Page 1
LP2980LV
Micropower SOT, 50 mA Low-Voltage Low-Dropout
April 2000
LP2980LV Micropower SOT, 50 mA Low-Voltage Low-Dropout Regulator For Applications With
Output Voltages
Regulator For Applications With Output Voltages
General Description
The LP2980LVisa50mA,fixed-outputvoltageregulatordesigned for high performance in applications requiring output
voltages below 2V.
Using an optimized VIP
cess, the LP2980LV delivers unequalled performance in all
specifications critical to battery-powered designs:
Low Ground Pin Current. Typically 280 µA
and 75 µA
Sleep Mode. Less than 1 µA quiescent current when ON/
OFF pin is pulled low.
Smallest Possible Size. SOT-23 package uses absolute
minimum board space.
Precision Output. 0.5% tolerance output voltages available
(A grade).
@
1 mA load.
™
(Vertically Integrated PNP) pro-
@
50 mA load,
Block Diagram
Features
n Guaranteed 50 mA output current
n Smallest possible size (SOT-23 Package)
n Requires few external components
<
n
1 µA quiescent current when shutdown
n Low ground pin current at all load currents
n Output voltage accuracy 0.5% (A Grade)
n High peak current capability (150 mA typical)
n Wide supply voltage range (16V max)
n Fast dynamic response to line and load
n Low Z
n Overtemperature/overcurrent protection
n −40˚C to +125˚C junction temperature range
0.1Ω typical (10 Hz to 1 MHz)
OUT
Applications
n Cellular Phone
n Palmtop/Laptop Computer
n Personal Digital Assistant (PDA)
n Camcorder, Personal Stereo, Camera
<
2V
<
2V
DS101091-1
VIP™is a trademark of National Semiconductor Corporation.
© 2000 National Semiconductor Corporation DS101091 www.national.com
Page 2
Connection Diagram
LP2980LV
Ordering Information
Output
Voltage (V)
1.5V A LP2980AIM5X-1.5 LANA 3k Units on Tape and Reel
1.5V A LP2980AIM5-1.5 LANA 250 Units on Tape and Reel
1.5V STD LP2980IM5X-1.5 LANB 3k Units on Tape and Reel
1.5V STD LP2980IM5-1.5 LANB 250 Units on Tape and Reel
1.8V A LP2980AIM5X-1.8 LAGA 3k Units on Tape and Reel
1.8V A LP2980AIM5-1.8 LAGA 250 Units on Tape and Reel
1.8V STD LP2980IM5X-1.8 LAGB 3k Units on Tape and Reel
1.8V STD LP2980IM5-1.8 LAGB 250 Units on Tape and Reel
For output voltages
>
5-lead Small Outline Package (M5)
DS101091-2
Top View
For Ordering Information See
See NS Package Number MA05B
TABLE 1. Package Marking and Ordering Information
Grade Order Information Package
2V, refer to LP2980 datasheet. If a non-standard voltage is required, see LP2980-ADJ.
Table 1
Supplied as:
Marking
Basic Application Circuit
DS101091-3
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Page 3
LP2980LV
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Storage Temperature Range −65˚C to +150˚C
Operating Junction Temperature
Range −40˚C to +125˚C
Lead Temperature
(Soldering, 5 sec.) 260˚C
ESD Rating (Note 2) 2 kV
Power Dissipation (Note 3) Internally Limited
Input Supply Voltage (Survival) −0.3V to +16V
Input Supply Voltage (Operating) 2.1V to +16V
ON/OFF Input Voltage (Survival) −0.3V to +16V
Output Voltage (Survival), (Note 4) −0.3V to +9V
(Survival) Short Circuit Protected
I
OUT
Input-Output Voltage (Survival),
(Note 5) −0.3V to +16V
Electrical Characteristics
Limits in standard typeface are for TJ= 25˚C, and limits in boldface type apply over the full operating temperature range. Unless otherwise specified: VIN=V
Symbol Parameter Conditions Typ LP2980LVAI-XX
O
Output Voltage
Tolerance
∆V
Output Voltage Line
Regulation
I
GND
V
(min) Minimum input voltage
IN
Ground Pin Current
required to maintain
output regulation
V
ON/OFF
ON/OFF Input Voltage
(Note 7)
I
ON/OFF
I
O(PK)
e
n
ON/OFF Input Current V
Peak Output Current V
Output Noise Voltage
(RMS)
Ripple Rejection f = 1kHz C
+ 1V, IL= 1 mA, CIN= 1 µF, C
O(NOM)
= 4.7 µF, V
OUT
ON/OFF
= 2V.
(Note 6)
Min Max Min Max
= 1 mA −0.50 0.50 −1.00 1.00
I
L
1mA<I
V
O(NOM)
16V
=0
I
L
=1mA
I
L
I
=10mA
L
I
=50mA
L
V
ON/OFF
=50mA
I
L
<
50 mA −0.75
L
−2.50
+1V≤VIN≤
0.007
65
75
120
280
<
0.18V 0 11
0.75
2.50
0.014
0.032
85
110
95
160
175
325
475
850
2.05 2.20 2.20 V
High = O/P ON 1.4 1.6 1.6
Low = O/P OFF 0.55 0.18 0.18
=0 0 −1 −1
ON/OFF
V
BW = 300 Hz to 50 kHz,
C
=5V 5 15 15
ON/OFF
OUT
OUT
≥ V
=10µF
− 5% 150 100 100 mA
O(NOM)
125 µV
=10µF
OUT
63 dB
LP2980LVI-XX
(Note 6)
−1.50
−3.50
1.50
−3.50
0.014
0.032
85
110
95
160
175
325
475
850
Units
%V
%/V
µA
V
µA
NOM
I
O(MAX)
Note 1: Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the device outside of its rated operating conditions.
Note 2: The ESD rating of pins 3 and 4 is 1 kV.
Note 3: The maximum allowable power dissipation is a function of the maximum junction temperature, T
the ambient temperature, T
The value of θJAfor the SOT-23 package is 220˚C/W. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator
will go into thermal shutdown.
Note 4: If used in a dual-supply system where the regulator load is returned to a negative supply, the LP2980LV output must be diode-clamped to ground.
Short Circuit Current RL= 0 (Steady State)
(Note 8)
. The maximum allowable power dissipation at any ambient temperature is calculated using:
A
150 mA
, the junction-to-ambient thermal resistance, θJA, and
J(MAX)
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Page 4
Electrical Characteristics (Continued)
Note 5: The output PNP structure contains a diode between the VINand V
will turn on this diode and possibly damage the device (see Application Hints).
LP2980LV
Note 6: Limits are 100% production tested at 25˚C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control
(SQC) methods. The limits are used to calculate National’s Average Outgoing Quality Level (AOQL).
Note 7: The ON/OFF input must be properly driven to prevent misoperation. For details, refer toApplication Hints.
Note 8: See Typical Performance Characteristics curves.
terminals that is normally reverse-biased. Reversing the polarity from VINto V
OUT
OUT
Typical Performance Characteristics Unless otherwise specified: T
C
= 1µF, ON/OFF pin tied to VIN,VIN=V
IN
V
vs
OUT
Temperature
Min Input Voltage vs Temperature
O(NOM)
DS101091-5
+1V,V
OUT(NOM)
= 1.8V.
Output Characteristics
Ground Pin Current vs Temperature
= 25˚C, C
A
OUT
DS101091-7
= 4.7 µF,
DS101091-8
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DS101091-22
Page 5
LP2980LV
Typical Performance Characteristics Unless otherwise specified: T
C
= 1µF, ON/OFF pin tied to VIN,VIN=V
IN
Ground Pin Current vs
Load Current
Input Current vs V
IN
DS101091-23
O(NOM)
+ 1V, V
OUT(NOM)
= 1.8V. (Continued)
Input Current vs V
Input Current vs V
IN
IN
= 25˚C, C
A
OUT
DS101091-9
= 4.7 µF,
Line Transient
DS101091-10
DS101091-24
DS101091-11
Line Transient
DS101091-25
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Page 6
Typical Performance Characteristics Unless otherwise specified: T
C
= 1µF, ON/OFF pin tied to VIN,VIN=V
IN
LP2980LV
Load Transient Response
O(NOM)
+ 1V, V
OUT(NOM)
= 1.8V. (Continued)
Load Transient Response
= 25˚C, C
A
OUT
= 4.7 µF,
Short Circuit Current
Short Circuit Current
DS101091-14
DS101091-26
DS101091-15
Instantaneous Short Circuit Current vs
Temperature
DS101091-27
Instantaneous Short Circuit Current vs
Output Voltage
DS101091-28
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DS101091-29
Page 7
LP2980LV
Typical Performance Characteristics Unless otherwise specified: T
C
= 1µF, ON/OFF pin tied to VIN,VIN=V
IN
Output Impedance vs Frequency
Ripple Rejection
O(NOM)
DS101091-6
+ 1V, V
OUT(NOM)
= 1.8V. (Continued)
Output Noise Density
Input to Output Leakage vs
Temperature
= 25˚C, C
A
OUT
DS101091-13
= 4.7 µF,
Output Reverse Leakage vs
Temperature
DS101091-12
DS101091-31
DS101091-30
Turn-On Waveform
DS101091-16
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Page 8
Typical Performance Characteristics Unless otherwise specified: T
C
= 1µF, ON/OFF pin tied to VIN,VIN=V
IN
LP2980LV
Turn-Off Waveform
O(NOM)
+ 1V, V
OUT(NOM)
= 1.8V. (Continued)
ON/OFF Pin current vs V
A
ON/OFF
= 25˚C, C
OUT
= 4.7 µF,
DS101091-17
Application Hints
INPUT CAPACITOR
An input capacitor whose capacitance is ≥ 1 µF is required
between the LP2980 input pin and ground (the amount of capacitance may be increased without limit).
The input capacitor must be located a distance of not more
than 1 cm away 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.
IMPORTANT: Tantalum capacitors may suffer catastrophic
failure due to surge current when connected to a
low-impedance source of power (like a battery or very large
capacitor). If a Tantalum input capacitor is used, it must be
guaranteed by the manufacturer to have a surge current rating sufficient for the application.
There are no requirements for ESR on the input capacitor,
but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance
will be ≥ 1 µF over the entire operating range.
OUTPUT CAPACITOR
The LP2980 requires an output capacitor to maintain loop
stability.The capacitor must be selected to meet the requirements of capacitance and ESR (equivalent series resistance) over the full operating temperaturerange of the application (see SELECTING THE OUTPUT CAPACITOR).
The minimum amount of capacitance which can be used on
the output is 2.2 µF, but this value may be increased without
limit.
Four curves are provided which show the stable ESR range
of the LP2980-1.8V operated with output capacitances of
2.2, 4.7, 10, and 15 µF:
DS101091-32
DS101091-18
2.2 µF ESR Curves For 1.8V Output
DS101091-19
4.7 µF ESR Curves For 1.8V Output
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Page 9
Application Hints (Continued)
10 µF ESR Curves For 1.8V Output
DS101091-20
LP2980LV
It should also be noted that the ESR typically increases
about 2X - 3X when going from +125˚C down to −40˚C.
Another factor to consider is that Tantalum manufacturers
are presently designing their products toward the goal of getting the lowest possible ESR, in an attempt to compete with
the new high-value ceramic capacitors. This means that the
typical values will probably continue to decline in the future.
SELECTING THE OUTPUT CAPACITOR
This section contains guidelines for selecting an output capacitor which will maintain good regulator stability over the
entire operating temperature range (refer to ESR CURVES).
2.2 µF OUTPUT CAPACITOR
The smallest output capacitor which can be used with the
LP2980-1.8 is 2.2 µF. However, care must be exercised if
this value is used because of the ESR requirement.
At load currents ≤ 25mA, the stable ESR range is approximately 0.5Ω to 6Ω. This range is probably sufficiently wide
that most 2.2 µF Tantalum capacitors would fall within it.
At higher values of load currents (using a 2.2 µF output capacitor), the stable ESR window gets very narrow. It is likely
that a Tantalum capacitor would not be a good choice for a
design that must be robust enough for mass production. Instead, a 2.2 µF capacitor with very low ESR (either ceramic
or film) should be used with a 2Ω external resistor placed in
series to provide the ESR.
DS101091-21
15 µF ESR Curves For 1.8V Output
It should be noted that for the lower values of the output capacitance (
and series resistance to provide sufficient ESR. To understand why this is true, the basic characteristics of capacitance types must be explained:
CAPACITOR CHARACTERISTICS:
Ceramic Capacitors have an extremely low ESR (in the
range of 5-15mΩ), and can only be used on theoutput of the
LP2980 if an external resistor is placed in series to supply
the needed ESR (a resistance value of about 2Ω +/− 30% is
recommended).
Be careful of the temperature coefficient of ceramics: select
X7R or X5R if possible, because those types typically vary
less than +/− 25% over the range of −40 to +125˚C. Z5U
types are worse, and will typically lose half (or more) of their
capacitance over the same temperature range.
A source for large-value ceramics with good performance is
Taiyo-Yuden. Their web address is :
http://www.t-yuden.com/hicap.html
Tantalum capacitors have ESR values that are more diffi-
cult to determine: the manufacturers specify only a maximum limit, which is typically 10X or 20X the typical value.
ESR values can vary considerably from lot to lot and from
manufacturer to manufacturer. For example, some 4.7
µF/10V devices tested showed typical values in the range of
0.5-1Ω, but values as high as 6Ω have been seen.
<
10 µF), it may be necessary to use a capacitor
4.7 µF OUTPUT CAPACITOR
If a 4.7 µF capacitor is used, the stable range of ESR values
for 50 mAoperation is approximately 0.6Ω to 6Ω. Because of
the reduced ESR values of the new Tantalum, it is possible
to find 4.7 µF Tantalum capacitors with ESR values at or below 0.6Ω. To ensure a stable design, it is recommended that
an external resistor (value about 0.5Ω) be added in series
with the 4.7 µF Tantalumto provide adequate minimum ESR.
At values of load current ≤ 20 mA, the ESR range is wide
enough that Tantalum can be used without external resistance for added ESR.
Another acceptable configuration for 50 mA operation is to
use a ceramic or film 4.7 µF capacitor (which has very low
ESR) with an external 2Ω resistor in series.
10 µF OUTPUT CAPACITOR
50 mA operation using a 10 µF output capacitor requires an
ESR in the range of approximately 0.4Ω to 7Ω. As stated
previously, it is possible that solid Tantalum capacitors can
be found with ESR values near to or below 0.4Ω.An external
resistor in series with the Tantalum (value of about 0.5Ω)is
recommended to assure unconditional stability.
At values of load current ≤ 20 mA, the ESR range is wide
enough that Tantalum can be used without external resistance for added ESR.
Another acceptable configuration for 50 mA operation is to
use a ceramic or film 10 µF capacitor (which has very low
ESR) with an external 2Ω resistor in series.
15 µF OUTPUT CAPACITOR
The stable ESR range (for 50 mAload current) using a 15 µF
output capacitor is approximately 0.1Ω to 10Ω.Itisextremely unlikely that a 15 µF Tantalum capacitor would be
found with an ESR below 0.1Ω, so no external resistance is
required with a Tantalum.
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Page 10
Application Hints (Continued)
As before, another acceptable configuration for 50 mA operation is to use a ceramic or film 15 µF capacitor with an ex-
LP2980LV
ternal 2Ω resistor in series.
ON/OFF INPUT OPERATION
The LP2980 is shut off by pulling the ON/OFF input low, and
turned on by pulling it high. If this feature is not to be used,
this pin should be tied to V
times.
To ensure proper operation, the signal source used to drive
the ON/OFF input must be able to swing above and below
the specified turn-on/turn-off voltage thresholds (see Electrical Characteristics).
It is also important that the turn-on (and turn-off) voltage signals applied to the ON/OFF input have a slew rate which is
not less than 40 mV/µs.
CAUTION: The regulator output state can not be guaranteed
if a slow-moving AC (or DC) signal is applied that it is in the
range between the turn-on/turn-off voltage thresholds specified in the Electrical Characteristics section.
to keep the regulator on at all
IN
REVERSE INPUT/OUTPUT VOLTAGE
The PNP power transistor used as the pass element in the
LP2980 has an inherent diode connected between the regulator output and input. During normal operation (where the
input voltage is higher than the output) this diode is
reverse-biased.
However, if the output is pulled above the input, this diode
will turn ON and current will flow into the regulator output. In
such cases, a parasitic SCR can latch which will allow a high
current to flow into V
(and out the ground pin), which can
IN
damage the part.
In any application where the output may be pulled above the
input, an external Schottky diode must be connected from
V
to V
IN
(cathode on VIN, anode on V
OUT
), to limit the re-
OUT
verse voltage across the LP2980 to 0.3V (see Basic Application Circuit).
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Page 11
Physical Dimensions inches (millimeters) unless otherwise noted
LP2980LV Micropower SOT, 50 mA Low-Voltage Low-Dropout Regulator For Applications With
Output Voltages
<
2V
5-Lead Small Outline Package (M5)
NS Package Number MA05B
For Order Numbers, refer to
Table 1
in the “Order Information” section of this document.
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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:
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 provided in the
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.
labeling, can be reasonably expected to result in a
significant injury to the user.
National Semiconductor
Corporation
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Tel: 1-800-272-9959
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www.national.com
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