NSC LP3987

LP3987
Micropower micro SMD 150 mA Ultra Low-Dropout
CMOS Voltage Regulators with sleep MODE
General Description
Features
The LP3987 is a 150mA fixed output voltage regulator with
very low dropout voltage designed specially to meet requirements of battery-powered applications. The additional sleep
MODE feature will reduce current consumption during
standby operation to prolong the usage of battery.
Dropout Voltage: 100mV maximum dropout with 150mA
load.
Shutdown: Less than 1µA quiescent current.
n Miniature 5-I/O micro SMD package
n Stable with ceramic and high quality tantalum output
capacitors
n Logic controlled enable
n Thermal Shutdown and short-circuit current limit
Sleep Mode: Typically 14µA quiescent current during sleep
MODE to reduce battery consumption.
Enhanced Stability: The LP3987 is stable with minimum
1µF ± 20% low ESR ceramic output capacitor as low as 5mΩ
and high quality tantalum capacitors.
The LP3987 is available in thin and thick 5 Bump micro SMD
package. Performance is specified for −40˚C to 125˚C.
This device is available with output voltage options of 2.6V,
2.8V, & 2.85V. For other voltage options, please contact
National Semiconductor Corporation.
Key Specifications
n
n
n
n
n
n
n
n
2.7 to 6.0V input range
Guaranteed 150 mA output current
1µA quiescent current on shutdown
100 mV maximum dropout with 150 mA load
50dB PSRR at 10KHz
Sleep MODE features
Over temperature & over current protection
−40˚C to +125˚C junction temperature range for
operation
Applications
n
n
n
n
n
n
n
CDMA cellular handsets
Wideband CDMA cellular handsets
GSM cellular handsets
Portable information appliances
µP/DSP Power Supplies
Digital Cameras
SRAM Backup
Typical Application Circuit
20022201
© 2003 National Semiconductor Corporation
DS200222
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LP3987 Micropower micro SMD 150 mA Ultra Low-Dropout CMOS Voltage Regulators with sleep
MODE
February 2003
LP3987
Block Diagram
LP3987
20022202
Connection Diagram
20022271
Top View
5 I/O micro SMD Package
See NS Package Number BPA05/TLA05/BLA05
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2
LP3987
Pin Descriptions
Name
micro SMD*
Function
VEN
A1
Enable Input Logic, Enable High
GND
B2
Common Ground
VOUT
C1
Output voltage of the LDO
VIN
C3
Input voltage of the LDO
MODE
A3
Power Mode Control, Active = 1, Sleep
Mode = 0
* The pin numbering scheme for the micro SMD package was revised in April, 2002 to conform to JEDEC standard. Only the pin numbers
were revised. No changes to the physical location of the inputs/outputs were made. For reference purposes, the obsolete numbering
scheme had VEN as pin 1, GND as pin 2, VOUT as pin 3, VIN as pin 4, and MODE as pin 5.
Ordering Information
BP refers to a 0.170mm bump size with package height of 0.9mm
Output
Voltage (V)
Grade
2.85*
STD
LP3987 Supplied as 250
Units, Tape and Reel
LP3987IBP-2.85
LP3987 Supplied as 3000
Units, Tape and Reel
LP3987IBPX-2.85
* Please contact National Semiconductor for availability
BL refers to a 0.300mm bump size with package height of 0.9mm
Output
Voltage (V)
Grade
2.85
STD
LP3987 Supplied as 250
Units, Tape and Reel
LP3987IBL-2.85
LP3987 Supplied as 3000
Units, Tape and Reel
LP3987IBLX-2.85
* Please contact National Semiconductor for availability
TL refers to a 0.300mm bump size with package height of 0.6mm
Output
Voltage (V)
Grade
LP3987 Supplied as 250
Units, Tape and Reel
LP3987 Supplied as 3000
Units, Tape and Reel
2.5
STD
LP3987ITL-2.5
LP3987ITLX-2.5
2.6
STD
LP3987ITL-2.6
LP3987ITLX-2.6
2.8
STD
LP3987ITL-2.8
LP3987ITLX-2.8
2.85
STD
LP3987ITL-2.85
LP3987ITLX-2.85
3.0*
STD
LP3987ITL-3.0
LP3987ITLX-3.0
* Please contact National Semiconductor for availability
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LP3987
Absolute Maximum Ratings
ESD (Note 4)
(Notes 1,
2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Human Body Model
2KV
Machine Model
200V
Maximum Power Dissipation (Note 3)
θJA (micro SMD small bump)
255˚C/W
−0.3 to 6.5V
VIN
VEN, VMODE
Operating Ratings (Notes 1, 2)
−0.3 to 6.5V
VOUT
−0.3V to(V IN+
0.3V) ≤ 6.5
Storage Temperature
VIN
VOUT+ 200mV to 6V
VEN, VMODE
−65˚C to +150˚C
0 to 6.0V
Junction Temperature
−40˚C to +125˚C
Maximum Power Dissipation (Note 3)
392mW at 25˚C
Electrical Characteristics
Unless otherwise specified: VEN = 1.8V, MODE = 1.8V, VIN = VOUT(nom) + 0.5V, CIN = 1 µF, IOUT = 1mA, COUT = 1 µF. Typical
values and limits appearing in standard typeface are for TJ = 25˚C. Limits appearing in boldface type apply over the entire
junction temperature range for operation, −40˚C to +125˚C. (Note 10) (Note 11)
Symbol
Parameter
Output Voltage
Tolerance
Conditions
Limit
Units
Min
Max
IOUT = 1mA, 25˚C
-2
2
IOUT = 1mA
−3
3
% of
VOUT(nom)
−0.1
0.1
%/V
0.0004
0.002
%/mA
Line Regulation Error
VIN = (VOUT(nom) + 0.5V) to
6.0V,
IOUT = 1 mA
∆VOUT
Typ
Load Regulation Error
IOUT = 1mA to 150 mA
Dropout Voltage
(Note 6)
IOUT = 1mA
0.4
2
IOUT = 150mA
60
100
∆VOUT(SLEEP)
Output Voltage
difference at MODE =
0V
MODE = 0V, (Note 7)
Transient
Response
Line Transient
Response (Note 5)
MODE = 1.8V, ILOAD =
100mA, TRISE = TFALL =
10µS,
VIN = 600mV P-P AC Square
wave, (Note 8)
21
mVpp
Load Transient
Response (Note 5)
MODE = 1.8V, COUT = 4.7µF,
TRISE = TFALL = 100nS,
VIN = 3.1V, 3.6V, 4.2V, (Notes
9, 12)
100
mVpk
VIN = VOUT(nom) + 1V, MODE
= 1.8V, f = < 10 kHz,
IOUT = 1mA
50
VIN = VOUT(nom) + 1V, MODE
= 0V, f = < 10 kHz,
IOUT = 1mA
10
MODE = 1.8V, IOUT = 0mA,
VIN = 4.2V
85
120
MODE = 1.8V, IOUT = 150mA,
VIN = 4.2V
160
200
PSRR
Power Supply Rejection
Ratio (Note 5)
IQ(ON)
Quiescent Current
-150
+100
mV
mV
dB
µA
IQ(OFF)
Quiescent Current
ENABLE = 0V, VIN = 4.2V
1
3
µA
IQ(SLEEP)
Current in Standby
Mode
MODE = 0V, IOUT = 50µA, VIN
= 4.2V
14
21
µA
ISC
Short Circuit Current
Limit (Note 5)
Output Grounded
600
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4
mA
(Continued)
Unless otherwise specified: VEN = 1.8V, MODE = 1.8V, VIN = VOUT(nom) + 0.5V, CIN = 1 µF, IOUT = 1mA, COUT = 1 µF. Typical
values and limits appearing in standard typeface are for TJ = 25˚C. Limits appearing in boldface type apply over the entire
junction temperature range for operation, −40˚C to +125˚C. (Note 10) (Note 11)
Symbol
Parameter
Conditions
Typ
Limit
Min
Max
Units
ISC(SLEEP)
Short Circuit Current in
Sleep MODE
Output Grounded
IOUT(ON)
Maximum Output
Current at MODE =
1.8V
MODE = 1.8V
IOUT(SLEEP)
Maximum Output
Current at MODE = 0V
MODE = 0V
en
Output Noise Voltage,
(Note 5)
BW = 10 Hz to 100 kHz,
COUT = 1µF
70
µVrms
TSHUTDOWN
Shutdown Temperature
(Note 5)
Sleep MODE = 1.8V
155
˚C
0.015
µA
28
43
mA
150
mA
3
mA
Logic Control Characteristics
IEN
Maximum Input Current
at EN
VEN = 0 and VIN= 6.0V
VIL
Logic Low Input
Threshold
VIN = 3.05 to 6V
VIH
Logic High Input
Threshold
VIN = 3.05 to 6V
VMODE_L
Logic Low Input
Threshold
VIN = 3.05 to 6V
VMODE_H
Logic High Input
Threshold
VIN = 3.05 to 6V
IMODE
Maximum Input Current
at VMODE
VMODE = 0 and VIN = 6.0V
0.5
V
1.2
0.5
V
V
1.2
V
µA
0.015
Timing Characteristics
TON
Turn on Time (On
Mode), (Notes 5, 13)
MODE = 1.8V, COUT = 4.7µF
Turn on Time (Sleep
Mode), (Note 5), (Note
14)
MODE = 0V, COUT = 4.7µF
TSLEEP
Sleep to On Mode
Settle Time, (Note 5),
(Note 15)
COUT = 4.7µF, Enable = 1.8V
TMODE
250
170
µs
5
ms
0.5
300
µs
200
Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device
is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the Electrical
Characteristics tables.
Note 2: All voltages are with respect to the potential at the GND pin.
Note 3: The Absolute Maximum power dissipation depends on the ambient temperature and can be calculated using the formula:
PD = (TJ - TA)/θJA,
Where TJ is the junction temperature, TA is the ambient temperature, and θJA is the junction-to-ambient thermal resistance. For instant, if VIN in target application
is 4.2V and worse case current consumption is 90mA. Therefore PMAX_DISSIPATION = (4.2-2.7)*0.09 =135mW. With PMAX_DISSIPATION is 135mW, TJmax is 125˚C
and worse case ambient temperature (TA ) in target application is 85˚C, θJA = (125-85)/0.135 = 296˚C/W.
Note 4: The human body model is 100pF discharged through 1.5kΩ.
Note 5: This electrical specification is guaranteed by design.
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LP3987
Electrical Characteristics
LP3987
Electrical Characteristics
(Continued)
Note 6: Dropout voltage is defined as the input to output voltage differential at which the output voltage falls to 100mV below the nominal output voltage. VIN less
than minimum operating voltage may be used for test purposes.
Note 7: On/Sleep Mode voltage tolerance and current capability requirement.
20022205
Note 8: Line Transient response requirement:
20022206
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LP3987
Electrical Characteristics
(Continued)
Note 9: Load Transient response requirement:
20022207
Note 10: All limits are guaranteed. All electrical characteristics having room-temperature limits are tested during production with TJ = 25˚C. All hot and cold limits
are guaranteed by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Note 11: The nominal output voltage, which is labeled VOUT(nom), is the output voltage measured with the input 0.5V above VOUT(nom) and a 1mA load.
Note 12: During transient recovery, output voltage should not be oscillating.
Note 13: TON is measured from rising edge of Enable with MODE = 1.8V to when VOUT reaches 95% of final value.
Note 14: TSLEEP is measured from rising edge of Enable with MODE = 0V to when VOUT reaches 95% of final value.
Note 15: TMODE is measured from rising edge of MODE with ENABLE = 1.8V to time before full current capability.
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LP3987
Typical Performance Characteristics
Unless otherwise specified, CIN = COUT = 1 µF Ceramic, VIN
= VOUT(nom) + 0.5V, TA = 25˚C, Enable pin is tied to VIN, MODE = 1.8V.
Ground Current @ TA = 25˚C
Ground Current @ TA = 40˚C
20022228
20022226
Ground Current @ TA = 85˚C
Dropout Voltage vs Load Current
20022229
20022227
Ripple Rejection (VIN = VOUT(nom) + 1V,
CIN = COUT = 1µF, IL = 1mA)
Ripple Rejection (CIN = COUT = 1µF, IL = 1mA)
20022208
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20022209
8
TSLEEP @ MODE = 0V, COUT = 1µF,
IL = 1mA
TSLEEP @ MODE = 0V, COUT = 1µF,
IL = 1mA
20022213
20022214
TON @ MODE = 1.8V, COUT = 1µF,
IL = 150mA
TON @ MODE = 1.8V, COUT = 1µF,
IL = 150mA
20022215
20022216
TSLEEP @ MODE = 0V, COUT = 4.7µF,
IL = 1mA
TSLEEP @ MODE = 0V, COUT = 4.7µF,
IL = 1mA
20022217
20022218
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LP3987
Typical Performance Characteristics Unless otherwise specified, CIN = COUT = 1 µF Ceramic, VIN =
VOUT(nom) + 0.5V, TA = 25˚C, Enable pin is tied to VIN, MODE = 1.8V. (Continued)
LP3987
Typical Performance Characteristics Unless otherwise specified, CIN = COUT = 1 µF Ceramic, VIN =
VOUT(nom) + 0.5V, TA = 25˚C, Enable pin is tied to VIN, MODE = 1.8V. (Continued)
TON @ MODE = 1.8V, COUT = 4.7µF,
IL = 150mA
TON @ MODE = 1.8V, COUT = 4.7µF,
IL = 150mA
20022219
20022220
TMODE Measurement @ VIN = 3.05V
TMODE Measurement @ VIN = 3.6V
20022225
20022224
TMODE Measurement @ VIN = 4.2V
Output Short Circuit Current
20022222
20022223
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Load Transient Response @ VIN = 3.1V
Output Short Circuit Current
20022221
20022273
Load Transient Response @ VIN = 3.35V
Load Transient Response @ VIN = 3.6V
20022230
20022231
Load Transient Response @ VIN = 4.2V
Load Transient Response @ VIN = 3.1V, COUT = 1µF
20022232
20022272
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LP3987
Typical Performance Characteristics Unless otherwise specified, CIN = COUT = 1 µF Ceramic, VIN =
VOUT(nom) + 0.5V, TA = 25˚C, Enable pin is tied to VIN, MODE = 1.8V. (Continued)
LP3987
Typical Performance Characteristics Unless otherwise specified, CIN = COUT = 1 µF Ceramic, VIN =
VOUT(nom) + 0.5V, TA = 25˚C, Enable pin is tied to VIN, MODE = 1.8V. (Continued)
Load Transient Response @ VIN = 3.35V, COUT = 1µF
Load Transient Response @ VIN = 4.2V, COUT = 1µF
20022233
20022234
Load Transient Response @ VIN = 3.6V, COUT = 1µF
Output Voltage Change vs Temperature
20022235
20022236
Line Transient Response
Line Transient Response
20022265
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20022266
12
Line Transient Response
Line Transient Response
20022267
20022268
Line Transient Response
Line Transient Response
20022269
20022270
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LP3987
Typical Performance Characteristics Unless otherwise specified, CIN = COUT = 1 µF Ceramic, VIN =
VOUT(nom) + 0.5V, TA = 25˚C, Enable pin is tied to VIN, MODE = 1.8V. (Continued)
LP3987
Tantalum capacitors are less desirable than ceramic for use
as output capacitors because they are more expensive when
comparing equivalent capacitance and voltage ratings in the
1µF to 4.7µF range.
Another important consideration is that tantalum capacitors
have higher ESR values than equivalent size ceramics. This
means that while it may be possible to find a tantalum
capacitor with an ESR value within the stable range, it would
have to be larger in capacitance (which means bigger and
more costly ) than a ceramic capacitor with the same ESR
value. It should also be noted that the ESR of a typical
tantalum will increase about 2:1 as the temperature goes
from 25˚C down to −40˚C, so some guard band must be
allowed.
Application Hints
EXTERNAL CAPACITORS
Like any low-dropout regulator, the LP3987 requires external
capacitors for regulator stability. The LP3987 is specifically
designed for portable applications requiring minimum board
space and smallest components. These capacitors must be
correctly selected for good performance.
INPUT CAPACITOR
An input capacitance of ) 1µF is required between the
LP3987 input pin and ground (the amount of the capacitance
may be increased without limit).
This capacitor must be located a distance of not more than
1cm from the input pin and returned to a clean analog
ground. Any good quality ceramic, tantalum, or film capacitor
may be used at the input.
ON/OFF INPUT OPERATION
The LP3987 is turned off by pulling the VEN pin low, and
turned on by pulling it high. If this feature is not used, the VEN
pin should be tied to VIN to keep the regulator output on at all
time. To assure proper operation, the signal source used to
drive the VEN input must be able to swing above and below
the specified turn-on/off voltage thresholds listed in the Electrical Characteristics section under VIL and VIH.
Important: Tantalum capacitors can suffer catastrophic failures due to surge current when connected to a lowimpedance source of power (like a battery or a very large
capacitor). If a tantalum capacitor is used at the input, it must
be guaranteed by the manufacturer to have a surge current
rating sufficient for the application.
MODE OPERATION
The LP3987 enters sleep mode by pulling MODE = 0V
externally to reduce current during standby operation. During
sleep mode, LP3987 consumes only 14µA of quiescent current and supplies up to 3mA of current. The device returns to
active mode by pulling MODE = 1.8V. If this function is not
used, the MODE pin should be tied to VIN.
There are no requirements for the ESR on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance will be ) 1µF over the entire operating temperature
range.
OUTPUT CAPACITOR
The LP3987 is designed specifically to work with very small
ceramic output capacitors. A ceramic capacitor (dielectric
types Z5U, Y5V or X7R) in 1 to 4.7 µF range with 5mΩ to
500mΩ ESR range is suitable in the LP3987 application
circuit.
It may also be possible to use tantalum or film capacitors at
the output, but these are not as attractive for reasons of size
and cost (see next section Capacitor Characteristics).
The output capacitor must meet the requirement for minimum amount of capacitance and also have an ESR (Equivalent Series Resistance) value which is within a stable range
(5 mΩ to 500 mΩ).
THERMAL PROTECTION
The LP3987 has internal thermal protection circuitry to disable the internal pass transistor if the junction temperature
exceeds 125˚C to allow the device to cool down. The pass
transistor will turn on when temperature falls below the maximum operating junction temperature of 125˚C. This feature
is designed to protect the device in the event of fault conditions. For normal operation, it is suggested to limit the device
junction temperature to less than 125˚C.
MICRO SMD MOUNTING
The micro SMD package requires specific mounting techniques which are detailed in National Semiconductor Application Note (AN-1112). Referring to the section Surface
Mount Technology (SMT) Assembly Considerations, it
should be noted that the pad style which must be used with
the 5 pin package is NSMD (non-solder mask defined) type.
For best results during assembly, alignment ordinals on the
PC board may be used to facilitate placement of the micro
SMD device.
NO-LOAD STABILITY
The LP3987 will remain stable and in regulation with no
external load. This is specially important in CMOS RAM
keep-alive applications.
CAPACITOR CHARACTERISTICS
The LP3987 is designed to work with ceramic capacitors on
the output to take advantage of the benefits they offer: for
capacitance values in the range of 1µF to 4.7µF range,
ceramic capacitors are the smallest, least expensive and
have the lowest ESR values (which makes them best for
eliminating high frequency noise). The ESR of a typical 1µF
ceramic capacitor is in the range of 20 mΩ to 40 mΩ, which
easily meets the ESR requirement for stability by the
LP3987. The ceramic capacitor’s capacitance can vary with
temperature. Most large value ceramic capacitors () 2.2µF)
are manufactured with Z5U or Y5V temperature characteristics, which results in the capacitance dropping by more than
50% as the temperature goes from 25˚C to 85˚C.
A better choice for temperature coefficient in a ceramic
capacitor is X7R, which holds the capacitance within ± 15%.
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MICRO SMD LIGHT SENSITIVITY
Exposing the micro SMD device to direct sunlight will cause
misoperation of the device. Light sources such as Halogen
lamps can effect electrical performance if brought near to the
device. The wavelengths which have most detrimental effect
are reds and infra-reds, which means that the fluorescent
lighting used inside most buildings has very little effect on
performance. A micro SMD test board was brought to within
1cm of a fluorescent desk lamp and the effect on the regulated output voltage was negligible, showing a deviation of
less than 0.1% from nominal.
14
LP3987
Physical Dimensions
inches (millimeters) unless otherwise noted
micro SMD, 5 Bump, Package (TLA05)
NS Package Number TLA05ADA
The dimensions for X1, X2 and X3 are given as:
X1 = 1.006 +/− 0.03mm
X2 = 1.438 +/− 0.03mm
X3 = 0.600 +/− 0.075mm
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LP3987
Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
micro SMD, 5 Bump, Package (BLA05)
NS Package Number BLA05ADC
The dimensions for X1, X2 and X3 are given as:
X1 = 1.006 +/− 0.03mm
X2 = 1.438 +/− 0.03mm
X3 = 0.995 +/− 0.10mm
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16
inches (millimeters) unless otherwise noted (Continued)
micro SMD, 5 Bump, Package (BPA05)
NS Package Number BPA05CMC
The dimensions for X1, X2 and X3 are given as:
X1 = 0.828 +/− 0.03mm
X2 = 1.387 +/− 0.03mm
X3 = 0.900 +/− 0.10mm
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DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
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into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
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Support Center
Email: [email protected]
Tel: 1-800-272-9959
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LP3987 Micropower micro SMD 150 mA Ultra Low-Dropout CMOS Voltage Regulators with sleep
MODE
Physical Dimensions