20.0µs  
10.00%  
A
CH3  
700mA  
CH1 2.00V  
CH3 1.00A Ω  
A
CH3  
700mA  
T
T
OUTPUT CAPACITOR: 10µF + 4.7µF  
INDUCTOR: CDRH5D18, 4.1µH  
COMPENSATION RESISTOR: 135kΩ  
COMPENSATION CAPACITOR: 82pF  
OUTPUT CAPACITOR: 22µF + 4.7µF  
INDUCTOR: CDRH5D18, 4.1µH  
COMPENSATION RESISTOR: 270kΩ  
COMPENSATION CAPACITOR: 39pF  
Figure 52. 1 A Load Transient Response for ADP2105-3.3  
with External Components Chosen for 10% Overshoot  
Figure 49. 1 A Load Transient Response for ADP2105-3.3  
with External Components Chosen for 5% Overshoot  
Rev. D | Page 21 of 36  
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
Transition Losses  
EFFICIENCY CONSIDERATIONS  
Transition losses occur because the P-channel MOSFET power  
switch cannot turn on or turn off instantaneously. At the middle of  
an LX (switch) node transition, the power switch is providing all  
the inductor current, while the source to drain voltage of the  
power switch is half the input voltage, resulting in power loss.  
Transition losses increase with load current and input voltage  
and occur twice for each switching cycle.  
Efficiency is the ratio of output power to input power. The high  
efficiency of the ADP2105/ADP2106/ADP2107 has two distinct  
advantages. First, only a small amount of power is lost in the dc-  
to-dc converter package that reduces thermal constraints. Second,  
the high efficiency delivers the maximum output power for the  
given input power, extending battery life in portable applications.  
There are four major sources of power loss in dc-to-dc  
converters like the ADP2105/ADP2106/ADP2107:  
The amount of power loss can be calculated by  
VIN  
2
PTRAN  
=
× IOUT ×(tON +tOFF )× fSW  
•
•
•
•
Power switch conduction losses  
Inductor losses  
Switching losses  
where tON and tOFF are the rise time and fall time of the LX  
(switch) node, and are both approximately 3 ns.  
Transition losses  
THERMAL CONSIDERATIONS  
Power Switch Conduction Losses  
In most applications, the ADP2105/ADP2106/ADP2107 do not  
dissipate a lot of heat due to their high efficiency. However, in  
applications with high ambient temperature, low supply voltage,  
and high duty cycle, the heat dissipated in the package is large  
enough that it can cause the junction temperature of the die to  
exceed the maximum junction temperature of 125°C. Once the  
junction temperature exceeds 140°C, the converter goes into  
thermal shutdown. To prevent any permanent damage it recovers  
only after the junction temperature has decreased below 100°C.  
Therefore, thermal analysis for the chosen application solution  
is very important to guarantee reliable performance over all  
conditions.  
Power switch conduction losses are caused by the flow of output  
current through the P-channel power switch and the N-channel  
synchronous rectifier, which have internal resistances (RDS(ON)  
)
associated with them. The amount of power loss can be approxi-  
mated by  
2
P
SW − COND = [RDS(ON) − P × D + RDS(ON) − N × (1 − D)] × IOUT  
where D = VOUT/VIN.  
The internal resistance of the power switches increases with  
temperature but decreases with higher input voltage. Figure 20  
and Figure 21 show the change in RDS(ON) vs. input voltage,  
whereas Figure 29 and Figure 30 show the change in RDS(ON) vs.  
temperature for both power devices.  
The junction temperature of the die is the sum of the ambient  
temperature of the environment and the temperature rise of the  
package due to the power dissipation, as shown in the following  
equation:  
Inductor Losses  
Inductor conduction losses are caused by the flow of current  
through the inductor, which has an internal resistance (DCR)  
associated with it. Larger sized inductors have smaller DCR,  
which can improve inductor conduction losses.  
TJ = TA + TR  
where:  
TJ is the junction temperature.  
TA is the ambient temperature.  
TR is the rise in temperature of the package due to the power  
dissipation in the package.  
Inductor core losses are related to the magnetic permeability of  
the core material. Because the ADP2105/ADP2106/ADP2107  
are high switching frequency dc-to-dc converters, shielded ferrite  
core material is recommended for its low core losses and low EMI.  
The rise in temperature of the package is directly proportional  
to the power dissipation in the package. The proportionality  
constant for this relationship is defined as the thermal resistance  
from the junction of the die to the ambient temperature, as  
shown in the following equation:  
The total amount of inductor power loss can be calculated by  
PL = DCR × IOUT2 + Core Losses  
Switching Losses  
Switching losses are associated with the current drawn by the  
driver to turn on and turn off the power devices at the  
switching frequency. Each time a power device gate is turned on  
and turned off, the driver transfers a charge ΔQ from the input  
supply to the gate and then from the gate to ground.  
TR = θJA × PD  
where:  
TR is the rise in temperature of the package.  
PD is the power dissipation in the package.  
The amount of power loss can by calculated by  
θ
JA is the thermal resistance from the junction of the die to the  
P
SW = (CGATE − P + CGATE − N) × VIN2 × fSW  
ambient temperature of the package.  
where:  
(CGATE − P + CGATE − N) ≈ 600 pF.  
fSW = 1.2 MHz, the switching frequency.  
Rev. D | Page 22 of 36  
 
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
For example, in an application where the ADP2107(1.8 V) is  
used with an input voltage of 3.6 V, a load current of 2 A, and a  
maximum ambient temperature of 85°C, at a load current of 2 A,  
the most significant contributor of power dissipation in the dc-to-  
dc converter package is the conduction loss of the power switches.  
Using the graph of switch on resistance vs. temperature (see  
Figure 30), as well as the equation of power loss given in the  
Power Switch Conduction Losses section, the power dissipation  
in the package can be calculated by the following:  
2
The θJA for the LFCSP_VQ package is 40°C/W, as shown in  
Table 3. Therefore, the rise in temperature of the package due to  
power dissipation is  
TR = θJA × PD = 40°C/W × 0.40 W = 16°C  
The junction temperature of the converter is  
TJ = TA + TR = 85°C + 16°C = 101°C  
Because the junction temperature of the converter is below the  
maximum junction temperature of 125°C, this application operates  
reliably from a thermal point of view.  
P
SW − COND = [RDS(ON) − P × D + RDS(ON) − N × (1 − D)] × IOUT  
=
[109 mΩ × 0.5 + 90 mΩ × 0.5] × (2 A)2 ≈ 400 mW  
Rev. D | Page 23 of 36  
ADP2105/ADP2106/ADP2107  
Data Sheet  
DESIGN EXAMPLE  
Consider an application with the following specifications:  
4. The closest standard inductor value is 2.2 μH. The maximum  
rms current of the inductor is to be greater than 1.2 A, and  
the saturation current of the inductor is to be greater than  
2 A. One inductor that meets these criteria is the LPS4012-  
2.2 μH from Coilcraft.  
5. Choose the output capacitor based on the transient response  
requirements. The worst-case load transient is 1.2 A, for  
which the overshoot must be less than 100 mV, which is 5%  
of the output voltage. For a 1 A load transient, the overshoot  
must be less than 4% of the output voltage, then from  
Figure 39:  
Input Voltage = 3.6 V to 4.2 V.  
Output Voltage = 2 V.  
Typical Output Current = 600 mA.  
Maximum Output Current = 1.2 A.  
Soft Start Time = 2 ms.  
Overshoot ≤ 100 mV under all load transient conditions.  
1. Choose the dc-to-dc converter that satisfies the maximum  
output current requirement. Because the maximum output  
current for this application is 1.2 A, the ADP2106 with a  
maximum output current of 1.5 A is ideal for this  
application.  
2. See whether the output voltage desired is available as a  
fixed output voltage option. Because 2 V is not one of the  
fixed output voltage options available, choose the adjustable  
version of ADP2106.  
Output Capacitor × Output Voltage = 60 μC  
60 μC  
⇒ Output Capacitor =  
≈ 30 μF  
2.0 V  
Taking into account the loss of capacitance due to dc bias, as  
shown in Figure 40, two 22 μF X5R MLCC capacitors from  
Murata (GRM21BR60J226M) are sufficient for this  
application.  
3. The first step in external component selection for an  
adjustable version converter is to calculate the resistance of  
the resistive voltage divider that sets the output voltage.  
6. Because the ADP2106 is being used in this application, the  
input capacitors are 10 μF and 4.7 μF X5R Murata capacitors  
(GRM21BR61A106K and GRM21BR61A475K).  
7. The input filter consists of a small 0.1 μF ceramic capacitor  
placed between IN and AGND and a 10 Ω resistor placed  
between IN and PWIN1.  
0.8 V  
VFB  
RBOT  
=
=
= 40 kΩ  
ISTRING 20 μA  
2 V −0.8 V  
VOUT −VFB  
RTOP = R  
= 40 kΩ ×  
= 60 kΩ  
BOT   
VFB  
0.8 V  
8. Choose a soft start capacitor of 2 nF to achieve a soft start  
time of 2 ms.  
9. Calculate the compensation resistor and capacitor as  
follows:  
Calculate the minimum inductor value as follows:  
For the ADP2106:  
L > (0.83 μH/V) × VOUT  
⇒
L > 0.83 μH/V × 2 V  
⇒
L > 1.66 μH  
  
(2π)FCROSS COUTVOUT  
  
  
RCOMP = 0.8  
=
Next, calculate the ideal inductor value that sets the  
GmGCS  
VREF  
  
inductor peak-to-peak current ripple (ΔIL) to 1/3 of the  
maximum load current at the maximum input voltage as  
follows:  
  
  
  
  
(2π)×80 kHz  
30 μF×2 V  
0.8  
= 215 kΩ  
50 μA / V×2.8125 A / V  
0.8 V  
2.5×VOUT ×(VIN −VOUT  
)
2
2
LIDEAL  
=
μH =  
CCOMP  
=
=
= 39 pF  
VIN × ILOAD  
(MAX)  
πFCROSS RCOMP π×80 kHz×215 kΩ  
2.5×2×(4.2 − 2)  
4.2×1.2  
μH = 2.18 μH  
Rev. D | Page 24 of 36  
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
EXTERNAL COMPONENT RECOMMENDATIONS  
For popular output voltage options at 80 kHz crossover frequency with 10% overshoot for a 1 A load transient (refer to Figure 37 and  
Figure 38).  
Table 11. Recommended External Components  
Part  
VOUT (V)  
CIN1 1 (μF)  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
10  
CIN21 (μF)  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
10  
10  
10  
10  
10  
COUT 2 (μF)  
22 + 10  
22 + 4.7  
10 + 10  
10 + 10  
10 + 4.7  
10 + 4.7  
22 + 10  
22 + 4.7  
10 + 10  
10 + 10  
10 + 4.7  
10 + 4.7  
22 + 10  
22 + 4.7  
10 + 10  
10 + 10  
10 + 4.7  
10 + 4.7  
22 + 4.7  
10 + 10  
10 + 10  
10 + 4.7  
22 + 4.7  
10 + 10  
10 + 10  
10 + 4.7  
22 + 4.7  
10 + 10  
10 + 10  
10 + 4.7  
L (μH)  
2.0  
2.5  
3.0  
3.3  
3.6  
4.1  
1.5  
1.8  
2.0  
2.2  
2.5  
3.0  
1.2  
1.5  
1.5  
1.8  
1.8  
2.5  
2.5  
3.0  
3.3  
4.1  
1.8  
2.0  
2.2  
3.0  
1.5  
1.5  
1.8  
2.5  
RCOMP (kΩ)  
135  
135  
135  
135  
135  
135  
90  
90  
90  
90  
90  
CCOMP (pF)  
82  
82  
82  
82  
RTOP3 (kΩ) RBOT3 (kΩ)  
ADP2105(ADJ) 0.9  
ADP2105(ADJ) 1.2  
ADP2105(ADJ) 1.5  
ADP2105(ADJ) 1.8  
ADP2105(ADJ) 2.5  
ADP2105(ADJ) 3.3  
ADP2106(ADJ) 0.9  
ADP2106(ADJ) 1.2  
ADP2106(ADJ) 1.5  
ADP2106(ADJ) 1.8  
ADP2106(ADJ) 2.5  
ADP2106(ADJ) 3.3  
ADP2107(ADJ) 0.9  
ADP2107(ADJ) 1.2  
ADP2107(ADJ) 1.5  
ADP2107(ADJ) 1.8  
ADP2107(ADJ) 2.5  
ADP2107(ADJ) 3.3  
5
40  
20  
40  
35  
40  
50  
40  
82  
82  
85  
40  
125  
5
40  
100  
100  
100  
100  
100  
100  
120  
120  
120  
120  
120  
120  
82  
40  
20  
40  
35  
40  
50  
40  
85  
40  
10  
90  
125  
5
40  
10  
10  
10  
10  
10  
10  
70  
70  
70  
70  
70  
70  
40  
10  
10  
10  
10  
20  
40  
35  
40  
50  
40  
85  
40  
10  
125  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
40  
ADP2105-1.2  
ADP2105-1.5  
ADP2105-1.8  
ADP2105-3.3  
ADP2106-1.2  
ADP2106-1.5  
ADP2106-1.8  
ADP2106-3.3  
ADP2107-1.2  
ADP2107-1.5  
ADP2107-1.8  
ADP2107-3.3  
1.2  
1.5  
1.8  
3.3  
1.2  
1.5  
1.8  
3.3  
1.2  
1.5  
1.8  
3.3  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
10  
4.7  
4.7  
4.7  
4.7  
10  
10  
10  
10  
135  
135  
135  
135  
90  
90  
90  
90  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
82  
82  
82  
100  
100  
100  
100  
120  
120  
120  
120  
10  
10  
10  
10  
70  
70  
70  
70  
10  
10  
10  
1 4.7 μF 0805 X5R 10 V Murata—GRM21BR61A475KA73L. 10 μF 0805 X5R 10 V Murata—GRM21BR61A106KE19L.  
2 4.7 μF 0805 X5R 10 V Murata—GRM21BR61A475KA73L. 10 μF 0805 X5R 10 V Murata—GRM21BR61A106KE19L. 22 μF 0805 X5R 6.3 V Murata—GRM21BR60J226ME39L.  
3 0.5% accuracy resistor.  
Rev. D | Page 25 of 36  
 
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
For popular output voltage options at 80 kHz crossover frequency with 5% overshoot for a 1 A load transient (refer to Figure 37 and  
Figure 38).  
Table 12. Recommended External Components  
Part  
VOUT (V)  
0.9  
1.2  
1.5  
1.8  
2.5  
3.3  
0.9  
1.2  
1.5  
1.8  
2.5  
3.3  
0.9  
1.2  
1.5  
1.8  
2.5  
3.3  
1.2  
1.5  
1.8  
3.3  
1.2  
1.5  
1.8  
3.3  
1.2  
1.5  
1.8  
3.3  
CIN11 (μF)  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
10  
CIN21 (μF) COUT2 (μF)  
L (μH)  
2.0  
2.5  
3.0  
3.3  
3.6  
4.1  
1.5  
1.8  
2.0  
2.2  
2.5  
3.0  
1.2  
1.5  
1.5  
1.8  
1.8  
2.5  
2.5  
3.0  
3.3  
4.1  
1.8  
2.0  
2.2  
3.0  
1.5  
1.5  
1.8  
2.5  
RCOMP (kΩ) CCOMP (pF)  
RTOP3 (kΩ)  
5
20  
35  
50  
85  
125  
5
20  
35  
50  
85  
125  
5
20  
35  
50  
85  
125  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
RBOT 3(kΩ)  
40  
40  
40  
40  
40  
40  
ADP2105(ADJ)  
ADP2105(ADJ)  
ADP2105(ADJ)  
ADP2105(ADJ)  
ADP2105(ADJ)  
ADP2105(ADJ)  
ADP2106(ADJ)  
ADP2106(ADJ)  
ADP2106(ADJ)  
ADP2106(ADJ)  
ADP2106(ADJ)  
ADP2106(ADJ)  
ADP2107(ADJ)  
ADP2107(ADJ)  
ADP2107(ADJ)  
ADP2107(ADJ)  
ADP2107(ADJ)  
ADP2107(ADJ)  
ADP2105-1.2  
ADP2105-1.5  
ADP2105-1.8  
ADP2105-3.3  
ADP2106-1.2  
ADP2106-1.5  
ADP2106-1.8  
ADP2106-3.3  
ADP2107-1.2  
ADP2107-1.5  
ADP2107-1.8  
ADP2107-3.3  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
10  
10  
10  
10  
10  
10  
10  
10  
10  
10  
10  
10  
4.7  
4.7  
4.7  
4.7  
10  
10  
10  
10  
10  
10  
10  
10  
22 + 22 + 22  
22 + 22 + 4.7  
22 + 22  
22 + 22  
22 + 10  
270  
270  
270  
270  
270  
270  
180  
180  
180  
180  
180  
180  
140  
140  
140  
140  
140  
140  
270  
270  
270  
270  
180  
180  
180  
180  
140  
140  
140  
140  
39  
39  
39  
39  
39  
39  
56  
56  
56  
56  
56  
56  
68  
68  
68  
68  
68  
68  
39  
39  
39  
39  
56  
56  
56  
56  
68  
68  
68  
68  
22 + 4.7  
22 + 22 + 22  
22 + 22 + 4.7  
22 + 22  
22 + 22  
22 + 10  
40  
40  
40  
40  
40  
40  
22 + 4.7  
22 + 22 + 22  
22 + 22 + 4.7  
22 + 22  
22 + 22  
22 + 10  
40  
40  
40  
40  
40  
40  
10  
10  
10  
10  
10  
22 + 4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
4.7  
10  
22 + 22 + 4.7  
22 + 22  
22 + 22  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
22 + 4.7  
22 + 22 + 4.7  
22 + 22  
22 + 22  
22 + 4.7  
22 + 22 + 4.7  
22 + 22  
22 + 22  
10  
10  
10  
22 + 4.7  
1 4.7μF 0805 X5R 10V Murata—GRM21BR61A475KA73L. 10μF 0805 X5R 10V Murata—GRM21BR61A106KE19L.  
2 4.7μF 0805 X5R 10V Murata—GRM21BR61A475KA73L. 10μF 0805 X5R 10V Murata—GRM21BR61A106KE19L. 22μF 0805 X5R 6.3V Murata—GRM21BR60J226ME39L.  
3 0.5% accuracy resistor.  
Rev. D | Page 26 of 36  
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
CIRCUIT BOARD LAYOUT RECOMMENDATIONS  
Good circuit board layout is essential to obtaining the best  
performance from the ADP2105/ADP2106/ADP2107. Poor  
circuit layout degrades the output ripple, as well as the  
electromagnetic interference (EMI) and electromagnetic  
compatibility (EMC) performance.  
•
•
Make the high current path from the PGND pin through L  
and COUT back to the PGND plane as short as possible. To  
accomplish this, ensure that the PGND pin is tied to the  
PGND plane as close as possible to the input and output  
capacitors.  
Figure 54 and Figure 55 show the ideal circuit board layout for  
the ADP2105/ADP2106/ADP2107 to achieve the highest  
performance. Refer to the following guidelines if adjustments to  
the suggested layout are needed:  
The feedback resistor divider network is to be placed as  
close as possible to the FB pin to prevent noise pickup. The  
length of trace connecting the top of the feedback resistor  
divider to the output is to be as short as possible while  
keeping away from the high current traces and the LX  
(switch) node that can lead to noise pickup. An analog  
ground plane is to be placed on either side of the FB trace  
to reduce noise pickup. For the low fixed voltage options  
(1.2 V and 1.5 V), poor routing of the OUT_SENSE trace  
can lead to noise pickup, adversely affecting load regulation.  
This can be fixed by placing a 1 nF bypass capacitor close to  
the FB pin.  
•
Use separate analog and power ground planes. Connect  
the ground reference of sensitive analog circuitry (such as  
compensation and output voltage divider components) to  
analog ground; connect the ground reference of power  
components (such as input and output capacitors) to power  
ground. In addition, connect both the ground planes to the  
exposed pad of the ADP2105/ADP2106/ADP2107.  
•
For each PWIN pin, place an input capacitor as close to the  
PWIN pin as possible and connect the other end to the closest  
power ground plane.  
•
The placement and routing of the compensation components  
are critical for proper behavior of the ADP2105/ADP2106/  
ADP2107. The compensation components are to be placed  
as close to the COMP pin as possible. It is advisable to use  
0402-sized compensation components for closer placement,  
leading to smaller parasitics. Surround the compensation  
components with an analog ground plane to prevent noise  
pickup. The metal layer under the compensation components  
is to be the analog ground plane.  
•
•
Place the 0.1 μF, 10 Ω low-pass input filter between the IN  
pin and the PWIN1 pin, as close to the IN pin as possible.  
Ensure that the high current loops are as short and as wide  
as possible. Make the high current path from CIN through  
L, COUT, and the PGND plane back to CIN as short as possible.  
To accomplish this, ensure that the input and output  
capacitors share a common PGND plane.  
Rev. D | Page 27 of 36  
 
ADP2105/ADP2106/ADP2107  
Data Sheet  
EVALUATION BOARD  
EVALUATION BOARD SCHEMATIC FOR ADP2107 (1.8 V)  
C7  
0.1µF  
VCC  
R3  
10Ω  
INPUT VOLTAGE = 2.7V TO 5.5V  
VIN  
VCC  
C1  
1
10µF  
OUT  
GND  
J1  
U1  
16  
15  
GND IN PWIN1  
LX2  
14  
13  
FB  
1
12  
11  
10  
9
EN  
EN  
R2  
100kΩ  
2
3
4
GND  
GND  
GND  
PGND  
LX1  
2
L1  
ADP2107-1.8  
2µH  
OUTPUT VOLTAGE = 1.8V, 2A  
1
2
V
OUT  
VCC  
R4  
0Ω  
C4  
22µF  
C3  
1
1
22µF  
PWIN2  
OUT  
C2  
10µF  
GND  
COMP SS AGND PADDLE NC  
1
5
6
7
8
R5  
NS  
R1  
140kΩ  
1
2
MURATA X5R 0805  
C6  
68pF  
C5  
1nF  
10μF: GRM21BR61A106KE19L  
22μF: GRM21BR60J226ME39L  
2μH INDUCTOR D62LCB TOKO  
NC = NO CONNECT  
Figure 53. Evaluation Board Schematic of the ADP2107-1.8 (Bold Traces are High Current Paths)  
RECOMMENDED PCB LAYOUT (EVALUATION BOARD LAYOUT)  
JUMPER TO ENABLE  
ENABLE  
GROUND  
V
IN  
100kΩ PULL-DOWN  
GROUND  
INPUT  
INPUT CAPACITOR  
CONNECT THE GROUND RETURN OF  
ALL POWER COMPONENTS SUCH AS  
INPUT AND OUTPUT CAPACITORS TO  
THE POWER GROUND PLANE.  
POWER GROUND  
PLANE  
PLACE THE FEEDBACK RESISTORS AS  
CLOSE TO THE FB PIN AS POSSIBLE.  
OUTPUT CAPACITOR  
C
C
R
R
IN  
LX  
OUT  
TOP BOT  
OUTPUT  
INDUCTOR (L)  
PGND  
LX  
V
ADP2105/ADP2106/ADP2107  
OUT  
R
COMP  
C
C
C
OUT  
COMP  
IN  
OUTPUT CAPACITOR  
C
SS  
PLACE THE COMPENSATION  
COMPONENTS AS CLOSE TO  
THE COMP PIN AS POSSIBLE.  
ANALOG GROUND PLANE  
POWER GROUND  
CONNECT THE GROUND RETURN OF ALL  
SENSITIVE ANALOG CIRCUITRY SUCH AS  
COMPENSATION AND OUTPUT VOLTAGE  
DIVIDER TO THE ANALOG GROUND PLANE.  
INPUT CAPACITOR  
Figure 54. Recommended Layout of Top Layer of ADP2105/ADP2106/ADP2107  
Rev. D | Page 28 of 36  
 
 
 
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
ENABLE  
V
GND  
IN  
GND  
ANALOG GROUND PLANE  
POWER GROUND PLANE  
INPUT VOLTAGE PLANE  
CONNECTING THE TWO  
PWIN PINS AS CLOSE  
AS POSSIBLE.  
V
IN  
V
OUT  
CONNECT THE EXPOSED PAD OF  
THE ADP2105/ADP2106/ADP2107  
TO A LARGE GROUND PLANE TO  
AID POWER DISSIPATION.  
CONNECT THE PGND PIN  
TO THE POWER GROUND  
PLANE AS CLOSE TO THE  
ADP2105/ADP2106/ADP2107  
AS POSSIBLE.  
FEEDBACK TRACE: THIS TRACE CONNECTS THE TOP OF THE  
RESISTIVE VOLTAGE DIVIDER ON THE FB PIN TO THE OUTPUT.  
PLACE THIS TRACE AS FAR AWAY FROM THE LX NODE AND HIGH  
CURRENT TRACES AS POSSIBLE TO PREVENT NOISE PICKUP.  
Figure 55. Recommended Layout of Bottom Layer of ADP2105/ADP2106/ADP2107  
Rev. D | Page 29 of 36  
 
ADP2105/ADP2106/ADP2107  
APPLICATION CIRCUITS  
Data Sheet  
0.1μF  
V
INPUT VOLTAGE = 5V  
10Ω  
IN  
1
10μF  
V
OUT  
16  
15  
GND IN PWIN1  
LX2  
14  
13  
FB  
ON  
1
2
3
4
12  
EN  
OFF  
2
2.5μH  
V
OUTPUT VOLTAGE = 3.3V  
OUT  
GND  
GND  
GND  
PGND  
LX1  
11  
10  
9
1
1
10μF  
4.7μF  
ADP2107-3.3  
LOAD  
0A TO 2A  
V
IN  
PWIN2  
1
1
2
10μF  
MURATA X5R 0805  
COMP SS AGND NC  
10μF: GRM21BR61A106KE19L  
4.7μF: GRM21BR61A475KA73L  
SUMIDA CDRH5D28: 2.5μH  
5
6
7
8
1nF  
70kΩ  
120pF  
NOTES  
1. NC = NO CONNECT.  
2. EXTERNAL COMPONENTS WERE  
CHOSEN FOR A 10% OVERSHOOT  
FOR A 1A LOAD TRANSIENT.  
Figure 56. Application Circuit—VIN = 5 V, VOUT = 3.3 V, Load = 0 A to 2 A  
0.1μF  
V
INPUT VOLTAGE = 3.6V  
10Ω  
IN  
1
10μF  
V
OUT  
16  
15  
GND IN PWIN1  
LX2  
14  
13  
FB  
ON  
1
2
3
4
12  
EN  
OFF  
2
1.5μH  
V
OUTPUT VOLTAGE = 1.5V  
1
OUT  
PGND  
LX1  
11  
10  
9
GND  
GND  
GND  
1
22μF  
22μF  
ADP2107-1.5  
LOAD  
0A TO 2A  
V
IN  
PWIN2  
1
1
2
10μF  
MURATA X5R 0805  
COMP SS AGND NC  
10μF: GRM21BR61A106KE19L  
22μF: GRM21BR60J226ME39L  
5
6
7
8
TOKO D62LCB OR COILCRAFT LPS4012  
1nF  
140kΩ  
NOTES  
1. NC = NO CONNECT.  
68pF  
2. EXTERNAL COMPONENTS WERE  
CHOSEN FOR A 5% OVERSHOOT  
FOR A 1A LOAD TRANSIENT.  
Figure 57. Application Circuit—VIN = 3.6 V, VOUT = 1.5 V, Load = 0 A to 2 A  
Rev. D | Page 30 of 36  
 
 
Data Sheet  
ADP2105/ADP2106/ADP2107  
0.1μF  
V
INPUT VOLTAGE = 2.7V TO 4.2V  
10Ω  
IN  
1
4.7μF  
V
OUT  
16  
15  
GND IN PWIN1  
LX2  
14  
13  
FB  
ON  
1
2
3
4
12  
EN  
OFF  
2
2.7μH  
V
OUTPUT VOLTAGE = 1.8V  
1
OUT  
PGND  
LX1  
11  
10  
9
GND  
GND  
GND  
1
22μF  
22μF  
ADP2105-1.8  
LOAD  
0A TO 1A  
V
IN  
PWIN2  
1
1
2
4.7μF  
MURATA X5R 0805  
COMP SS AGND NC  
4.7μF: GRM21BR61A475KA73L  
22μF: GRM21BR60J226ME39L  
TOKO 1098AS-DE2812: 2.7μH  
5
6
7
8
1nF  
270kΩ  
NOTES  
1. NC = NO CONNECT.  
39pF  
2. EXTERNAL COMPONENTS WERE  
CHOSEN FOR A 5% OVERSHOOT  
FOR A 1A LOAD TRANSIENT.  
Figure 58. Application Circuit—VIN = Li-Ion Battery, VOUT = 1.8 V, Load = 0 A to 1 A  
0.1μF  
V
INPUT VOLTAGE = 2.7V TO 4.2V  
10Ω  
IN  
1
4.7μF  
V
OUT  
16  
15  
GND IN PWIN1  
LX2  
14  
13  
FB  
ON  
1
2
3
4
12  
EN  
OFF  
2
2.4μH  
V
OUTPUT VOLTAGE = 1.2V  
OUT  
PGND  
LX1  
11  
10  
9
GND  
GND  
GND  
1
1
22μF  
4.7μF  
ADP2105-1.2  
LOAD  
0A TO 1A  
V
IN  
PWIN2  
1
1
2
4.7μF  
MURATA X5R 0805  
COMP SS AGND NC  
4.7μF: GRM21BR61A475KA73L  
22μF: GRM21BR60J226ME39L  
TOKO 1069AS-DB3018HCT OR  
TOKO 1070AS-DB3020HCT  
5
6
7
8
1nF  
135kΩ  
82pF  
NOTES  
1. NC = NO CONNECT.  
2. EXTERNAL COMPONENTS WERE  
CHOSEN FOR A 10% OVERSHOOT  
FOR A 1A LOAD TRANSIENT.  
Figure 59. Application Circuit—VIN = Li-Ion Battery, VOUT = 1.2 V, Load = 0 A to 1 A  
Rev. D | Page 31 of 36  
ADP2105/ADP2106/ADP2107  
Data Sheet  
0.1μF  
V
INPUT VOLTAGE = 5V  
10Ω  
IN  
1
10μF  
FB  
16  
15  
14  
IN PWIN1  
LX2  
13  
FB GND  
ON  
1
2
3
4
12  
EN  
OFF  
2
2.5μH  
OUTPUT VOLTAGE = 2.5V  
GND  
GND  
GND  
PGND  
11  
10  
9
1 1  
10μF 22μF  
85kΩ  
ADP2106-ADJ  
LOAD  
0A TO 1.5A  
LX1  
FB  
V
IN  
40kΩ  
PWIN2  
1
4.7μF  
COMP SS AGND NC  
5
6
7
8
1
2
MURATA X5R 0805  
1nF  
4.7μF: GRM21BR61A475KA73L  
10μF: GRM21BR61A106KE19L  
22μF: GRM21BR60J226ME39L  
COILTRONICS SD14: 2.5μH  
180kΩ  
56pF  
NOTES  
1. NC = NO CONNECT.  
2. EXTERNAL COMPONENTS WERE  
CHOSEN FOR A 5% OVERSHOOT  
FOR A 1A LOAD TRANSIENT.  
Figure 60. Application Circuit—VIN = 5 V, VOUT = 2.5 V, Load = 0 A to 1.5 A  
Rev. D | Page 32 of 36  
Data Sheet  
ADP2105/ADP2106/ADP2107  
OUTLINE DIMENSIONS  
4.10  
4.00 SQ  
3.90  
0.60 MAX  
1.95 REF  
0.60 MAX  
PIN 1  
INDICATOR  
13  
12  
16  
1
PIN 1  
INDICATOR  
2.50  
2.35 SQ  
2.20  
0.65  
BSC  
3.75 BSC  
SQ  
EXPOSED  
PAD  
9
4
8
5
0.50  
0.40  
0.30  
0.25 MIN  
TOP VIEW  
BOTTOM VIEW  
0.80 MAX  
0.65 TYP  
12° MAX  
FOR PROPER CONNECTION OF  
THE EXPOSED PAD, REFER TO  
THE PIN CONFIGURATION AND  
FUNCTION DESCRIPTIONS  
1.00  
0.85  
0.80  
0.05 MAX  
0.02 NOM  
SECTION OF THIS DATA SHEET.  
COPLANARITY  
0.08  
0.35  
0.30  
0.25  
SEATING  
PLANE  
0.20 REF  
COMPLIANT TO JEDEC STANDARDS MO-220-VGGC  
Figure 61. 16-Lead Lead Frame Chip Scale Package [LFCSP_VQ]  
4 mm × 4 mm Body, Very Thin Quad  
(CP-16-10)  
Dimensions shown in millimeters  
ORDERING GUIDE  
Output  
Current  
Temperature  
Range  
Model1  
Output Voltage  
Package Description  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
16-Lead LFCSP_VQ  
Evaluation Board  
Evaluation Board  
Evaluation Board  
Evaluation Board  
Evaluation Board  
Evaluation Board  
Package Option  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
CP-16-10  
ADP2105ACPZ-1.2-R7  
ADP2105ACPZ-1.5-R7  
ADP2105ACPZ-1.8-R7  
ADP2105ACPZ-3.3-R7  
ADP2105ACPZ-R7  
ADP2106ACPZ-1.2-R7  
ADP2106ACPZ-1.5-R7  
ADP2106ACPZ-1.8-R7  
ADP2106ACPZ-3.3-R7  
ADP2106ACPZ-R7  
ADP2107ACPZ-1.2-R7  
ADP2107ACPZ-1.5-R7  
ADP2107ACPZ-1.8-R7  
ADP2107ACPZ-3.3-R7  
ADP2107ACPZ-R7  
ADP2105-1.8-EVALZ  
ADP2105-EVALZ  
1 A  
1 A  
1 A  
1 A  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
−40°C to +125°C  
1.2 V  
1.5 V  
1.8 V  
3.3 V  
1 A  
ADJ  
1.5 A  
1.5 A  
1.5 A  
1.5 A  
1.5 A  
2 A  
2 A  
2 A  
2 A  
2 A  
1.2 V  
1.5 V  
1.8 V  
3.3 V  
ADJ  
1.2 V  
1.5 V  
1.8 V  
3.3 V  
ADJ  
1.8 V  
Adjustable, but set to 2.5 V  
1.8 V  
Adjustable, but set to 2.5 V  
1.8 V  
ADP2106-1.8-EVALZ  
ADP2106-EVALZ  
ADP2107-1.8-EVALZ  
ADP2107-EVALZ  
Adjustable, but set to 2.5 V  
1 Z = RoHS Compliant Part.  
Rev. D | Page 33 of 36  
 
 
 
ADP2105/ADP2106/ADP2107  
NOTES  
Rev. D | Page 34 of 36  
Data Sheet  
NOTES  
ADP2105/ADP2106/ADP2107  
Rev. D | Page 35 of 36  
ADP2105/ADP2106/ADP2107  
NOTES  
©2006–2012 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D06079-0-8/12(D)  
Rev. D | Page 36 of 36  

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