1.2 A, Low VIN, Low Dropout
Linear Regulator
ADP1754/ADP1755
Data Sheet
FEATURES
TYPICAL APPLICATION CIRCUITS
APPLICATIONS
VIN = 1.8V
VOUT = 1.5V
4.7µF
4.7µF
16
VIN
13
14
15
VIN VOUT VOUT
1 VIN
100kΩ
VOUT 12
ADP1754
2 VIN
VOUT 11
3 VIN
TOP VIEW
(Not to Scale) VOUT 10
4 EN
SENSE 9
PG
PG
5
GND
6
NC
8
SS
7
07722-001
Maximum output current: 1.2 A
Input voltage range: 1.6 V to 3.6 V
Low shutdown current: <2 µA
Very low dropout voltage: 105 mV at 1.2 A load
Initial accuracy: ±1%
Accuracy over line, load, and temperature: ±2%
7 fixed output voltage options with soft start
0.75 V to 2.5 V (ADP1754)
Adjustable output voltage option with soft start
0.75 V to 3.3 V (ADP1755)
High PSRR
65 dB at 1 kHz
65 dB at 10 kHz
54 dB at 100 kHz
23 μV rms at 0.75 V output
Stable with small 4.7 µF ceramic output capacitor
Excellent load and line transient response
Current-limit and thermal overload protection
Power-good indicator
Logic-controlled enable
Reverse current protection
10nF
Figure 1. ADP1754 with Fixed Output Voltage, 1.5 V
VIN = 1.8V
VOUT = 0.5V(1 + R1/R2)
4.7µF
4.7µF
16
VIN
13
14
15
VIN VOUT VOUT
1 VIN
100kΩ
VOUT 12
2 VIN
ADP1755
VOUT 11
3 VIN
TOP VIEW
(Not to Scale) VOUT 10
4 EN
ADJ 9
R1
PG
PG
5
GND
6
SS
7
NC
8
R2
10nF
07722-002
Server computers
Memory components
Telecommunications equipment
Network equipment
DSP/FPGA/microprocessor supplies
Instrumentation equipment/data acquisition systems
Figure 2. ADP1755 with Adjustable Output Voltage, 0.75 V to 3.3 V
GENERAL DESCRIPTION
The ADP1754/ADP1755 are low dropout (LDO) CMOS linear
regulators that operate from 1.6 V to 3.6 V and provide up to
1.2 A of output current. These low VIN/VOUT LDOs are ideal for
regulation of nanometer FPGA geometries operating from 2.5 V
down to 1.8 V I/O rails, and for powering core voltages down to
0.75 V. Using an advanced proprietary architecture, the ADP1754/
ADP1755 provide high power supply rejection ratio (PSRR) and
low noise, and achieve excellent line and load transient response
with only a small 4.7 µF ceramic output capacitor.
The ADP1754 is available in seven fixed output voltage options.
The ADP1755 is the adjustable version, which allows output
Rev. G
voltages that range from 0.75 V to 3.3 V via an external divider.
The ADP1754/ADP1755 allow an external soft start capacitor
to be connected to program the startup. A digital power-good
output allows power system monitors to check the health of the
output voltage.
The ADP1754/ADP1755 are available in a 16-lead, 4 mm × 4 mm
LFCSP, making them not only very compact solutions, but also
providing excellent thermal performance for applications that
require up to 1.2 A of output current in a small, low profile
footprint.
Document Feedback
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 registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 ©2008–2014 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
ADP1754/ADP1755
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Soft Start Function (ADP1754/ADP1755) ............................. 11
Applications ....................................................................................... 1
Adjustable Output Voltage (ADP1755) ................................... 12
Typical Application Circuits............................................................ 1
Enable Feature ............................................................................ 12
General Description ......................................................................... 1
Power-Good Feature .................................................................. 12
Revision History ............................................................................... 2
Reverse Current Protection Feature ........................................ 13
Specifications..................................................................................... 3
Applications Information .............................................................. 14
Input and Output Capacitor, Recommended Specifications .. 4
Capacitor Selection .................................................................... 14
Absolute Maximum Ratings............................................................ 5
Undervoltage Lockout ............................................................... 15
Thermal Data ................................................................................ 5
Current-Limit and Thermal Overload Protection ................. 15
Thermal Resistance ...................................................................... 5
Thermal Considerations............................................................ 15
ESD Caution .................................................................................. 5
PCB Layout Considerations ...................................................... 18
Pin Configurations and Function Descriptions ........................... 6
Outline Dimensions ....................................................................... 19
Typical Performance Characteristics ............................................. 7
Ordering Guide .......................................................................... 19
Theory of Operation ...................................................................... 11
REVISION HISTORY
4/14—Rev. F to Rev. G
4/09—Rev. 0 to Rev. A
Changes to Figure 1 and Figure 2 ................................................... 1
Change to Table 4 ............................................................................. 5
Changes to Figure 3 and Figure 4 ................................................... 6
Updated Outline Dimensions ....................................................... 19
Changes to Ordering Guide .......................................................... 19
Changes to Adjustable Output Voltage Accuracy (ADP1755)
Parameter, Table 1 .............................................................................3
Changes to Table 3.............................................................................5
10/08—Revision 0: Initial Version
8/13—Rev. E to Rev. F
Changes to Ordering Guide .......................................................... 19
6/13—Rev. D to Rev. E
Changed Adjustable Output Voltage Option with Soft Start
(ADP1755) from 0.75 V to 3.0 V to 0.75 V to 3.3 V
(Throughout) .................................................................................... 1
Updated Outline Dimensions ....................................................... 19
12/12—Rev. C to Rev. D
Added Junction Temperature of 150°C, Table 3 ........................... 5
9/12—Rev. B to Rev. C
Changes to Absolute Maximum Ratings, Table 3......................... 5
Changes to Ordering Guide .......................................................... 19
2/10—Rev. A to Rev. B
Changes to Table 4 ............................................................................ 5
Changes to Ordering Guide .......................................................... 19
Rev. G | Page 2 of 20
Data Sheet
ADP1754/ADP1755
SPECIFICATIONS
VIN = (VOUT + 0.4 V) or 1.6 V (whichever is greater), IOUT = 10 mA, CIN = COUT = 4.7 µF, TA = 25°C, unless otherwise noted.
Table 1.
Parameter
INPUT VOLTAGE RANGE
OPERATING SUPPLY CURRENT 1
Symbol
VIN
IGND
SHUTDOWN CURRENT
IGND-SD
OUTPUT VOLTAGE ACCURACY
Fixed Output Voltage Accuracy
(ADP1754)
VOUT
Adjustable Output Voltage Accuracy
(ADP1755) 2
LINE REGULATION
LOAD REGULATION 3
DROPOUT VOLTAGE 4
VADJ
∆VOUT/∆VIN
∆VOUT/∆IOUT
VDROPOUT
START-UP TIME 5
tSTART-UP
CURRENT-LIMIT THRESHOLD 6
THERMAL SHUTDOWN
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
ILIMIT
PG OUTPUT LOGIC LEVEL
PG Output Logic High
PG Output Logic Low
PG Output Delay from EN Transition
Low to High
PG OUTPUT THRESHOLD
Output Voltage Falling
Output Voltage Rising
EN INPUT
EN Input Logic High
EN Input Logic Low
EN Input Leakage Current
UNDERVOLTAGE LOCKOUT
Input Voltage Rising
Input Voltage Falling
Hysteresis
SOFT START CURRENT
ADJ INPUT BIAS CURRENT (ADP1755)
SENSE INPUT BIAS CURRENT
Test Conditions/Comments
TJ = −40°C to +125°C
IOUT = 500 μA
IOUT = 100 mA
IOUT = 100 mA, TJ = −40°C to +125°C
IOUT = 1.2 A
IOUT = 1.2 A, TJ = −40°C to +125°C
EN = GND, VIN = 1.6 V
EN = GND, VIN = 1.6 V, TJ = −40°C to +85°C
EN = GND, VIN = 3.6 V, TJ = −40°C to +85°C
Min
1.6
IOUT = 10 mA
IOUT = 10 mA to 1.2 A
10 mA < IOUT < 1.2 A, TJ = −40°C to +125°C
IOUT = 10 mA
IOUT = 10 mA to 1.2 A
10 mA < IOUT < 1.2 A, TJ = −40°C to +125°C
VIN = (VOUT + 0.4 V) to 3.6 V, TJ = −40°C to +125°C
IOUT = 10 mA to 1.2 A, TJ = −40°C to +125°C
IOUT = 100 mA, VOUT ≥ 1.8 V
IOUT = 100 mA, VOUT ≥ 1.8 V, TJ = −40°C to +125°C
IOUT = 1.2 A, VOUT ≥ 1.8 V
IOUT = 1.2 A, VOUT ≥ 1.8 V, TJ = −40°C to +125°C
CSS = 0 nF, IOUT = 10 mA
CSS = 10 nF, IOUT = 10 mA
−1
−1.5
−2
0.495
0.495
0.490
−0.3
TJ rising
PGHIGH
PGLOW
1.6 V ≤ VIN ≤ 3.6 V, IOH < 1 µA
1.6 V ≤ VIN ≤ 3.6 V, IOL < 2 mA
1.6 V ≤ VIN ≤ 3.6 V, CSS = 10 nF
PGFALL
PGRISE
1.6 V ≤ VIN ≤ 3.6 V
1.6 V ≤ VIN ≤ 3.6 V
VIH
VIL
VI-LEAKAGE
UVLO
UVLORISE
UVLOFALL
UVLOHYS
ISS
ADJI-BIAS
SNSI-BIAS
1.6 V ≤ VIN ≤ 3.6 V
1.6 V ≤ VIN ≤ 3.6 V
EN = VIN or GND
TJ = −40°C to +125°C
TJ = −40°C to +125°C
TJ = 25°C
1.6 V ≤ VIN ≤ 3.6 V
1.6 V ≤ VIN ≤ 3.6 V, TJ = −40°C to +125°C
1.6 V ≤ VIN ≤ 3.6 V
Rev. G | Page 3 of 20
Max
3.6
90
400
800
1.1
2
0.5
1.4
6
30
100
+1
+1.5
+2
0.505
0.505
0.510
+0.3
0.6
10
16
105
200
1.5
TSSD
TSSD-HYS
Typ
200
5.2
2
5
150
15
%
%
%
V
V
V
%/V
%/A
mV
mV
mV
mV
µs
ms
A
°C
°C
1.0
5.5
V
V
ms
−10
−6.5
%
%
0.4
1.2
0.1
0.4
1
1.58
1.25
0.6
Unit
V
µA
µA
µA
mA
mA
µA
µA
µA
100
0.9
10
10
1.2
150
V
V
µA
V
V
mV
µA
nA
µA
ADP1754/ADP1755
Data Sheet
Parameter
OUTPUT NOISE
Symbol
OUTNOISE
POWER SUPPLY REJECTION RATIO
PSRR
Test Conditions/Comments
10 Hz to 100 kHz, VOUT = 0.75 V
10 Hz to 100 kHz, VOUT = 2.5 V
VIN = VOUT + 1 V, IOUT = 10 mA
1 kHz, VOUT = 0.75 V
1 kHz, VOUT = 2.5 V
10 kHz, VOUT = 0.75 V
10 kHz, VOUT = 2.5 V
100 kHz, VOUT = 0.75 V
100 kHz, VOUT = 2.5 V
Min
Typ
23
65
Max
65
56
65
56
54
51
Unit
µV rms
µV rms
dB
dB
dB
dB
dB
dB
Minimum output load current is 500 μA.
Accuracy when VOUT is connected directly to ADJ. When VOUT voltage is set by external feedback resistors, absolute accuracy in adjust mode depends on the
tolerances of resistors used.
3
Based on an end-point calculation using 10 mA and 1.2 A loads. See Figure 6 for typical load regulation performance.
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 1.6 V.
5
Start-up time is defined as the time between the rising edge of EN to VOUT being at 95% of its nominal value.
6
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 1.0 V
output voltage is defined as the current that causes the output voltage to drop to 90% of 1.0 V, or 0.9 V.
1
2
INPUT AND OUTPUT CAPACITOR, RECOMMENDED SPECIFICATIONS
Table 2.
Parameter
MINIMUM INPUT AND OUTPUT CAPACITANCE1
CAPACITOR ESR
1
Symbol
CMIN
RESR
Test Conditions/Comments
TA = −40°C to +125°C
TA = −40°C to +125°C
Min
3.3
0.001
Typ
Max
0.1
Unit
µF
Ω
The minimum input and output capacitance should be greater than 3.3 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 with this LDO.
Rev. G | Page 4 of 20
Data Sheet
ADP1754/ADP1755
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
VIN to GND
VOUT to GND
EN to GND
SS to GND
PG to GND
SENSE/ADJ to GND
Storage Temperature Range
Junction Temperature Range
Junction Temperature
Soldering Conditions
Rating
−0.3 V to +4.0 V
−0.3 V to VIN
−0.3 V to VIN
−0.3 V to VIN
−0.3 V to +4.0 V
−0.3 V to VIN
−65°C to +150°C
−40°C to +125°C
150°C
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.
THERMAL DATA
Absolute maximum ratings apply individually only, not in
combination. The ADP1754/ADP1755 may be damaged if the
junction temperature limits are exceeded. Monitoring ambient
temperature does not guarantee that TJ is within the specified
temperature limits. In applications with high power dissipation
and poor 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 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). TJ is calculated using the following formula:
TJ = TA + (PD × θJA)
Junction-to-ambient thermal resistance (θJA) of the package is
based on modeling and calculation using a 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. The value of θJA may vary, depending
on PCB material, layout, and environmental conditions. The
specified values of θJA are based on a 4-layer, 4 in × 3 in circuit
board. Refer to JEDEC JESD51-7 for detailed information about
board construction. For more information, see the AN-772
Application Note, A Design and Manufacturing Guide for the
Lead Frame Chip Scale Package (LFCSP).
ΨJB is the junction-to-board thermal characterization parameter
with units of °C/W. ΨJB of the package is based on modeling and
calculation using a 4-layer board. The JESD51-12 document,
Guidelines for Reporting and Using Electronic Package Thermal
Information, states that thermal characterization parameters are
not the same as thermal resistances. ΨJB measures the component
power flowing through multiple thermal paths rather than through
a single path as in thermal resistance, θJB. Therefore, ΨJB thermal
paths include convection from the top of the package as well as
radiation from the package, factors that make ΨJB more useful in
real-world applications. Maximum junction temperature (TJ)
is calculated from the board temperature (TB) and the power
dissipation (PD) using the following formula:
TJ = TB + (PD × ΨJB)
Refer to the JEDEC JESD51-8 and JESD51-12 documents for more
detailed information about ΨJB.
THERMAL RESISTANCE
θJA and ΨJB are specified for the worst-case conditions, that is, a
device soldered in a circuit board for surface-mount packages.
Table 4. Thermal Resistance
Package Type
16-Lead LFCSP with Exposed Pad (CP-16-23)
ESD CAUTION
Rev. G | Page 5 of 20
θJA
42
ΨJB
25.5
Unit
°C/W
ADP1754/ADP1755
Data Sheet
13 VOUT
14 VOUT
16 VIN
15 VIN
VIN 1
12 VOUT
VIN 1
12 VOUT
VIN 2
ADP1754
11 VOUT
VIN 2
VIN 3
TOP VIEW
(Not to Scale)
ADP1755
11 VOUT
10 VOUT
VIN 3
TOP VIEW
(Not to Scale)
10 VOUT
9 SENSE
EN 4
SS 7
NC 8
GND 6
9 ADJ
PG 5
NOTES
1. NC = NO CONNECT.
2. THE EXPOSED PAD ON THE BOTTOM OF THE LFCSP ENHANCES
THERMAL PERFORMANCE AND IS ELECTRICALLY CONNECTED TO GND
INSIDE THE PACKAGE. IT IS RECOMMENDED THAT THE EXPOSED PAD
BE CONNECTED TO THE GROUND PLANE ON THE BOARD.
07722-003
SS 7
NC 8
PG 5
GND 6
EN 4
NOTES
1. NC = NO CONNECT.
2. THE EXPOSED PAD ON THE BOTTOM OF THE LFCSP ENHANCES
THERMAL PERFORMANCE AND IS ELECTRICALLY CONNECTED TO GND
INSIDE THE PACKAGE. IT IS RECOMMENDED THAT THE EXPOSED PAD
BE CONNECTED TO THE GROUND PLANE ON THE BOARD.
Figure 3. ADP1754 Pin Configuration
07722-004
13 VOUT
14 VOUT
16 VIN
15 VIN
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Figure 4. ADP1755 Pin Configuration
Table 5. Pin Function Descriptions
ADP1754
Pin No.
1, 2, 3, 15,
16
4
ADP1755
Pin No.
1, 2, 3, 15,
16
4
5
5
PG
6
7
8
9
6
7
8
N/A
GND
SS
NC
SENSE
N/A
10, 11, 12,
13, 14
17 (EPAD)
9
10, 11, 12,
13, 14
17 (EPAD)
ADJ
VOUT
Mnemonic
VIN
EN
Exposed
paddle
(EPAD)
Description
Regulator Input Supply. Bypass VIN to GND with a 4.7 µF or greater capacitor. Note that all five
VIN pins must be connected to the source.
Enable Input. Drive EN high to turn on the regulator; drive it low to turn off the regulator. For
automatic startup, connect EN to VIN.
Power Good. This open-drain output requires an external pull-up resistor to VIN. If the part is in
shutdown mode, current-limit mode, thermal shutdown, or if it falls below 90% of the nominal
output voltage, PG immediately transitions low.
Ground.
Soft Start. A capacitor connected to this pin determines the soft start time.
Not Connected. No internal connection.
Sense. This pin measures the actual output voltage at the load and feeds it to the error
amplifier. Connect SENSE as close as possible to the load to minimize the effect of IR drop
between the regulator output and the load.
Adjust. A resistor divider from VOUT to ADJ sets the output voltage.
Regulated Output Voltage. Bypass VOUT to GND with a 4.7 µF or greater capacitor. Note that all
five VOUT pins must be connected to the load.
The exposed pad on the bottom of the LFCSP package enhances thermal performance and is
electrically connected to GND inside the package. It is recommended that the exposed pad be
connected to the ground plane on the board.
Rev. G | Page 6 of 20
Data Sheet
ADP1754/ADP1755
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 1.9 V, VOUT = 1.5 V, IOUT = 10 mA, CIN = 4.7 µF, COUT = 4.7 µF, TA = 25°C, unless otherwise noted.
1.520
1200
1.510
1000
LOAD = 800mA
GROUND CURRENT (µA)
1.515
OUTPUT VOLTAGE (V)
LOAD = 1.2A
LOAD = 10mA
LOAD = 100mA
LOAD = 400mA
LOAD = 800mA
LOAD = 1.2A
1.505
1.500
1.495
1.490
800
LOAD = 400mA
600
LOAD = 100mA
400
LOAD = 10mA
200
1.485
–5
25
85
125
0
JUNCTION TEMPERATURE (°C)
–40
–5
25
85
07722-008
–40
07722-005
1.480
125
JUNCTION TEMPERATURE (°C)
Figure 5. Output Voltage vs. Junction Temperature
Figure 8. Ground Current vs. Junction Temperature
1.520
1200
1.515
GROUND CURRENT (µA)
OUTPUT VOLTAGE (V)
1000
1.510
1.505
1.500
1.495
1.490
800
600
400
200
100
1k
10k
LOAD CURRENT (mA)
0
10
07722-006
1.480
10
1k
10k
LOAD CURRENT (mA)
Figure 6. Output Voltage vs. Load Current
Figure 9. Ground Current vs. Load Current
1200
1.520
LOAD = 10mA
LOAD = 100mA
LOAD = 400mA
LOAD = 800mA
LOAD = 1.2A
1.510
LOAD = 1.2A
1000
GROUND CURRENT (µA)
1.515
1.505
1.500
1.495
1.490
LOAD = 800mA
800
LOAD = 400mA
600
400
LOAD = 100mA
200
LOAD = 10mA
1.480
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
INPUT VOLTAGE (V)
3.4
3.6
Figure 7. Output Voltage vs. Input Voltage
0
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
INPUT VOLTAGE (V)
Figure 10. Ground Current vs. Input Voltage
Rev. G | Page 7 of 20
3.4
3.6
07722-010
1.485
07722-007
OUTPUT VOLTAGE (V)
100
07722-009
1.485
ADP1754/ADP1755
Data Sheet
80
70
3500
60
50
40
30
3000
2500
2000
1500
20
1000
10
500
–15
10
35
60
85
TEMPERATURE (°C)
0
2.3
07722-011
0
–40
LOAD = 10mA
LOAD = 100mA
LOAD = 400mA
LOAD = 800mA
LOAD = 1.2A
4000
GROUND CURRENT (µA)
90
Figure 11. Shutdown Current vs. Temperature at Various Input Voltages
2.4
2.7
2.8
T
ILOAD
0.12
0.10
1
1mA TO 1.2A LOAD STEP, 2.5A/µs, 500mA/DIV
0.08
0.06
VOUT
2
0.04
50mV/DIV
1.6V
2.5V
0
1
10
100
LOAD CURRENT (mA)
VIN = 3.6V
VOUT = 1.5V
1k
10k
CH1 500mA Ω BW CH2 50mV
Figure 12. Dropout Voltage vs. Load Current, VOUT = 1.6 V, 2.5 V
B
W M10µs
A CH1
T 10.40%
380mA
07722-015
0.02
07722-012
DROPOUT VOLTAGE (V)
2.6
Figure 14. Ground Current vs. Input Voltage (in Dropout), VOUT = 2.5 V
0.14
Figure 15. Load Transient Response, CIN = 4.7 μF, COUT = 4.7 μF
2.60
T
ILOAD
2.55
1mA TO 1.2A LOAD STEP, 2.5A/µs,
500mA/DIV
2.50
1
2.45
2.40
2
2.35
LOAD = 10mA
LOAD = 100mA
LOAD = 400mA
LOAD = 800mA
LOAD = 1.2A
2.30
2.25
2.20
2.3
2.4
2.5
2.6
INPUT VOLTAGE (V)
2.7
VOUT
20mV/DIV
VIN = 3.6V
VOUT = 1.5V
2.8
07722-013
OUTPUT VOLTAGE (V)
2.5
INPUT VOLTAGE (V)
CH1 500mA Ω BW CH2 20mV
B M10µs
W
A CH1
T 10.20%
340mA
Figure 16. Load Transient Response, CIN = 22 μF, COUT = 22 μF
Figure 13. Output Voltage vs. Input Voltage (in Dropout), VOUT = 2.5 V
Rev. G | Page 8 of 20
07722-016
SHUTDOWN CURRENT (µA)
4500
1.9V
2.0V
2.4V
2.6V
3.0V
3.6V
07722-014
100
Data Sheet
ADP1754/ADP1755
0
T
VIN
1.2A
800mA
400mA
100mA
10mA
–10
–20
3V TO 3.5V INPUT VOLTAGE STEP, 2V/µs
PSRR (dB)
–30
VOUT
2
5mV/DIV
–40
–50
–60
–70
–80
VOUT = 1.5V
CIN = COUT = 4.7µF
B
W
M10µs
A CH4
T 9.60%
–100
10
07722-017
CH1 500mV BW CH2 5mV
800mV
1k
10k
100k
1M
10M
FREQUENCY (Hz)
Figure 17. Line Transient Response, Load Current = 1200 mA
Figure 20. Power Supply Rejection Ratio vs. Frequency,
VOUT = 0.75 V, VIN = 1.75 V
0
70
1.2A
800mA
400mA
100mA
10mA
–10
2.5V
60
–20
50
–30
40
PSRR (dB)
NOISE (µV rms)
100
07722-020
–90
1
1.5V
30
–50
–60
–70
0.75V
20
–40
–80
10
0.001
0.01
0.1
1
10
LOAD CURRENT (A)
–100
10
07722-018
0
0.0001
1k
10k
100k
1M
10M
FREQUENCY (Hz)
Figure 21. Power Supply Rejection Ratio vs. Frequency,
VOUT = 1.5 V, VIN = 2.5 V
Figure 18. Noise vs. Load Current and Output Voltage
10
0
1.2A
800mA
400mA
100mA
10mA
–10
–20
–30
PSRR (dB)
1
1.5V
2.5V
0.1
–40
–50
–60
–70
–80
0.75V
0.01
10
100
1k
10k
100k
FREQUENCY (Hz)
Figure 19. Noise Spectral Density vs. Output Voltage, ILOAD = 10 mA
–100
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
Figure 22. Power Supply Rejection Ratio vs. Frequency,
VOUT = 2.5 V, VIN = 3.5 V
Rev. G | Page 9 of 20
10M
07722-122
–90
07081-019
NOISE SPECTRAL DENSITY (µV/ Hz)
100
07722-121
–90
ADP1754/ADP1755
Data Sheet
0
–10
1.5V/1200mA
2.5V/1200mA
0.75V/1200mA
1.5V/10mA
2.5V/10mA
0.75V/10mA
–20
PSRR (dB)
–30
–40
–50
–60
–70
–90
10
100
1k
10k
100k
FREQUENCY (Hz)
1M
10M
07722-123
–80
Figure 23. Power Supply Rejection Ratio vs. Frequency and Output Voltage
Rev. G | Page 10 of 20
Data Sheet
ADP1754/ADP1755
THEORY OF OPERATION
The ADP1754/ADP1755 are low dropout linear regulators that
use an advanced, proprietary architecture to provide high power
supply rejection ratio (PSRR) and excellent line and load transient
response with only a small 4.7 µF ceramic output capacitor. Both
devices operate from a 1.6 V to 3.6 V input rail and provide up
to 1.2 A of output current. Supply current in shutdown mode is
typically 2 µA.
The ADP1754 is available in seven fixed output voltage options
between 0.75 V and 2.5 V. The ADP1754 allows for connection
of an external soft start capacitor that controls the output
voltage ramp during startup. The ADP1755 is the adjustable
version with an output voltage that can be set to a value
between 0.75 V and 3.3 V by an external voltage divider. Both
devices are controlled by an enable pin (EN).
SOFT START FUNCTION (ADP1754/ADP1755)
ADP1754
REVERSE POLARITY
PROTECTION
VIN
For applications that require a controlled startup, the ADP1754/
ADP1755 provide a programmable soft start function. The
programmable soft start is useful for reducing inrush current
upon startup and for providing voltage sequencing. To implement
soft start, connect a small ceramic capacitor from SS to GND.
Upon startup, a 0.9 µA current source charges this capacitor.
The ADP1754/ADP1755 start-up output voltage is limited by
the voltage at SS, providing a smooth ramp-up to the nominal
output voltage. The soft start time is calculated as follows:
VOUT
UVLO
GND
SHORT-CIRCUIT
AND THERMAL
PROTECTION
SENSE
R1
0.5V
REF
PG
R2
tSS = VREF × (CSS/ISS)
PG
DETECT
EN
SS
SHUTDOWN
07722-021
0.9µA
Figure 24. ADP1754 Internal Block Diagram
ADP1755
REVERSE POLARITY
PROTECTION
VIN
where:
tSS is the soft start period.
VREF is the 0.5 V reference voltage.
CSS is the soft start capacitance from SS to GND.
ISS is the current sourced from SS (0.9 µA).
When the ADP1754/ADP1755 is disabled (using the EN pin), the
soft start capacitor is discharged to GND through an internal 100 Ω
resistor.
VOUT
UVLO
GND
(1)
2.50
2.25
EN
SHORT-CIRCUIT
AND THERMAL
PROTECTION
2.00
ADJ
PG
DETECT
0.9µA
SHUTDOWN
1.25
4.7nF
1.00
10nF
SS
0.75
07722-022
EN
1nF
1.50
0.50
0.25
Figure 25. ADP1755 Internal Block Diagram
Internally, the ADP1754/ADP1755 consist of a reference, an
error amplifier, a feedback voltage divider, and a PMOS pass
transistor. Output current is delivered via the PMOS pass
transistor, which is controlled by the error amplifier. The error
amplifier compares the reference voltage with the feedback
voltage from the output and amplifies the difference. If the
feedback voltage is lower than the reference voltage, the gate
of the PMOS device is pulled lower, allowing more current
to pass and increasing the output voltage. If the feedback
voltage is higher than the reference voltage, the gate of the
PMOS device is pulled higher, allowing less current to pass
and decreasing the output voltage.
Rev. G | Page 11 of 20
0
0
2
4
6
8
TIME (ms)
Figure 26. VOUT Ramp-Up with External Soft Start Capacitor
10
07722-023
0.5V
REF
PG
VOLTAGE (V)
1.75
ADP1754/ADP1755
T
Data Sheet
As shown in Figure 28, the EN pin has hysteresis built in. This
hysteresis prevents on/off oscillations that can occur due to
noise on the EN pin as it passes through the threshold points.
EN
1
The EN pin active/inactive thresholds are derived from the VIN
voltage. Therefore, these thresholds vary with changing input
voltage. Figure 29 shows typical EN active/inactive thresholds
when the input voltage varies from 1.6 V to 3.6 V.
1.1
VOUT
1.0
CH2 500mV BW M40µs
T 9.8%
A CH1
920mV
Figure 27. VOUT Ramp-Up with Internal Soft Start
ADJUSTABLE OUTPUT VOLTAGE (ADP1755)
The output voltage of the ADP1755 can be set over a 0.75 V to
3.3 V range. The output voltage is set by connecting a resistive
voltage divider from VOUT to ADJ. The output voltage is calculated using the following equation:
VOUT = 0.5 V × (1 + R1/R2)
0.9
EN ACTIVE
0.8
EN INACTIVE
0.7
0.6
0.5
1.6
(2)
1.8
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
INPUT VOLTAGE (V)
3.6
07722-026
CH1 2.0V BW
VOUT = 1.5V
CIN = COUT = 4.7µF
EN THRESHOLD (V)
500mV/DIV
07722-024
2
Figure 29. Typical EN Pin Thresholds vs. Input Voltage
where:
R1 is the resistor from VOUT to ADJ.
R2 is the resistor from ADJ to GND.
POWER-GOOD FEATURE
The maximum bias current into ADJ is 150 nA. Therefore, to
achieve less than 0.5% error due to the bias current, use values
less than 60 kΩ for R2.
ENABLE FEATURE
The ADP1754/ADP1755 use the EN pin to enable and disable
the VOUT pins under normal operating conditions. As shown
in Figure 28, when a rising voltage on EN crosses the active
threshold, VOUT turns on. When a falling voltage on EN crosses
the inactive threshold, VOUT turns off.
T
The ADP1754/ADP1755 provide a power-good pin, PG, to
indicate the status of the output. This open-drain output
requires an external pull-up resistor to VIN. If the part is in
shutdown mode, current-limit mode, thermal shutdown, or
if it falls below 90% of the nominal output voltage, PG immediately transitions low. During soft start, the rising threshold of
the power-good signal is 93.5% of the nominal output voltage.
The open-drain output is held low when the ADP1754/ADP1755
have sufficient input voltage to turn on the internal PG transistor.
An optional soft start delay can be detected. The PG transistor
is terminated via a pull-up resistor to VOUT or VIN.
Power-good accuracy is 93.5% of the nominal regulator output
voltage when this voltage is rising, with a 90% trip point when
this voltage is falling.
EN
Regulator input voltage brownouts or glitches trigger a power
no-good if VOUT falls below 90%.
VOUT
A normal power-down triggers a power no-good when VOUT
drops below 90%.
1
2
VOUT = 1.5V
CIN = COUT = 4.7µF
CH1 500mV BW CH2 500mV BW M2.0ms
T 29.6%
A CH1
1.05V
07722-025
500mV/DIV
Figure 28. Typical EN Pin Operation
Rev. G | Page 12 of 20
Data Sheet
ADP1754/ADP1755
REVERSE CURRENT PROTECTION FEATURE
T
VIN
1V/DIV
1
VOUT
500mV/DIV
PG
1V/DIV
2
CH1 1.0V BW
CH3 1.0V BW
CH2 500mV BW M40.0µs A CH3
T 50.40%
900mV
07722-027
VOUT = 1.5V
CIN = COUT = 4.7µF
Figure 30. Typical PG Behavior vs. VOUT, VIN Rising (VOUT = 1.5 V)
The ADP1754/ADP1755 have additional circuitry to protect
against reverse current flow from VOUT to VIN. For a typical
LDO with a PMOS pass device, there is an intrinsic body diode
between VIN and VOUT. When VIN is greater than VOUT, this
diode is reverse-biased. If VOUT is greater than VIN, the intrinsic
diode becomes forward-biased and conducts current from VOUT
to VIN, potentially causing destructive power dissipation. The
reverse current protection circuitry detects when VOUT is greater
than VIN and reverses the direction of the intrinsic diode connection, reverse-biasing the diode. The gate of the PMOS pass
device is also connected to VOUT, keeping the device off.
Figure 32 shows a plot of the reverse current vs. the VOUT to VIN
differential.
4000
3500
T
REVERSE CURRENT (µA)
VIN
1V/DIV
1
VOUT
500mV/DIV
2500
2000
1500
1000
VOUT = 1.5V
CIN = COUT = 4.7µF
CH1 1.0V BW
CH3 1.0V BW
CH2 500mV BW M40.0µs A CH3
T 50.40%
0
0
900mV
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
VOUT – VIN (V)
Figure 32. Reverse Current vs. VOUT − VIN
Figure 31. Typical PG Behavior vs. VOUT, VIN Falling (VOUT = 1.5 V)
Rev. G | Page 13 of 20
3.3
3.6
07722-132
500
PG
1V/DIV
07722-028
2
3000
ADP1754/ADP1755
Data Sheet
APPLICATIONS INFORMATION
CAPACITOR SELECTION
Input Bypass Capacitor
Output Capacitor
Connecting a 4.7 μF capacitor from the VIN pin to GND
reduces the circuit sensitivity to printed circuit board (PCB)
layout, especially when long input traces or high source
impedance are encountered. If output capacitance greater than
4.7 μF is required, it is recommended that the input capacitor be
increased to match it.
The ADP1754/ADP1755 are designed for operation with small,
space-saving ceramic capacitors, but they can function with most
commonly used capacitors as long as care is taken with the
effective series resistance (ESR) value. The ESR of the output
capacitor affects the stability of the LDO control loop. A minimum of 3.3 μF capacitance with an ESR of 500 mΩ or less is
recommended to ensure the stability of the ADP1754/ADP1755.
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 ADP1754/ADP1755 to
large changes in load current. Figure 33 and Figure 34 show the
transient responses for output capacitance values of 4.7 μF and
22 μF, respectively.
T
ILOAD
VOUT
50mV/DIV
B
W M1µs
A CH1
380mA
T 11.2%
5
07722-133
VIN = 3.6V, VOUT = 1.5V
CIN = COUT = 4.7µF
CH1 500mA BW CH2 50mV
Any good quality ceramic capacitors can be used with the
ADP1754, as long as they meet the minimum capacitance and
maximum ESR requirements. Ceramic capacitors are manufactured with a variety of dielectrics, each with 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 recommended. Y5V and Z5U dielectrics are not recommended, due
to their poor temperature and dc bias characteristics.
Figure 35 shows the capacitance vs. voltage bias characteristics
of an 0805 case, 4.7 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 with
a higher voltage rating exhibits better stability. The temperature
variation of the X5R dielectric is about ±15% over the −40°C to
+85°C temperature range and is not a function of package size
or voltage rating.
1mA TO 1.2A LOAD STEP, 2.5A/µs, 500mA/DIV
1
2
Input and Output Capacitor Properties
MURATA P/N GRM219R61A475KE34
4
CAPACITANCE (µF)
Figure 33. Output Transient Response, COUT = 4.7 μF
T
ILOAD
1mA TO 1.2A LOAD STEP, 2.5A/µs, 500mA/DIV
1
3
2
1
2
0
0
2
4
6
8
VOLTAGE BIAS (V)
VIN = 3.6V, VOUT = 1.5V
CIN = COUT = 22µF
B
W M1µs
A CH1
340mA
T 11.0%
Figure 34. Output Transient Response, COUT = 22 μF
Figure 35. Capacitance vs. Voltage Bias Characteristics
07722-134
CH1 500mA BW CH2 20mV
10
07722-031
VOUT
20mV/DIV
Equation 3 can be used to determine the worst-case capacitance,
accounting for capacitor variation over temperature, component
tolerance, and voltage.
CEFF = COUT × (1 − TEMPCO) × (1 − TOL)
where:
CEFF is the effective capacitance at the operating voltage.
TEMPCO is the worst-case capacitor temperature coefficient.
TOL is the worst-case component tolerance.
Rev. G | Page 14 of 20
(3)
Data Sheet
ADP1754/ADP1755
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 = 4.46 μF at 1.8 V, as shown in Figure 35.
Substituting these values in Equation 3 yields
CEFF = 4.46 μF × (1 − 0.15) × (1 − 0.1) = 3.41 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.
To guarantee the performance of the ADP1754/ADP1755, it is
imperative that the effects of dc bias, temperature, and tolerances on the behavior of the capacitors be evaluated for each
application.
UNDERVOLTAGE LOCKOUT
The ADP1754/ADP1755 have an internal undervoltage lockout
circuit that disables all inputs and the output when the input
voltage is less than approximately 1.58 V. This ensures that the
ADP1754/ADP1755 inputs and the output behave in a predictable manner during power-up.
CURRENT-LIMIT AND THERMAL OVERLOAD
PROTECTION
THERMAL CONSIDERATIONS
To guarantee reliable operation, the junction temperature of the
ADP1754/ADP1755 must not exceed 125°C. To ensure that the
junction temperature stays below this maximum value, the user
needs to be aware of the parameters that contribute to junction
temperature changes. These parameters include ambient temperature, power dissipation in the power device, and thermal
resistance between the junction and ambient air (θJA). The θJA
value is dependent on the package assembly compounds used
and the amount of copper to which the GND pin and the exposed
pad (EPAD) of the package are soldered on the PCB. Table 6 shows
typical θJA values for the 16-lead LFCSP for various PCB copper
sizes. Table 7 shows typical ΨJB values for the 16-lead LFCSP.
Table 6. Typical θJA Values
Copper Size (mm2)
01
100
500
1000
6400
1
The ADP1754/ADP1755 are protected against damage due to
excessive power dissipation by current-limit and thermal
overload protection circuits. The ADP1754/ADP1755 are
designed to reach current limit when the output load reaches
2 A (typical). When the output load exceeds 2 A, the output
voltage is reduced to maintain a constant current limit.
Thermal overload protection is included, which limits the
junction temperature to a maximum of 150°C (typical). Under
extreme conditions (that is, high ambient temperature and
power dissipation) when the junction temperature begins to
rise above 150°C, the output is turned off, reducing the output
current to zero. When the junction temperature drops below
135°C (typical), the output is turned on again and the output
current is restored to its nominal value.
Consider the case where a hard short from VOUT to ground
occurs. At first, the ADP1754/ADP1755 reach current limit so
that only 2 A is conducted into the short. If self-heating of the
junction becomes great enough to cause its temperature to
rise above 150°C, thermal shutdown activates, turning off the
output and reducing the output current to zero. As the junction
temperature cools and drops below 135°C, the output turns on
and conducts 2 A into the short, again causing the junction
temperature to rise above 150°C. This thermal oscillation between
135°C and 150°C causes a current oscillation between 2A and
0 A that continues as long as the short remains at the output.
Current-limit and thermal overload protections are intended to
protect the device against accidental overload conditions. For
reliable operation, device power dissipation should be externally
limited so that junction temperatures do not exceed 125°C.
θJA (°C/W), LFCSP
130
80
69
54
42
Device soldered to minimum size pin traces.
Table 7. Typical ΨJB Values
Copper Size (mm2)
100
500
1000
ΨJB (°C/W) at 1 W
32.7
31.5
25.5
The junction temperature of the ADP1754/ADP1755 can be
calculated from the following equation:
TJ = TA + (PD × θJA)
(4)
where:
TA is the ambient temperature.
PD is the power dissipation in the die, given by
PD = [(VIN − VOUT) × ILOAD] + (VIN × IGND)
(5)
where:
VIN and VOUT are the input and output voltages, respectively.
ILOAD is the load current.
IGND is the ground current.
Power dissipation due to ground current is quite small and can
be ignored. Therefore, the junction temperature equation can
be simplified as follows:
TJ = TA + {[(VIN − VOUT) × ILOAD] × θJA}
(6)
As shown in Equation 6, for a given ambient temperature, inputto-output voltage differential, and continuous load current, a
minimum copper size requirement exists for the PCB to ensure
that the junction temperature does not rise above 125°C.
Figure 36 through Figure 41 show junction temperature
calculations for different ambient temperatures, load currents,
VIN to VOUT differentials, and areas of PCB copper.
Rev. G | Page 15 of 20
ADP1754/ADP1755
140
JUNCTION TEMPERATURE, TJ (°C)
120
LOAD = 800mA
100
LOAD = 400mA
60
LOAD = 200mA
40
LOAD = 100mA
20
LOAD = 10mA
0
0.25
0.75
1.25
1.75
VIN – VOUT (V)
2.25
2.75
100
LOAD = 400mA
80
LOAD = 200mA
60
LOAD = 10mA
20
0
0.25
JUNCTION TEMPERATURE, TJ (°C)
LOAD = 800mA
80
LOAD = 200mA
60
LOAD = 100mA
40
LOAD = 10mA
20
1.25
1.75
VIN – VOUT (V)
2.25
2.75
LOAD = 800mA
80
LOAD = 200mA
LOAD = 10mA
40
20
JUNCTION TEMPERATURE, TJ (°C)
LOAD = 400mA
LOAD = 200mA
60
LOAD = 100mA
LOAD = 10mA
0.75
1.25
1.75
VIN – VOUT (V)
2.25
2.75
2.25
2.75
MAX JUNCTION
TEMPERATURE
120
LOAD =
800mA
Figure 38. 0 mm2 of PCB Copper, TA = 25°C, LFCSP
LOAD = 400mA
100
LOAD = 200mA
80
LOAD = 100mA
60
LOAD = 10mA
40
20
0
0.25
07722-034
JUNCTION TEMPERATURE, TJ (°C)
100
0
0.25
1.25
1.75
VIN – VOUT (V)
LOAD = 1.2A
LOAD = 1.2A
20
0.75
140
MAX JUNCTION
TEMPERATURE
40
LOAD = 100mA
60
Figure 40. 500 mm2 of PCB Copper, TA = 50°C, LFCSP
120
80
LOAD = 400mA
100
Figure 37. 500 mm2 of PCB Copper, TA = 25°C, LFCSP
LOAD =
800mA
2.75
120
0
0.25
07722-033
JUNCTION TEMPERATURE, TJ (°C)
LOAD = 400mA
100
2.25
MAX JUNCTION
TEMPERATURE
LOAD = 1.2A
LOAD = 1.2A
140
1.25
1.75
VIN – VOUT (V)
140
120
0.75
0.75
Figure 39. 6400 mm2 of PCB Copper, TA = 50°C, LFCSP
MAX JUNCTION
TEMPERATURE
0
0.25
LOAD = 100mA
40
Figure 36. 6400 mm2 of PCB Copper, TA = 25°C, LFCSP
140
LOAD = 800mA
LOAD = 1.2A
07722-036
80
120
0.75
1.25
1.75
VIN – VOUT (V)
2.25
2.75
07722-037
LOAD = 1.2A
MAX JUNCTION
TEMPERATURE
07722-035
MAX JUNCTION
TEMPERATURE
07722-032
JUNCTION TEMPERATURE, TJ (°C)
140
Data Sheet
Figure 41. 0 mm2 of PCB Copper, TA = 50°C, LFCSP
In cases where the board temperature is known, the thermal
characterization parameter, ΨJB, can be used to estimate the
junction temperature rise. Maximum junction temperature (TJ)
is calculated from the board temperature (TB) and power
dissipation (PD) using the following formula:
TJ = TB + (PD × ΨJB)
Rev. G | Page 16 of 20
(7)
Data Sheet
ADP1754/ADP1755
MAX JUNCTION
TEMPERATURE
120
LOAD = 1.2A
100
LOAD = 800mA
80
LOAD = 400mA
120
100
LOAD = 1.2A
60
LOAD = 400mA
LOAD = 200mA
40
LOAD = 10mA
20
LOAD = 100mA
LOAD = 200mA
40
0
0.25
0.75
LOAD = 10mA
20
2.25
2.75
Figure 42. 500 mm2 of PCB Copper, TB = 25°C, LFCSP
140
MAX JUNCTION
TEMPERATURE
120
LOAD = 1.2A
140
JUNCTION TEMPERATURE, TJ (°C)
1.25
1.75
VIN – VOUT (V)
07722-038
0.75
1.25
1.75
VIN – VOUT (V)
2.25
2.75
Figure 44. 1000 mm2 of PCB Copper, TB = 25°C, LFCSP
LOAD = 100mA
0
0.25
LOAD = 800mA
100
LOAD = 400mA
80
LOAD = 200mA
60
MAX JUNCTION
TEMPERATURE
120
LOAD = 1.2A
LOAD = 800mA
100
LOAD = 400mA
80
LOAD = 200mA
60
LOAD = 10mA
40
LOAD = 100mA
20
LOAD = 10mA
40
0
0.25
LOAD = 100mA
20
0.75
1.25
1.75
VIN – VOUT (V)
2.25
Figure 45. 1000 mm2 of PCB Copper, TB = 50°C, LFCSP
0
0.25
0.75
1.25
1.75
VIN – VOUT (V)
2.25
2.75
07722-039
JUNCTION TEMPERATURE, TJ (°C)
LOAD = 800mA
80
07722-040
60
MAX JUNCTION
TEMPERATURE
Figure 43. 500 mm2 of PCB Copper, TB = 50°C, LFCSP
Rev. G | Page 17 of 20
2.75
07722-041
JUNCTION TEMPERATURE, TJ (°C)
140
140
JUNCTION TEMPERATURE, TJ (°C)
Figure 42 through Figure 45 show junction temperature calculations for different board temperatures, load currents, VIN to
VOUT differentials, and areas of PCB copper.
ADP1754/ADP1755
Data Sheet
PCB LAYOUT CONSIDERATIONS
Heat dissipation from the package can be improved by increasing the amount of copper attached to the pins of the ADP1754/
ADP1755. However, as shown in Table 6, a point of diminishing
returns is eventually reached, beyond which an increase in the
copper size does not yield significant heat dissipation benefits.
Here are a few general tips when designing PCBs:
•
•
•
Place the input capacitor as close as possible to the VIN
and GND pins.
Place the output capacitor as close as possible to the VOUT
and GND pins.
Place the soft start capacitor as close as possible to the SS pin.
Connect the load as close as possible to the VOUT and
SENSE pins (ADP1754) or to the VOUT and ADJ pins
(ADP1755).
Use of 0603 or 0805 size capacitors and resistors achieves the
smallest possible footprint solution on boards where area is
limited.
07722-045
•
07722-044
07722-046
Figure 47. Typical Board Layout—Top Side
Figure 46. Evaluation Board
Rev. G | Page 18 of 20
Figure 48. Typical Board Layout—Bottom Side
Data Sheet
ADP1754/ADP1755
OUTLINE DIMENSIONS
PIN 1
INDICATOR
4.10
4.00 SQ
3.90
0.35
0.30
0.25
0.65
BSC
PIN 1
INDICATOR
16
13
1
12
EXPOSED
PAD
2.25
2.10 SQ
1.95
9
0.80
0.75
0.70
4
0.25 MIN
BOTTOM VIEW
0.05 MAX
0.02 NOM
COPLANARITY
0.08
0.20 REF
SEATING
PLANE
5
8
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
SECTION OF THIS DATA SHEET.
111908-A
TOP VIEW
0.70
0.60
0.50
COMPLIANT TO JEDEC STANDARDS MO-220-WGGC.
Figure 49. 16-Lead Lead Frame Chip Scale Package [LFCSP_WQ]
4 mm × 4 mm Body, Very Very Thin Quad
(CP-16-23)
Dimensions shown in millimeters
ORDERING GUIDE
Model 1
ADP1754ACPZ-0.75R7
ADP1754ACPZ-1.0-R7
ADP1754ACPZ-1.1-R7
ADP1754ACPZ-1.2-R7
ADP1754ACPZ-1.3-R7
ADP1754ACPZ-1.5-R7
ADP1754ACPZ-1.8-R7
ADP1754ACPZ-2.5-R7
ADP1755ACPZ-R7
ADP1754-1.5-EVALZ
ADP1755-EVALZ
1
Temperature Range
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
Output Voltage (V)
0.75
1.0
1.1
1.2
1.3
1.5
1.8
2.5
Adjustable from 0.75 to 3.3
1.5
Adjustable
Z = RoHS Compliant Part.
Rev. G | Page 19 of 20
Package Description
16-Lead LFCSP_WQ
16-Lead LFCSP_WQ
16-Lead LFCSP_WQ
16-Lead LFCSP_WQ
16-Lead LFCSP_WQ
16-Lead LFCSP_WQ
16-Lead LFCSP_WQ
16-Lead LFCSP_WQ
16-Lead LFCSP_WQ
Evaluation Board
Evaluation Board
Package Option
CP-16-23
CP-16-23
CP-16-23
CP-16-23
CP-16-23
CP-16-23
CP-16-23
CP-16-23
CP-16-23
ADP1754/ADP1755
Data Sheet
NOTES
©2008–2014 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D07722-0-4/14(G)
Rev. G | Page 20 of 20