Maximum output current: 0.8 A
Input voltage range: 1.6 V to 3.6 V
Low shutdown current: <2 µA
Very low dropout voltage: 70 mV @ 0.8 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 (ADP1752)
Adjustable output voltage option with soft start
0.75 V to 3.0 V (ADP1753)
High PSRR
65 dB @ 1 kHz
65 dB @ 10 kHz
54 dB @ 100 kHz
23 V 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
APPLICATIONS
Server computers
Memory components
Telecommunications equipment
Network equipment
DSP/FPGA/microprocessor supplies
Instrumentation equipment/data acquisition systems
Linear Regulator
ADP1752/ADP1753
TYPICAL APPLICATION CIRCUITS
= 1.8
IN
4.7µF
100kΩ
PG
1
2
3
4
VIN
VIN
VIN
EN
16
VIN
VIN
ADP1752
TOP VIEW
(Not to Scale)
GND
PG
5
15
6
Figure 1. ADP1752 with Fixed Output Voltage, 1.5 V
= 1.8
IN
4.7µF
100kΩ
PG
1
2
3
4
VIN
VIN
VIN
EN
16
VIN
ADP1753
TOP VIEW
(Not to Scale)
GND
PG
5
15
VIN
6
Figure 2. ADP1753 with Adjustable Output Voltage, 0.75 V to 3.0 V
VOUT
14
VOUT
SS
7
14
SS
7
10nF
10nF
13
VOUT
VOUT
VOUT
VOUT
ADJ
NC
8
13
VOUT
VOUT
VOUT
VOUT
SENSE
NC
8
12
11
10
9
= 0.5V(1 + R1/R2)
OUT
12
11
10
9
R1
R2
OUT
4.7µF
= 1.5
4.7µF
07718-001
07718-002
GENERAL DESCRIPTION
The ADP1752/ADP1753 are low dropout (LDO) CMOS linear
regulators that operate from 1.6 V to 3.6 V and provide up to
800 mA of output current. These low V
IN/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,
they 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 ADP1752 is available in seven fixed output voltage options.
The ADP1753 is the adjustable version, which allows output
Rev. B
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.
voltages that range from 0.75 V to 3.0 V via an external divider.
The ADP1752/ADP1753 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 ADP1752/ADP1753 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 800 mA of output current in a small, low profile
footprint.
Changes to Table 3 ............................................................................ 5
10/08—Revision 0: Initial Version
Rev. B | Page 2 of 20
Page 3
ADP1752/ADP1753
SPECIFICATIONS
VIN = (V
Table 1.
Parameter Symbol Test Conditions/Comments Min Typ Max Unit
INPUT VOLTAGE RANGE VIN T
OPERATING SUPPLY CURRENT1 I
I
I
I
I
SHUTDOWN CURRENT I
OUTPUT VOLTAGE ACCURACY
Fixed Output Voltage Accuracy
Adjustable Output Voltage Accuracy
LINE REGULATION V
LOAD REGULATION3 V
DROPOUT VOLTAGE4 V
I
I
I
START-UP TIME5 t
C
CURRENT-LIMIT THRESHOLD6 I
THERMAL SHUTDOWN
Thermal Shutdown Threshold TSSD T
Thermal Shutdown Hysteresis TS
PG OUTPUT LOGIC LEVEL
PG Output Logic High PG
PG Output Logic Low PG
PG Output Delay from EN Transition
PG OUTPUT THRESHOLD
Output Voltage Falling PG
Output Voltage Rising PG
EN INPUT
EN Input Logic High VIH 1.6 V ≤ VIN ≤ 3.6 V 1.2 V
EN Input Logic Low VIL 1.6 V ≤ VIN ≤ 3.6 V 0.4 V
EN Input Leakage Current V
UNDERVOLTAGE LOCKOUT UVLO
Input Voltage Rising UVLO
Input Voltage Falling UVLO
Hysteresis UVLO
SOFT START CURRENT ISS 1.6 V ≤ VIN ≤ 3.6 V 0.6 0.9 1.2 µA
ADJ INPUT BIAS CURRENT (ADP1753) ADJ
SENSE INPUT BIAS CURRENT SNS
+ 0.4 V) or 1.6 V (whichever is greater), I
OUT
(ADP1752)
2
(ADP1753)
Low to High
= 10 mA, CIN = C
OUT
= −40°C to +125°C 1.6 3.6 V
J
I
GND
EN = GND, V
GND-SD
= 500 A 90
OUT
= 100 mA 400
OUT
= 100 mA, TJ = −40°C to +125°C
OUT
= 0.8 A 0.9
OUT
= 0.8 A, TJ = −40°C to +125°C
OUT
= 1.6 V
IN
EN = GND, VIN = 1.6 V, TJ = −40°C to +85°C
EN = GND, VIN = 3.6 V, TJ = −40°C to +85°C
I
V
OUT
I
10 mA < I
I
V
ADJ
I
10 mA < I
/VIN VIN = (V
OUT
/I
OUT
OUT
I
DROPOUT
CSS = 0 nF, I
START-UP
1 1.4 5 A
LIMIT
15
SD-HYS
1.6 V ≤ VIN ≤ 3.6 V, IOH < 1 µA 1.0 V
HIGH
1.6 V ≤ VIN ≤ 3.6 V, IOL < 2 mA 0.4 V
LOW
1.6 V ≤ V
1.6 V ≤ VIN ≤ 3.6 V −10 %
FAL L
1.6 V ≤ VIN ≤ 3.6 V −6.5 %
RISE
EN = VIN or GND 0.1 1 µA
I-LEAKAGE
TJ = −40°C to +125°C
RISE
TJ = −40°C to +125°C 1.25
FAL L
TJ = 25°C
HYS
1.6 V ≤ VIN ≤ 3.6 V, TJ = −40°C to +125°C 10 150 nA
I-BIAS
1.6 V ≤ VIN ≤ 3.6 V 10 µA
I-BIAS
= 10 mA −1 +1 %
OUT
= 10 mA to 0.8 A −1.5 +1.5 %
OUT
< 0.8 A, TJ = −40°C to +125°C −2 +2 %
OUT
= 10 mA 0.495 0.5 0.505 V
OUT
= 10 mA to 0.8 A 0.492 0.508 V
OUT
< 0.8 A, TJ = −40°C to +125°C 0.490 0.510 V
OUT
+ 0.4 V) to 3.6 V, TJ = −40°C to +125°C −0.3 +0.3 %/V
OUT
I
= 10 mA to 0.8 A, TJ = −40°C to +125°C 0.8 %/A
OUT
= 100 mA, V
OUT
= 100 mA, V
OUT
= 0.8 A, V
OUT
= 0.8 A, V
OUT
= 10 nF, I
SS
rising 150
J
OUT
OUT
= 10 mA 200 µs
OUT
OUT
≤ 3.6 V, CSS = 10 nF 5.5 ms
IN
= 4.7 µF, TA = 25°C, unless otherwise noted.
OUT
800 µA
1.2 mA
≥ 1.8 V 10 mV
OUT
≥ 1.8 V, TJ = −40°C to +125°C 16 mV
OUT
2 6 µA
30 µA
100 µA
µA
µA
mA
≥ 1.8 V 70 mV
≥ 1.8 V, TJ = −40°C to +125°C 140 mV
= 10 mA 5.2 ms
°C
°C
1.58 V
100
V
mV
Rev. B | Page 3 of 20
Page 4
ADP1752/ADP1753
Parameter Symbol Test Conditions/Comments Min Typ Max Unit
OUTPUT NOISE OUT
10 Hz to 100 kHz, V
POWER SUPPLY REJECTION RATIO PSRR VIN = V
1
Minimum output load current is 500 A.
2
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 0.8 A loads. See for typical load regulation performance. Figure 6
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 V
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.
INPUT AND OUTPUT CAPACITOR, RECOMMENDED SPECIFICATIONS
Table 2.
Parameter Symbol Test Conditions/Comments Min Typ Max Unit
MINIMUM INPUT AND OUTPUT CAPACITANCE1 C
CAPACITOR ESR R
1
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.
10 Hz to 100 kHz, V
NOISE
+ 1 V, I
OUT
1 kHz, V
OUT
1 kHz, V
OUT
10 kHz, V
10 kHz, V
OUT
OUT
100 kHz, V
100 kHz, V
being at 95% of its nominal value.
OUT
TA = −40°C to +125°C 3.3 µF
MIN
T
ESR
= 0.75 V 23 µV rms
OUT
= 2.5 V 65 µV rms
OUT
= 10 mA
OUT
= 0.75 V
= 2.5 V
= 0.75 V
= 2.5 V
= 0.75 V
OUT
= 2.5 V
OUT
= −40°C to +125°C 0.001 0.1 Ω
A
65
56
65
56
54
51
dB
dB
dB
dB
dB
dB
Rev. B | Page 4 of 20
Page 5
ADP1752/ADP1753
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter Rating
VIN to GND −0.3 V to +3.6 V
VOUT to GND −0.3 V to +3.6 V
EN to GND −0.3 V to +3.6 V
SS to GND −0.3 V to +3.6 V
PG to GND −0.3 V to +3.6 V
SENSE/ADJ to GND −0.3 V to +3.6 V
Storage Temperature Range −65°C to +150°C
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.
THERMAL DATA
Absolute maximum ratings apply individually only, not in
combination. The ADP1752/ADP1753 may be damaged if the
junction temperature limits are exceeded. Monitoring ambient
temperature does not guarantee that T
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 (T
ambient temperature (T
(P
), and the junction-to-ambient thermal resistance of the
D
package (θ
). TJ is calculated using the following formula:
JA
= TA + (PD × θJA).
T
J
) of the device is dependent on the
J
), the power dissipation of the device
A
is within the specified
J
Junction-to-ambient thermal resistance (θ
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 θ
on PCB material, layout, and environmental conditions. The
specified values of θ
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) at www.analog.com.
Ψ
is the junction-to-board thermal characterization parameter
JB
with units of °C/W. Ψ
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. Ψ
power flowing through multiple thermal paths rather than
through a single path as in thermal resistance, θ
thermal paths include convection from the top of the package
Ψ
JB
as well as radiation from the package, factors that make Ψ
useful in real-world applications. Maximum junction temperature
(T
) is calculated from the board temperature (TB) and the power
J
dissipation (P
= TB + (PD × ΨJB)
T
J
Refer to the JEDEC JESD51-8 and JESD51-12 documents for more
detailed information about Ψ
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 θJA ΨJB Unit
16-Lead LFCSP with Exposed Pad (CP-16-4) 42 25.5 °C/W
are based on a 4-layer, 4 in × 3 in circuit
JA
of the package is based on modeling and
JB
) using the following formula:
D
.
JB
) of the package is
JA
may vary, depending
JA
measures the component
JB
. Therefore,
JB
more
JB
ESD CAUTION
Rev. B | Page 5 of 20
Page 6
ADP1752/ADP1753
T
T
2
T
T
2
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
VOU
VIN
VIN
VOU
14
13
15
16
PIN 1
INDICATOR
1VIN
2VIN
ADP1752
3VIN
TOP VIEW
(Not to S cale)
4EN
5
6
PG
NOTES
1. NC = NO CONNECT .
. THE EXPOSED PAD ON THE BO TTOM OF THE LFCS P E NHANCES
THERMAL PERF ORMANCE AND IS ELE CTRICALLY CONNECTED TO G ND
INSIDE THE PACKAGE. IT IS RECOMMENDED THAT THE EXP OSED PAD
BE CONNECTED TO THE GROUND PLANE ON THE BO ARD.
GND
7
SS
8
C
N
12 VOUT
11 VOUT
10 VOUT
9SENSE
1VIN
2VIN
ADP1753
3VIN
TOP VIEW
(Not to S cale)
4EN
NOTES
1. NC = NO CONNECT .
. THE EXPOSED PAD ON THE BO TTOM OF THE LFCS P E NHANCES
THERMAL PERF ORMANCE AND IS ELE CTRICALLY CONNECTED TO G ND
INSIDE THE PACKAGE. IT IS RECOMMENDED THAT THE EXP OSED PAD
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.
4 4 EN
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.
5 5 PG
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.
6 6 GND Ground.
7 7 SS Soft Start. A capacitor connected to this pin determines the soft start time.
8 8 NC Not Connected. No internal connection.
9 N/A SENSE
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.
N/A 9 ADJ Adjust. A resistor divider from VOUT to ADJ sets the output voltage.
10, 11, 12,
13, 14
10, 11, 12,
13, 14
17 (EPAD) 17 (EPAD)
VOUT
Exposed
paddle
(EPAD)
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.
07718-004
Rev. B | Page 6 of 20
Page 7
ADP1752/ADP1753
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 1.9 V, V
1.520
1.515
1.510
1.505
1.500
1.495
OUTPUT VOLTAGE (V)
1.490
1.485
1.480
= 1.5 V, I
OUT
LOAD = 400mA
–40–52585125
= 10 mA, CIN = 4.7 µF, C
OUT
LOAD = 10mA
LOAD = 100mA
LOAD = 800mA
JUNCTION TEM P ERATURE (°C)
Figure 5. Output Voltage vs. Junction Temperature
= 4.7 µF, TA = 25°C, unless otherwise noted.
OUT
1000
900
800
700
600
500
400
300
GROUND CURRENT (µA)
200
100
0
–40–52585125
07718-105
Figure 8. Ground Current vs. Junction Temperature
LOAD = 800mA
LOAD = 400mA
LOAD = 100mA
LOAD = 10mA
JUNCTION TE M P ERATURE (°C)
07718-108
1.520
1.515
1.510
1.505
1.500
1.495
OUTPUT VOLTAGE (V)
1.490
1.485
1.480
101001k
LOAD CURRENT (mA)
Figure 6. Output Voltage vs. Load Current
1.520
1.515
1.510
1.505
1.500
1.495
OUTPUT VOLTAGE (V)
1.490
1.485
1.480
1.83.63.43.23.02.82.62.42.22.0
LOAD = 10mA
LOAD = 400mA
INPUT VOLTAGE (V)
LOAD = 100mA
LOAD = 800mA
Figure 7. Output Voltage vs. Input Voltage
1000
900
800
700
600
500
400
300
GROUND CURRENT (µA)
200
100
0
101001k
07718-106
LOAD CURRENT (mA)
07718-109
Figure 9. Ground Current vs. Load Current
1000
900
800
700
600
500
400
300
GROUND CURRENT (µA)
200
100
0
1.83.63.43.23.02.82.62.42.22.0
07718-107
LOAD = 800mA
LOAD = 400mA
LOAD = 100mA
LOAD = 10mA
INPUT VOLTAGE (V)
07718-110
Figure 10. Ground Current vs. Input Voltage
Rev. B | Page 7 of 20
Page 8
ADP1752/ADP1753
100
90
80
70
60
50
40
30
SHUTDOWN CURRENT ( µA)
20
10
0
–4085603510–15
TEMPERATURE (°C)
1.9V
2.0V
2.4V
2.6V
3.0V
3.6V
Figure 11. Shutdown Current vs. Temperature at Various Input Voltages
Figure 22. Power Supply Rejection Ratio vs. Frequency,
V
= 2.5 V, VIN = 3.5 V
OUT
Rev. B | Page 9 of 20
Page 10
ADP1752/ADP1753
0
1.5V/800mA
–10
–20
–30
–40
–50
PSRR (dB)
–60
–70
–80
–90
2.5V/800mA
0.75V/800mA
101001k10k100k1M10M
1.5V/10mA
2.5V/10mA
0.75V/10mA
FREQUENCY (Hz)
Figure 23. Power Supply Rejection Ratio vs. Frequency and Output Voltage
07718-123
Rev. B | Page 10 of 20
Page 11
ADP1752/ADP1753
THEORY OF OPERATION
The ADP1752/ADP1753 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 0.8 A of output current. Supply current in
shutdown mode is typically 2 µA.
REVERSE POLARI T Y
PROTECTION
0.5V
REF
REVERSE POLARITY
PROTECTION
0.5V
REF
R1
R2
0.9µA
0.9µA
VOUTVIN
SENSE
SS
VOUTVIN
ADJ
SS
7718-019
7718-020
GND
PG
GND
EN
PG
EN
ADP1752
UVLO
SHORT-CIRCUIT
AND THERMAL
PROTECTION
PG
DETECT
SHUTDOWN
Figure 24. ADP1752 Internal Block Diagram
ADP1753
UVLO
SHORT-CIRCUIT
AND THERMAL
PROTECTION
PG
DETECT
SHUTDOWN
Figure 25. ADP1753 Internal Block Diagram
Internally, the ADP1752/ADP1753 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.
The ADP1752 is available in seven fixed output voltage options
between 0.75 V and 2.5 V. The ADP1752 allows for connection
of an external soft start capacitor that controls the output voltage
ramp during startup. The ADP1753 is the adjustable version
with an output voltage that can be set to a value between 0.75 V
and 3.0 V by an external voltage divider. Both devices are controlled by an enable pin (EN).
SOFT START FUNCTION (ADP1752/ADP1753)
For applications that require a controlled startup, the ADP1752/
ADP1753 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 ADP1752/ADP1753 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:
t
= V
SS
where:
t
is the soft start period.
SS
is the 0.5 V reference voltage.
V
REF
C
is the soft start capacitance from SS to GND.
SS
is the current sourced from SS (0.9 µA).
I
SS
When the ADP1752/ADP1753 are disabled (using EN), the soft
start capacitor is discharged to GND through an internal 100 Ω
resistor.
VOLTAGE (V)
× (CSS/ISS) (1)
REF
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
0
024681
Figure 26. V
EN
1nF
4.7nF
10nF
TIME (ms)
Ramp-Up with External Soft Start Capacitor
OUT
0
07718-021
Rev. B | Page 11 of 20
Page 12
ADP1752/ADP1753
1
2
CH1 2.0V
T
B
W
Figure 27. V
CH2 500mV
OUT
EN
V
OUT
V
= 1.5V
500mV/DIV
B
W
OUT
= C
C
M40µsA CH1 920mV
T 9.8%
= 4.7µF
IN
OUT
Ramp-Up with Internal Soft Start
07718-022
ADJUSTABLE OUTPUT VOLTAGE (ADP1753)
The output voltage of the ADP1753 can be set over a 0.75 V to
3.0 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:
V
= 0.5 V × (1 + R1/R2) (2)
OUT
where:
R1 is the resistor from VOUT to ADJ.
R2 is the resistor from ADJ to GND.
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 ADP1752/ADP1753 use the EN pin to enable and disable
the VOUT pin 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
EN
V
OUT
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
1.0
0.9
0.8
0.7
EN THRESHOLD ( V )
0.6
0.5
1.6 1.82.0 2.22.4 2.6 2.8 3.03.2 3.4 3.6
EN ACTIVE
EN INACTIVE
INPUT VOLTAG E ( V)
07718-024
Figure 29. Typical EN Pin Thresholds vs. Input Voltage
POWER-GOOD FEATURE
The ADP1752/ADP1753 provide a power-good pin, PG, to
indicate the status of the output. This open-drain output
requires an external pull-up resistor to V
shutdown, in current limit mode, in 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 ADP1752/ADP1753
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 V
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.
Regulator input voltage brownouts or glitches trigger a power
no-good if V
falls below 90%.
OUT
A normal power-down triggers a power no-good when V
drops below 90%.
. If the part is in
IN
or VIN.
OUT
OUT
1
2
V
= 1.5V
OUT
= C
C
M2.0msA CH1 1.05V
T 29.6%
= 4.7µF
IN
OUT
07718-023
CH1 500mV
B
CH2 500mV
W
500mV/DIV
B
W
Figure 28. Typical EN Pin Operation
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.
Rev. B | Page 12 of 20
Page 13
ADP1752/ADP1753
V
IN
1V/DIV
1
2
2
B
CH1 1.0V
CH3 1.0V
W
B
W
Figure 30. Typical PG Behavior vs. V
V
IN
1V/DIV
1
CH2 500mV
V
OUT
500mV/DIV
T
V
OUT
500mV/DIV
PG
1V/DIV
V
= 1.5V
OUT
= C
C
IN
OUT
B
M40.0µs A CH3 900mV
W
T 50.40%
, VIN Rising (V
OUT
T
= 4.7µF
= 1.5 V)
OUT
07718-025
REVERSE CURRENT PROTECTION FEATURE
The ADP1752/ADP1753 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 V
diode is reverse-biased. If V
OUT
diode becomes forward-biased and conducts current from VOUT
to VIN, potentially causing destructive power dissipation. The
reverse current protection circuitry detects when V
than V
and reverses the direction of the intrinsic diode connec-
IN
tion, 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 V
differential.
4000
3500
3000
2500
2000
1500
REVERSE CURRENT (µA)
1000
is greater than V
IN
OUT
, this
is greater than VIN, the intrinsic
is greater
OUT
to VIN
OUT
2
2
V
= 1.5V
OUT
= C
C
CH1 1.0V
CH3 1.0V
= 4.7µF
IN
OUT
B
W
B
W
Figure 31. Typical PG Behavior vs. V
CH2 500mV
PG
1V/DIV
B
M40.0µs A CH3 900mV
W
T 50.40%
, VIN Falling (V
OUT
= 1.5 V)
OUT
500
0
0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3 3.6
07718-026
Figure 32. Reverse Current vs. V
V
OUT
– VIN (V)
OUT
− VIN
07718-232
Rev. B | Page 13 of 20
Page 14
ADP1752/ADP1753
APPLICATIONS INFORMATION
CAPACITOR SELECTION
Output Capacitor
The ADP1752/ADP1753 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 ADP1752/ADP1753.
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 ADP1752/ADP1753 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
1
2
1mA TO 800mA LOAD STEP, 2V /µs, 500mA/DIV
CH1 500mA Ω
B
W
Figure 33. Output Transient Response, C
T
CH2 50mV
I
LOAD
V
OUT
50mV/DIV
VIN = 3.6V, V
C
IN
B
M1µsA CH1 380mA
W
T 11.6%
I
LOAD
= C
OUT
OUT
= 1.5V
OUT
= 4.7µF
= 4.7 μF
07718-132
Input Bypass 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.
Input and Output Capacitor Properties
Any good quality ceramic capacitors can be used with the
ADP1752/ADP1753, 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.
5
4
3
MURATA P/N GRM 2 19R61A475KE 34
1
2
1mA TO 800mA LOAD STEP, 2V /µs, 500mA/DIV
V
OUT
20mV/DIV
CH1 500mA Ω
B
CH2 20mV
W
B
M1µsA CH1 530mA
W
T 12.2%
Figure 34. Output Transient Response, C
VIN = 3.6V, V
= C
C
IN
OUT
OUT
= 1.5V
OUT
= 22µF
= 22 μF
07718-133
Rev. B | Page 14 of 20
2
CAPACITANCE (µF )
1
0
024681
VOLTAGE BIAS (V)
0
07718-029
Figure 35. Capacitance vs. Voltage Bias Characteristics
Equation 3 can be used to determine the worst-case capacitance
accounting for capacitor variation over temperature, component
tolerance, and voltage.
C
= C
EFF
× (1 − TEMPCO) × (1 − TOL) (3)
OUT
where:
C
is the effective capacitance at the operating voltage.
EFF
TEMPCO is the worst-case capacitor temperature coefficient.
TOL is the worst-case component tolerance.
Page 15
ADP1752/ADP1753
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 C
= 4.46 F at 1.8 V, as shown in Figure 35.
OUT
Substituting these values in Equation 3 yields
C
= 4.46 F × (1 − 0.15) × (1 − 0.1) = 3.41 F
EFF
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 ADP1752/ADP1753, 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 ADP1752/ADP1753 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
ADP1753/ADP1753 inputs and the output behave in a predictable manner during power-up.
CURRENT-LIMIT AND THERMAL OVERLOAD
PROTECTION
The ADP1752/ADP1753 are protected against damage due to
excessive power dissipation by current-limit and thermal
overload protection circuits. The ADP1752/ADP1753 are
designed to reach current limit when the output load reaches
1.4 A (typical). When the output load exceeds 1.4 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 ADP1752/ADP1753 reach current limit so
that only 1.4 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 1.4 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 1.4 A 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.
Rev. B | Page 15 of 20
THERMAL CONSIDERATIONS
To guarantee reliable operation, the junction temperature of the
ADP1752/ADP1753 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 (θ
dent 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. Tab le 6 shows typical
θ
values for the 16-lead LFCSP for various PCB copper sizes.
JA
Tabl e 7 shows typical Ψ
Table 6. Typical θ
values for the 16-lead LFCSP.
JB
Values
JA
Copper Size (mm2) θJA (°C/W), LFCSP
01 130
100 80
500 69
1000 54
6400 42
1
Device soldered to minimum size pin traces.
Table 7. Typical ΨJB Values
Copper Size (mm2) ΨJB (°C/W) @ 1 W
100 32.7
500 31.5
1000 25.5
The junction temperature of the ADP1752/ADP1753 can be
calculated from the following equation:
T
= TA + (PD × θJA) (4)
J
where:
T
is the ambient temperature.
A
P
is the power dissipation in the die, given by
D
= [(VIN − V
P
D
OUT
) × I
] + (VIN × I
LOAD
where:
V
and V
IN
I
is the load current.
LOAD
is the ground current.
I
GND
are the input and output voltages, respectively.
OUT
Power dissipation due to ground current is quite small and can
be ignored. Therefore, the junction temperature equation can
be simplified as follows:
T
= TA + {[(VIN − V
J
OUT
) × I
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, V
differentials, and areas of PCB copper.
). The θJA value is depen-
JA
) (5)
GND
] × θJA} (6)
LOAD
IN
to V
OUT
Page 16
ADP1752/ADP1753
T
T
T
T
T
T
140
120
(°C)
J
100
80
60
40
JUNCTION TEMPERATUR E ,
20
0
0.250.751.251.752.252.75
MAX JUNCTION
TEMPERATURE
LOAD = 800mA
LOAD = 10mA
VIN – V
OUT
(V)
LOAD = 400mA
LOAD = 200mA
LOAD = 100mA
LOAD = 50mA
Figure 36. 6400 mm2 of PCB Copper, TA = 25°C, LFCSP
07718-135
140
120
(°C)
J
100
80
60
40
JUNCTION TEMPERATUR E ,
20
0
0.250.751.251.752.252.75
MAX JUNCTION
TEMPERATURE
LOAD = 800mA
LOAD = 400mA
LOAD = 10mA
VIN – V
OUT
(V)
LOAD = 200mA
LOAD = 100mA
LOAD = 50mA
Figure 39. 6400 mm2 of PCB Copper, TA = 50°C, LFCSP
07718-138
140
120
(°C)
J
100
80
60
40
JUNCTION TEMPERATUR E ,
20
0
0.250.751.251.752.252.75
MAX JUNCTION
TEMPERATURE
LOAD = 800mA
LOAD = 10mA
VIN – V
LOAD = 400mA
LOAD = 50mA
(V)
OUT
LOAD = 200mA
LOAD = 100mA
Figure 37. 500 mm2 of PCB Copper, TA = 25°C, LFCSP
140
120
(°C)
J
100
80
60
40
JUNCTION TEMPERATUR E ,
20
0
0.250.751.251.752.252.75
MAX JUNCTION
TEMPERATURE
LOAD = 800mA
LOAD = 10mA
VIN – V
LOAD = 400mA
(V)
OUT
LOAD = 200mA
LOAD = 100mA
LOAD = 50mA
Figure 38. 0 mm2 of PCB Copper, TA = 25°C, LFCSP
140
120
(°C)
J
JUNCTION TEMPERATUR E ,
07718-136
LOAD = 800mA
100
80
60
40
20
0
0.250.751.251.752.252.75
VIN – V
MAX JUNCTION
TEMPERATURE
LOAD = 400mA
LOAD = 50mA
LOAD = 10mA
(V)
OUT
LOAD = 200mA
LOAD = 100mA
07718-139
Figure 40. 500 mm2 of PCB Copper, TA = 50°C, LFCSP
140
120
(°C)
J
100
80
60
40
JUNCTION TEMPERATUR E ,
20
0
0.250.751.251.752.252.75
07718-137
LOAD =
800mA
LOAD = 400mA
LOAD = 10mA
VIN – V
OUT
(V)
MAX JUNCTION
TEMPERATURE
LOAD = 200mA
LOAD = 100mA
LOAD = 50mA
07718-140
Figure 41. 0 mm2 of PCB Copper, TA = 50°C, LFCSP
Rev. B | Page 16 of 20
Page 17
ADP1752/ADP1753
T
T
T
T
In cases where the board temperature is known, the thermal
characterization parameter, Ψ
junction temperature rise. Maximum junction temperature (T
is calculated from the board temperature (T
dissipation (P
T
= TB + (PD × ΨJB) (7)
J
) using the following formula:
D
, can be used to estimate the
JB
) and power
B
)
J
Figure 42 through Figure 45 show junction temperature calculations for different board temperatures, load currents, V
V
differentials, and areas of PCB copper.
OUT
140
120
(°C)
J
100
80
60
40
JUNCTION TEMPERATUR E ,
20
0
0.250.751.251.752.252.75
Figure 42. 500 mm
140
120
(°C)
J
100
80
60
40
JUNCTION TE M PERATURE,
20
MAX JUNCTION
TEMPERATURE
LOAD = 800mA
LOAD = 400mA
LOAD = 200mA
LOAD = 100mA
LOAD = 50mA
LOAD = 10mA
VIN – V
(V)
OUT
2
of PCB Copper, TB = 25°C, LFCSP
MAX JUNCTION
TEMPERATURE
LOAD = 800mA
LOAD = 400mA
LOAD = 200mA
LOAD = 100mA
LOAD = 50mA
LOAD = 10mA
to
IN
07718-141
140
120
(°C)
J
100
80
60
40
JUNCTION TEMPERATUR E ,
20
0
0.250.751.251.752.252.75
Figure 44. 1000 mm
140
120
(°C)
J
100
80
60
40
JUNCTION TE M PERATURE,
20
0
0.250.751.251.752.252.75
Figure 45. 1000 mm
MAX JUNCTION
TEMPERATURE
LOAD = 800mA
LOAD = 400mA
LOAD = 200mA
LOAD = 100mA
LOAD = 50mA
LOAD = 10mA
VIN – V
2
of PCB Copper, TB = 25°C, LFCSP
MAX JUNCTION
TEMPERATURE
VIN – V
2
of PCB Copper, TB = 50°C, LFCSP
(V)
OUT
LOAD = 50mA
LOAD = 10mA
(V)
OUT
LOAD = 800mA
LOAD = 400mA
LOAD = 200mA
LOAD = 100mA
07718-143
07718-144
0
0.250.751.251.752.252.75
Figure 43. 500 mm
VIN – V
(V)
OUT
2
of PCB Copper, TB = 50°C, LFCSP
07718-142
Rev. B | Page 17 of 20
Page 18
ADP1752/ADP1753
PCB LAYOUT CONSIDERATIONS
Heat dissipation from the package can be improved by increasing the amount of copper attached to the pins of the ADP1752/
ADP1753. However, as shown in Tab l e 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.
Figure 46. Evaluation Board
07718-145
Figure 47. Typical Board Layout—Top Side
Figure 48. Typical Board Layout—Bottom Side
7718-233
7718-146
Rev. B | Page 18 of 20
Page 19
ADP1752/ADP1753
OUTLINE DIMENSIONS
PIN 1
INDICATOR
1.00
0.85
0.80
12° MAX
SEATING
PLANE
4.00
BSC SQ
TOP
VIEW
0.80 MAX
0.65 TYP
0.35
0.30
0.25
3.75
BSC SQ
0.20 REF
0.60 MAX
0.65 BSC
0.05 MAX
0.02 NOM
COPLANARITY
0.75
0.60
0.50
0.08
0.60 MAX
(BOTTOM VIEW)
16
13
12
9
8
5
1.95 BSC
FOR PROPER CONNECTION O F
THE EXPOSED PAD, REFER TO
THE PIN CONF IGURATION AND
FUNCTION DES CRI PTIONS
SECTION O F THIS DATA S HE E T.
PIN 1
INDICATOR
1
4
5
2
.
2
0
1
.
2
9
.
1
5
0.25 MIN
Q
S
COMPLIANT TO JEDEC STANDARDS MO-220-VGGC
072808-A
Figure 49. 16-Lead Lead Frame Chip Scale Package [LFCSP_VQ]
4 mm × 4 mm Body, Very Thin Quad
(CP-16-4)
Dimensions shown in millimeters
ORDERING GUIDE
Model1 Temperature Range Output Voltage (V) Package Description Package Option
ADP1752ACPZ-0.75R7 −40°C to +125°C 0.75 16-Lead LFCSP_VQ CP-16-4
ADP1752ACPZ-1.0-R7 −40°C to +125°C 1.0 16-Lead LFCSP_VQ CP-16-4
ADP1752ACPZ-1.1-R7 −40°C to +125°C 1.1 16-Lead LFCSP_VQ CP-16-4
ADP1752ACPZ-1.2-R7 −40°C to +125°C 1.2 16-Lead LFCSP_VQ CP-16-4
ADP1752ACPZ-1.5-R7 −40°C to +125°C 1.5 16-Lead LFCSP_VQ CP-16-4
ADP1752ACPZ-1.8-R7 −40°C to +125°C 1.8 16-Lead LFCSP_VQ CP-16-4
ADP1752ACPZ-2.5-R7 −40°C to +125°C 2.5 16-Lead LFCSP_VQ CP-16-4
ADP1753ACPZ-R7 −40°C to +125°C Adjustable from 0.75 to 3.0 16-Lead LFCSP_VQ CP-16-4
ADP1752-1.5-EVALZ 1.5 Evaluation Board
ADP1752-BL1-EVAL Blank Evaluation Board
ADP1753-EVALZ Adjustable Evaluation Board
ADP1753-BL1-EVAL Blank Evaluation Board