LP2985
April 26, 2011
Micropower 150 mA Low-Noise Ultra Low-Dropout
Regulator in SOT-23 and micro SMD Packages
Designed for Use with Very Low ESR Output Capacitors
General Description
The LP2985 is a 150 mA, fixed-output voltage regulator de-
signed to provide ultra low-dropout and low noise in battery
powered applications.
Using an optimized VIP® (Vertically Integrated PNP) process,
the LP2985 delivers unequalled performance in all specifica-
tions critical to battery-powered designs:
Dropout Voltage: Typically 300 mV @ 150 mA load, and
7 mV @ 1 mA load.
Ground Pin Current: Typically 850 µA @ 150 mA load, and
75 µA @ 1 mA load.
Enhanced Stability: The LP2985 is stable with output ca-
pacitor ESR as low as 5 mΩ, which allows the use of ceramic
capacitors on the output.
Sleep Mode: Less than 1 µA quiescent current when ON/OFF
pin is pulled low.
Smallest Possible Size: SOT-23 and micro SMD packages
use absolute minimum board space.
Precision Output: 1% tolerance output voltages available (A
grade).
Low Noise: By adding a 10 nF bypass capacitor, output noise
can be reduced to 30 µV (typical).
Multiple voltage options, from 2.5V to 5.0V, are available as
standard products. Consult factory for custom voltages.
Features
■Ultra low dropout voltage
■Guaranteed 150 mA output current
■Smallest possible size (SOT-23, micro SMD package)
■Requires minimum external components
■Stable with low-ESR output capacitor
■<1 µA quiescent current when shut down
■Low ground pin current at all loads
■Output voltage accuracy 1% (A Grade)
■High peak current capability
■Wide supply voltage range (16V max)
■Low ZOUT: 0.3Ω typical (10 Hz to 1 MHz)
■Overtemperature/overcurrent protection
■−40°C to +125°C junction temperature range
■Custom voltages available
Applications
■Cellular Phone
■Palmtop/Laptop Computer
■Personal Digital Assistant (PDA)
■Camcorder, Personal Stereo, Camera
Block Diagram
10014001
VIP® is a registered trademark of National Semiconductor Corporation.
© 2011 National Semiconductor Corporation 100140 www.national.com
LP2985 Micropower 150 mA Low-Noise Ultra Low-Dropout Regulator in SOT-23 and micro SMD
Packages
Basic Application Circuit
10014002
*ON/OFF input must be actively terminated. Tie to VIN if this function is not to be used.
**Minimum capacitance is shown to ensure stability (may be increased without limit). Ceramic capacitor required for output (see Application Hints).
***Reduces output noise (may be omitted if application is not noise critical). Use ceramic or film type with very low leakage current (see Application Hints).
Connection Diagrams
SOT-23, 5-Lead Small Outline Package (M5)
10014003
Top View
See NS Package Number MF05A
micro SMD, 5 Bump Package
10014046
Note: The actual physical placement of the package marking will vary from part
to part. Package marking contains date code and lot traceability information, and
will vary considerably. Package marking does not correlate to device type.
Top View
See NS Package Numbers TPA05 and TLA05
Pin Descriptions
Name Pin Number Function
SOT-23 micro SMD
VIN 1 C3 Input Voltage
GND 2 A1 Common Ground (device substrate)
ON/OFF 3 A3 Logic high enable input
BYPASS 4 B2 Bypass capacitor for low noise operation
VOUT 5 C1 Regulated output voltage
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LP2985
Ordering Information
TABLE 1. Package Marking and Ordering Information
Output Voltage
(V) Grade Order Information Package Marking Supplied as:
For output voltages ≤ 2.0V, refer to LP2985LV datasheet.
SOT-23, 5-Lead Small Outline Package (M5)
2.5
ALP2985AIM5-2.5 LAUA 1000 Units on Tape and Reel
LP2985AIM5X-2.5 LAUA 3000 Units on Tape and Reel
STD LP2985IM5-2.5 LAUB 1000 Units on Tape and Reel
LP2985IM5X-2.5 LAUB 3000 Units on Tape and Reel
2.6 A LP2985AIM5-2.6 LCEA 1000 Units on Tape and Reel
LP2985AIM5X-2.6 LCEA 3000 Units on Tape and Reel
2.7
ALP2985AIM5-2.7 LALA 1000 Units on Tape and Reel
LP2985AIM5X-2.7 LALA 3000 Units on Tape and Reel
STD LP2985IM5-2.7 LALB 1000 Units on Tape and Reel
LP2985IM5X-2.7 LALB 3000 Units on Tape and Reel
2.8
ALP2985AIM5-2.8 L0KA 1000 Units on Tape and Reel
LP2985AIM5X-2.8 L0KA 3000 Units on Tape and Reel
STD LP2985IM5-2.8 L0KB 1000 Units on Tape and Reel
LP2985IM5X-2.8 L0KB 3000 Units on Tape and Reel
2.9
ALP2985AIM5-2.9 LAXA 1000 Units on Tape and Reel
LP2985AIM5X-2.9 LAXA 3000 Units on Tape and Reel
STD LP2985IM5-2.9 LAXB 1000 Units on Tape and Reel
LP2985IM5X-2.9 LAXB 3000 Units on Tape and Reel
3.0
ALP2985AIM5-3.0 L0OA 1000 Units on Tape and Reel
LP2985AIM5X-3.0 L0OA 3000 Units on Tape and Reel
STD LP2985IM5-3.0 L0OB 1000 Units on Tape and Reel
LP2985IM5X-3.0 L0OB 3000 Units on Tape and Reel
3.1
ALP2985AIM5-3.1 L0PA 1000 Units on Tape and Reel
LP2985AIM5X-3.1 L0PA 3000 Units on Tape and Reel
STD LP2985IM5-3.1 L0PB 1000 Units on Tape and Reel
LP2985IM5X-3.1 L0PB 3000 Units on Tape and Reel
3.2 STD LP2985IM5-3.2 L0QB 1000 Units on Tape and Reel
3.3
ALP2985AIM5-3.3 L0RA 1000 Units on Tape and Reel
LP2985AIM5X-3.3 L0RA 3000 Units on Tape and Reel
STD LP2985IM5-3.3 L0RB 1000 Units on Tape and Reel
LP2985IM5X-3.3 L0RB 3000 Units on Tape and Reel
3.5 A LP2985AIM5-3.5 LAIA 1000 Units on Tape and Reel
STD LP2985IM5-3.5 LAIB 1000 Units on Tape and Reel
3.6
ALP2985AIM5-3.6 L0SA 1000 Units on Tape and Reel
LP2985AIM5X-3.6 L0SA 3000 Units on Tape and Reel
STD LP2985IM5-3.6 L0SB 1000 Units on Tape and Reel
LP2985IM5X-3.6 L0SB 3000 Units on Tape and Reel
3.8
ALP2985AIM5-3.8 L0YA 1000 Units on Tape and Reel
LP2985AIM5X-3.8 L0YA 3000 Units on Tape and Reel
STD LP2985IM5-3.8 L0YB 1000 Units on Tape and Reel
LP2985IM5X-3.8 L0YB 3000 Units on Tape and Reel
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LP2985
Output Voltage
(V) Grade Order Information Package Marking Supplied as:
4.0
ALP2985AIM5-4.0 L0TA 1000 Units on Tape and Reel
LP2985AIM5X-4.0 L0TA 3000 Units on Tape and Reel
STD LP2985IM5-4.0 L0TB 1000 Units on Tape and Reel
LP2985IM5X-4.0 L0TB 3000 Units on Tape and Reel
4.5
ALP2985AIM5-4.5 LA7A 1000 Units on Tape and Reel
LP2985AIM5X-4.5 LA7A 3000 Units on Tape and Reel
STD LP2985IM5X-4.5 LA7B 1000 Units on Tape and Reel
LP2985IM5-4.5 LA7B 3000 Units on Tape and Reel
5.0
ALP2985AIM5-5.0 L0UA 1000 Units on Tape and Reel
LP2985AIM5X-5.0 L0UA 3000 Units on Tape and Reel
STD LP2985IM5-5.0 L0UB 1000 Units on Tape and Reel
LP2985IM5X-5.0 L0UB 3000 Units on Tape and Reel
5.7
ALP2985AIM5-5.7 LKTA 1000 Units on Tape and Reel
LP2985AIM5X-5.7 LKTA 3000 Units on Tape and Reel
STD LP2985IM5-5.7 LKTB 1000 Units on Tape and Reel
LP2985IM5X-5.7 LKTB 3000 Units on Tape and Reel
6.1
ALP2985AIM5-6.1 LF6A 1000 Units on Tape and Reel
LP2985AIM5X-6.1 LF6A 3000 Units on Tape and Reel
STD LP2985IM5-6.1 LF6B 1000 Units on Tape and Reel
LP2985IM5X-6.1 LF6B 3000 Units on Tape and Reel
micro SMD, 5 Bump Package (TPA05 - 170 µm ball)
2.5 A LP2985AITPX-2.5 3000 Units on Tape and Reel
STD LP2985ITP-2.5 250 Units on Tape and Reel
2.6
ALP2985AITP-2.6 250 Units on Tape and Reel
LP2985AITPX-2.6 3000 Units on Tape and Reel
STD LP2985ITP-2.6 250 Units on Tape and Reel
LP2985ITPX-2.6 3000 Units on Tape and Reel
2.7
ALP2985AITP-2.7 250 Units on Tape and Reel
LP2985AITPX-2.7 3000 Units on Tape and Reel
STD LP2985ITP-2.7 250 Units on Tape and Reel
LP2985ITPX-2.7 3000 Units on Tape and Reel
2.8
ALP2985AITP-2.8 250 Units on Tape and Reel
LP2985AITPX-2.8 3000 Units on Tape and Reel
STD LP2985ITP-2.8 250 Units on Tape and Reel
LP2985ITPX-2.8 3000 Units on Tape and Reel
2.9
ALP2985AITP-2.9 250 Units on Tape and Reel
LP2985AITPX-2.9 3000 Units on Tape and Reel
STD LP2985ITP-2.9 250 Units on Tape and Reel
LP2985ITPX-2.9 3000 Units on Tape and Reel
3.0
ALP2985AITP-3.0 250 Units on Tape and Reel
LP2985AITPX-3.0 3000 Units on Tape and Reel
STD LP2985ITP-3.0 250 Units on Tape and Reel
LP2985ITPX-3.0 3000 Units on Tape and Reel
3.3
ALP2985AITP-3.3 250 Units on Tape and Reel
LP2985AITPX-3.3 3000 Units on Tape and Reel
STD LP2985ITP-3.3 250 Units on Tape and Reel
LP2985ITPX-3.3 3000 Units on Tape and Reel
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LP2985
Output Voltage
(V) Grade Order Information Package Marking Supplied as:
5.0
ALP2985AITP-5.0 250 Units on Tape and Reel
LP2985AITPX-5.0 3000 Units on Tape and Reel
STD LP2985ITP-5.0 250 Units on Tape and Reel
LP2985ITPX-5.0 3000 Units on Tape and Reel
micro SMD, 5 Bump Package (TLA05 - 300 µm ball)
3.3
ALP2985AITL-3.3 250 Units on Tape and Reel
LP2985AITLX-3.3 3000 Units on Tape and Reel
STD LP2985ITL-3.3 250 Units on Tape and Reel
LP2985ITLX-3.3 3000 Units on Tape and Reel
For LP2985 Ordering and Availability Information see: http://www.national.com/mpf/LP/LP2985.html#Order
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LP2985
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 Temp. (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) 2.5V to +16V
Shutdown Input Voltage (Survival) −0.3V to +16V
Output Voltage (Survival, (Note 4)) −0.3V to +9V
IOUT (Survival) Short Circuit
Protected
Input-Output Voltage (Survival, −0.3V to +16V
(Note 5))
Electrical Characteristics (Note 10)
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 = VO(NOM) + 1V, IL = 1 mA, CIN = 1 µF, COUT = 4.7 µF, VON/OFF = 2V.
Symbol Parameter Conditions Typ
LP2985AI-X.X LP2985I-X.X
Units
(Note 6) (Note 6)
Min Max Min Max
ΔVOOutput Voltage
Tolerance
IL = 1 mA −1.0 1.0 −1.5 1.5
%VNOM
1 mA ≤ IL ≤ 50 mA −1.5 1.5 −2.5 2.5
−2.5 2.5 −3.5 3.5
1 mA ≤ IL ≤ 150 mA −2.5 2.5 −3.0 3.0
−3.5 3.5 −4.0 4.0
Output Voltage VO(NOM)+1V ≤ VIN ≤ 16V 0.007 0.014 0.014
%/V
Line Regulation 0.032 0.032
VIN–VODropout Voltage
(Note 7)
IL = 0 1 3 3
mV
5 5
IL = 1 mA 7 10 10
15 15
IL = 10 mA 40 60 60
90 90
IL = 50 mA 120 150 150
225 225
IL = 150 mA 280 350 350
575 575
IGND Ground Pin Current IL = 0 65 95 95
µA
125 125
IL = 1 mA 75 110 110
170 170
IL = 10 mA 120 220 220
400 400
IL = 50 mA 350 600 600
1000 1000
IL = 150 mA 850 1500 1500
2500 2500
VON/OFF < 0.3V 0.01 0.8 0.8
VON/OFF < 0.15V 0.05 2 2
VON/OFF ON/OFF Input Voltage
(Note 8)
High = O/P ON 1.4 1.6 1.6 V
Low = O/P OFF 0.55 0.15 0.15
ION/OFF ON/OFF Input Current VON/OFF = 0 0.01 −2 −2 µA
VON/OFF = 5V 5 15 15
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LP2985
Symbol Parameter Conditions Typ
LP2985AI-X.X LP2985I-X.X
Units
(Note 6) (Note 6)
Min Max Min Max
enOutput Noise BW = 300 Hz to 50 kHz,
Voltage (RMS) COUT = 10 µF 30 µV
CBYPASS = 10 nF
Ripple Rejection f = 1 kHz, CBYPASS = 10 nF
45
dB
COUT = 10 µF
IO(SC) Short Circuit Current RL = 0 (Steady State) 400 mA
(Note 9)
IO(PK) Peak Output Current VOUT ≥ Vo(NOM) −5% 350 mA
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 for the SOT-23 package, or pins 5 and 2 for the micro SMD package, 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, θJ-
A, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperture is calculated using:
Where the value of θJ-A for the SOT-23 package is 220°C/W in a typical PC board mounting and the micro SMD package is 225°C/W. Exceeding the maximum
allowable dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown.
Note 4: For 12V option, output voltage survival: -0.3 to +16V. If used in a dual-supply system where the regulator load is returned to a negative supply, the LP2985
output must be diode-clamped to ground.
Note 5: The output PNP structure contains a diode between the VIN to VOUT terminals that is normally reverse-biased. Reversing the polarity from VIN to VOUT
will turn on this diode.
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 input must be properly driven to prevent possible misoperation. For details, refer to Application Hints.
Note 9: The LP2985 has foldback current limiting which allows a high peak current when VOUT > 0.5V, and then reduces the maximum output current as VOUT is
forced to ground (see Typical Performance Characteristics curves).
Note 10: Exposing the micro SMD device to direct sunlight will cause misoperation. See Application Hints for additional information.
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LP2985
Typical Performance Characteristics Unless otherwise specified: CIN = 1µF, COUT = 4.7µF, VIN = VOUT
(NOM) +1, TA = 25°C, ON/OFF pin is tied to VIN.
VOUT vs Temperature
10014008
Short-Circuit Current
10014009
Short-Circuit Current
10014010
Short Circuit Current vs Output Voltage
10014011
Ripple Rejection
10014013
Ripple Rejection
10014014
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LP2985
Ripple Rejection
10014015
Ripple Rejection
10014016
Ripple Rejection
10014017
Ripple Rejection
10014018
Ripple Rejection
10014019
Ripple Rejection
10014023
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LP2985
Ripple Rejection
10014022
Output Impedance vs Frequency
10014020
Output Impedance vs Frequency
10014021
Output Noise Density
10014024
Output Noise Density
10014025
Ground Pin vs Load Current
10014026
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LP2985
Dropout Voltage vs Temperature
10014027
Input Current vs Pin
10014029
GND Pin Current vs Temperature
10014030
Instantaneous Short Circuit Current
10014031
Load Transient Response
10014032
Load Transient Response
10014033
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LP2985
Load Transient Response
10014034
Line Transient Response
10014035
Line Transient Response
10014036
Line Transient Response
10014037
Line Transient Response
10014038
Turn-On Time
10014039
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LP2985
Turn-On Time
10014040
Turn-On Time
10014041
Turn-On Time
10014042
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LP2985
Application Hints
EXTERNAL CAPACITORS
Like any low-dropout regulator, the LP2985 requires external
capacitors for regulator stability. These capacitors must be
correctly selected for good performance.
Input Capacitor
An input capacitor whose capacitance is ≥ 1 µF is required
between the LP2985 input and ground (the amount of capac-
itance may be increased without limit).
This capacitor must be located a distance of not more than 1
cm 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 can suffer catastrophic fail-
ure due to surge current when connected to a low-impedance
source of power (like a battery or 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 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 temperature range.
Output Capacitor
The LP2985 is designed specifically to work with ceramic out-
put capacitors, utilizing circuitry which allows the regulator to
be stable across the entire range of output current with an
output capacitor whose ESR is as low as 5 mΩ. 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 se-
ries resistance) value which is within the stable range. Curves
are provided which show the stable ESR range as a function
of load current (see ESR graph below).
10014007
Important: The output capacitor must maintain its ESR within
the stable region over the full operating temperature range of
the application to assure stability.
The LP2985 requires a minimum of 2.2 µF on the output (out-
put capacitor size can be increased without limit).
It is important to remember that capacitor tolerance and vari-
ation with temperature must be taken into consideration when
selecting an output capacitor so that the minimum required
amount of output capacitance is provided over the full oper-
ating temperature range. It should be noted that ceramic
capacitors can exhibit large changes in capacitance with tem-
perature (see next section, Capacitor Characteristics).
The output capacitor must be located not more than 1 cm from
the output pin and returned to a clean analog ground.
Noise Bypass Capacitor
Connecting a 10 nF capacitor to the Bypass pin significantly
reduces noise on the regulator output. It should be noted that
the capacitor is connected directly to a high-impedance circuit
in the bandgap reference.
Because this circuit has only a few microamperes flowing in
it, any significant loading on this node will cause a change in
the regulated output voltage. For this reason, DC leakage
current through the noise bypass capacitor must never ex-
ceed 100 nA, and should be kept as low as possible for best
output voltage accuracy.
The types of capacitors best suited for the noise bypass ca-
pacitor are ceramic and film. High-quality ceramic capacitors
with either NPO or COG dielectric typically have very low
leakage. 10 nF polypropolene and polycarbonate film capac-
itors are available in small surface-mount packages and typ-
ically have extremely low leakage current.
CAPACITOR CHARACTERISTICS
The LP2985 was designed to work with ceramic capacitors
on the output to take advantage of the benefits they offer: for
capacitance values in the 2.2 µF to 4.7 µF range, ceramics
are the least expensive and also have the lowest ESR values
(which makes them best for eliminating high-frequency
noise). The ESR of a typical 2.2 µF ceramic capacitor is in the
range of 10 mΩ to 20 mΩ, which easily meets the ESR limits
required for stability by the LP2985.
One disadvantage of ceramic capacitors is that their capaci-
tance can vary with temperature. Most large value ceramic
capacitors (≥ 2.2 µF) are manufactured with the Z5U or Y5V
temperature characteristic, which results in the capacitance
dropping by more than 50% as the temperature goes from 25°
C to 85°C.
This could cause problems if a 2.2 µF capacitor were used on
the output since it will drop down to approximately 1 µF at high
ambient temperatures (which could cause the LM2985 to os-
cillate). If Z5U or Y5V capacitors are used on the output, a
minimum capacitance value of 4.7 µF must be observed.
A better choice for temperature coefficient in ceramic capac-
itors is X7R, which holds the capacitance within ±15%. Un-
fortunately, the larger values of capacitance are not offered
by all manufacturers in the X7R dielectric.
Tantalum
Tantalum capacitors are less desirable than ceramics for use
as output capacitors because they are more expensive when
comparing equivalent capacitance and voltage ratings in the
1 µF to 4.7 µF 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 ca-
pacitor 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.
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LP2985
On/Off Input Operation
The LP2985 is shut off by driving the ON/OFF input low, and
turned on by pulling it high. If this feature is not to be used,
the ON/OFF input should be tied to VIN to keep the regulator
output on at all times.
To assure 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 listed in the Elec-
trical Characteristics section under VON/OFF. To prevent mis-
operation, the turn-on (and turn-off) voltage signals applied to
the ON/OFF input must have a slew rate which is
≥ 40 mV/µs.
Caution: the regulator output voltage can not be guaranteed
if a slow-moving AC (or DC) signal is applied that is in the
range between the specified turn-on and turn-off voltages list-
ed under the electrical specification VON/OFF (see Electrical
Characteristics).
REVERSE INPUT-OUTPUT VOLTAGE
The PNP power transistor used as the pass element in the
LP2985 has an inherent diode connected between the regu-
lator output and input. During normal operation (where the
input voltage is higher than the output) this diode is reverse-
biased.
10014054
FIGURE 1. Reverse Current Path
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 cur-
rent to flow into VIN (and out the ground pin), which can
damage the part.
In any application where the output may be pulled above the
input, an external Schottky diode must be connected from
VIN to VOUT (cathode on VIN, anode on VOUT), to limit the re-
verse voltage across the LP2985 to 0.3V (see Absolute Max-
imum Ratings).
10014055
FIGURE 2. Reverse Current Protection
MICRO SMD MOUNTING
The micro SMD package requires specific mounting tech-
niques which are detailed in National Semiconductor Appli-
cation 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.
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.
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 perfor-
mance. 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.
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LP2985
Physical Dimensions inches (millimeters) unless otherwise noted
SOT-23, 5-Lead Small Outline Package (M5)
NS Package Number MF05A.
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LP2985
NOTES: UNLESS OTHERWISE SPECIFIED
1. EPOXY COATING
2. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD.
3. PIN 1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION. REMAINING PINS ARE NUMBERED COUNTER CLOCK-
WISE.
4. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS PACK-
AGE HEIGHT.
5.NO JEDEC REGISTRATION AS OF AUG.1999.
micro SMD, 5 Bump, Package (TPA05 - 170 µm ball)
NS Package Number TPA05
The dimensions for X1, X2 and X3 are as given:
X1 = 0.930 +/− 0.030mm
X2 = 1.107 +/− 0.030mm
X3 = 0.500 +/− 0.075mm
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LP2985
NOTES: UNLESS OTHERWISE SPECIFIED
1. EPOXY COATING
2. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD.
3. PIN 1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION. REMAINING PINS ARE NUMBERED COUNTER CLOCK-
WISE.
4. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS PACK-
AGE HEIGHT.
5.NO JEDEC REGISTRATION AS OF AUG.1999.
micro SMD, 5 Bump, Package (TLA05 - 300 µm ball)
NS Package Number TLA05
The dimensions for X1, X2 and X3 are as given:
X1 = 1.031 +/− 0.030mm
X2 = 1.412 +/− 0.030mm
X3 = 0.600 +/− 0.075mm
www.national.com 18
LP2985
Notes
19 www.national.com
LP2985
Notes
LP2985 Micropower 150 mA Low-Noise Ultra Low-Dropout Regulator in SOT-23 and micro SMD
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