NSC LP2981 Micropower 100 ma ultra low-dropout regulator Datasheet

LP2981
Micropower 100 mA Ultra Low-Dropout Regulator
General Description
Features
The LP2981 is a 100 mA, fixed-output voltage regulator designed specifically to meet the requirements of
battery-powered applications.
Using an optimized VIP™ (Vertically Integrated PNP) process, the LP2981 delivers unequaled performance in all
specifications critical to battery-powered designs:
Dropout Voltage. Typically 200 mV @ 100 mA load, and
7 mV @ 1 mA load.
Ground Pin Current. Typically 600 µA @ 100 mA load, and
80 µA @ 1 mA load.
Sleep Mode. Less than 1 µA quiescent current when ON/
OFF pin is pulled low.
Smallest Possible Size. SOT-23and micro SMD packages
use an absolute minimum board space.
Precision Output. 0.75% tolerance output voltages available (A grade).
Eleven voltage options, from 2.5V to 5.0V, are available as
standard products.
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Ultra low dropout voltage
Output voltage accuracy 0.75% (A Grade)
Guaranteed 100 mA output current
Smallest possible size (SOT-23, micro SMD package)
< 1 µA quiescent current when shutdown
Low ground pin current at all load currents
High peak current capability (300 mA typical)
Wide supply voltage range (16V max)
Fast dynamic response to line and load
Low ZOUT over wide frequency range
Overtemperature/overcurrent protection
−40˚C to +125˚C junction temperature range
Applications
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Cellular Phone
Palmtop/Laptop Computer
Personal Digital Assistant (PDA)
Camcorder, Personal Stereo, Camera
Block Diagram
DS012506-1
VIP™ is a trademark of National Semiconductor Corporation.
© 2000 National Semiconductor Corporation
DS012506
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LP2981 Micropower 100 mA Ultra Low-Dropout Regulator
March 2000
LP2981
Connection Diagrams
5-Lead Small Outline Package (M5)
micro SMD, 5 Bump Package (BPA05)
DS012506-50
DS012506-2
Bottom View
See NS Package Number BPA05
Top View
See NS Package Number MF05A
For ordering information see Table 1
Ordering Information
TABLE 1. Package Marking and Order Information
Output Voltage
(V)
Grade
Order Information
Package
Marking
Supplied as:
5-Lead Small Outline Package (M5)
2.5
A
LP2981AIM5X-2.5
L0CA
3000 Units on Tape and Reel
2.5
A
LP2981AIM5-2.5
L0CA
1000 Units on Tape and Reel
2.5
STD
LP2981IM5X-2.5
L0CB
3000 Units on Tape and Reel
2.5
STD
LP2981IM5-2.5
L0CB
1000 Units on Tape and Reel
2.7
A
LP2981AIM5X-2.7
L0DA
3000 Units on Tape and Reel
2.7
A
LP2981AIM5-2.7
L0DA
1000 Units on Tape and Reel
2.7
STD
LP2981IM5X-2.7
L0DB
3000 Units on Tape and Reel
2.7
STD
LP2981IM5-2.7
L0DB
1000 Units on Tape and Reel
2.8
A
LP2981AIM5X-2.8
L77A
3000 Units on Tape and Reel
2.8
A
LP2981AIM5-2.8
L77A
1000 Units on Tape and Reel
2.8
STD
LP2981IM5X-2.8
L77B
3000 Units on Tape and Reel
2.8
STD
LP2981IM5-2.8
L77B
1000 Units on Tape and Reel
2.9
A
LP2981AIM5X-2.9
L0VA
3000 Units on Tape and Reel
2.9
A
LP2981AIM5-2.9
L0VA
1000 Units on Tape and Reel
2.9
STD
LP2981IM5X-2.9
L0VB
3000 Units on Tape and Reel
2.9
STD
LP2981IM5-2.9
L0VB
1000 Units on Tape and Reel
3.0
A
LP2981AIM5X-3.0
L05A
3000 Units on Tape and Reel
3.0
A
LP2981AIM5-3.0
L05A
1000 Units on Tape and Reel
3.0
STD
LP2981IM5X-3.0
L05B
3000 Units on Tape and Reel
3.0
STD
LP2981IM5-3.0
L05B
1000 Units on Tape and Reel
3.1
A
LP2981AIM5X-3.1
L38A
3000 Units on Tape and Reel
3.1
A
LP2981AIM5-3.1
L38A
1000 Units on Tape and Reel
3.1
STD
LP2981IM5X-3.1
L38B
3000 Units on Tape and Reel
3.1
STD
LP2981IM5-3.1
L38B
1000 Units on Tape and Reel
3.2
A
LP2981AIM5X-3.2
L35A
3000 Units on Tape and Reel
3.2
A
LP2981AIM5-3.2
L35A
1000 Units on Tape and Reel
3.2
STD
LP2981IM5X-3.2
L35B
3000 Units on Tape and Reel
3.2
STD
LP2981IM5-3.2
L35B
1000 Units on Tape and Reel
3.3
A
LP2981AIM5X-3.3
L04A
3000 Units on Tape and Reel
3.3
A
LP2981AIM5-3.3
L04A
1000 Units on Tape and Reel
3.3
STD
LP2981IM5X-3.3
L04B
3000 Units on Tape and Reel
3.3
STD
LP2981IM5-3.3
L04B
1000 Units on Tape and Reel
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LP2981
Ordering Information
(Continued)
TABLE 1. Package Marking and Order Information (Continued)
Output Voltage
(V)
Grade
Order Information
Package
Marking
Supplied as:
5-Lead Small Outline Package (M5)
3.6
A
LP2981AIM5X-3.6
L0JA
3000 Units on Tape and Reel
3.6
A
LP2981AIM5-3.6
L0JA
1000 Units on Tape and Reel
3.6
STD
LP2981IM5X-3.6
L0JB
3000 Units on Tape and Reel
3.6
STD
LP2981IM5-3.6
L0JB
1000 Units on Tape and Reel
3.8
A
LP2981AIM5X-3.8
L36A
3000 Units on Tape and Reel
3.8
A
LP2981AIM5-3.8
L36A
1000 Units on Tape and Reel
3.8
STD
LP2981IM5X-3.8
L36B
3000 Units on Tape and Reel
3.8
STD
LP2981IM5-3.8
L36B
1000 Units on Tape and Reel
4.0
A
LP2981AIM5X-4.0
L0ZA
3000 Units on Tape and Reel
4.0
A
LP2981AIM5-4.0
L0ZA
1000 Units on Tape and Reel
4.0
STD
LP2981IM5X-4.0
L0ZB
3000 Units on Tape and Reel
4.0
STD
LP2981IM5-4.0
L0ZB
1000 Units on Tape and Reel
4.7
A
LP2981AIM5X-4.7
L0GA
3000 Units on Tape and Reel
4.7
A
LP2981AIM5-4.7
L0GA
1000 Units on Tape and Reel
4.7
STD
LP2981IM5X-4.7
L0GB
3000 Units on Tape and Reel
4.7
STD
LP2981IM5-4.7
L0GB
1000 Units on Tape and Reel
5.0
A
LP2981AIM5X-5.0
L03A
3000 Units on Tape and Reel
5.0
A
LP2981AIM5-5.0
L03A
1000 Units on Tape and Reel
5.0
STD
LP2981IM5X-5.0
L03B
3000 Units on Tape and Reel
5.0
STD
LP2981IM5-5.0
L03B
1000 Units on Tape and Reel
micro SMD, 5 Bump Package (BPA05)
2.5
A
LP2981AIBP-2.5
250 Units on Tape and Reel
2.5
A
LP2981AIBPX-2.5
3000 Units on Tape and Reel
2.5
STD
LP2981IBP-2.5
250 Units on Tape and Reel
2.5
STD
LP2981IBPX-2.5
3000 Units on Tape and Reel
3.2
A
LP2981AIBP-3.2
250 Units on Tape and Reel
3.2
A
LP2981AIBPX-3.2
3000 Units on Tape and Reel
3.2
STD
LP2981IBP-3.2
250 Units on Tape and Reel
3.2
STD
LP2981IBPX-3.2
3000 Units on Tape and Reel
3.3
A
LP2981AIBP-3.3
250 Units on Tape and Reel
3.3
A
LP2981AIBPX-3.3
3000 Units on Tape and Reel
3.3
STD
LP2981IBP-3.3
250 Units on Tape and Reel
3.3
STD
LP2981IBPX-3.3
3000 Units on Tape and Reel
3
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LP2981
Absolute Maximum Ratings (Note 1)
Power Dissipation (Note 3)
Input Supply Voltage (Survival)
Input Supply Voltage (Operating)
Shutdown Input Voltage (Survival)
Output Voltage (Survival, (Note 4))
IOUT (Survival)
Input-Output Voltage
(Survival, (Note 5))
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Storage Temperature Range
Operating Junction Temperature
Range
Lead Temperature
(Soldering, 5 sec.)
ESD Rating (Note 2)
−65˚C to +150˚C
−40˚C to +125˚C
Internally Limited
−0.3V to +16V
2.1V to +16V
−0.3V to +16V
−0.3V to +9V
Short Circuit Protected
−0.3V to +16V
260˚C
2 kV
Electrical Characteristics
Limits in standard typeface are for TJ = 25˚C, and limits in boldface type applyover the full operating temperature range. Unless otherwise specified: VIN = VO(NOM) + 1V, CIN = 1 µF, IL = 1 mA, COUT = 4.7 µF,VON/OFF = 2V.
Symbol
Parameter
Conditions
Typ
LP2981AI-XX
(Note 6)
∆VO
VIN–VO
Output Voltage
Tolerance
Max
Min
Max
IL = 1mA
−0.75
0.75
−1.25
1.25
1 mA < IL < 100 mA
−1.0
1.0
−2.0
2.0
−2.5
2.5
−3.5
3.5
Output Voltage
VO(NOM) + 1V
Line Regulation
≤ VIN ≤ 16V
Dropout Voltage
IL = 0
0.007
1
IL = 1 mA
Ground Pin Current
7
IL = 25 mA
70
IL = 100 mA
200
IL = 0
65
IL = 1 mA
80
IL = 25 mA
200
IL = 100 mA
VON/OFF
ION/OFF
600
0.014
0.014
0.032
0.032
3
3
5
5
10
10
15
15
100
100
150
150
250
250
375
375
95
95
125
125
110
110
170
170
300
300
550
550
800
800
1500
1500
0.8
VON/OFF < 0.3V
0.01
0.8
VON/OFF < 0.15V
0.05
2
ON/OFF Input Voltage
High = O/P ON
1.4
(Note 8)
Low = O/P OFF
0.50
0.15
0.15
ON/OFF Input Current
VON/OFF = 0
0.01
−1
−1
5
15
15
VON/OFF = 5V
Units
(Note 6)
Min
(Note 7)
IGND
LP2981I-XX
1.6
%VNOM
%/V
mV
µA
2
1.6
V
µA
VOUT ≥ VO(NOM) − 5%
400
Output Noise
BW = 300 Hz–50 kHz,
160
µV
Voltage (RMS)
COUT = 10 µF
Ripple Rejection
f = 1 kHz
63
dB
150
mA
IO(PK)
Peak Output Current
en
150
150
mA
COUT = 10 µF
IO(MAX)
Short Circuit Current
RL = 0 (Steady State)
(Note 9)
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(Continued)
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, TJ(MAX), the junction-to-ambient thermal resistance, θJA, and
the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using:
The value of θJA for the SOT-23 package is 220˚C/W and the micro SMD package is 320˚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 LP2981 output must be diode-clamped to ground.
Note 5: The output PNP structure contains a diode between the VIN and VOUT terminals that is normally reverse-biased. Reversing the polarity from VIN to VOUT
will turn on this diode (see Application Hints).
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: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a 1V differential.
Note 8: The ON/OFF inputs must be properly driven to prevent misoperation. For details, refer to Application Hints.
Note 9: See Typical Performance Characteristics curves.
Basic Application Circuit
DS012506-4
*ON/OFF input must be actively terminated. Tie to VIN if this function is not to be used.
**Minimum Output Capacitance is shown to insure stability over full load current range. More capacitance provides superior dynamic performance and
additional stability margin (see Application Hints).
***Do not make connections to this pin.
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LP2981
Electrical Characteristics
LP2981
Typical Performance Characteristics
Unless otherwise specified: TA = 25˚C, VIN = VO(NOM) + 1V,
COUT = 4.7 µF, CIN = 1 µF all voltage options, ON/OFF pin tied to VIN.
Output Voltage vs
Temperature
Output Voltage vs
Temperature
DS012506-7
DS012506-6
Output Voltage vs
Temperature
Dropout Characteristics
DS012506-9
DS012506-8
Dropout Characteristics
Dropout Characteristics
DS012506-11
DS012506-10
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Unless otherwise specified: TA = 25˚C, VIN = VO(NOM) + 1V,
COUT = 4.7 µF, CIN = 1 µF all voltage options, ON/OFF pin tied to VIN. (Continued)
Dropout Voltage vs
Temperature
Dropout Voltage vs
Load Current
DS012506-12
Ground Pin Current vs
Temperature
DS012506-13
Ground Pin Current vs
Load Current
DS012506-14
Input Current vs VIN
DS012506-15
Input Current vs VIN
DS012506-17
DS012506-16
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LP2981
Typical Performance Characteristics
LP2981
Typical Performance Characteristics
Unless otherwise specified: TA = 25˚C, VIN = VO(NOM) + 1V,
COUT = 4.7 µF, CIN = 1 µF all voltage options, ON/OFF pin tied to VIN. (Continued)
Line Transient Response
Line Transient Response
DS012506-18
Load Transient Response
DS012506-19
Load Transient Response
DS012506-21
DS012506-20
Load Transient Response
Load Transient Response
DS012506-22
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DS012506-23
8
Unless otherwise specified: TA = 25˚C, VIN = VO(NOM) + 1V,
COUT = 4.7 µF, CIN = 1 µF all voltage options, ON/OFF pin tied to VIN. (Continued)
Short Circuit Current
Instantaneous Short Circuit
Current vs Temperature
DS012506-24
DS012506-25
Short Circuit Current
Instantaneous Short Circuit
Current vs Output Voltage
DS012506-26
DS012506-27
Output Impedance vs
Frequency
Ripple Rejection
DS012506-29
DS012506-28
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LP2981
Typical Performance Characteristics
LP2981
Typical Performance Characteristics
Unless otherwise specified: TA = 25˚C, VIN = VO(NOM) + 1V,
COUT = 4.7 µF, CIN = 1 µF all voltage options, ON/OFF pin tied to VIN. (Continued)
Output Noise Density
Output Impedance vs
Frequency
DS012506-30
DS012506-31
Input to Output Leakage
vs Temperature
Output Reverse Leakage vs
Temperature
DS012506-32
Turn-On Waveform
DS012506-33
Turn-Off Waveform
DS012506-35
DS012506-34
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Unless otherwise specified: TA = 25˚C, VIN = VO(NOM) + 1V,
COUT = 4.7 µF, CIN = 1 µF all voltage options, ON/OFF pin tied to VIN. (Continued)
ON/OFF Pin Current vs
VON/OFF
ON/OFF Threshold
vs Temperature
DS012506-37
DS012506-36
CERAMIC: Ceramic capacitors are not recommended for
use at the output of the LP2981. This is because the ESR of
a ceramic can be low enough to go below the minimum
stable value for the LP2981. A 2.2 µF ceramic was measured
and found to have an ESR of about 15 mΩ, which is low
enough to cause oscillations.
If a ceramic capacitor is used on the output, a 1Ω resistor
should be placed in series with the capacitor.
ALUMINUM: Because of large physical size, aluminum electrolytics are not typically used with the LP2981. They must
meet the same ESR requirements over the operating temperature range, more difficult because of their steep increase
at cold temperature.
An aluminum electrolytic can exhibit an ESR increase of as
much as 50X when going from 20˚C to −40˚C. Also, some
aluminum electrolytics are not operational below −25˚C because the electrolyte can freeze.
Application Hints
EXTERNAL CAPACITORS
Like any low-dropout regulator, the external capacitors used
with the LP2981 must be carefully selected to assure regulator loop stability.
INPUT CAPACITOR: An input capacitor whose value is
≥ 1 µF is required with the LP2981 (amount of capacitance
can be increased without limit).
This capacitor must be located a distance of not more than
0.5" from the input pin of the LP2981 and returned to a clean
analog ground. Any good quality ceramic or tantalum can be
used for this capacitor.
OUTPUT CAPACITOR: The output capacitor must meet
both the requirement for minimum amount of capacitance
and E.S.R. (equivalent series resistance) value. Curves are
provided which show the allowable ESR range as a function
of load current for various output voltages and capacitor values (refer to Figures 1, 2, 3, 4).
IMPORTANT: The output capacitor must maintain its ESR in
the stable region over the full operating temperature range to
assure stability. Also, capacitor tolerance and variation with
temperature must be considered to assure the minimum
amount of capacitance is provided at all times.
This capacitor should be located not more than 0.5" from the
output pin of the LP2981 and returned to a clean analog
ground.
CAPACITOR CHARACTERISTICS
TANTALUM: Tantalum capacitors are the best choice for
use with the LP2981. Most good quality tantalums can be
used with the LP2981, but check the manufacturer’s data
sheet to be sure the ESR is in range.
It is important to remember that ESR increases at lower temperatures and a capacitor that is near the upper limit for stability at room temperature can cause instability when it gets
cold.
In applications which must operate at very low temperatures,
it may be necessary to parallel the output tantalum capacitor
with a ceramic capacitor to prevent the ESR from going up
too high (see next section for important information on ceramic capacitors).
DS012506-38
FIGURE 1. 5V/3.3 µF ESR Curves
11
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LP2981
Typical Performance Characteristics
LP2981
Application Hints
(Continued)
DS012506-41
If the output is forced above the input by more than a VBE,
this diode will become forward biased and current will flow
from the VOUT terminal to VIN.
This current must be limited to < 100 mA to prevent damage
to the part.
The internal diode can also be turned on by abruptly stepping the input voltage to a value below the output voltage.
To prevent regulator mis-operation, a Schottky diode should
be used in any application where input/output voltage conditions can cause the internal diode to be turned on (see below).
DS012506-39
FIGURE 2. 5V/10 µF ESR Curves
DS012506-43
As shown, the Schottky diode is connected in parallel with
the internal parasitic diode and prevents it from being turned
on by limiting the voltage drop across it to about 0.3V.
ON/OFF INPUT OPERATION
The LP2981 is shut off by pulling the ON/OFF input low, and
turned on by driving the input high. If this feature is not to be
used, the ON/OFF input should be tied to VIN to keep the
regulator on at all times (the ON/OFF input must not be left
floating).
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 which guarantee an ON or OFF state (see Electrical Characteristics).
The ON/OFF signal may come from either a totem-pole output, or an open-collector output with pull-up resistor to the
LP2981 input voltage or another logic supply. The high-level
voltage may exceed the LP2981 input voltage, but must remain within the Absolute Maximum Ratings for the ON/OFF
pin.
It is also important that the turn-on/turn-off voltage signals
applied to the ON/OFF input have a slew rate which is
greater than 40 mV/µs.
Important: the regulator shutdown function will operate incorrectly if a slow-moving signal is applied to the ON/OFF input.
DS012506-40
FIGURE 3. 3V/3.3 µF ESR Curves
DS012506-42
FIGURE 4. 3V/10 µF ESR Curves
Micro SMD Mounting
The micro SMD package requires specific mounting techniques which are detailed in National Semiconductor Application Note # 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 the NSMD (non-solder mask defined) type.
REVERSE CURRENT PATH
The power transistor used in the LP2981 has an inherent diode connected between the regulator input and output (see
below).
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The wavelenghts which have the 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 1 cm
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.
(Continued)
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 sunlight will cause
misoperation of the device. Light sources such as Halogen
lamps can also affect electrical performance if brought near
to the device.
13
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LP2981
Application Hints
LP2981
Physical Dimensions
inches (millimeters) unless otherwise noted
5-Lead Small Outline Package (M5)
NS Package Number MF05A
For Order Numbers, refer to Table 1 in the “Ordering Information” section of this document.
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LP2981
Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
NOTES: UNLESS OTHERWISE SPECIFIED
1. EPOXY COATING
2. 63Sn/37Pb EUTECTIC BUMP
3. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD.
4. PIN 1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION. REMAINING PINS ARE
NUMBERED COUNTER CLOCKWISE.
5. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS PACKAGE HEIGHT.
6.NO JEDEC REGISTRATION AS OF AUG.1999.
micro SMD, 5 Bump Package (BPA05)
NS Package Number BPA05A
For Order Numbers, refer to Table 1 in the “Order Information” section of this document.
The dimensions for X1, X2 and X3 are as given:
X1 = 0.930 +/− 0.030mm
X2 = 1.107 +/− 0.030mm
X3 = 0.850 +/− 0.050mm
15
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LP2981 Micropower 100 mA Ultra Low-Dropout Regulator
Notes
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