AD ADP2121

600 mA, 6 MHz, Synchronous
Step-Down DC-to-DC Converter
ADP2121
FEATURES
Mobile phones
Digital cameras
Digital audio
Portable equipment
VIN
SW B1
C2
GND
FB C1
EN
MODE
B2
A1
ON
OFF
0.47µH
COUT
4.7µF
PWM
07407-001
AUTO
*FOR OUTPUT VOLTAGE = 2.3 V, INPUT VOLTAGE = 2.9 V TO 5.5V.
Figure 1.
TYPICAL PERFORMANCE
95
AUTO MODE
VIN = 2.7 V
(VIN = 2.9V FOR VOUT = 2.3V)
85
75
65
GENERAL DESCRIPTION
At high load currents, the device uses a voltage regulating pulsewidth modulation (PWM) mode that maintains a constant
frequency with excellent stability and transient response. In forced
PWM mode, the converter continues operating in PWM for light
loads. At light load conditions in auto mode, the ADP2121 can
automatically enter a power-saving mode that uses pulse-frequency
modulation (PFM) to reduce the effective switching frequency and
ensure the longest battery life in portable applications. During logic
controlled shutdown (EN ≤ 0.4 V), the input is disconnected
from the output and draws less than 0.3 μA current (typical)
from the source.
A2
OUTPUT VOLTAGE
1.8V, 1.82V, 1.85V, 1.875V, 2.3V
CIN
2.2µF
55
0.1
The ADP2121 is a high frequency, low quiescent current
step-down dc-to-dc converter optimized for portable applications
in which board area and battery life are critical constraints. The
6 MHz operating frequency enables the use of tiny ceramic inductors and capacitors. Additionally, the synchronous rectification
improves efficiency and results in fewer external components.
L
VOUT = 1.8V
VOUT = 1.82V
VOUT = 1.85V
VOUT = 1.875V
VOUT = 2.3V
1
10
100
1000
LOAD CURRENT (mA)
07407-062
APPLICATIONS
ADP2121
INPUT VOLTAGE*
2.3V TO 5.5V
EFFICIENCY (%)
Peak efficiency: 92%
Operating frequency: 6 MHz
Typical quiescent current in auto mode: 36 µA
Fixed output voltage: 1.8 V, 1.82 V, 1.85 V, 1.875 V, 2.3 V
Maximum guaranteed load current: 600 mA at VIN = 2.7 V to 5.5 V
Input voltage: 2.3 V to 5.5 V
Typical shutdown supply current: 0.3 µA
Automatic power-saving mode
Compatible with tiny multilayer inductors
Internal synchronous rectifier
Internal compensation
Internal soft start
Output to ground short-circuit protection
Cycle-by-cycle current-limit protection
Enable/shutdown logic input
Undervoltage lockout
Thermal shutdown protection
Ultrasmall 6-ball, 0.4 mm pitch, 1.17 mm2 WLCSP
TYPICAL APPLICATION CIRCUIT
Figure 2. Efficiency vs. Load Current for Each Voltage Option
The ADP2121 has an input voltage range of 2.3 V to 5.5 V (2.9 V
to 5.5 V for VOUT = 2.3 V), allowing the use of a single Li+/Li−
polymer cell, 3-cell alkaline or Ni-MH cell, and other standard
power sources. The converter can source up to 600 mA and is
internally compensated to minimize external components. Other
key features, such as cycle-by-cycle peak current limit, soft start,
undervoltage lockout (UVLO), output-to-ground short-circuit
protection, and thermal shutdown, protect the internal and
external circuit components.
Table 1. Output Voltage Options
Input Voltage
Range (V)
2.3 to 5.5
2.3 to 5.5
2.9 to 5.5
Typical Start-Up
Time (μs)
75
275
100
Fixed Output
Voltage (V)
1.8, 1.85, 1.875
1.82
2.3
Rev. B
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rights of third parties that may result from its use. Specifications subject to change without notice. No
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Tel: 781.329.4700
Fax: 781.461.3113 ©2009–2011 Analog Devices, Inc. All rights reserved.
ADP2121
TABLE OF CONTENTS
Features .............................................................................................. 1
Theory of Operation ...................................................................... 14
Applications ....................................................................................... 1
Overview ..................................................................................... 14
General Description ......................................................................... 1
Mode Selection ........................................................................... 14
Typical Application Circuit ............................................................. 1
Enable/Shutdown ....................................................................... 15
Typical Performance......................................................................... 1
Internal Control Features .......................................................... 15
Revision History ............................................................................... 2
Applications Information .............................................................. 17
Specifications..................................................................................... 3
Inductor Selection ...................................................................... 17
Absolute Maximum Ratings ............................................................ 4
Input Capacitor Selection .......................................................... 17
Thermal Data ................................................................................ 4
Output Capacitor Selection....................................................... 17
Thermal Resistance ...................................................................... 4
PCB Layout Guidelines .................................................................. 19
ESD Caution .................................................................................. 4
Outline Dimensions ....................................................................... 20
Pin Configuration and Function Descriptions ............................. 5
Ordering Guide .......................................................................... 20
Typical Performance Characteristics ............................................. 6
REVISION HISTORY
1/11—Rev. A to Rev. B
Changes to Table 2 Summary.......................................................... 3
Changes to Undervoltage Lockout Threshold Parameter and
Output Voltage Accuracy Parameter in Table 2 ........................... 3
6/10—Rev. 0 to Rev. A
Changes to Features, General Description, Figure 1, and
Figure 2; Added Table 1; Renumbered Sequentially ................ 1
Changes to Table 2 ............................................................................ 3
Changes to Table 3 ............................................................................ 4
Change to Typical Performance Characteristics Condition
Statement; Reorganized Typical Performance Characteristics
Section; Changes to Figure 4, Figure 6, Figure 7, and Figure 9;
Added Figure 5 and Figure 8; Renumbered Sequentially ....... 6
Changes to Figure 10 to Figure 12; Added Figure 13 to Figure 15 ... 7
Changes to Figure 16, Figure 17, Figure 19, and Figure 20..........8
Changes to Figure 22; Added Figure 23 and Figure 24 ................9
Added Figure 40, Figure 42, Figure 43, and Figure 45 .............. 12
Added Figure 46 and Figure 48; Changes to Figure 47 ............. 13
Changes to Figure 51 and the Overview Section ....................... 14
Changes to the Auto Mode (PFM and PWM Switching) Section,
Figure 53, the Mode Transition Section, and the Enable/
Shutdown Section ....................................................................... 15
Changes to the Output Short-Circuit Protection Section and
Figure 55 ...................................................................................... 16
Changes to the Output Capacitor Selection Section ................. 17
Changes to Table 6, Table 7, and Table 8 ..................................... 18
Changes to Ordering Guide .......................................................... 20
4/09—Revision 0: Initial Version
Rev. B | Page 2 of 20
ADP2121
SPECIFICATIONS
VIN = EN = 3.6 V; VOUT = 1.8 V, 1.82 V, 1.85 V, 1.875 V, and 2.3 V; typical values are at TA = 25°C; and minimum/maximum limits
guaranteed for TJ = −40°C to +125°C, 1 unless otherwise noted.
Table 2.
Parameters
SUPPLY
Input Voltage Range
Quiescent Current
Shutdown Current
UNDERVOLTAGE LOCKOUT
Undervoltage Lockout Threshold
Conditions
Min
VOUT = 1.8 V, 1.82 V, 1.85 V, 1.875 V
VOUT = 2.3 V
Auto mode, no load, not switching, TA = −40°C to 85°C
PWM mode, no load
VOUT = 1.8 V, 1.82 V, 1.85 V, 1.875 V, VEN = 0 V, TA = −40°C to 85°C
VOUT = 2.3 V, VEN = 0 V, TA = −40°C to 85°C
2.3
2.9
VOUT = 1.8 V, 1.82 V, 1.85 V, 1.875 V, VIN rising
VOUT = 1.8 V, 1.82 V, 1.85 V, 1.875 V, VIN falling
1.6
VOUT = 2.3 V, VIN rising
OUTPUT
Maximum Continuous Output Current 2
Output Voltage Accuracy 3
Load Regulation 4
Feedback Bias Current
SWITCHING CHARACTERISTICS
SW On Resistance (RDSon)
SW Leakage Current
SW Current Limit
Oscillator Frequency
EN/MODE INPUT LOGIC
High Threshold Voltage
Low Threshold Voltage
Leakage Current
SOFT START
Soft Start Period 5
1.9
VOUT = 1.8 V, 1.82 V, 1.85 V, 1.875 V, VIN = 2.3 V
VOUT = 1.8 V, 1.82 V, 1.85 V, 1.875 V, VIN = 2.5 V
VOUT = 1.8 V, 1.82 V, 1.85 V, 1.875 V, VIN = 2.7 V to 5.5 V
VOUT = 2.3 V, VIN = 2.9 V to 5.5 V
Auto mode, VIN = 3.6 V, TA = 25°C, no load, with respect to VOUT
PWM mode, VIN = 2.5 V to 4.5 V, no load, with respect to VOUT
PWM mode, ILOAD = 1 mA to 600 mA
VOUT = 1.8 V, VFB = 1.8 V and VOUT = 1.82 V, VFB = 1.82 V
VOUT = 1.85, VFB = 1.85 V and VOUT = 1.875 V, VFB = 1.875 V
VOUT = 2.3 V, VFB = 2.3 V
300
500
600
600
−3
−3
Unit
5.5
5.5
56
V
V
µA
mA
µA
µA
1
1.5
2.1
2.3
2.0
V
V
2.6
V
2.3
V
−0.2
3.8
4.1
6.4
8
8
8
mA
mA
mA
mA
%
%
%/A
µA
µA
µA
1000
1000
6
440
550
5
1222
1222
6.64
mΩ
mΩ
µA
mA
mA
MHz
0.01
0.4
1
V
V
µA
+3
+3
220
260
790
828
5.36
Max
36
10
0.3
0.4
2.4
VOUT = 2.3 V, VIN falling
P-channel switch
N-channel synchronous rectifier
VIN = 5.5 V, VSW = 0 V and 5.5 V
P-channel switch, open loop, TA = −40°C to 125°C
P-channel switch, open loop, TA = −40°C to 85°C
Typ
VIN = 2.3 V to 5.5 V
1.3
VIN = VEN = VMODE = 5.5 V
Time from EN ≥ 1.2 V to stable VOUT
VOUT = 1.82 V, RLOAD = 5.1 Ω
VOUT = 1.8 V, 1.85 V, 1.875 V, RLOAD = 5.1 Ω
VOUT = 2.3 V, RLOAD = 5.1 Ω
SHORT-CIRCUIT THRESHOLD
THERMAL SHUTDOWN
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
275
75
100
1.24
150
15
310
85
115
µs
µs
µs
V
°C
°C
1
All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC); typical values are at TA = 25°C.
Guaranteed by design. The maximum output current guarantee for 2.3 V to 2.5 V increases linearly from 300 mA to 500 mA. The maximum output current guarantee for 2.5 V to
2.7 V increases linearly from 500 mA to 600 mA. For greater than 2.7 V, the maximum output current guarantee is 600 mA.
3
Transients not included in voltage accuracy specifications. For PFM mode, the VOUT accuracy specification is for the upper point of the ripple.
2
4
The load regulation typical value includes all voltage options. The typical value is different for each voltage option, but can be up to −0.2%/A.
5
Typical value characterized on bench. Maximum specification guaranteed by design. CIN = 2.2 µF (GRM155R60J225M), L = 0.47 µH (LQM2HPNR47MG0L), COUT = 4.7 µF
(GRM155R60J475ME87D).
Rev. B | Page 3 of 20
ADP2121
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
VIN to GND
EN, MODE to GND
FB, SW to GND
Operating Ambient Temperature Range
(ILOAD ≤ 600 mA)
Operating Junction Temperature Range
Storage Temperature
Soldering Conditions
ESD (Electrostatic Discharge)
Human Body Model
Rating
−0.3 V to +6 V
−0.3 V to VIN
−0.3 V to VIN + 0.2 V
–40°C to +85°C
The junction temperature (TJ) of the device is dependent on the
ambient temperature (TA), the power dissipation of the device
(PD), and the junction-to-ambient thermal resistance of the
package (θJA). Maximum junction temperature (TJ) is calculated
from the ambient temperature (TA) and power dissipation (PD)
using the following formula:
TJ = TA + (PD × θJA)
The junction-to-ambient thermal resistance (θJA) of the package
is based on modeling and calculation using a 2- and 4-layer
board. The junction-to-ambient thermal resistance is highly
dependent on the application and board layout. In applications
where high maximum power dissipation exists, close attention
to thermal board design is required.
–40°C to + 125°C
–45°C to +150°C
JEDEC J-STD-020
±4 kV
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.
THERMAL DATA
Absolute maximum ratings apply individually only, not in
combination. The ADP2121 can be damaged when the junction
temperature limits are exceeded. Monitoring ambient temperature does not guarantee that the junction temperature (TJ) is
within the specified temperature limits. In applications with
high power dissipation and poor PCB thermal resistance, the
maximum ambient temperature may need to be derated. In
applications with moderate power dissipation and low PCB
thermal resistance, the maximum ambient temperature can
exceed the maximum limit as long as the junction temperature
is within specification limits.
The value of θJA may vary, depending on PCB material, layout,
and environmental conditions. Refer to JEDEC JESD51-9 for
detailed information about board construction.
THERMAL RESISTANCE
The junction-to-ambient thermal resistance of the system (θJA)
is specified for worst-case conditions, that is, a device soldered
in a circuit board for surface-mount packages.
Table 4.
Package Type
6-Ball WLCSP
2-Layer Board
4-Layer Board
ESD CAUTION
Rev. B | Page 4 of 20
θJA
Unit
198
105
°C/W
°C/W
ADP2121
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
BALL A1
INDICATOR
1
2
MODE VIN
A
SW
EN
FB
GND
B
TOP VIEW
(BALL SIDE DOWN)
(BUMPS ON OPPOSITE SIDE)
Not to Scale
07407-003
C
Figure 3. Pin Configuration
Table 5. Pin Function Descriptions
Pin No.
A1
Mnemonic
MODE
B1
C1
SW
FB
A2
B2
C2
VIN
EN
GND
Description
Mode Select. This pin toggles between auto mode (PFM and PWM switching) and PWM mode. Set MODE low to
allow the part to operate in auto mode. Pull MODE high to force the part to operate in PWM mode. The voltage
applied to MODE should never be higher than the voltage applied to VIN. Do not leave this pin floating.
Switch Node.
Feedback Divider Input. Connect the output capacitor from FB to GND as close as possible to the ADP2121 to set
the output voltage ripple and to complete the control loop.
Power Supply Input. Connect the input capacitor from VIN to GND as close as possible to the ADP2121.
Enable. Pull this pin high to enable the part. Set this pin low to disable the part. Do not leave this pin floating.
Ground Pin.
Rev. B | Page 5 of 20
ADP2121
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6 V, VOUT = 1.82 V, L = 0.47 µH (1800 mA, 1008, LQM2HPNR47MG0L), CIN = 2.2 µF (6.3 V, 0402, X5R, GRM155R60J225M),
COUT = 4.7 µF (6.3 V, 0402, X5R, GRM155R60J475ME87D), EN = VIN, and TA = 25°C, unless otherwise noted.
100
100
90
AUTO MODE
80
80
70
VIN = 2.7V
60
40
30
VIN = 3.6V
PWM MODE
VIN = 4.2V
IOUT = 1mA
40
10
VOUT = 1.82 V
VOUT = 1.82V
10
LOAD CURRENT (mA)
100
1000
07407-004
1
0
2.3
Figure 4. Efficiency vs. Load Current
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
5.5
Figure 7. Efficiency vs. Input Voltage (Auto Mode)
100
93
IOUT = 100mA
90
AUTO MODE
90
80
EFFICIENCY (%)
70
EFFICIENCY (%)
IOUT = 10mA
20
10
60
50
40
30
PWM MODE
VOUT = 1.8V
VOUT = 1.82V
VOUT = 1.85V
VOUT = 1.875V
VOUT = 2.3V
10
1
10
100
1000
LOAD CURRENT (mA)
87
84
81
78
75
2.3
07407-049
20
0
0.1
IOUT = 100mA
50
30
VIN = 5.0V
20
0
0.1
IOUT = 300mA
60
07407-007
50
EFFICIENCY (%)
EFFICIENCY (%)
70
VOUT = 1.8V
VOUT = 1.82V
VOUT = 1.85V
VOUT = 1.875V
VOUT = 2.3V
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
INPUT VOLTAGE (V)
07407-050
90
Figure 8. Efficiency vs. Input Voltage for All Output Voltages (Auto Mode)
Figure 5. Efficiency vs. Load Current for All Output Voltages
100
100
L = 0.47µH
1008
95
90
AUTO MODE
90
L = 0.47µH
0805
EFFICIENCY (%)
PWM MODE
50
40
L = 0.47µH
0805
70
L = 0.45µH
0603
60
10
LOAD CURRENT (mA)
100
1000
AUTO MODE
VIN = 2.7V
VOUT = 1.82V
55
VIN = 2.7V
VOUT = 1.82V
1
75
65
L = 0.45µH
0603
30
20
0.1
80
50
2.3
Figure 6. Efficiency vs. Load Current for Various Inductor Sizes
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
5.5
Figure 9. Efficiency vs. Input Voltage for Various Inductor Sizes
Rev. B | Page 6 of 20
07407-019
60
85
L = 0.47µH
1008
70
07407-016
EFFICIENCY (%)
80
ADP2121
40
44
VOUT = 1.82V
40
38
TA = +25°C
36
34
TA = –40°C
38
36
34
VOUT = 1.8V
VOUT = 1.82V
VOUT = 1.85V
VOUT = 1.875V
VOUT = 2.3V
32
32
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
5.5
30
2.3
07407-010
30
2.3
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
INPUT VOLTAGE (V)
Figure 10. Auto Mode Quiescent Current vs. Input Voltage Over Temperature
(Nonswitching, No Load)
07407-051
TA = +85°C
QUIESCENT CURRENT (µA)
QUIESCENT CURRENT (µA)
42
Figure 13. Auto Mode Quiescent Current vs. Input Voltage for All Voltage
Options (Nonswitching, No Load)
0.8
0.7
VOUT = 1.82V
0.6
0.6
TA = +85°C
0.5
0.4
TA = +25°C
0.3
TA = –40°C
0.2
0.5
0.4
0.3
0.2
VOUT = 1.8V
VOUT = 1.82V
VOUT = 1.85V
VOUT = 1.875V
VOUT = 2.3V
0.1
0.1
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
5.5
0
2.3
07407-011
0
2.3
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
INPUT VOLTAGE (V)
Figure 11. Shutdown Current vs. Input Voltage Over Temperature
07407-052
SHUTDOWN CURRENT (µA)
SHUTDOWN CURRENT (µA)
0.7
Figure 14. Shutdown Current vs. Input Voltage for All Voltage Options
16
15
VOUT = 1.82V
TA = +85°C
13
TA = +25°C
12
10
TA = –40°C
8
11
9
7
VOUT = 1.8V
VOUT = 1.82V
VOUT = 1.85V
VOUT = 1.875V
VOUT = 2.3V
5
6
VOUT = 1.82V
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
5.5
3
2.3
07407-013
4
2.3
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
INPUT VOLTAGE (V)
Figure 12. PWM Mode Quiescent Current vs. Input Voltage Over Temperature
(Switching, No Load)
Rev. B | Page 7 of 20
Figure 15. PWM Mode Quiescent Current vs. Input Voltage
for All Voltage Options (Switching, No Load)
07407-053
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
14
ADP2121
100
90
85
90
TA = –40°C
200
TA = +25°C
65
60
VIN = 5.0V
60
VIN = 4.2V
50
40
TA = +85°C
VIN = 2.7V
20
AUTO MODE
VIN = 3.6V
VOUT = 1.82V
10
LOAD CURRENT (mA)
100
50
POWER
LOSS
10
1000
0
0.1
07407-006
50
1
100
VIN = 3.6V
30
55
45
0.1
150
Figure 16. Efficiency vs. Load Current Over Temperature
1
10
LOAD CURRENT (mA)
0
1000
100
07407-009
70
POWER LOSS (mW)
70
75
EFFICIENCY (%)
EFFICIENCY (%)
EFFICIENCY
80
80
Figure 19. Efficiency and Power Loss vs. Load Current (Auto Mode)
1.87
1.835
VOUT = 1.82V
VIN = 2.7V
VIN = 5.0V
1.86
VIN = 5.0V
1.830
VIN = 4.2V
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
250
VOUT = 1.82 V
1.85
1.84
VIN = 3.6V
1.825
VIN = 3.6V
VIN = 4.2V
VIN = 2.7V
1.820
1.83
VOUT = 1.82V
100
1000
1
PWM MODE
Figure 17. Output Voltage Accuracy (Auto Mode)
10
100
LOAD CURRENT (mA)
1000
07407-008
10
LOAD CURRENT (mA)
1.815
07407-005
AUTO MODE
1.82
0.1
1
Figure 20. Output Voltage Accuracy (PWM Mode)
360
400
340
350
P-CHANNEL R DSON (mΩ)
300
280
TA = +85°C
260
240
TA = +25°C
300
250
TA = +85°C
TA = +25°C
200
220
150
TA = –40°C
200
TA = –40°C
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
5.5
100
2.3
Figure 18. N-Channel Drain-Source On Resistance
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
Figure 21. P-Channel Drain-Source On Resistance
Rev. B | Page 8 of 20
5.5
07407-012
180
2.3
07407-015
N-CHANNEL R DSON (mΩ)
320
ADP2121
160
OUTPUT VOLTAGE (50mV/DIV)
PWM OPERATION
140
120
100
LOAD CURRENT (100mA/DIV)
80
PFM OPERATION
60
40
VOUT = 1.82V
0
2.3
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
5.5
TIME (20µs/DIV)
Figure 25. Load Transient Response, 0 mA to 150 mA
(VIN = 2.5 V, Auto Mode)
190
VOUT = 1.8V
VOUT = 1.82V
VOUT = 1.85V
VOUT = 1.875V
VOUT = 2.3V
180
170
OUTPUT VOLTAGE (50mV/DIV)
160
150
LOAD CURRENT (100mA/DIV)
140
130
PFM OPERATION
110
2.3
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
INPUT VOLTAGE (V)
TIME (20µs/DIV)
Figure 26. Load Transient Response, 0 mA to 150 mA
(VIN = 3.6 V, Auto Mode)
200
OUTPUT VOLTAGE (50mV/DIV)
180
160
PWM OPERATION
140
120
LOAD CURRENT (100mA/DIV)
VOUT = 1.8V
VOUT = 1.82V
VOUT = 1.85V
VOUT = 1.875V
VOUT = 2.3V
80
60
40
2.3
2.7
3.1
3.5
3.9
4.3
INPUT VOLTAGE (V)
4.7
5.1
5.5
TIME (20µs/DIV)
Figure 24. Auto Mode Falling Switching Threshold vs. Input Voltage for All
Voltage Options
Rev. B | Page 9 of 20
Figure 27. Load Transient Response, 0 mA to 150 mA
(VIN = 4.5 V, Auto Mode)
07407-024
100
07407-055
AUTO MODE FALLING SWITCHING THRESHOLD (mA)
Figure 23. Auto Mode Rising Switching Threshold vs. Input Voltage for All
Voltage Options
07407-023
120
07407-054
AUTO MODE RISING SWITCHING THRESHOLD (mA)
Figure 22. Auto Mode Switching Threshold vs. Input Voltage
07407-022
20
07407-014
AUTO MODE SWITCHING THRESHOLD (mA)
180
ADP2121
OUTPUT VOLTAGE (50mV/DIV)
OUTPUT VOLTAGE (50mV/DIV)
LOAD CURRENT (100mA/DIV)
Figure 31. Load Transient Response, 50 mA to 250 mA
(VIN = 2.5 V, Auto Mode)
OUTPUT VOLTAGE (50mV/DIV)
LOAD CURRENT (100mA/DIV)
LOAD CURRENT (100mA/DIV)
TIME (20µs/DIV)
07407-026
OUTPUT VOLTAGE (50mV/DIV)
TIME (20µs/DIV)
Figure 29. Load Transient Response, 0 mA to 150 mA
(VIN = 3.6 V, PWM Mode)
Figure 32. Load Transient Response, 50 mA to 250 mA
(VIN = 3.6 V Auto Mode)
OUTPUT VOLTAGE (50mV/DIV, 1.82V OFFSET)
LOAD CURRENT (100mA/DIV)
LOAD CURRENT (100mA/DIV)
07407-027
OUTPUT VOLTAGE (50mV/DIV)
TIME (20µs/DIV)
07407-029
Figure 28. Load Transient Response, 0 mA to 150 mA
(VIN = 2.5 V, PWM Mode)
07407-028
TIME (20µs/DIV)
TIME (20µs/DIV)
Figure 30. Load Transient Response, 0 mA to 150 mA
(VIN = 4.5 V, PWM Mode)
Figure 33. Load Transient Response, 50 mA to 250 mA
(VIN = 4.5 V, Auto Mode)
Rev. B | Page 10 of 20
07407-030
TIME (20µs/DIV)
07407-025
LOAD CURRENT (100mA/DIV)
ADP2121
OUTPUT VOLTAGE (50mV/DIV, 1.82V DC OFFSET)
OUTPUT VOLTAGE (50mV/DIV, 1.82V DC OFFSET)
LOAD CURRENT (100mA/DIV)
TIME (20µs/DIV)
07407-034
07407-031
TIME (20µs/DIV)
LOAD CURRENT (100mA/DIV)
Figure 37. Load Transient Response, 150 mA to 400 mA
(VIN = 2.5 V, PWM Mode)
Figure 34. Load Transient Response, 50 mA to 250 mA
(VIN = 2.5 V, PWM Mode)
OUTPUT VOLTAGE (50mV/DIV, 1.82V DC OFFSET)
OUTPUT VOLTAGE (50mV/DIV, 1.82V DC OFFSET)
LOAD CURRENT (100mA/DIV)
TIME (20µs/DIV)
07407-035
TIME (20µs/DIV)
07407-032
LOAD CURRENT (100mA/DIV)
Figure 38. Load Transient Response,150 mA to 400 mA
(VIN = 3.6 V, PWM Mode)
Figure 35. Load Transient Response, 50 mA to 250 mA
(VIN = 3.6 V, PWM Mode)
OUTPUT VOLTAGE (50mV/DIV, 1.82V DC OFFSET)
OUTPUT VOLTAGE (50mV/DIV, 1.82V DC OFFSET)
LOAD CURRENT (100mA/DIV)
TIME (20µs/DIV)
Figure 39. Load Transient Response, 150 mA to 400 mA
(VIN = 4.5 V, PWM Mode)
Figure 36. Load Transient Response, 50 mA to 250 mA
(VIN = 4.5 V, PWM Mode)
Rev. B | Page 11 of 20
07407-036
TIME (20µs/DIV)
07407-033
LOAD CURRENT (100mA/DIV)
ADP2121
VIN = 3.6V
VOUT = 1.8V
NO LOAD
VIN = 3.6V
VOUT = 1.8V
RLOAD = 5.1Ω
OUTPUT VOLTAGE
(500mV/DIV)
OUTPUT VOLTAGE
(500mV/DIV)
07407-056
EN PIN VOLTAGE (5V/DIV)
07407-058
INDUCTOR
CURRENT
(200mA/DIV)
INDUCTOR
CURRENT
(200mA/DIV)
EN PIN VOLTAGE (5V/DIV)
TIME (10μs/DIV)
TIME (10µs/DIV)
Figure 40. Start-Up Waveform, No Load
Figure 43. Start-Up Waveform, Heavy Load
OUTPUT VOLTAGE (500mV/DIV)
OUTPUT VOLTAGE (500mV/DIV)
VIN = 3.6V
VOUT = 1.82V
RLOAD = 5.1Ω
VIN = 3.6V
VOUT = 1.82V
NO LOAD
INDUCTOR CURRENT (200mA/DIV)
INDUCTOR CURRENT (200mA/DIV)
07407-018
TIME (40µs/DIV)
TIME (40µs/DIV)
Figure 41. Start-Up Waveform, No Load
VIN = 3.6V
VOUT = 2.3V
NOLOAD
07407-021
ENABLE PIN VOLTAGE (5V/DIV)
ENABLE PIN VOLTAGE (5V/DIV)
Figure 44. Start-Up Waveform, Heavy Load
VIN = 3.6V
VOUT = 2.3V
RLOAD = 5.1Ω
OUTPUT VOLTAGE
(500mV/DIV)
OUTPUT VOLTAGE
(500mV/DIV)
07407-057
EN PIN VOLTAGE (5V/DIV)
EN PIN VOLTAGE (5V/DIV)
TIME (10μs/DIV)
TIME (10μs/DIV)
Figure 45. Start-Up Waveform, Heavy Load
Figure 42. Start-Up Waveform, No Load
Rev. B | Page 12 of 20
07407-059
INDUCTOR
CURRENT
(200mA/DIV)
INDUCTOR
CURRENT
(200mA/DIV)
ADP2121
VIN = 3.6V
VOUT = 1.8V
OUTPUT VOLTAGE (20mV/DIV, 1.82V DC OFFSET)
OUTPUT VOLTAGE (200mV/DIV)
SWITCH NODE VOLTAGE
(2V/DIV)
INDUCTOR CURRENT (500mA/DIV)
VIN = 3.6V
VOUT = 1.82V
IOUT = 25mA
TIME (200μs/DIV)
07407-017
07407-060
INDUCTOR CURRENT
(200mA/DIV)
TIME (1µs/DIV)
Figure 49. PFM Mode Operation
Figure 46. Output Short-Circuit Response
OUTPUT VOLTAGE (200mV/DIV)
OUTPUT VOLTAGE (20mV/DIV, 1.82V DC OFFSET)
SWITCH NODE VOLTAGE (1V/DIV)
VOUT = 1.82V
TIME (1ms/DIV)
VIN = 3.6V
VOUT = 1.82V
IOUT = 200mA
07407-037
INDUCTOR CURRENT (500mA/DIV)
TIME (100ns/DIV)
Figure 50. PWM Mode Operation
Figure 47. Output Short-Circuit Response
VIN = 3.6V
VOUT = 2.3V
OUTPUT VOLTAGE (200mV/DIV)
07407-061
INDUCTOR CURRENT (500mA/DIV)
TIME (200μs/DIV)
Figure 48. Output Short-Circuit Response
Rev. B | Page 13 of 20
07407-020
INDUCTOR CURRENT (200mA/DIV)
ADP2121
THEORY OF OPERATION
VBAT
2.3V TO 5.5V
2.2µF
X5R
6.3V
VIN
A2
PVIN
FB
VOUT
AVIN
C1
PDRIVE
R1
PWM
COMP
EAMP
R2
AGND
BG
SW
SHOOTTHROUGH
CONTROL
NDRIVE
V(VIN)
GND
COMPENSATION
C2
PILIM
THERMAL
SHUTDOWN
PREF
6MHz
OSCILLATOR
SOFT START
REFPFM
VOUT
4.7µF
X5R
6.3V
PGND
RAMP
AGND
470nH
B1
PFM
COMPARATOR
LOGIC
AND
PWM/PFM
CONTROL
AGND
ZXCOMP
NREF
PFM
DETECT
VIN
FB
THRESHOLD
DETECT
BG
BANDGAP
THRESHOLD
DETECT
A1 MODE
PWM
ON
OFF
07407-038
B2 EN
AUTO
Figure 51. Internal Block Diagram
OVERVIEW
MODE SELECTION
The ADP2121 is a high efficiency, synchronous step-down
dc-to-dc converter that provides up to 600 mA of continuous
output current. It operates from a 2.3 V to 5.5 V input voltage
for the 1.8 V, 1.82 V, 1.85 V, and 1.875 V (typical) fixed-output
voltages, and from a 2.9 V to 5.5 V input voltage for the 2.3 V
(typical) output voltage. The 6 MHz operating frequency
enables the use of tiny external components. The internal
control schemes of the ADP2121 give excellent stability and
transient response. External control for mode selection and
device enable provide power-saving options that are aided by
internal features such as synchronous rectification and compensation. Other internal features, such as cycle-by-cycle peak current
limit, soft start, undervoltage lockout, output-to-ground shortcircuit protection, and thermal shutdown, protect the internal
and external circuit components.
The ADP2121 has two modes of operation (PWM mode and
auto mode), determined by the state of the MODE pin.
Pull the MODE pin high to force the converter to operate in
PWM mode regardless of the output current. Otherwise, set
MODE low to allow the converter to automatically enter the
power-saving PFM mode at light load currents. Do not leave
this pin floating. The MODE pin is not designed for dynamic
control and should not be changed after the ADP2121 is enabled.
Pulse-Width Modulation (PWM) Mode
The PWM mode forces the part to maintain a fixed frequency
of 6 MHz (typical) over all load conditions. The ADP2121 uses
a hybrid proprietary voltage mode control scheme to control
the duty cycle over load current and line voltage variation. This
control provides excellent stability, transient response, and output
regulation but results in lower efficiencies at light load currents.
Rev. B | Page 14 of 20
ADP2121
repeats. The output voltage, switching node voltage, and
inductor current during this process are shown in Figure 54.
OUTPUT VOLTAGE (20mV/DIV, 1.82V DC OFFSET)
OUTPUT VOLTAGE (20mV/DIV, 1.82V DC OFFSET)
SWITCH NODE VOLTAGE (1V/DIV)
SWITCH NODE VOLTAGE
(2V/DIV)
INDUCTOR CURRENT (200mA/DIV)
TIME (100ns/DIV)
VIN = 3.6V
VOUT = 1.82V
IOUT = 25mA
Figure 52. Typical PWM Operation
Auto Mode (PFM and PWM Switching)
TIME (1µs/DIV)
Auto mode is a power-saving feature that enables the converter
to switch between PWM and PFM in response to the output
load. Auto mode is enabled when the MODE pin is pulled low.
In auto mode, the ADP2121 operates in PFM mode for light load
currents and switches to PWM mode for medium and heavy load
currents. Figure 53 uses the typical threshold values of the 1.82 V
output voltage option to demonstrate the behavior of the ADP2121
in auto mode. The threshold values will shift accordingly for other
output voltages.
MODE TRANSITION POINT*
IOUT = 70mA TO 170mA (TYPICAL)
07407-041
INDUCTOR CURRENT
(200mA/DIV)
07407-039
VIN = 3.6V
VOUT = 1.82V
IOUT = 200mA
Figure 54. Typical PFM Operation
Mode Transition
When the MODE pin is low, the converter switches between
PFM and PWM modes automatically to maintain optimal
transient response and efficiency. The mode transition point
depends on the input voltage. Hysteresis exists in the transition
point to prevent instability and decreased efficiencies that could
result if the converter were able to oscillate between PFM and
PWM for a fixed input voltage and load current. See Figure 22,
Figure 23, and Figure 24 for typical values.
A switch from PFM to PWM occurs when the output voltage dips
below the nominal value of the output voltage option. Switching
to PWM allows the converter to maintain efficiency and supply
a larger current to the load.
1.875V
OUTPUT VOLTAGE (V)
1.820V
TIME (µs)
The switch from PWM to PFM occurs when the output current
is below the PFM threshold for multiple consecutive switching
cycles. Switching to PFM allows the converter to save power by
supplying the lighter load current with fewer switching cycles.
INDUCTOR CURRENT (mA)
TIME (µs)
07407-040
0mA
*PFM AND PWM THRESHOLD VARIES WITH INPUT VOLTAGE.
SEE FIGURE 22, FIGURE 23 and FIGURE 24 FOR TYPICAL VALUES.
Figure 53. PFM-to-PWM Transition Point, VOUT = 1.82 V
Figure 53 shows that the output voltage in PFM mode is slightly
higher to keep the ADP2121 from oscillating between modes,
ensuring stable operation.
Pulse Frequency Modulation (PFM)
ENABLE/SHUTDOWN
When the converter is operating under light load conditions,
the effective switching frequency and supply current are
decreased and varied using PFM to regulate the output voltage.
This results in improved efficiencies and lower quiescent
currents. In PFM mode, the converter only switches when
necessary to keep the output voltage within the PFM limits set
by an internal comparator (see Figure 53). Switching stops
when the upper limit is reached and resumes when the lower
limit is reached.
The EN input turns the ADP2121 on or off. Connect EN to
GND or logic low to shut down the part and reduce the current
consumption to 1.0 µA (maximum). Connect EN to VIN or to
logic high to enable the part. Do not leave this pin floating.
When the upper level is reached, the output stage and oscillator
turn off to reduce the quiescent current. During this stage, the
output capacitor supplies the current to the load. As the output
capacitor discharges and the output voltage reaches the lower
PFM comparator threshold, switching resumes and the process
INTERNAL CONTROL FEATURES
Overcurrent Protection
To ensure that excessively high currents do not damage the
inductor, the ADP2121 incorporates cycle-by-cycle overcurrent
protection. This function is accomplished by monitoring the
instantaneous peak current on the power PMOS switch. If this
current exceeds the maximum level (1 A typical), the PMOS is
immediately turned off. This minimizes the potential for damage
to power components during certain faults and transient events.
The value listed in Table 2 is an open loop dc tested value. Inherent
Rev. B | Page 15 of 20
ADP2121
delays in the current-limit comparator allow a slight increase and
variation in this specification.
Soft Start
To prevent excessive input inrush current at startup, the ADP2121
operates with an internal soft start. When EN goes high, or when
the part recovers from a fault (UVLO, TSD, or short-circuit
protection), a soft start timer begins. The soft start timer corresponds to the maximum soft start period for the given fixed
output voltage. During this time, the peak current limit is gradually
increased to its maximum. As seen in Figure 40 through Figure 45,
the output voltage passes through several stages to ensure that the
converter is able to start up effectively and in proper sequence.
After the soft start period has expired, the peak current limit
remains at 1 A (typical), and the part enters the operating mode
determined by the MODE pin.
Output Short-Circuit Protection
If the output voltage is inadvertently shorted to GND, a standard
dc-to-dc controller delivers maximum power into that short.
This may result in a potentially catastrophic failure. To prevent
this, the ADP2121 senses when the output voltage is below the
short-circuit protection threshold (typically 1.24 V).
At this point, the controller turns off for approximately 1.8 ms
(VOUT = 1.82 V), 0.44 ms (VOUT = 1.8 V and 1.85 V), or 0.48 ms
(VOUT = 2.3 V), and then automatically initiates a soft start
sequence. This cycle repeats until the short is removed or the
part is disabled. This dramatically reduces the power delivered
into the short circuit, yet still allows the converter to recover if
the fault is removed.
OUTPUT VOLTAGE (200mV/DIV)
Synchronous Rectification
In addition to the P-channel MOSFET switch, the ADP2121
includes an N-channel MOSFET switch to build the synchronous
rectifier. The synchronous rectifier improves efficiency, especially
for small load currents, and reduces cost and board space by
eliminating the need for an external rectifier.
The control loop is internally compensated to deliver maximum performance with no additional external components.
The ADP2121 is designed to work with 0.47 μH chip inductors
and 4.7 μF capacitors (see Table 6, Table 7, and Table 8.) Other
values may reduce performance and/or stability.
Undervoltage Lockout (UVLO)
If the input voltage is below the UVLO threshold, the ADP2121
automatically turns off the power switches and places the part
into a low power consumption mode. This prevents potentially
erratic operation at low input voltages. The UVLO levels have
approximately 100 mV of hysteresis to ensure glitch-free startup.
INDUCTOR CURRENT (500mA/DIV)
TIME (1ms/DIV)
07407-042
Compensation
Figure 55. Output Short-Circuit Protection, VOUT = 1.82 V
Thermal Shutdown (TSD) Protection
The ADP2121 also includes TSD protection. If the die
temperature exceeds 150°C (typical), the TSD protection
activates and turns off the power devices. They remain off
until the die temperature falls below 135°C (typical), at
which point the converter restarts.
Rev. B | Page 16 of 20
ADP2121
APPLICATIONS INFORMATION
The external component selection for the ADP2121 applications circuit is driven by the load requirement and begins with
the selection of the inductor. After the inductor is chosen, CIN
and COUT can be selected. Components can be identified using
the selection guide and recommended selection tables in this
section.
INDUCTOR SELECTION
The high switching frequency of the ADP2121 allows for minimal
output voltage ripple, even with small inductors. Inductor sizing
is a trade-off between efficiency and transient response. A small
inductor leads to a larger inductor current ripple, which provides
better transient response but degrades efficiency. Due to the high
switching frequency of the ADP2121, multilayer ceramic inductors
can be used for an overall smaller solution size. Shielded ferrite
core inductors are recommended for their low core losses and
low electromagnetic interference (EMI).
As a guideline, the peak-to-peak current ripple of the inductor
is typically set to
ΔIL = 0.45 × ILOAD
(1)
where ILOAD is the maximum output current. The largest ripple
current, ΔIL, occurs at the maximum input voltage.
It is important that the inductor be capable of handling the
maximum peak inductor current, IPK, determined by the
following equation:
IPK = ILOAD(MAX) + ΔIL/2
(2)
The dc current rating of the inductor should be greater than the
calculated IPK to prevent core saturation. The ADP2121 is designed
for applications with a 0.47 µH inductor. Other values are not
recommended, and stable operation over all conditions is not
guaranteed with their use. Table 6 shows the available 0.47 µH
surface-mount inductors that have been tested with the ADP2121.
INPUT CAPACITOR SELECTION
The input capacitor must be able to support the maximum
input operating voltage and the maximum rms input current.
Select an input capacitor capable of withstanding the rms input
current for the maximum load current in the application using
the following equation:
I rms = I OUT ( MAX ) ×
VOUT × (VIN − VOUT )
VIN
(3)
The input capacitor reduces the input voltage ripple caused by
the switch currents on the VIN pin. Place the input capacitor
as close as possible to the VIN pin.
In principle, different types of capacitors can be considered, but for
battery-powered applications, the best choice is the multilayer
ceramic capacitor, due to its small size and low equivalent series
resistance (ESR). Table 7 offers suggestions for suitable input
capacitors. All capacitors listed in the table are multilayer
ceramic capacitors.
It is recommended that the VIN pin be bypassed with a 2.2 µF
or larger ceramic input capacitor if the supply line has a distributed capacitance of at least 10 μF. If not, then at least a 10 μF
capacitor is recommended on the input supply pin. The input
capacitor can be increased without any limit for better input
voltage filtering. X5R or X7R dielectrics with a voltage rating of
6.3 V or 10 V are recommended. Y5U and Z5U dielectrics are
not recommended, due to their poor temperature and dc bias
characteristics.
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. The ADP2121
has been designed to operate with small ceramic capacitors in
the 4.7 µF to 10 µF range that have low ESR and equivalent
series inductance (ESL). These components are able, therefore,
to meet stringent output voltage ripple specifications. X5R or
X7R dielectrics with a voltage rating of 6.3 V are recommended.
Table 8 shows a list of output MLCC capacitors recommended
for ADP2121 applications. The minimum effective capacitance
required for stable operation is 1.5 µF.
When choosing output capacitors, it is also important to account
for the loss of capacitance due to output voltage dc bias. This
may result in using a capacitor with a higher rated voltage to
achieve the desired capacitance value. Additionally, if ceramic
output capacitors are used, the capacitor rms ripple current
rating should always meet the application requirements. The
rms ripple current is calculated as
I rms(COUT ) =
1
2 3
×
VOUT × (VIN ( MAX ) − VOUT )
L × f SW × VIN ( MAX )
(4)
At nominal load currents, the converter operates in pulse
frequency mode (PFM), and the overall output voltage ripple is the
sum of the voltage spike caused by the output capacitor ESR plus
the voltage ripple caused by charging and discharging the
output capacitor.
ΔVOUT = ΔIL × (ESR + 1/(8 × COUT × fSW))
The largest voltage ripple occurs at the highest input voltage.
At light load currents, if MODE is set low, then the converter
operates in the power-saving mode (PFM), and the output
voltage ripple increases.
Rev. B | Page 17 of 20
(5)
ADP2121
Table 6. Recommended Inductor Selection
Manufacturer
Murata
Taiyo Yuden
TDK
Series
LQM2HPNR47MG0L
LQM21PNR47MC0D
BRC1608TR45M
MLZ2012DR47MT
GLFR1608TR47M-LR
Inductance (µH)
0.47 ± 20%
0.47 ± 20%
0.45 ± 20%
0.47 ± 20%
0.47 ± 20%
DCR (mΩ)
40 ± 25%
120 ± 25%
90 ± 30%
180 ± 30%
50 ± 30%
Current Rating (mA)
1800
1100
800
550
475
Size (L × W × H) (mm)
2.50 × 2.00 × 0.90
2.00 × 1.25 × 0.50
1.60 × 0.80 × 0.80
2.00 × 1.25 × 1.25
1.6 × 0.80 × 0.80
Package
1008
0805
0603
0805
0603
Voltage Rating (V)
6.3
6.3
Temperature
Coefficient
X5R
X5R
Size (L × W × H) (mm)
1.0 × 0.5 × 0.5
1.0 × 0.5 × 0.5
Package
0402
0402
Voltage Rating (V)
6.3
6.3
4
Temperature
Coefficient
X5R
X5R
X5R
Size (L × W × H) (mm)
1.6 × 0.8 × 0.8
1.0 × 0.5 × 0.5
1.0 × 0.5 × 0.5
Package
0603
0402
0402
Table 7. Recommended Input Capacitor Selection
Manufacturer
Murata
Taiyo Yuden
Part Number
GRM155R60J225M
JMK105BJ225MV-F
Capacitance ( μF)
2.2
2.2
Table 8. Recommended Output Capacitor Selection
Manufacturer
Murata
Taiyo Yuden
Part Number
GRM188R60J475KE19D
GRM155R60J475ME87D
AMK105BJ475MV-F
Capacitance (μF)
4.7
4.7
4.7
Rev. B | Page 18 of 20
ADP2121
PCB LAYOUT GUIDELINES
MODE
MODE
VIN
ADP2121
VIN
ADP2121
L1
SW
EN
CIN
1.8mm
VOUT
L1
EN
SW
CIN
VOUT
GND
COUT
2.2mm
07407-043
GND
COUT
3.4mm
Figure 56. Solution Size with a 1008 Inductor
07407-045
2.5mm
Figure 58. Solution Size with a 0603 Inductor
For high efficiency, good regulation, and stability with the
ADP2121, a well-designed PCB is required.
Use the following guidelines when designing PCBs:
MODE
•
VIN
ADP2121
•
•
SW
EN
CIN
L1
•
VOUT
GND
COUT
2.65mm
07407-044
2.0mm
Figure 57. Solution Size with a 0805 Inductor
Rev. B | Page 19 of 20
Keep the low ESR input capacitor, CIN, close to VIN
and GND.
Keep high current traces as short and as wide as possible.
Avoid routing high impedance traces near any node
connected to SW or near the inductor to prevent radiated
noise injection.
Keep the low ESR output capacitor, COUT, close to FB and
GND of the ADP2121. Long trace lengths from the part to
the output capacitor add series inductance and may cause
instability or increased ripple.
ADP2121
OUTLINE DIMENSIONS
0.660
0.600
0.540
0.430
0.400
0.370
2
1
A
0.280
0.260
0.240
1.340
1.300
1.260
B
C
0.800
BSC
TOP VIEW
0.230
0.200
0.170
(BALL SIDE DOWN)
0.400 BSC
BALL PITCH
BOTTOM VIEW
0.075 NOM
COPLANARITY
(BALL SIDE UP)
021908-A
A1 BALL
CORNER
0.940
0.900
0.860
Figure 59. 6-Ball Wafer Level Chip Scale Package (WLCSP)
(CB-6-4)
Dimensions shown in millimeters
ORDERING GUIDE
Model 1
ADP2121ACBZ-1.8-R7
ADP2121ACBZ-1.82R7
ADP2121ACBZ-1.85R7
ADP2121ACBZ-1875R7
ADP2121ACBZ-2.3-R7
ADP2121-1.8-EVALZ
ADP2121-1.82-EVALZ
ADP2121-1.85-EVALZ
ADP2121-1.875EVALZ
ADP2121-2.3-EVALZ
1
2
Temperature
Range
−40 °C to +85 °C
−40 °C to +85 °C
−40 °C to +85 °C
−40 °C to +85 °C
−40 °C to +85 °C
Output
Voltage (V)
1.8
1.82
1.85
1.875
2.3
1.8
1.82
1.85
1.875
2.3
Package Description
6-Ball Wafer Level Chip Scale Package [WLCSP]
6-Ball Wafer Level Chip Scale Package [WLCSP]
6-Ball Wafer Level Chip Scale Package [WLCSP]
6-Ball Wafer Level Chip Scale Package [WLCSP]
6-Ball Wafer Level Chip Scale Package [WLCSP]
Evaluation Board for 1.8 V
Evaluation Board for 1.82 V
Evaluation Board for 1.85 V
Evaluation Board for 1.875 V
Evaluation Board for 2.3 V
Z = RoHS Compliant Part.
Halide free.
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D07407-0-1/11(B)
Rev. B | Page 20 of 20
Package
Option 2
CB-6-4
CB-6-4
CB-6-4
CB-6-4
CB-6-4
Branding
L92
L7N
L94
L95
L9G