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
5 www.national.com
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
Notes
LP2985 Micropower 150 mA Low-Noise Ultra Low-Dropout Regulator in SOT-23 and micro SMD
Packages
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