ADP5023CP-EVALZ [ADI]
Dual 3 MHz, 800 mA Buck; 双3兆赫， 800毫安巴克
| 型号： | ADP5023CP-EVALZ |
| 厂家： | 
ADI |
| 描述： | Dual 3 MHz, 800 mA Buck |
| 文件： | 总28页 (文件大小：814K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Dual 3 MHz, 800 mA Buck
Regulators with One 300 mA LDO
Data Sheet
ADP5023
FEATURES
GENERAL DESCRIPTION
Main input voltage range: 2.3 V to 5.5 V
Two 800 mA buck regulators and one 300 mA LDO
24-lead, 4 mm × 4 mm LFCSP package
Regulator accuracy: 3ꢀ
The ADP5023 combines two high performance buck regulators
and one low dropout (LDO) regulator in a small, 24-lead 4 mm ×
4 mm LFCSP to meet demanding performance and board space
requirements.
Factory programmable or external adjustable VOUTx
3 MHz buck operation with forced PWM and auto PWM/PSM
modes
BUCK1/BUCK2: output voltage range from 0.8 V to 3.8 V
LDO: output voltage range from 0.8 V to 5.2 V
LDO: input supply voltage from 1.7 V to 5.5 V
LDO: high PSRR and low output noise
The high switching frequency of the buck regulators enables tiny
multilayer external components and minimizes the board space.
When the MODE pin is set high, the buck regulators operate in
forced PWM mode. When the MODE pin is set low, the buck
regulators operate in PWM mode when the load current is
above a predefined threshold. When the load current falls below
a predefined threshold, the regulator operates in power save
mode (PSM) improving the light-load efficiency.
APPLICATIONS
Power for processors, ASIC, FPGAs, and RF chipsets
Portable instrumentation and medical devices
Space constrained devices
The two bucks operate out of phase to reduce the input capaci-
tor requirement. The low quiescent current, low dropout voltage,
and wide input voltage range of the ADP5023 LDO extends the
battery life of portable devices. The ADP5023 LDO maintains
power supply rejection greater than 60 dB for frequencies as
high as 10 kHz while operating with a low headroom voltage.
Regulators in the ADP5023 are activated though dedicated
enable pins. The default output voltages can be externally set in
the adjustable version or factory programmable to a wide range
of preset values in the fixed voltage version.
TYPICAL APPLICATION CIRCUIT
AVIN
HOUSEKEEPING
C
0.1µF
FILT
VOUT1
L1 1µH
VIN1
SW1
FB1
2.3V TO
5.5V
V
AT
OUT1
800mA
C1
R1
R2
BUCK1
MODE
4.7µF
C5
10µF
PGND1
ON
EN1
EN1
OFF
PWM
MODE
PSM/PWM
VOUT2
VIN2
EN2
MODE
L2 1µH
SW2
FB2
V
AT
AT
OUT2
C2
4.7µF
800mA
R3
R4
BUCK2
C6
10µF
EN2
EN3
ON
PGND2
OFF
EN3
VOUT3
FB3
V
OUT3
300mA
VIN3
R5
R6
1.7V TO
5.5V
LDO
C7
1µF
C3
1µF
ADP5023
AGND
Figure 1.
Rev. A
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
rights of third parties that may result from its 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 and registeredtrademarks arethe 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 ©2011-2012 Analog Devices, Inc. All rights reserved.
ADP5023
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Power Dissipation and Thermal Considerations ....................... 15
Buck Regulator Power Dissipation .......................................... 15
Junction Temperature................................................................ 16
Theory of Operation ...................................................................... 17
Power Management Unit........................................................... 17
BUCK1 and BUCK2 .................................................................. 19
LDO.............................................................................................. 20
Applications Information.............................................................. 21
Buck External Component Selection....................................... 21
LDO External Component Selection ...................................... 23
PCB Layout Guidelines.................................................................. 24
Typical Application Schematics.................................................... 25
Bill of Materials............................................................................... 26
Outline Dimensions....................................................................... 27
Ordering Guide .......................................................................... 27
Applications....................................................................................... 1
General Description......................................................................... 1
Typical Application Circuit ............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
General Specifications ................................................................. 3
BUCK1 and BUCK2 Specifications ........................................... 4
LDO Specifications ...................................................................... 5
Input and Output Capacitor, Recommended Specifications.. 5
Absolute Maximum Ratings............................................................ 6
Thermal Resistance ...................................................................... 6
ESD Caution.................................................................................. 6
Pin Configuration and Function Descriptions............................. 7
Typical Performance Characteristics ............................................. 8
REVISION HISTORY
1/12—Rev. 0 to Rev. A
Changes to Features Section............................................................ 1
Changes to Table 2............................................................................ 4
Changes to Table 3 and Table 4....................................................... 5
Changes to Table 5............................................................................ 6
Changes to Table 7............................................................................ 7
Changes to Figure 34...................................................................... 13
Changes to Buck Regulator Power Dissipation Section ............ 15
Changes to Undervoltage Lockout Section................................. 18
Changes to LDO Section and Figure 48 ...................................... 20
Changes to Table 9.......................................................................... 22
Changes to Figure 52...................................................................... 25
Changes to Ordering Guide .......................................................... 27
8/11—Revision 0: Initial Version
Rev. A | Page 2 of 28
Data Sheet
ADP5023
SPECIFICATIONS
GENERAL SPECIFICATIONS
VAVIN = VIN1 = VIN2 = 2.3 V to 5.5 V; VIN3 = 1.7 V to 5.5 V; TJ = −40°C to +125°C for minimum/maximum specifications, and TA = 25°C for
typical specifications, unless otherwise noted.
Table 1.
Parameter
Symbol
Test Conditions/Comments
Min
Typ
Max
Unit
INPUT VOLTAGE RANGE
THERMAL SHUTDOWN
Threshold
VAVIN, VIN1, VIN2
2.3
5.5
V
TSSD
TSSD-HYS
TJ rising
150
20
°C
°C
Hysteresis
START-UP TIME1
BUCK1, LDO
BUCK2
tSTART1
tSTART2
250
300
µs
µs
EN1, EN2, EN3, MODE INPUTS
Input Logic High
VIH
1.1
V
Input Logic Low
Input Leakage Current
INPUT CURRENT
VIL
VI-LEAKAGE
0.4
1
V
µA
0.05
All Channels Enabled
All Channels Disabled
VIN1 UNDERVOLTAGE LOCKOUT
High UVLO Input Voltage Rising
High UVLO Input Voltage Falling
Low UVLO Input Voltage Rising
Low UVLO Input Voltage Falling
ISTBY-NOSW
ISHUTDOWN
No load, no buck switching
TJ = −40°C to +85°C
108
0.3
175
1
µA
µA
UVLOVIN1RISE
UVLOVIN1FALL
UVLOVIN1RISE
UVLOVIN1FALL
3.9
V
V
V
V
3.1
2.275
1.95
1 Start-up time is defined as the time from EN1 = EN2 = EN3 from 0 V to VAVIN to VOUT1, VOUT2, and VOUT3 reaching 90% of their nominal level. Start-up times are
shorter for individual channels if another channel is already enabled. See the Typical Performance Characteristics section for more information.
Rev. A | Page 3 of 28
ADP5023
Data Sheet
BUCK1 AND BUCK2 SPECIFICATIONS
VAVIN = VIN1 = VIN2 = 2.3 V to 5.5 V; TJ = −40°C to +125°C for minimum/maximum specifications, and TA = 25°C for typical
specifications, unless otherwise noted.1
Table 2.
Parameter
Symbol
Test Conditions/Comments
Min
Typ
Max
Unit
OUTPUT CHARACTERISTICS
Output Voltage Accuracy
ΔVOUT1/VOUT1
ΔVOUT2/VOUT2
(ΔVOUT1/VOUT1)/ΔVIN1
(ΔVOUT2/VOUT2)/ΔVIN2
(ΔVOUT1/VOUT1)/ΔIOUT1
(ΔVOUT2/VOUT2)/ΔIOUT2
,
PWM mode; ILOAD1 = ILOAD2 = 0 mA to 800 mA −3
PWM mode
+3
%
Line Regulation
Load Regulation
,
−0.05
−0.1
0.5
%/V
%/A
V
,
PWM mode; ILOAD = 0 mA to 800 mA
VOLTAGE FEEDBACK
OPERATING SUPPLY CURRENT
BUCK1 Only
VFB1, VFB2
Models with adjustable outputs
MODE = ground
0.485
0.515
IIN
ILOAD1 = 0 mA, device not switching, all
other channels disabled
ILOAD2 = 0 mA, device not switching, all
other channels disabled
ILOAD1 = ILOAD2 = 0 mA, device not switching,
LDO channels disabled
44
μA
μA
μA
mA
BUCK2 Only
IIN
55
BUCK1 and BUCK2
IIN
67
PSM CURRENT THRESHOLD
SW CHARACTERISTICS
SW On Resistance
IPSM
PSM to PWM operation
100
RNFET
RPFET
RNFET
RPFET
ILIMIT1, ILIMIT2
RPDWN-B
fSW
VIN1 = VIN2 = 3.6 V
VIN1 = VIN2 = 3.6 V
VIN1 = VIN2 = 5.5 V
VIN1 = VIN2 = 5.5 V
155
205
137
162
1950
75
240
310
204
243
2300
mΩ
mΩ
mΩ
mΩ
mA
Ω
Current Limit
pFET switch peak current limit
Channel disabled
1600
2.5
ACTIVE PULL-DOWN
OSCILLATOR FREQUENCY
3.0
3.5
MHz
1 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC).
Rev. A | Page 4 of 28
Data Sheet
ADP5023
LDO SPECIFICATIONS
VIN3 = (VOUT3 + 0.5 V) or 1.7 V (whichever is greater) to 5.5 V; CIN = COUT = 1 µF; TJ = −40°C to +125°C for minimum/maximum
specifications, and TA = 25°C for typical specifications, unless otherwise noted.1
Table 3.
Parameter
Symbol
Test Conditions/Comments
Min
Typ
Max
Unit
INPUT VOLTAGE RANGE
OPERATING SUPPLY CURRENT
Bias Current per LDO2
VIN3
1.7
5.5
V
IVIN3BIAS
IOUT3 = 0 µA
IOUT3 = 10 mA
IOUT3 = 300 mA
10
60
165
30
100
245
µA
µA
µA
IIN
Total System Input Current
Includes all current into AVIN, VIN1, VIN2, and
VIN3
LDO Only
IOUT3 = 0 µA, all other channels disabled
53
µA
%
OUTPUT CHARACTERISTICS
Output Voltage Accuracy
Line Regulation
ΔVOUT3/VOUT3
(ΔVOUT3/VOUT3)/ΔVIN3
(ΔVOUT3/VOUT3)/ΔIOUT3
VFB3
100 µA < IOUT3 < 300 mA
IOUT3 = 1 mA
IOUT3 = 1 mA to 300 mA
−3
−0.03
+3
+0.03 %/V
0.001 0.003 %/mA
Load Regulation3
VOLTAGE FEEDBACK
DROPOUT VOLTAGE4
0.485 0.5
0.515
V
VDROPOUT
VOUT3 = 5.2 V, IOUT3 = 300 mA
VOUT3 = 3.3 V, IOUT3 = 300 mA
VOUT3 = 2.5 V, IOUT3 = 300 mA
VOUT3 = 1.8 V, IOUT3 = 300 mA
50
75
100
180
mV
mV
mV
mV
mA
Ω
140
CURRENT-LIMIT THRESHOLD5
ACTIVE PULL-DOWN
OUTPUT NOISE
ILIMIT3
335
600
600
RPDWN-L
Channel disabled
Regulator LDO
NOISELDO
PSRR
10 Hz to 100 kHz, VIN3 = 5 V, VOUT3 = 2.8 V
100
µV rms
POWER SUPPLY REJECTION
RATIO
Regulator LDO
10 kHz, VIN3 = 3.3 V, VOUT3 = 2.8 V, IOUT3 = 1 mA
100 kHz, VIN3 = 3.3 V, VOUT3 = 2.8 V, IOUT3 = 1 mA
1 MHz, VIN3 = 3.3 V, VOUT3 = 2.8 V, IOUT3 = 1 mA
60
62
63
dB
dB
dB
1 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC).
2 This is the input current into VIN3, which is not delivered to the output load.
3 Based on an endpoint calculation using 1 mA and 300 mA loads.
4 Dropout voltage is defined as the input-to-output voltage differential when the input voltage is set to the nominal output voltage. This applies only to output voltages
above 1.7 V.
5 Current-limit threshold is defined as the current at which the output voltage drops to 90% of the specified typical value. For example, the current limit for a 3.0 V
output voltage is defined as the current that causes the output voltage to drop to 90% of 3.0 V, or 2.7 V.
INPUT AND OUTPUT CAPACITOR, RECOMMENDED SPECIFICATIONS
TA = −40°C to +125°C, unless otherwise specified.
Table 4.
Parameter
Symbol
Min
Typ
Max
Unit
NOMINAL INPUT AND OUTPUT CAPACITOR RATINGS
BUCK1, BUCK2 Input Capacitor Ratings
BUCK1, BUCK2 Output Capacitor Ratings
LDO1 Input and Output Capacitor Ratings
CAPACITOR ESR
CMIN1, CMIN2
CMIN1, CMIN2
CMIN3, CMIN4
RESR
4.7
10
1.0
40
40
µF
µF
µF
Ω
0.001
1
1 The minimum input and output capacitance should be greater than 0.70 µF over the full range of operating conditions. The full range of operating conditions in
the application must be considered during device selection to ensure that the minimum capacitance specification is met. X7R- and X5R-type capacitors are
recommended; Y5V and Z5U capacitors are not recommended for use because of their poor temperature and dc bias characteristics.
Rev. A | Page 5 of 28
ADP5023
Data Sheet
ABSOLUTE MAXIMUM RATINGS
Table 5.
THERMAL RESISTANCE
θJA is specified for the worst-case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Parameter
Rating
AVIN to AGND
VIN1, VIN2 to AVIN
PGND1, PGND2 to AGND
VIN3, VOUT1, VOUT2, FB1, FB2, FB3,
EN1, EN2, EN3, MODE to AGND
−0.3 V to +6 V
−0.3 V to +0.3 V
−0.3 V to +0.3 V
−0.3 V to (AVIN + 0.3 V)
Table 6. Thermal Resistance
Package Type
θJA
θJC
Unit
24-Lead, 0.5 mm pitch LFCSP
35
3
°C/W
VOUT3 to AGND
SW1 to PGND1
SW2 to PGND2
Storage Temperature Range
−0.3 V to (VIN3 + 0.3 V)
−0.3 V to (VIN1 + 0.3 V)
−0.3 V to (VIN2 + 0.3 V)
−65°C to +150°C
ESD CAUTION
Operating Junction Temperature
Range
−40°C to +125°C
Soldering Conditions
JEDEC J-STD-020
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.
For detailed information on power dissipation, see the Power
Dissipation and Thermal Considerations section.
Rev. A | Page 6 of 28
Data Sheet
ADP5023
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
1
2
3
18
17
16
15
14
13
GND
GND
VIN2
AGND
AVIN
VIN1
ADP5023
TOP VIEW
(Not to Scale)
SW1
SW2 4
5
6
PGND2
NC
PGND1
MODE
NOTES
1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN.
2. IT IS RECOMMENDED THAT THE EXPOSED PAD
BE SOLDERED TO THE GROUND PLANE.
Figure 2. Pin Configuration—View from Top of Die
Table 7. Pin Function Descriptions
Pin No. Mnemonic Description
1
2
3
4
5
6
7
8
AGND
AGND
VIN2
SW2
PGND2
NC
Analog Ground.
Analog Ground.
BUCK2 Input Supply (2.3 V to 5.5 V). Connect VIN2 to VIN1 and AVIN.
BUCK2 Switching Node.
Dedicated Power Ground for BUCK2.
No Connect. Leave this pin unconnected.
BUCK2 Enable Pin. High level turns on this regulator, and low level turns it off.
EN2
FB2
BUCK2 Feedback Input. For device models with adjustable output voltage, connect this pin to the middle of the
BUCK2 resistor divider. For device models with fixed output voltage, leave this pin unconnected.
9
10
11
VOUT2
VOUT1
FB1
BUCK2 Output Voltage Sensing Input. Connect VOUT2 to the top of the capacitor on VOUT2.
BUCK1 Output Voltage Sensing Input. Connect VOUT1 to the top of the capacitor on VOUT1.
BUCK1 Feedback Input. For device models with adjustable output voltage, connect this pin to the middle of the
BUCK1 resistor divider. For device models with fixed output voltage, connect this pin to the top of the capacitor
on VOUT3.
12
13
14
15
16
17
18
19
EN1
BUCK1 Enable Pin. High level turns on this regulator, and low level turns it off.
BUCK1/BUCK2 Operating Mode. MODE = high: forced PWM operation. MODE = low: auto PWM/PSM operation.
Dedicated Power Ground for BUCK1.
MODE
PGND1
SW1
VIN1
AVIN
AGND
FB3
BUCK1 Switching Node
BUCK1 Input Supply (2.3 V to 5.5 V). Connect VIN1 to VIN2 and AVIN.
Analog Input Supply (2.3 V to 5.5 V). Connect AVIN to VIN1 and VIN2.
Analog Ground.
LDO Feedback Input. For device models with adjustable output voltage, connect this pin to the middle of the LDO
resistor divider. For device models with fixed output voltage, leave this pin unconnected.
20
21
22
23
24
VOUT3
VIN3
EN3
AGND
AGND
EPAD (EP)
LDO Output Voltage.
LDO Input Supply (1.7 V to 5.5 V).
LDO Enable Pin. High level turns on this regulator, and low level turns it off.
Analog Ground.
Analog Ground.
Exposed Pad. It is recommended that the exposed pad be soldered to the ground plane.
Rev. A | Page 7 of 28
ADP5023
Data Sheet
TYPICAL PERFORMANCE CHARACTERISTICS
VIN1 = VIN2 = VIN3 = 3.6 V, TA = 25°C, unless otherwise noted.
3.35
3.33
3.31
3.29
3.27
3.25
V
V
V
= 4.2V, +85°C
= 4.2V, +25°C
= 4.2V, –40°C
IN
IN
IN
140
120
100
80
60
40
20
0
2.3
2.8
3.3
3.8
4.3
4.8
5.3
0
0.1
0.2
0.3
0.4
(A)
0.5
0.6
0.7
0.8
I
OUT
INPUT VOLTAGE (V)
Figure 6. BUCK1 Load Regulation Across Temperature, VOUT1 = 3.3 V,
Auto Mode
Figure 3. System Quiescent Current vs. Input Voltage, VOUT1 = 3.3 V,
OUT2 = 1.8 V, VOUT3 = 1.2 V, VOUT4 = 3.3 V, All Channels Unloaded
V
1.864
T
V
V
V
= 3.6V, +85°C
= 3.6V, +25°C
= 3.6V, –40°C
IN
IN
IN
SW
1.844
1.824
1.804
1.784
1.764
4
2
IOUT
VOUT
EN
1
3
CH1 2.00V
CH3 5.00V
CH2 50.0mA Ω
CH4 5.00V
M 40.0µs
T 11.20%
A CH3
2.2V
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
I
(A)
OUT
Figure 7. BUCK2 Load Regulation Across Temperature, VOUT2 = 1.8 V,
Auto Mode
Figure 4. BUCK1 Startup, VOUT1 = 1.8 V, IOUT1 = 5 mA
0.799
T
V
V
V
= 3.6V, +85°C
= 3.6V, +25°C
= 3.6V, –40°C
IN
IN
IN
0.798
0.797
0.796
0.795
0.794
0.793
0.792
0.791
0.790
0.789
SW
4
2
IOUT
VOUT
EN
1
3
CH1 2.00V
CH3 5.00V
CH2 50.0mA Ω
CH4 5.00V
M 40.0µs
T 11.20%
A CH3
2.2V
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
I
(A)
OUT
Figure 5. BUCK2 Startup, VOUT2 = 3.3 V, IOUT2 = 10 mA
Figure 8. BUCK1 Load Regulation Across Input Voltage, VOUT1 = 3.3 V,
PWM Mode
Rev. A | Page 8 of 28
Data Sheet
ADP5023
100
90
80
70
60
50
40
30
20
10
100
90
80
70
60
50
40
30
20
10
0
V
= 2.4V
= 3.6V
= 4.5V
= 5.5V
IN
IN
IN
IN
V
V
V
= 3.9V
= 4.2V
= 5.5V
IN
IN
IN
V
V
V
0
0.0001
0.001
0.01
(A)
0.1
1
0.001
0.01
0.1
1
I
I
(A)
OUT
OUT
Figure 9. BUCK1 Efficiency vs. Load Current, Across Input Voltage,
OUT1 = 3.3 V, Auto Mode
Figure 12. BUCK2 Efficiency vs. Load Current, Across Input Voltage,
OUT2 = 1.8 V, PWM Mode
V
V
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
V
V
V
V
= 2.3V
= 3.6V
= 4.2V
= 5.5V
IN
IN
IN
IN
V
V
V
= 3.9V
= 4.2V
= 5.5V
IN
IN
IN
0.001
0.01
0.1
1
0.001
0.01
0.1
1
I
(A)
I
(A)
OUT
OUT
Figure 13. BUCK1 Efficiency vs. Load Current, Across Input Voltage,
OUT1 = 0.8 V, Auto Mode
Figure 10. BUCK1 Efficiency vs. Load Current, Across Input Voltage,
OUT1 = 3.3 V, PWM Mode
V
V
100
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
V
V
V
V
= 2.3V
= 3.6V
= 4.2V
= 5.5V
V
V
V
V
= 2.3V
= 3.6V
= 4.2V
= 5.5V
IN
IN
IN
IN
IN
IN
IN
IN
0.001
0.01
0.1
1
0.001
0.01
0.1
1
I
(A)
I
(A)
OUT
OUT
Figure 14. BUCK1 Efficiency vs. Load Current, Across Input Voltage,
OUT1 = 0.8 V, PWM Mode
Figure 11. BUCK2 Efficiency vs. Load Current, Across Input Voltage,
OUT2 = 1.8 V, Auto Mode
V
V
Rev. A | Page 9 of 28
ADP5023
Data Sheet
100
90
80
70
60
50
40
30
20
10
3.3
3.2
3.1
3.0
2.9
2.8
2.7
2.6
2.5
T
T
T
= +25°C
= –40°C
= +85°C
A
A
A
+25°C
+85°C
–40°C
0
0
0.2
0.4
0.6
(A)
0.8
1.0
1.2
0.001
0.01
0.1
1
I
I
(A)
OUT
OUT
Figure 18. BUCK2 Switching Frequency vs. Output Current, Across
Temperature, VOUT2 = 1.8 V, PWM Mode
Figure 15. BUCK1 Efficiency vs. Load Current, Across Temperature,
VIN = 3.9 V, VOUT1 = 3.3 V, Auto Mode
100
90
80
70
60
50
40
30
T
VOUT
1
I
SW
2
SW
20
+85°C
+25°C
10
4
–40°C
0
0.001
CH1 50.0mV
CH2 500mA Ω
CH4 2.00V
M 4.00µs A CH2
28.40%
240mA
0.01
0.1
1
I
(A)
T
OUT
Figure 19. Typical Waveforms, VOUT1 = 3.3 V, IOUT1 = 30 mA, Auto Mode
Figure 16. BUCK2 Efficiency vs. Load Current, Across Temperature,
OUT2 = 1.8 V, Auto Mode
V
100
90
80
70
60
50
40
30
20
10
0
T
VOUT
1
I
SW
2
SW
+85°C
+25°C
–40°C
4
CH1 50.0mV
CH2 500mA Ω
CH4 2.00V
M 4.00µs A CH2
28.40%
220mA
0.001
0.01
0.1
1
I
(A)
T
OUT
Figure 20. Typical Waveforms, VOUT2 = 1.8 V, IOUT2 = 30 mA, Auto Mode
Figure 17. BUCK1 Efficiency vs. Load Current, Across Temperature,
OUT1 = 0.8 V, Auto Mode
V
Rev. A | Page 10 of 28
Data Sheet
ADP5023
T
T
VOUT
1
2
VIN
I
SW
VOUT
SW
1
SW
4
3
4
CH1 50.0mV
CH3 1.00V
M 1.00ms
30.40%
A CH3
4.80V
CH1 50mV
CH2 500mA Ω
CH4 2.00V
M 400ns A CH2
28.40%
220mA
CH4 2.00V
T
T
Figure 24. BUCK2 Response to Line Transient, VIN = 4.5 V to 5.0 V,
OUT2 = 1.8 V, PWM Mode
Figure 21. Typical Waveforms, VOUT1 = 3.3 V, IOUT1 = 30 mA, PWM Mode
V
T
T
SW
VOUT
1
4
1
I
SW
VOUT
2
SW
I
OUT
2
4
CH1 50mV
CH2 500mA Ω
CH4 2.00V
M 400ns A CH2
28.40%
220mA
CH1 50.0mV
CH2 50.0mA Ω
CH4 5.00V
M 20.0µs A CH2
60.000µs
356mA
T
T
Figure 25. BUCK1 Response to Load Transient, IOUT1 = 1 mA to 50 mA,
OUT1 = 3.3 V, Auto Mode
Figure 22. Typical Waveforms, VOUT2 = 1.8 V, IOUT2 = 30 mA, PWM Mode
V
T
T
SW
4
1
VIN
VOUT
VOUT
1
SW
I
OUT
2
3
CH1 50.0mV
CH2 50.0mA Ω
CH4 5.00V
M 20.0µs A CH2
22.20%
379mA
CH1 50.0mV
CH3 1.00V
M 1.00ms
30.40%
A CH3
4.80V
CH4 2.00V
T
T
Figure 26. BUCK2 Response to Load Transient, IOUT2 = 1 mA to 50 mA,
OUT2 = 1.8 V, Auto Mode
Figure 23. BUCK1 Response to Line Transient, VIN = 4.5 V to 5.0 V, VOUT1 = 3.3 V,
PWM Mode
V
Rev. A | Page 11 of 28
ADP5023
Data Sheet
T
T
SW
4
1
I
IN
2
1
3
VOUT
VOUT
EN
I
OUT
2
CH1 50.0mV
CH2 200mA Ω
CH4 5.00V
M 20.0µs A CH2
20.40%
408mA
CH1 2.00V
CH3 5.00V
CH2 50.0mA Ω
M 40.0µs
T 11.20%
A CH3
2.2V
T
Figure 27. BUCK1 Response to Load Transient, IOUT1 = 20 mA to 180 mA,
OUT1 = 3.3 V, Auto Mode
Figure 30. LDO Startup, VOUT3 = 3.0 V, IOUT3 = 5 mA
V
2.820
2.815
2.810
2.805
2.800
2.795
2.790
2.785
2.780
T
V
V
V
V
= 3.3V
= 4.5V
= 5.0V
= 5.5V
IN
IN
IN
IN
SW
4
1
VOUT
I
OUT
2
CH1 100mV
CH2 200mA Ω
CH4 5.00V
M 20.0µs A CH2
19.20%
88.0mA
0
0.05
0.10
0.15
(A)
0.20
0.25
0.30
I
T
OUT
Figure 28. BUCK2 Response to Load Transient, IOUT2 = 20 mA to 180 mA,
OUT2 = 1.8 V, Auto Mode
Figure 31. LDO Load Regulation Across Input Voltage, VOUT3 = 2.8 V
V
400
350
T
VOUT2
SW1
2
3
300
+125°C
250
200
150
100
50
+25°C
–40°C
VOUT1
SW2
1
4
0
CH1 5.00V
CH3 5.00V
CH2 5.00V
CH4 5.00V
M 400ns A CH4
50.00%
1.90V
2.3
2.8
3.3
3.8
4.3
4.8
5.3
T
INPUT VOLTAGE (V)
Figure 29. VOUT and SW Waveforms for BUCK1 and BUCK2 in PWM Mode
Showing Out-of-Phase Operation
Figure 32. NMOS RDSON vs. Input Voltage Across Temperature
Rev. A | Page 12 of 28
Data Sheet
ADP5023
50
45
40
35
30
25
20
15
10
5
250
200
150
100
50
+125°C
+25°C
–40°C
0
2.3
0
2.8
3.3
3.8
4.3
4.8
5.3
0
0.05
0.10
0.15
(A)
0.20
0.25
INPUT VOLTAGE (V)
I
OUT
Figure 33. PMOS RDSON vs. Input Voltage Across Temperature
Figure 36. LDO Ground Current vs. Output Load, VIN3 = 3.3 V, VOUT3 = 2.8 V
3.45
3.40
3.35
3.30
3.25
3.20
3.15
T
V
V
V
= 4.2V, +85°C
= 4.2V, +25°C
= 4.2V, –40°C
IN
IN
IN
I
OUT
2
1
VOUT
CH1 100mV
CH2 100mA Ω
M 40.0µs A CH2
19.20%
52.0mA
0
0.05
0.10
0.15
(A)
0.20
0.25
0.30
I
OUT
T
Figure 34. LDO Load Regulation Across Temperature, VIN3 = 4.2 V, VOUT3 = 3.3 V
Figure 37. LDO Response to Load Transient, IOUT3 = 1 mA to 80 mA,
OUT3 = 2.8 V
V
3.0
2.5
2.0
T
VIN
1.5
1.0
VOUT
1
3
I
I
I
I
I
I
= 300mA
= 150mA
= 100mA
= 10mA
= 1mA
OUT
OUT
OUT
OUT
OUT
OUT
0.5
0
= 100µA
CH1 20.0mV
CH3 1.00V
M 100µs
28.40%
A CH3
4.80V
2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4
T
V
(V)
IN
Figure 38. LDO Response to Line Transient, VIN = 4.5 V to 5.5 V, VOUT3 = 2.8 V
Figure 35. LDO Line Regulation Across Output Load, VOUT3 = 2.8 V
Rev. A | Page 13 of 28
ADP5023
Data Sheet
60
55
50
45
0
V
= 5V
IN
–20
–40
–60
–80
V
= 3.3V
IN
40
35
30
100µA
1mA
10mA
50mA
100mA
150mA
–100
–120
25
0.001
0.01
0.1
1
(mA)
10
100
10
100
1k
10k
100k
1M
10M
I
FREQUENCY (Hz)
OUT
Figure 39. LDO Output Noise vs. Load Current, Across Input Voltage,
OUT3 = 2.8 V
Figure 42. LDO PSRR Across Output Load, VIN3 = 3.3 V, VOUT3 = 3.0 V
V
0
65
60
100µA
1mA
10mA
50mA
100mA
150mA
V
= 5V
IN
–20
–40
–60
–80
V
= 3.3V
IN
55
50
45
40
35
30
–100
–120
25
0.001
0.01
0.1
1
10
100
10
100
1k
10k
100k
1M
10M
I
(mA)
FREQUENCY (Hz)
OUT
Figure 43. LDO PSRR Across Output Load, VIN3 = 5.0 V, VOUT3 = 2.8 V
Figure 40. LDO Output Noise vs. Load Current, Across Input Voltage,
OUT3 = 3.0 V
V
0
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
100µA
1mA
10mA
50mA
100mA
150mA
100µA
1mA
10mA
50mA
100mA
150mA
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
10
100
1k
10k
100k
1M
10M
10
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
FREQUENCY (Hz)
Figure 44. LDO PSRR Across Output Load, VIN3 = 5.0 V, VOUT3 = 3.0 V
Figure 41. LDO PSRR Across Output Load, VIN3 = 3.3 V, VOUT3 = 2.8 V
Rev. A | Page 14 of 28
Data Sheet
ADP5023
POWER DISSIPATION AND THERMAL CONSIDERATIONS
The ADP5023 is a highly efficient µPMU, and, in most cases,
the power dissipated in the device is not a concern. However,
if the device operates at high ambient temperatures and maxi-
mum loading condition, the junction temperature can reach
the maximum allowable operating limit (125°C).
BUCK REGULATOR POWER DISSIPATION
The power loss of the buck regulator is approximated by
LOSS = PDBUCK + PL
where:
DBUCK is the power dissipation on one of the ADP5023 buck
P
(3)
P
When the temperature exceeds 150°C, the ADP5023 turns off
all the regulators, allowing the device to cool down. When the
die temperature falls below 130°C, the ADP5023 resumes
normal operation.
regulators.
PL is the inductor power losses.
The inductor losses are external to the device and do not have
any effect on the die temperature.
This section provides guidelines to calculate the power dissi-
pated in the device and ensure that the ADP5023 operates
below the maximum allowable junction temperature.
The inductor losses are estimated (without core losses) by
PL IOUT1(RMS)2 × DCRL
(4)
≈
The efficiency for each regulator on the ADP5023 is given by
where:
DCRL is the inductor series resistance.
POUT
PIN
η =
×100%
(1)
IOUT1(RMS) is the rms load current of the buck regulator.
where:
η is the efficiency.
PIN is the input power.
r
12
IOUT1(RMS) = IOUT1 × 1+
(5)
(6)
where r is the normalized inductor ripple current
r = VOUT1 × (1 − D)/(IOUT1 × L × fSW)
P
OUT is the output power.
Power loss is given by
where:
L is the inductance.
P
P
LOSS = PIN − POUT
(2a)
(2b)
or
fSW is the switching frequency.
LOSS = POUT (1− η)/η
D is the duty cycle.
Power dissipation can be calculated in several ways. The most
intuitive and practical is to measure the power dissipated at the
input and all the outputs. Perform the measurements at the
worst-case conditions (voltages, currents, and temperature).
The difference between input and output power is dissipated in
the device and the inductor. Use Equation 4 to derive the power
lost in the inductor, and from this use Equation 3 to calculate
the power dissipation in the ADP5023 buck converter.
D = VOUT1/VIN1
(7)
ADP5023 buck regulator power dissipation, PDBUCK, includes the
power switch conductive losses, the switch losses, and the transi-
tion losses of each channel. There are other sources of loss, but
these are generally less significant at high output load currents,
where the thermal limit of the application is. Equation 8
captures the calculation that must be made to estimate the
power dissipation in the buck regulator.
A second method to estimate the power dissipation uses the
efficiency curves provided for the buck regulator, and the power
lost on the LDO can be calculated using Equation 12. When the
buck efficiency is known, use Equation 2b to derive the total
power lost in the buck regulator and inductor, use Equation 4 to
derive the power lost in the inductor, and then calculate the
power dissipation in the buck converter using Equation 3. Add
the power dissipated in the buck and in the LDO to find the
total dissipated power.
P
DBUCK = PCOND + PSW + PTRAN
The power switch conductive losses are due to the output current,
OUT1, flowing through the P-MOSFET and the N-MOSFET
(8)
I
power switches that have internal resistance, RDSON-P and
RDSON-N. The amount of conductive power loss is found by
2
P
COND = [RDSON-P × D + RDSON-N × (1 − D)] × IOUT1
(9)
where RDSON-P is approximately 0.2 Ω, and RDSON-N is approxi-
mately 0.16 Ω at 125°C junction temperature and VIN1 = VIN2 =
3.6 V. At VIN1 = VIN2 = 2.3 V, these values change to 0.31 Ω and
0.21 Ω, respectively, and at VIN1 = VIN2 = 5.5 V, the values are
0.16 Ω and 0.14 Ω, respectively.
Note that the buck efficiency curves are typical values and may
not be provided for all possible combinations of VIN, VOUT, and
I
OUT. To account for these variations, it is necessary to include a
safety margin when calculating the power dissipated in the buck.
A third way to estimate the power dissipation is analytical and
involves modeling the losses in the buck circuit provided by
Equation 8 to Equation 11 and the losses in the LDO provided
by Equation 12.
Rev. A | Page 15 of 28
ADP5023
Data Sheet
Switching losses are associated with the current drawn by the
driver to turn on and turn off the power devices at the switching
frequency. The amount of switching power loss is given by
JUNCTION TEMPERATURE
In cases where the board temperature TA is known, the thermal
resistance parameter, θJA, can be used to estimate the junction
temperature rise. TJ is calculated from TA and PD using the
formula
P
SW = (CGATE-P + CGATE-N) × VIN12 × fSW
(10)
where:
C
C
GATE-P is the P-MOSFET gate capacitance.
GATE-N is the N-MOSFET gate capacitance.
TJ = TA + (PD × θJA)
(14)
The typical θJA value for the 24-lead, 4 mm × 4 mm LFCSP is
35°C/W (see Table 6). A very important factor to consider is
that θJA is based on 4-layer, 4 in × 3 in, 2.5 oz copper, as per
JEDEC standard, and real applications may use different sizes
and layers. It is important to maximize the copper used to remove
the heat from the device. Copper exposed to air dissipates heat
better than copper used in the inner layers. The exposed pad
should be connected to the ground plane with several vias.
For the ADP5023, the total of (CGATE-P + CGATE-N) is
approximately 150 pF.
The transition losses occur because the P-channel power
MOSFET cannot be turned on or off instantaneously, and the
SW node takes some time to slew from near ground to near
VOUT1 (and from VOUT1 to ground). The amount of transition
loss is calculated by
If the case temperature can be measured, the junction
temperature is calculated by
P
TRAN = VIN1 × IOUT1 × (tRISE + tFALL) × fSW
(11)
where tRISE and tFALL are the rise time and the fall time of the
switching node, SW. For the ADP5023, the rise and fall times of
SW are in the order of 5 ns.
TJ = TC + (PD × θJC)
(15)
where TC is the case temperature and θJC is the junction-to-case
thermal resistance provided in Table 6.
If the preceding equations and parameters are used for estimat-
ing the converter efficiency, it must be noted that the equations
do not describe all of the converter losses, and the parameter
values given are typical numbers. The converter performance
also depends on the choice of passive components and board
layout; therefore, a sufficient safety margin should be included
in the estimate.
When designing an application for a particular ambient
temperature range, calculate the expected ADP5023 power
dissipation (PD) due to the losses of all channels by using
Equation 8 to Equation 13. From this power calculation, the
junction temperature, TJ, can be estimated using Equation 14.
The reliable operation of the converter and the two LDO regulators
can be achieved only if the estimated die junction temperature of
the ADP5023 (Equation 14) is less than 125°C. Reliability and
mean time between failures (MTBF) is highly affected by increas-
ing the junction temperature. Additional information about
product reliability can be found from the ADI Reliability Handbook,
which can be found at www.analog.com/reliability_handbook.
LDO Regulator Power Dissipation
The power loss of a LDO regulator is given by
P
DLDO = [(VIN − VOUT) × ILOAD] + (VIN × IGND
where:
LOAD is the load current of the LDO regulator.
)
(12)
I
VIN and VOUT are input and output voltages of the LDO,
respectively.
IGND is the ground current of the LDO regulator.
Power dissipation due to the ground current is small and it
can be ignored.
The total power dissipation in the ADP5023 simplifies to
PD = PDBUCK1 + PDBUCK2 + PDLDO
(13)
Rev. A | Page 16 of 28
Data Sheet
ADP5023
THEORY OF OPERATION
VOUT1 FB1 FB2 VOUT2
ENBK1
ENBK2
75Ω
75Ω
GM ERROR
AMP
GM ERROR
AMP
ADP5023
AVIN
PWM
COMP
PWM
COMP
SOFT START
SOFT START
VIN2
VIN1
I
LIMIT
I
LIMIT
PSM
COMP
PSM
COMP
PWM/
PSM
PWM/
PSM
CONTROL
BUCK1
CONTROL
BUCK2
LOW
CURRENT
LOW
CURRENT
SW2
SW1
DRIVER
AND
OSCILLATOR
DRIVER
AND
ANTISHOOT
THROUGH
ANTISHOOT
THROUGH
SYSTEM
UNDERVOLTAGE
LOCKOUT
OPMODE
PGND2
MODE
SEL
MODE2
B
THERMAL
SHUTDOWN
Y
PGND1
A
LDO
UNDERVOLTAGE
LOCK OUT
EN1
EN2
EN3
ENBK1
ENBK2
ENLDO
R1
ENABLE
AND MODE
CONTROL
LDO
CONTROL
VDDA
ENLDO
600Ω
R2
VIN3
AGND FB3 VOUT3
Figure 45. Functional Block Diagram
function of the current load and the output capacitor value.
This operating mode reduces the switching and quiescent
current losses. The auto PWM/PSM mode transition is
controlled independently for each buck regulator. The two
bucks operate synchronized to each other.
POWER MANAGEMENT UNIT
The ADP5023 is a micropower management unit (micro PMU)
combining two step-down (buck) dc-to-dc converters and one
low dropout linear regulator (LDO). The high switching
frequency and tiny 24-lead LFCSP package allows a small
power management solution.
The ADP5023 has individual enable pins (EN1 to EN3) control-
ling the activation of each regulator. The regulators are activated
by a logic level high applied to the respective EN pin. EN1 controls
BUCK1, EN2 controls BUCK2, and EN3 controls LDO.
To combine these high performance regulators into the micro
PMU, there is a system controller allowing them to operate
together.
Regulator output voltages are set through external resistor
dividers or can be optionally factory programmed to default
values (see the Ordering Guide section).
The buck regulators can operate in forced PWM mode if the
MODE pin is at a logic high level. In forced PWM mode, the
buck switching frequency is always constant and does not
change with the load current. If the MODE pin is at a logic
low level, the switching regulators operate in auto PWM/PSM
mode. In this mode, the regulators operate at fixed PWM
frequency when the load current is above the PSM current
threshold. When the load current falls below the PSM current
threshold, the regulator in question enters PSM, where the
switching occurs in bursts. The burst repetition rate is a
When a regulator is turned on, the output voltage ramp rate is
controlled though a soft start circuit to avoid a large inrush
current due to the charging of the output capacitors.
Thermal Protection
In the event that the junction temperature rises above 150°C,
the thermal shutdown circuit turns off all the regulators.
Extreme junction temperatures can be the result of high current
Rev. A | Page 17 of 28
ADP5023
Data Sheet
operation, poor circuit board design, or high ambient
temperature. A 20°C hysteresis is included so that when thermal
shutdown occurs, the regulators do not return to operation until
the on-chip temperature drops below 130°C. When coming out
of thermal shutdown, all regulators restart with soft-start
control.
models, the device reaches the turn-off threshold when the
input supply drops to 3.65 V typical.
In case of a thermal or UVLO event, the active pull-downs (if
factory enabled) are enabled to discharge the output capacitors
quickly. The pull-down resistors remain engaged until the thermal
fault event is no longer present, or the input supply voltage falls
below the VPOR voltage level. The typical value of VPOR is approx-
imately 1 V.
Undervoltage Lockout
To protect against battery discharge, undervoltage lockout
(UVLO) circuitry is integrated into the system. If the input
voltage on VIN1 drops below a typical 2.15 V UVLO threshold,
all channels shut down. In the buck channels, both the power
switch and the synchronous rectifier turn off. When the voltage
on VIN1 rises above the UVLO threshold, the part is enabled
once more.
Enable/Shutdown
The ADP5023 has an individual control pin for each regulator.
A logic level high applied to the ENx pin activates a regulator,
whereas a logic level low turns off a regulator.
Figure 46 shows the regulator activation timings for the
ADP5023 when all enable pins are connected to AVIN. Also
shown is the active pull-down activation.
Alternatively, the user can select device models with a UVLO
set at a higher level, suitable for USB applications. For these
AVIN
VUVLO
VPOR
VOUT1
VOUT3
30µs (MIN)
30µs (MIN)
50µs (MIN)
50µs (MIN)
VOUT2
BUCK1, LDO1
PULL-DOWNS
BUCK2
PULL-DOWN
Figure 46. Regulator Sequencing on ADP5023 (EN1 = EN2 = EN3 = VAVIN
)
Rev. A | Page 18 of 28
Data Sheet
ADP5023
drives the inductor to make the output voltage rise again to the
upper threshold. This process is repeated while the load current
is below the PSM current threshold.
BUCK1 AND BUCK2
The buck uses a fixed frequency and high speed current mode
architecture. The buck operates with an input voltage of 2.3 V
to 5.5 V.
The ADP5023 has a dedicated MODE pin controlling the PSM
and PWM operation. A high logic level applied to the MODE
pin forces both bucks to operate in PWM mode. A logic level
low sets the bucks to operate in auto PSM/PWM.
The buck output voltage is set through external resistor
dividers, shown in Figure 47 for BUCK1. The output voltage
can optionally be factory programmed to default values as
indicated in the Ordering Guide section. In this event, R1 and
R2 are not needed, and FB1 can be left unconnected. In all
cases, VOUT1 must be connected to the output capacitor. FB1
is 0.5 V.
PSM Current Threshold
The PSM current threshold is set to 100 mA. The bucks employ
a scheme that enables this current to remain accurately
controlled, independent of input and output voltage levels. This
scheme also ensures that there is very little hysteresis between
the PSM current threshold for entry to and exit from the PSM.
The PSM current threshold is optimized for excellent efficiency
over all load currents.
VOUT1
VIN1
L1
1µH
SW1
VOUT1
BUCK
R1
R2
C5
10µF
FB1
Oscillator/Phasing of Inductor Switching
PGND
The ADP5023 ensures that both bucks operate at the same
switching frequency when both bucks are in PWM mode.
R1
R2
V
= V
FB1
+ 1
OUT1
Additionally, the ADP5023 ensures that when both bucks are
in PWM mode, they operate out of phase, whereby the BUCK2
pFET starts conducting exactly half a clock period after the
BUCK1 pFET starts conducting.
Figure 47. BUCK1 External Output Voltage Setting
Control Scheme
The bucks operate with a fixed frequency, current mode PWM
control architecture at medium to high loads for high efficiency,
but shift to a power save mode (PSM) control scheme at light
loads to lower the regulation power losses. When operating in
fixed frequency PWM mode, the duty cycle of the integrated
switches is adjusted and regulates the output voltage. When
operating in PSM at light loads, the output voltage is controlled
in a hysteretic manner, with higher output voltage ripple. During
part of this time, the converter is able to stop switching and
enters an idle mode, which improves conversion efficiency.
Short-Circuit Protection
The bucks include frequency foldback to prevent output current
runaway on a hard short. When the voltage at the feedback pin
falls below half the target output voltage, indicating the possi-
bility of a hard short at the output, the switching frequency is
reduced to half the internal oscillator frequency. The reduction
in the switching frequency allows more time for the inductor to
discharge, preventing a runaway of output current.
Soft Start
PWM Mode
The bucks have an internal soft start function that ramps the
output voltage in a controlled manner upon startup, thereby
limiting the inrush current. This prevents possible input voltage
drops when a battery or a high impedance power source is
connected to the input of the converter.
In PWM mode, the bucks operate at a fixed frequency of 3 MHz
set by an internal oscillator. At the start of each oscillator cycle,
the pFET switch is turned on, sending a positive voltage across
the inductor. Current in the inductor increases until the current
sense signal crosses the peak inductor current threshold that
turns off the pFET switch and turns on the nFET synchronous
rectifier. This sends a negative voltage across the inductor,
causing the inductor current to decrease. The synchronous
rectifier stays on for the rest of the cycle. The buck regulates the
output voltage by adjusting the peak inductor current threshold.
Current Limit
Each buck has protection circuitry to limit the amount of
positive current flowing through the pFET switch and the
amount of negative current flowing through the synchronous
rectifier. The positive current limit on the power switch limits
the amount of current that can flow from the input to the
output. The negative current limit prevents the inductor
current from reversing direction and flowing out of the load.
Power Save Mode (PSM)
The bucks smoothly transition to PSM operation when the load
current decreases below the PSM current threshold. When
either of the bucks enters PSM, an offset is induced in the PWM
regulation level, which makes the output voltage rise. When the
output voltage reaches a level approximately 1.5% above the
PWM regulation level, PWM operation is turned off. At this
point, both power switches are off, and the buck enters an idle
mode. The output capacitor discharges until the output voltage
falls to the PWM regulation voltage, at which point the device
100% Duty Operation
With a drop in input voltage, or with an increase in load
current, the buck may reach a limit where, even with the pFET
switch on 100% of the time, the output voltage drops below the
desired output voltage. At this limit, the buck transitions to a
mode where the pFET switch stays on 100% of the time. When
Rev. A | Page 19 of 28
ADP5023
Data Sheet
the input conditions change again and the required duty cycle
falls, the buck immediately restarts PWM regulation without
allowing overshoot on the output voltage.
The LDO output voltage is set through external resistor dividers
as shown in Figure 48 for LDO. The output voltage can
optionally be factory programmed to default values as indicated
in the Ordering Guide section. In this event, Ra and Rb are not
needed, and FB3 must be connected to the top of the capacitor on
VOUT3. FB3 is 0.5 V.
Active Pull-Downs
All regulators have optional, factory-programmable, active pull-
down resistors discharging the respective output capacitors
when the regulators are disabled. The pull-down resistors are
connected between VOUTx and AGND. Active pull-downs are
disabled when the regulators are turned on. The typical value of
the pull-down resistor is 600 Ω for the LDO and 75 Ω for the
bucks. Figure 46 shows the activation timings for the active
pull-downs during regulator activation and deactivation.
VOUT3
VOUT3
VIN3
C7
1µF
Ra
Rb
FB3
LDO
LDO
The ADP5023 contains one LDO with low quiescent current
and low dropout voltage, and provides up to 300 mA of output
current. Drawing a low 10 μA quiescent current (typical) at no
load makes the LDO ideal for battery-operated portable
equipment.
Ra
Rb
V
= V
+ 1
OUT3
FB3
Figure 48. LDO External Output Voltage Setting
The LDO also provides high power supply rejection ratio
(PSRR), low output noise, and excellent line and load transient
response with only a small 1 µF ceramic input and output
capacitor.
The LDO operates with an input voltage of 1.7 V to 5.5 V. The
wide operating range makes these LDO suitable for cascading
configurations where the LDO supply voltage is provided from
one of the buck regulators.
Rev. A | Page 20 of 28
Data Sheet
ADP5023
APPLICATIONS INFORMATION
Ceramic capacitors are manufactured with a variety of dielec-
trics, each with a different behavior over temperature and
applied voltage. Capacitors must have a dielectric adequate
to ensure the minimum capacitance over the necessary
temperature range and dc bias conditions. X5R or X7R
dielectrics with a voltage rating of 6.3 V or 10 V are recom-
mended for best performance. Y5V and Z5U dielectrics are
not recommended for use with any dc-to-dc converter because
of their poor temperature and dc bias characteristics.
BUCK EXTERNAL COMPONENT SELECTION
Trade-offs between performance parameters such as efficiency
and transient response can be made by varying the choice of
external components in the applications circuit, as shown in
Figure 1.
Feedback Resistors
For the adjustable model, referring to Figure 47, the total
combined resistance for R1 and R2 is not to exceed 400 kΩ.
Inductor
The worst-case capacitance accounting for capacitor variation
over temperature, component tolerance, and voltage is calcu-
lated using the following equation:
The high switching frequency of the ADP5023 bucks allows the
selection of small chip inductors. For best performance, use
inductor values between 0.7 μH and 3 μH. Suggested inductors
are shown in Table 8.
C
EFF = COUT × (1 − TEMPCO) × (1 − TOL)
where:
EFF is the effective capacitance at the operating voltage.
The peak-to-peak inductor current ripple is calculated using
the following equation:
C
TEMPCO is the worst-case capacitor temperature coefficient.
TOL is the worst-case component tolerance.
VOUT ×(VIN −VOUT
)
IRIPPLE
=
In this example, the worst-case temperature coefficient
(TEMPCO) over −40°C to +85°C is assumed to be 15% for an
X5R dielectric. The tolerance of the capacitor (TOL) is assumed
to be 10% and COUT is 9.2 μF at 1.8 V, as shown in Figure 49.
V
IN × fSW ×L
where:
SW is the switching frequency.
L is the inductor value.
f
Substituting these values in the equation yields
The minimum dc current rating of the inductor must be greater
than the inductor peak current. The inductor peak current is
calculated using the following equation:
CEFF = 9.2 μF × (1 − 0.15) × (1 − 0.1) = 7.0 μF
To guarantee the performance of the bucks, it is imperative
that the effects of dc bias, temperature, and tolerances on the
behavior of the capacitors be evaluated for each application.
12
IRIPPLE
2
IPEAK = ILOAD(MAX)
+
Inductor conduction losses are caused by the flow of current
through the inductor, which has an associated internal dc
resistance (DCR). Larger sized inductors have smaller DCR,
which may decrease inductor conduction losses. Inductor core
losses are related to the magnetic permeability of the core material.
Because the bucks are high switching frequency dc-to-dc
converters, shielded ferrite core material is recommended for
its low core losses and low EMI.
10
8
6
4
Output Capacitor
2
Higher output capacitor values reduce the output voltage ripple
and improve load transient response. When choosing this value,
it is also important to account for the loss of capacitance due to
output voltage dc bias.
0
0
1
2
3
4
5
6
DC BIAS VOLTAGE (V)
Figure 49. Capacitance vs. Voltage Characteristic
Table 8. Suggested 1.0 μH Inductors
Vendor
Model
Dimensions (mm)
2.0 × 1.6 × 0.9
3.2 × 2.5 × 1.5
3.2 × 2.5 × 2.5
4.0 × 4.0 × 2.1
1.9 × 2.0 × 1.0
2.5 × 2.0 × 1.2
ISAT (mA)
1400
2300
2000
5400
DCR (mΩ)
Murata
Murata
Taiyo Yuden
Coilcraft
Coilcraft
Toko
LQM2MPN1R0NG0B
LQM18FN1R0M00B
CBC3225T1R0MR
XFL4020-102ME
XPL2010-102ML
MDT2520-CN
85
54
71
11
89
85
3750
1350
Rev. A | Page 21 of 28
ADP5023
Data Sheet
The peak-to-peak output voltage ripple for the selected output
capacitor and inductor values is calculated using the following
equation:
To minimize supply noise, place the input capacitor as close as
possible to the VINx pin of the buck. As with the output
capacitor, a low ESR capacitor is recommended.
The effective capacitance needed for stability, which includes
temperature and dc bias effects, is a minimum of 3 µF and a
maximum of 10 µF. A list of suggested capacitors is shown in
Table 10.
IRIPPLE
VIN
2 × L×COUT
VRIPPLE
=
≈
8× fSW ×COUT
(
2π × fSW
)
Capacitors with lower equivalent series resistance (ESR) are
preferable to guarantee low output voltage ripple, as shown in
the following equation:
Table 9. Suggested 10 μF Capacitors
Voltage
VRIPPLE
IRIPPLE
Case Rating
ESRCOUT
≤
Vendor
Murata
TDK
Type
X5R
X5R
X5R
Model
Size (V)
0603 6.3
0603 6.3
0603 6.3
GRM188R60J106
C1608JB0J106K
ECJ1VB0J106M
The effective capacitance needed for stability, which includes
temperature and dc bias effects, is a minimum of 7 µF and a
maximum of 40 µF.
Panasonic
The buck regulators require 10 µF output capacitors to guaran-
tee stability and response to rapid load variations and to transition
into and out of the PWM/PSM modes. A list of suggested capaci-
tors is shown in Table 9. In certain applications where one or
both buck regulator powers a processor, the operating state is
known because it is controlled by software. In this condition,
the processor can drive the MODE pin according to the operating
state; consequently, it is possible to reduce the output capacitor
from 10 µF to 4.7 µF because the regulator does not expect a
large load variation when working in PSM mode (see Figure 50).
Table 10. Suggested 4.7 μF Capacitors
Voltage
Case Rating
Size (V)
GRM188R60J475ME19D 0402 6.3
Vendor
Type
Model
Murata
X5R
Taiyo Yuden X5R
Panasonic X5R
JMK107BJ475
ECJ-0EB0J475M
0402 6.3
0402 6.3
Table 11. Suggested 1.0 μF Capacitors
Voltage
Case Rating
Size (V)
Vendor
Murata
TDK
Panasonic
Taiyo
Type
X5R
X5R
X5R
X5R
Model
Input Capacitor
GRM155B30J105K
C1005JB0J105KT
ECJ0EB0J105K
LMK105BJ105MV-F
0402 6.3
0402 6.3
0402 6.3
0402 10.0
Higher value input capacitors help to reduce the input voltage
ripple and improve transient response. Maximum input
capacitor current is calculated using the following equation:
Yuden
VOUT (VIN −VOUT
)
ICIN ≥ ILOAD(MAX)
VIN
AVIN
VIN1
HOUSEKEEPING
BUCK1
C
0.1µF
FILT
VOUT1
L1 1µH
SW1
FB1
2.3V TO
5.5V
V
AT
OUT1
800mA
C1
R1
R2
4.7µF
C5
10µF
PGND1
ON
EN1
EN1
OFF
MODE
PWM
MODE
PSM/PWM
VOUT2
VIN2
EN2
MODE
L2 1µH
SW2
FB2
V
AT
OUT2
800mA
C2
4.7µF
R3
R4
BUCK2
C6
10µF
EN2
EN3
ON
PGND2
OFF
EN3
VOUT3
FB3
V
AT
OUT3
300mA
LDO
(ANALOG)
VIN3
R5
R6
1.7V TO
5.5V
C7
1µF
C3
1µF
ADP5023
AGND
Figure 50. Processor System Power Management with PSM/PWM Control
Rev. A | Page 22 of 28
Data Sheet
ADP5023
X5R dielectric is about 15% over the −40°C to +85°C tempera-
ture range and is not a function of package or voltage rating.
LDO EXTERNAL COMPONENT SELECTION
Feedback Resistors
1.2
1.0
0.8
0.6
For the adjustable model, the maximum value of Rb is not to
exceed 200 kΩ (see Figure 48).
Output Capacitor
The ADP5023 LDO is designed for operation with small, space-
saving ceramic capacitors, but functions with most commonly
used capacitors as long as care is taken with the ESR value. The
ESR of the output capacitor affects stability of the LDO control
loop. A minimum of 0.70 µF capacitance with an ESR of 1 Ω or
less is recommended to ensure stability of the ADP5023. Transient
response to changes in load current is also affected by output
capacitance. Using a larger value of output capacitance improves
the transient response of the ADP5023 to large changes in load
current.
0.4
0.2
0
0
1
2
3
4
5
6
DC BIAS VOLTAGE (V)
Figure 51. Capacitance vs. Voltage Characteristic
Input Bypass Capacitor
Use the following equation to determine the worst-case capa-
citance accounting for capacitor variation over temperature,
component tolerance, and voltage.
Connecting a 1 µF capacitor from VIN3 to ground reduces
the circuit sensitivity to printed circuit board (PCB) layout,
especially when long input traces or high source impedance
are encountered. If greater than 1 µF of output capacitance is
required, increase the input capacitor to match it.
CEFF = CBIAS × (1 − TEMPCO) × (1 − TOL)
where:
Input and Output Capacitor Properties
C
BIAS is the effective capacitance at the operating voltage.
TEMPCO is the worst-case capacitor temperature coefficient.
TOL is the worst-case component tolerance.
Use any good quality ceramic capacitors with the ADP5023 as
long as they meet the minimum capacitance and maximum ESR
requirements. Ceramic capacitors are manufactured with a variety
of dielectrics, each with a different behavior over temperature
and applied voltage. Capacitors must have a dielectric adequate
to ensure the minimum capacitance over the necessary tempera-
ture range and dc bias conditions. X5R or X7R dielectrics with a
voltage rating of 6.3 V or 10 V are recommended for best perfor-
mance. Y5V and Z5U dielectrics are not recommended for use
with any LDO because of their poor temperature and dc bias
characteristics.
In this example, the worst-case temperature coefficient
(TEMPCO) over −40°C to +85°C is assumed to be 15% for an
X5R dielectric. The tolerance of the capacitor (TOL) is assumed
to be 10% and CBIAS is 0.85 μF at 1.8 V as shown in Figure 51.
Substituting these values into the following equation:
CEFF = 0.85 μF × (1 − 0.15) × (1 − 0.1) = 0.65 μF
Therefore, the capacitor chosen in this example meets the
minimum capacitance requirement of the LDO over
temperature and tolerance at the chosen output voltage.
Figure 51 depicts the capacitance vs. voltage bias characteristic
of a 0402 1 µF, 10 V, X5R capacitor. The voltage stability of a
capacitor is strongly influenced by the capacitor size and voltage
rating. In general, a capacitor in a larger package or higher voltage
rating exhibits better stability. The temperature variation of the
To guarantee the performance of the ADP5023, it is imperative
that the effects of dc bias, temperature, and tolerances on the
behavior of the capacitors are evaluated for each application.
Rev. A | Page 23 of 28
ADP5023
Data Sheet
PCB LAYOUT GUIDELINES
Poor layout can affect ADP5023 performance, causing electro-
magnetic interference (EMI) and electromagnetic compatibility
(EMC) problems, ground bounce, and voltage losses. Poor
layout can also affect regulation and stability. A good layout is
implemented using the following guidelines. Also, refer to User
Guide UG-271.
•
•
Maximize the size of ground metal on the component side
to help with thermal dissipation.
Use a ground plane with several vias connecting to the
component side ground to further reduce noise
interference on sensitive circuit nodes.
•
Connect VIN1, VIN2, and AVIN together close to the IC
using short tracks.
•
Place the inductor, input capacitor, and output capacitor
close to the IC using short tracks. These components carry
high switching frequencies, and large tracks act as antennas.
Route the output voltage path away from the inductor and
SW node to minimize noise and magnetic interference.
•
Rev. A | Page 24 of 28
Data Sheet
ADP5023
TYPICAL APPLICATION SCHEMATICS
AVIN
HOUSEKEEPING
BUCK1
C
0.1µF
FILT
VOUT1
L1 1µH
VIN1
EN1
SW1
FB1
2.3V TO
5.5V
V
AT
OUT1
800mA
C1
4.7µF
C5
10µF
PGND1
ON
EN1
OFF
MODE
PWM
MODE
PSM/PWM
VOUT2
VIN2
EN2
MODE
L2 1µH
SW2
FB2
V
AT
AT
OUT2
C2
4.7µF
800mA
BUCK2
C6
10µF
EN2
EN3
ON
PGND2
OFF
EN3
VOUT3
FB3
V
OUT3
LDO
(ANALOG)
300mA
VIN3
1.7V TO
5.5V
C7
1µF
C3
1µF
ADP5023
AGND
Figure 52. ADP5023 Fixed Output Voltages with Enable Pins
AVIN
HOUSEKEEPING
C
0.1µF
FILT
VOUT1
L1 1µH
VIN1
EN1
SW1
FB1
2.3V TO
5.5V
V
AT
OUT1
800mA
C1
R1
R2
BUCK1
MODE
4.7µF
C5
10µF
PGND1
ON
EN1
OFF
PWM
MODE
PSM/PWM
VOUT2
VIN2
EN2
MODE
L2 1µH
SW2
FB2
V
AT
OUT2
800mA
C2
4.7µF
R3
R4
BUCK2
C6
10µF
EN2
EN3
ON
PGND2
OFF
EN3
VOUT3
FB3
V
AT
OUT3
300mA
LDO
(ANALOG)
VIN3
R5
R6
1.7V TO
5.5V
C7
1µF
C3
1µF
ADP5023
AGND
Figure 53. ADP5023 Adjustable Output Voltages with Enable Pins
Rev. A | Page 25 of 28
ADP5023
Data Sheet
BILL OF MATERIALS
Table 12.
Reference
Value
Part Number
Vendor
Package or Dimension (mm)
CAVIN
0.1 µF, X5R, 6.3 V
1 µF, X5R, 6.3 V
4.7 µF, X5R, 6.3 V
10 µF, X5R, 6.3 V
1 µH, 0.18 Ω, 850 mA
1 µH, 0.085 Ω, 1400 mA
1 µH, 0.059 Ω, 900 mA
1 µH, 0.086 Ω, 1350 mA
JMK105BJ104MV-F
LMK105BJ105MV-F
ECJ-0EB0J475M
JMK107BJ106MA-T
BRC1608T1R0M
LQM2MPN1R0NG0B
EPL2014-102ML
MDT2520-CN
Taiyo-Yuden
Taiyo-Yuden
Panasonic-ECG
Taiyo-Yuden
Taiyo-Yuden
Murata
Coilcraft
Toko
Analog Devices
0402
0402
0402
0603
C3, C7
C1, C2
C5, C6
L1, L2
0603
2.0 × 1.6 × 0.9
2.0 × 2.0 × 1.4
2.5 × 2.0 × 1.2
24-lead LFCSP
IC1
Three-regulator micro PMU ADP5023
Rev. A | Page 26 of 28
Data Sheet
ADP5023
OUTLINE DIMENSIONS
4.10
4.00 SQ
3.90
0.30
0.25
0.20
PIN 1
INDICATOR
PIN 1
INDICATOR
19
24
0.50
BSC
18
1
6
EXPOSED
PAD
2.20
2.10 SQ
2.00
13
12
BOTTOM VIEW
7
0.50
0.40
0.30
0.25 MIN
TOP VIEW
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
0.80
0.75
0.70
0.05 MAX
0.02 NOM
SECTION OF THIS DATA SHEET.
COPLANARITY
0.08
SEATING
PLANE
0.20 REF
COMPLIANT TO JEDEC STANDARDS MO-220-WGGD-8.
Figure 54. 24-Lead Lead Frame Chip Scale Package [LFCSP_WQ]
4 mm × 4 mm Body, Very Very Thin Quad
(CP-24-10)
Dimensions shown in millimeters
ORDERING GUIDE
Temperature
Range
Output
Active
Package
Option
Model1
Voltage2
UVLO3
Pull-Down4
Package Description
ADP5023ACPZ-R7
−40°C to +125°C
Adjustable
Low
Enabled on
buck channels
24-Lead Frame Chip Scale Package
[LFCSP_WQ]
CP-24-10
ADP5023ACPZ-1-R7 −40°C to +125°C
ADP5023CP-EVALZ
VOUT1 = 1.2 V
VOUT2 = 3.3 V
VOUT3 = 2.8 V
Low
Enabled on
buck channels
24-Lead Frame Chip Scale Package
[LFCSP_WQ]
CP-24-10
Evaluation Board for
ADP5023ACPZ-R7
1 Z = RoHS Compliant Part.
2 For additional options, contact a local sales or distribution representative. Additional options available are:
BUCK1 and BUCK2: 3.3 V, 3.0 V, 2.8 V, 2.5 V, 2.3 V, 2.0 V, 1.8 V, 1.6 V, 1.5 V, 1.4 V, 1.3 V, 1.2 V, 1.1 V, 1.0 V, 0.9 V or adjustable.
LDO: 3.3 V, 3.0 V, 2.8 V, 2.5 V, 2.25 V, 2 V, 1.8 V, 1.7 V, 1.6 V, 1.5 V, 1.2 V, 1.1 V, 1.0 V, 0.9 V, 0.8 V or adjustable.
3 UVLO: Low or High.
4 BUCK1, BUCK2, LDO: Active pull-down resistor is programmable to be either enabled or disabled.
Rev. A | Page 27 of 28
ADP5023
NOTES
Data Sheet
©2011-2012 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D09889-0-1/12(A)
Rev. A | Page 28 of 28
相关型号：
ADP5030ACBZ-1228R7
DUAL OUTPUT, FIXED POSITIVE LDO REGULATOR, PBGA16, 1.60 X 1.60 MM, 0.40 MM PITCH, ROHS COMPLIANT, WLCSP-16
ROCHESTER
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