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LP3990
150mA Linear Voltage Regulator for Digital Applications
LP3990 150mA Linear Voltage Regulator for Digital Applications
November 2004
General Description
The LP3990 regulator is designed to meet the requirements
of portable, battery-powered systems providing an accurate
output voltage, low noise, and low quiescent current. The
LP3990 will provide a 0.8V output from the low input voltage
of 2V at up to 150mA load current. When switched into
shutdown mode via a logic signal at the enable pin, the
power consumption is reduced to virtually zero.
The LP3990 is designed to be stable with space saving
ceramic capacitors as small as 0.47µF.
Performance is specified for a -40˚C to 125˚C junction temperature range.
For output voltages other than 0.8V, 1.35V, 1.5V, 1.8V, 2.5V,
2.8V, or 3.3V please contact your local NSC sales office.
Features
n 1% Voltage Accuracy at Room Temperature
n Stable with Ceramic Capacitor
n Logic Controlled Enable
n No Noise Bypass Capacitor Required
n Thermal-Overload and Short-Circuit Protection
Typical Application Circuit
Key Specifications
n Input Voltage Range 2.0 to 6.0V
n Output Voltage Range 0.8 to 3.3V
n Output Current 150mA
n Output Stable - Capacitors 0.47uF
n Virtually Zero I
n Very Low I
n Low Output Noise 150uV
n PSRR 55dB at 1kHz
n Fast Start Up 105us
(Disabled)
Q
(Enabled) 43uA
Q
<
10nA
RMS
Package
All available in Lead Free option.
4 Pin micro SMD 1 mm x 1.28mm
6 pin LLP (SOT23 footprint)
SOT23 - 5
For other package options contact your NSC sales office.
Applications
n Cellular Handsets
n Hand-Held Information Appliances
20076801
© 2004 National Semiconductor Corporation DS200768 www.national.com
Pin Descriptions
LP3990
Pin No Symbol Name and Function
micro
LLP
5A23 V
2 A1 2 GND Common Ground. Connect to Pad.
1B15 V
6B21 VINVoltage Supply Input. A 1.0µF capacitor should be connected
3 4 N/C No Connection. Do not connect to any other pin.
4 N/C No Connection. Do not connect to any other pin.
Pad GND Common Ground. Connect to Pin 2.
SMD SOT23-5
Connection Diagrams
Packages
EN
Enable Input; Enables the Regulator when ≥ 0.95V.
Disables the Regulator when ≤ 0.4V.
Enable Input has 1MΩ pulldown resistor to GND.
OUT
Voltage output. A 0.47µF Low ESR Capacitor should be
connected to this Pin. Connect this output to the load circuit.
at this input.
Micro SMD, 4 Bump Package
See NS package number TLA04
LLP-6 Package
See NS package number SDE06A
20076803
20076806
www.national.com 2
Connection Diagrams (Continued)
LP3990
SOT23 - 5 Package (MF)
See NS package number MF05A
20076808
www.national.com3
Ordering Information
LP3990
* Please contact Sales Office for Availability
Output
Voltage (V)
0.8 STD LP3990TL-0.8 LP3990TLX-0.8
1.2* STD LP3990TL-1.2 LP3990TLX-1.2
1.35 STD LP3990TL-1.35 LP3990TLX-1.35
1.5 STD LP3990TL-1.5 LP3990TLX-1.5
1.8 STD LP3990TL-1.8 LP3990TLX-1.8
2.5* STD LP3990TL-2.5 LP3990TLX-2.5
2.8 STD LP3990TL-2.8 LP3990TLX-2.8
3.3* STD LP3990TL-3.3 LP3990TLX-3.3
* Please contact Sales Office for Availability
Output
Voltage (V)
0.8 STD LP3990SD-0.8 LP3990SDX-0.8 L085B
1.2* STD LP3990SD-1.2 LP3990SDX-1.2 L086B
1.35* STD LP3990SD-1.35 LP3990SDX-1.35 L150B
1.5 STD LP3990SD-1.5 LP3990SDX-1.5 L087B
1.8 STD LP3990SD-1.8 LP3990SDX-1.8 L088B
2.5 STD LP3990SD-2.5 LP3990SDX-2.5 L090B
2.8* STD LP3990SD-2.8 LP3990SDX-2.8 L091B
3.3* STD LP3990SD-3.3 LP3990SDX-3.3 L092B
Grade
Grade
For micro SMD Package
LP3990 Supplied as 250
Units, Tape and Reel
For LLP-6 Package
LP3990 Supplied as 1000
Units, Tape and Reel
LP3990 Supplied as 3000
Units, Tape and Reel
LP3990 Supplied as 3000
Units, Tape and Reel Package Marking
Package Marking
For SOT23 - 5 Package
* Please contact Sales Office for Availability
Output
Voltage (V)
0.8* STD LP3990MF-0.8 LP3990MFX-0.8 SCCB
1.2* STD LP3990MF-1.2 LP3990MFX-1.2 SCDB
1.35* STD LP3990MF-1.35 LP3990MFX-1.35 SHRB
1.5* STD LP3990MF-1.5 LP3990MFX-1.5 SCEB
1.8* STD LP3990MF-1.8 LP3990MFX-1.8 SCFB
2.5* STD LP3990MF-2.5 LP3990MFX-2.5 SCJB
2.8* STD LP3990MF-2.8 LP3990MFX-2.8 SCKB
3.3* STD LP3990MF-3.3 LP3990MFX-3.3 SCLB
Grade
LP3990 Supplied as 1000
Units, Tape and Reel
LP3990 Supplied as 3000
Units, Tape and Reel Package Marking
www.national.com 4
LP3990
Absolute Maximum Ratings
(Notes 1, 2)
If Military/Aerospace specified devices are required,
ESD (Note 5)
Human Body Model 2KV
Machine Model 200V
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Input Voltage -0.3 to 6.5V
Output Voltage -0.3 to (V
+ 0.3V) to
IN
6.5V (max)
Enable Input Voltage -0.3 to (VIN+ 0.3V) to
6.5V (max)
Junction Temperature 150˚C
Lead/Pad Temp. (Note 3)
Operating Ratings(Note 1)
Input Voltage 2V to 6V
Enable Input Voltage 0 to (V
Junction Temperature -40˚C to 125˚C
Ambient Temperature T
(Note 6)
LLP/SOT23 235˚C
micro SMD 260˚C
Storage Temperature -65 to 150˚C
Continuous Power Dissipation
Internally Limited(Note 4)
Thermal Properties(Note 1)
Junction To Ambient Thermal
Resistance(Note 8)
θ
(LLP-6) 88˚C/W
JA
θ
(microSMD) 220˚C/W
JA
θ
SOT23-5 220˚C/W
JA
Electrical Characteristics
Unless otherwise noted, VEN=950mV, VIN=V
µF. Typical values and limits appearing in normal type apply for T
full junction temperature range for operation, −40 to +125˚C. (Note 13)
Symbol Parameter Conditions Typ
V
∆V
IN
OUT
Input Voltage (Note 14) 2 6 V
Output Voltage Tolerance I
Line Regulation Error V
Load Regulation Error I
V
I
LOAD
I
Q
I
SC
I
OUT
DO
Dropout Voltage I
Load Current (Notes 9, 10) 0 µA
Quiescent Current VEN= 950mV, I
Short Circuit Current Limit (Note 11) 550 1000 mA
Maximum Output Current 150 mA
PSRR Power Supply Rejection Ratio f = 1kHz, I
+ 1.0V, or 2.0V, whichever is higher. CIN= 1 µF, I
OUT
= 1 mA Micro SMD -1 +1
LOAD
= 27˚C. Limits appearing in boldface type apply over the
J
LLP -1.5 +1.5
Over full line
and load
regulation.
=(V
IN
OUT(NOM)
= 1mA
OUT
to 150mA
Micro SMD -2.5 +2.5
LLP -3 +3
+ 1.0V) to 6.0V, 0.02 -0.1 0.1 %/V
V
= 0.8 to 1.95V
OUT
MicroSMD
= 0.8 to 1.95V
V
OUT
LLP, SOT-23
V
= 2.0 to 3.3V
OUT
MicroSMD
= 2.0 to 3.3V
V
OUT
LLP, SOT-23
= 150mA
OUT
(Note 7)
= 0mA 43 80
OUT
= 950mV, I
EN
V
= 0.4V 0.002 0.2
EN
OUT
f = 10kHz, I
OUT
= 150mA 65 120
OUT
= 1mA to 150mA 55
= 150mA 35
Range
A
OUT
-40˚C to 85˚C
= 1 mA, C
Limit
Min Max
0.002 -0.005 0.005
0.003 -0.008 0.008
0.0005 -0.002 0.002
0.002 -0.005 0.005
120
+ 0.3V) to
IN
6.0V (max)
OUT
Units
%/mA
=0.47
%
mV
µAV
dB
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Electrical Characteristics (Continued)
Unless otherwise noted, VEN=950mV, VIN=V
LP3990
µF. Typical values and limits appearing in normal type apply for T
full junction temperature range for operation, −40 to +125˚C. (Note 13)
Symbol Parameter Conditions Typ
e
n
T
SHUTDOWN
Output noise Voltage (Note 10) BW = 10Hz to
Thermal Shutdown Temperature 155
Enable Control Characteristics
I
EN
(Note 12)
V
IL
V
IH
Maximum Input Current at
VENInput
Low Input Threshold VIN=2Vto6V 0.4 V
High Input Threshold VIN=2Vto6V 0.95 V
Timing Characteristics
T
ON
Transient
Turn On Time (Note 10) To 95% Level
Line Transient Response |δV
OUT|Trise=Tfall
Response
Load Transient Response
|δV
|
OUT
Note 1: Absolute Maximum Ratings are limits beyond which damage can 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: For further information on these packages please refer to the following application notes;AN-1112 Micro SMD Package Wafer Level Chip Scale
Package,AN-1187 Leadless Leadframe Package.
Note 4: Internal thermal shutdown circuitry protects the device from permanent damage.
Note 5: The human body model is 100pF discharged through a 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor discharged directly into each
pin.
Note 6: The maximum ambient temperature (T
dissipation of the device in the application (P
following equation: T
Note 7: Dropout voltage is voltage difference between input and output at which the output voltage drops to 100mV below its nominal value. This parameter only
for output voltages above 2.0V.
Note 8: Junction to ambient thermal resistance is dependant on the application and board layout. In applications where high maximum power dissipation is possible,
special care must be paid to thermal dissipation issues in board design.
Note 9: The device maintains the regulated output voltage without the load.
Note 10: This electrical specification is guaranteed by design.
Note 11: Short circuit current is measured with V
Note 12: Enable Pin has 1MΩ typical, resistor connected to GND.
Note 13: All limits are guaranteed. All electrical characteristics having room-temperature limits are tested during production at T
Statistical Quality Control methods. Operation over the temperature specification is guaranteed by correlating the electrical characteristics to process and
temperature variations and applying statistical process control.
Note 14: V
A(max)=TJ(max-op)
IN(MIN)=VOUT(NOM)
-(θJAxP
+ 0.5V, or 2.0V, whichever is higher.
) is dependant on the maximum operating junction temperature (T
A(max)
), and the junction to ambient thermal resistance of the part/package in the application (θJA), as given by the
D(max)
).
D(max)
pulled to 0V and VINworst case = 6.0V.
OUT
+ 1.0V, or 2.0V, whichever is higher. CIN= 1 µF, I
OUT
= 27˚C. Limits appearing in boldface type apply over the
J
OUT
Min Max
V
= 0.8 60
OUT
100kHz,
V
= 1.5 125
OUT
V
= 3.3 180
OUT
Hysteresis 15
V
= 0.0V 0.001 0.1
EN
V
=6V 6 2.5 10
EN
V
= 0.8 80 150
OUT
IN(MIN)
= 600mV
IN
rise=Tfall
= 1µF
OUT
to 6.0V
OUT
V
OUT
= 30µs (Note 10)
= 1µs (Note 10)I
= 1.5 105 200
= 3.3 175 250
8 16
= 1mA
OUT
55 80 mV
= 125˚C), the maximum power
J(max-op)
V
δV
T
to 150mA
C
= 1 mA, C
Limit
= 25˚C or correlated using
J
OUT
Units
µV
(pk - pk)
=0.47
RMS
˚C
µA
µsV
mV
Output Capacitor, Recommended Specifications
Symbol Parameter Conditions Typ
C
OUT
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Output Capacitor Capacitance
(Note 15)
ESR 5 500 mΩ
-40˚C to +125˚C 1.0 0.68
0˚C to +125˚C 0.47 0.33
Limit
Min Max
Units
µF
Output Capacitor, Recommended Specifications (Continued)
Note 15: The capacitor tolerance should be 30% or better over temperature. The full operating conditions for the application should be considered when selecting
a suitable capacitor to ensure that the minimum value of capacitance is always met. Recommended capacitor type is X7R. However, dependent on application, X5R,
Y5V, and Z5U can also be used. (See capacitor section in Applications Hints)
LP3990
Typical Performance Characteristics. Unless otherwise specified, C
0.47 µF Ceramic, V
Output Voltage Change vs Temperature Ground Current vs Load Current
Ground Current vs VIN.I
IN=VOUT(NOM)
+ 1.0V, TA= 25˚C, V
= 0mA Ground Current vs VIN.I
LOAD
OUT(NOM)
20076810
= 1.5V , Shutdown pin is tied to VIN.
= 1.0µF Ceramic, C
IN
= 1mA
LOAD
OUT
20076831
=
20076812 20076813
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Typical Performance Characteristics. Unless otherwise specified, C
0.47 µF Ceramic, V
LP3990
IN=VOUT(NOM)
+ 1.0V, TA= 25˚C, V
OUT(NOM)
= 1.5V , Shutdown pin is tied to VIN. (Continued)
= 1.0µF Ceramic, C
IN
OUT
=
Ground Current vs V
Short Circuit Current Line transient
IN.ILOAD
= 150mA Short Circuit Current
20076815
20076814
20076816
Power Supply Rejection Ratio Power Supply Rejection Ratio
20076819 20076820
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20076817
LP3990
Typical Performance Characteristics. Unless otherwise specified, C
0.47 µF Ceramic, V
IN=VOUT(NOM)
+ 1.0V, TA= 25˚C, V
OUT(NOM)
Enable Start-up Time Enable Start-up Time
20076821 20076822
Load Transient Noise Density
= 1.5V , Shutdown pin is tied to VIN. (Continued)
= 1.0µF Ceramic, C
IN
OUT
=
20076825
20076828
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Application Hints
LP3990
EXTERNAL CAPACITORS
In common with most regulators, the LP3990 requires external capacitors for regulator stability. The LP3990 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 capacitor is required for stability. It is recommended
that a 1.0µF capacitor be connected between the LP3990
input pin and ground (this capacitance value 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 analogue
ground. Any good quality ceramic, tantalum, or film capacitor
may be used at the input.
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.
There are no requirements for the ESR (Equivalent Series
Resistance) on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the
capacitor to ensure the capacitance will remain ) 1.0µF over
the entire operating temperature range.
In particular, the output capacitor selection should take account of all the capacitor parameters, to ensure that the
specification is met within the application. The capacitance
can vary with DC bias conditions as well as temperature and
frequency of operation. Capacitor values will also show
some decrease over time due to aging. The capacitor parameters are also dependant on the particular case size,
with smaller sizes giving poorer performance figures in general. As an example, Figure 1 shows a typical graph comparing different capacitor case sizes in a Capacitance vs. DC
Bias plot. As shown in the graph, increasing the DC Bias
condition can result in the capacitance value falling below
the minimum value given in the recommended capacitor
specifications table (0.33µF in this case). Note that the graph
shows the capacitance out of spec for the 0402 case size
capacitor at higher bias voltages. It is therefore recommended that the capacitor manufacturers’ specifications for
the nominal value capacitor are consulted for all conditions,
as some capacitor sizes (e.g. 0402) may not be suitable in
the actual application.
OUTPUT CAPACITOR
The LP3990 is designed specifically to work with very small
ceramic output capacitors. A 0.47µF ceramic capacitor (temperature types Z5U, Y5V or X7R) with ESR between 5mΩ to
500mΩ, is suitable in the LP3990 application circuit.
For this device the output capacitor should be connected
between the V
pin and ground.
OUT
It is also possible to use tantalum or film capacitors at the
device output, C
OUT
(or V
), but these are not as attrac-
OUT
tive for reasons of size and cost (see the section Capacitor
Characteristics).
The output capacitor must meet the requirement for the
minimum value of capacitance and also have an ESR value
that is within the range 5mΩ to 500mΩ for stability.
NO-LOAD STABILITY
The LP3990 will remain stable and in regulation with no
external load. This is an important consideration in some
circuits, for example CMOS RAM keep-alive applications.
CAPACITOR CHARACTERISTICS
The LP3990 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 0.47µF to 4.7µF, ceramic
capacitors are the smallest, least expensive and have the
lowest ESR values, thus making them best for eliminating
high frequency noise. The ESR of a typical 0.47µF ceramic
capacitor is in the range of 20mΩ to 40mΩ, which easily
meets the ESR requirement for stability for the LP3990.
For both input and output capacitors, careful interpretation of
the capacitor specification is required to ensure correct device operation. The capacitor value can change greatly, depending on the operating conditions and capacitor type.
20076840
FIGURE 1. Graph Showing a Typical Variation in
Capacitance vs DC Bias
The ceramic capacitor’s capacitance can vary with temperature. The capacitor type X7R, which operates over a temperature range of -55˚C to +125˚C, will only vary the capaci-
±
tance to within
15%. The capacitor type X5R has a similar
tolerance over a reduced temperature range of -55˚C to
+85˚C. Many large value ceramic capacitors, larger than 1µF
are manufactured with Z5U or Y5V temperature characteristics. Their capacitance can drop by more than 50% as the
temperature varies from 25˚C to 85˚C. Therefore X7R is
recommended over Z5U and Y5V in applications where the
ambient temperature will change significantly above or below 25˚C.
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
0.47µF 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
www.national.com 10
Application Hints (Continued)
tantalum will increase about 2:1 as the temperature goes
from 25˚C down to -40˚C, so some guard band must be
allowed.
ENABLE CONTROL
The LP3990 features an active high Enable pin, V
turns the device on when pulled high. When not enabled the
regulator output is off and the device typically consumes
2nA.
If the application does not require the Enable switching
feature, the V
pin should be tied to VINto keep the
EN
regulator output permanently on.
To ensure proper operation, the signal source used to drive
the V
input must be able to swing above and below the
EN
specified turn-on/off voltage thresholds listed in the Electrical
Characteristics section under V
and VIH.
IL
, which
EN
LP3990
Micro SMD MOUNTING
The micro SMD package requires specific mounting techniques, which are detailed in National Semiconductor Application Note AN-1112.
For best results during assembly, alignment ordinals on the
PC board may be used to facilitate placement of the micro
SMD device.
Micro SMD LIGHT SENSITIVITY
Exposing the micro SMD device to direct light may affect the
operation of the device. Light sources, such as halogen
lamps, can affect electrical performance, if placed in close
proximity to the device.
Light with wavelengths in the infra-red portion of the spectrum is the most detrimental, and so, fluorescent lighting
used inside most buildings, has little or no effect on performance.
www.national.com11
Physical Dimensions inches (millimeters) unless otherwise noted
LP3990
micro SMD, 4 Bump, Package (TLA04)
NS Package Number TLA04ALA
The dimensions for X1, X2 and X3 are given as:
X1 = 1.003 +/− 0.03mm
X2 = 1.283 +/− 0.03mm
X3 = 0.600 +/− 0.075mm
LLP, 6 Lead, Package (SOT23 Land)
NS Package Number SDE06A
www.national.com 12
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
LP3990 150mA Linear Voltage Regulator for Digital Applications
SOT23 - 5 Package
NS Package Number MF05A
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
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NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS
WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body, or
(b) support or sustain life, and whose failure to perform when
properly used in accordance with instructions for use
2. A critical component is any component of a life support
device or system whose failure to perform can be reasonably
expected to cause the failure of the life support device or
system, or to affect its safety or effectiveness.
provided in the labeling, can be reasonably expected to result
in a significant injury to the user.
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National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship
Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned
Substances’’ as defined in CSP-9-111S2.
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