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LP2983
SNVS170D – OCTOBER 2001 – REVISED APRIL 2016
LP2983 Micropower 150-mA Voltage Regulator in SOT-23 Package
for Output Voltages ≤ 1.2 VDesigned for Use With Very Low-ESR Output Capacitors
1 Features
3 Description
•
•
•
•
•
•
•
•
•
•
•
The LP2983 is a 150-mA, fixed-output voltage
regulator designed to provide tight voltage regulation
in applications with output voltages ≤ 1.2 V.
1
Operating Input Supply Voltage: 2.2 V to 16 V
Output Current: 150 mA
Low ZOUT: 0.3 Ω Typical (10 Hz to 1 MHz)
Stable with Low-ESR Output Capacitor
Low Ground Pin Current at All Loads
Output Voltage Accuracy 1% (A Grade)
High Peak Current Capability
Wide Supply Voltage Range (16 V Maximum)
Overtemperature and Overcurrent Protection
−40°C to +125°C Junction Temperature Range
Requires Minimum External Components
2 Applications
•
•
•
•
Cellular Phones
Palmtop/Laptop Computers
Personal Digital Assistants (PDA)
Camcorders, Personal Stereos, Cameras
Using an optimized vertically integrated PNP (VIP)
process, the LP2983 delivers unequaled performance
in all critical specifications:
• Ground pin current: Typically 825 µA at a 150-mA
load, and 75 µA at a 1-mA load.
• Enhanced stability: The LP2983 is stable with
output capacitor ESR down to zero, which allows
the use of ceramic capacitors on the output.
• Precision output: 1% tolerance output voltages
available (A grade).
• Smallest possible size: SOT-23 package uses
absolute minimum board space.
Device Information(1)
PART NUMBER
LP2983
PACKAGE
SOT-23 (5)
BODY SIZE (NOM)
2.90 mm × 1.60 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
space
space
space
Typical Application
VIN
IN
OUT
VOUT
GND
ON/OFF
ON/OFF
ESR
Copyright © 2016, Texas Instruments Incorporated
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
LP2983
SNVS170D – OCTOBER 2001 – REVISED APRIL 2016
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Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
6.1
6.2
6.3
6.4
6.5
6.6
4
4
4
4
5
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
Detailed Description ............................................ 10
7.1 Overview ................................................................. 10
7.2 Functional Block Diagram ....................................... 10
7.3 Feature Description................................................. 10
7.4 Device Functional Modes........................................ 12
8
Application and Implementation ........................ 13
8.1 Application Information............................................ 13
8.2 Typical Application ................................................. 13
9 Power Supply Recommendations...................... 16
10 Layout................................................................... 17
10.1 Layout Guidelines ................................................. 17
10.2 Layout Example .................................................... 17
11 Device and Documentation Support ................. 18
11.1
11.2
11.3
11.4
11.5
Documentation Support ........................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
18
18
18
18
18
12 Mechanical, Packaging, and Orderable
Information ........................................................... 18
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision C (April 2013) to Revision D
Page
•
Added Pin Configuration and Functions section, ESD Ratings table and Thermal Information table with update
thermal values, Feature Description section, Device Functional Modes, Application and Implementation section,
Power Supply Recommendations section, Layout section, Device and Documentation Support section, and
Mechanical, Packaging, and Orderable Information section; change pin names VOUT and VIN to OUT and IN ................... 1
•
Changed footnote 3 to Abs Max to replace out-of-date thetaJA temperature with general information ................................ 4
•
Added Thermal Information table .......................................................................................................................................... 4
Changes from Revision B (April 2013) to Revision C
•
2
Page
Changed layout of National Data Sheet to TI format ........................................................................................................... 11
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5 Pin Configuration and Functions
DBV Package
5-Pin SOT-23
Top View
Pin Functions
PIN
NUMBER
1
NAME
IN
TYPE
Input
2
GND
—
3
ON/OFF
Input
4
ESR
—
5
OUT
Output
DESCRIPTION
Input voltage
Common ground (device substrate)
Logic high enable input
Low side connection for low-ESR output capacitors
Regulated output voltage
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6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
MAX
UNIT
−0.3
16
V
Input supply voltage (operating)
2.3
16
V
Shutdown input voltage (survival)
−0.3
16
V
Output voltage (survival) (2)
−0.3
9
V
Input supply voltage (survival)
IOUT (survival)
Short-circuit protected
Input-output voltage (survival) (3)
−0.3
16
V
Operating junction temperature
−40
125
°C
Power dissipation (4)
Internally limited
Storage temperature
(1)
(2)
(3)
(4)
–65
150
°C
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
If used in a dual-supply system where the regulator load is returned to a negative supply, the LP2983 output must be diode-clamped to
ground.
The output PNP structure contains a diode between the IN and OUT pins that is normally reverse-biased. Reversing the polarity from
VIN to VOUT turn on this diode (See Reverse Input-Output Voltage).
The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(MAX), the junction-to-ambient thermal
resistance, RθJA, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated
using P(MAX) = (TJ(MAX) – TA) / RθJA. The value of RθJA for the SOT-23 package varies depending on the application board — the value
given inThermal Information can be considered as the worstcase scenario. Exceeding the maximum allowable power dissipation causes
excessive die temperature, and the regulator will go into thermal shutdown.
6.2 ESD Ratings
VALUE
Electrostatic
discharge
V(ESD)
(1)
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (all pins
except pin 3) (1)
±2000
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (pin 3) (1)
±1000
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
MAX
UNIT
Operating junction temperature
−40
125
°C
Input supply voltage (operating)
2.2
16
V
6.4 Thermal Information
LP2983
THERMAL METRIC (1)
DBV (SOT-23)
UNIT
5 PINS
RθJA
Junction-to-ambient thermal resistance, High-K (2)
169.0
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
121.8
°C/W
RθJB
Junction-to-board thermal resistance
29.5
°C/W
ψJT
Junction-to-top characterization parameter
16.1
°C/W
ψJB
Junction-to-board characterization parameter
29.0
°C/W
(1)
(2)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
Thermal resistance value RθJA is based on the EIA/JEDEC High-K printed circuit board defined by: JESD51-7 - High Effective Thermal
Conductivity Test Board for Leaded Surface Mount Packages.
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6.5 Electrical Characteristics
Unless otherwise specified: TJ = 25°C, VIN = VO(NOM) + 1 V, IL = 1 mA, COUT = 1 μF, VON/OFF = 2 V.
PARAMETER
TEST CONDITIONS
ΔVO/ΔVIN
Output voltage
tolerance
Output voltage line
regulation
MIN
MIN
−1%
1%
−1.5%
1.5%
–2%
2%
–2.5%
2.5
1 mA < IL < 50 mA
–40°C ≤ TJ ≤ 125°C
−2.5%
2.5%
−3.5%
3.5%
1 mA < IL < 150 mA
−2.5%
2.5%
−3%
3%
1 mA < IL < 150 mA
–40°C ≤ TJ ≤ 125°C
−3.5%
3.5%
−4%
4%
VO(NOM) + 1 V ≤ VIN ≤ 16 V
TYP
0.01
VO(NOM) + 1 V ≤ VIN ≤ 16 V
–40°C ≤ TJ ≤ 125°C
65
IL = 0 mA, –40°C ≤ TJ ≤ 125°C
75
IL = 1 mA, –40°C ≤ TJ ≤ 125°C
120
IL = 10 mA, –40°C ≤ TJ ≤ 125°C
825
1200
IL = 150 mA, –40°C ≤ TJ ≤ 125°C
VON/OFF < 0.05 V
–40°C ≤ TJ ≤ 125°C
Minimum VIN required
to maintain output
–40°C ≤ TJ ≤ 125°C
regulation
220
400
500
825
1500
μA
900
2000
12
6
12
0.2
2
0.2
2
2.2
1.4
Low = O/P OFF
1.6
0.1
V
0.1
0.05
0.01
VON/OFF = 0 V
–40°C ≤ TJ ≤ 125°C
VON/OFF = 5 V
V
1.4
1.6
0.05
0.01
–2
5
VON/OFF = 5 V
–40°C ≤ TJ ≤ 125°C
(2)
110
300
2.2
VON/OFF = 0 V
(1)
95
6
Low = O/P OFF
–40°C ≤ TJ ≤ 125°C
ON/OFF input current
%/V
2.05
High = O/P ON
High = O/P ON
–40°C ≤ TJ ≤ 125°C
0.016
170
120
2000
VON/OFF < 0.15 V
ION/OFF
75
220
500
UNIT
125
900
IL = 150 mA
VON/OFF
65
110
300
IL = 50 mA, –40°C ≤ TJ ≤ 125°C
ON/OFF input
voltage (2)
95
400
IL = 50 mA
MAX
0.032
170
IL = 10 mA
VIN (min)
0.01
125
IL = 1 mA
Ground pin current
0.016
TYP
0.032
IL = 0 mA
IGND
LP2981I-XX (1)
MAX
1 mA < IL < 50 mA
ΔVO
LP2981AI-XX (1)
–2
μA
5
15
15
Limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlation using Statistical
Quality Control (SQC) methods. The limits are used to calculate Average Outgoing Quality Level (AOQL).
The ON/OFF inputs must be properly driven to prevent misoperation. For details, see Operation With ON/OFF Control.
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Electrical Characteristics (continued)
Unless otherwise specified: TJ = 25°C, VIN = VO(NOM) + 1 V, IL = 1 mA, COUT = 1 μF, VON/OFF = 2 V.
PARAMETER
Output noise voltage
(RMS)
en
ΔVO/ΔVIN Ripple rejection
TEST CONDITIONS
MIN
TYP
LP2981I-XX (1)
MAX
MIN
TYP
MAX
UNIT
BW = 300 Hz to 50 kHz
VOUT = 1.2 V, COUT = 10 μF
60
60
μV
ƒ = 1 kHz, COUT = 2.2 μF
65
65
dB
(3)
400
400
mA
250
250
mA
IO(MAX)
Short-circuit current
RL = 0 Ω (steady state)
IO(PK)
Peak output current
VOUT ≥ VO(NOM) − 5%
(3)
LP2981AI-XX (1)
The LP2983 has foldback current limiting which allows a high peak current when VOUT > 0.5 V, and then reduces the maximum output
current as VOUT is forced down to ground. See related curve(s) in Typical Characteristics section.
6.6 Typical Characteristics
Unless otherwise specified: CIN = 1 µF, COUT = 2.2 µF, VIN = VOUT(NOM) + 1, TA = 25°C, ON/OFF pin is tied to VIN.
Figure 1. LP2983 Tempco
Load = 0 mA
Figure 2. Minimum Input Voltage vs Temperature
Load = 1 mA
Figure 3. Input Current vs VIN
6
Figure 4. Input Current vs VIN
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Typical Characteristics (continued)
Unless otherwise specified: CIN = 1 µF, COUT = 2.2 µF, VIN = VOUT(NOM) + 1, TA = 25°C, ON/OFF pin is tied to VIN.
Load = 50 mA and 150 mA
Figure 6. GND Pin vs Load Current
Figure 5. Input Current vs VIN
Load = 1 mA
Figure 7. GND Pin vs Temperature and Load
Load = 150 mA
ΔVIN = 1 V
ΔVIN = 1 V
Figure 8. Line Transient Response
Load = 1 mA
Figure 9. Line Transient Response
ΔVIN = 13.8 V
Figure 10. Line Transient Response
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Typical Characteristics (continued)
Unless otherwise specified: CIN = 1 µF, COUT = 2.2 µF, VIN = VOUT(NOM) + 1, TA = 25°C, ON/OFF pin is tied to VIN.
Load = 150 mA
ΔVIN = 13.8 V
Figure 11. Line Transient Response
Figure 12. Noise Density
COUT = 2.2 µF
Figure 14. Turnon Time
Figure 13. Ripple Rejection
VIN = 16 V
Figure 15. Short-Circuit Current vs Temperature
8
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Figure 16. Short-Circuit Current
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Typical Characteristics (continued)
Unless otherwise specified: CIN = 1 µF, COUT = 2.2 µF, VIN = VOUT(NOM) + 1, TA = 25°C, ON/OFF pin is tied to VIN.
VIN = 2.8 V
VIN = 6 V
Figure 17. Short-Circuit Current
Figure 18. Short-Circuit Current
COUT = 4.7 µF
COUT = 2.2 µF
Figure 19. Load Transient Response
Figure 20. Load Transient Response
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7 Detailed Description
7.1 Overview
The LP2983 is a voltage regulator with optimized vertically integrated PNP designed for use with very low ESR
output capacitors, excellent for low noise applications that require a clean voltage supply. The LP2983 has a
wide input voltage range (16 V maximum), high accuracy (A grade 1%), and a fixed output voltage supply
capable of delivering 150 mA. In addition the LP2983 device provides the following features:
• High accuracy output voltage
• Low ground current, typically 825 μA at 150-mA load and 75 μA at 1-mA load
• A sleep mode feature is available, allowing the regulator to consume only 1 µA (typical) when the ON/OFF pin
is pulled low.
• Overtemperature protection and overcurrent protection circuitry designed to safeguard the device during
unexpected conditions.
• Thermal protection
7.2 Functional Block Diagram
7.3 Feature Description
7.3.1 High-Accuracy Output Voltage
With special careful design to minimize all contributions to the output voltage error, the LP2983 distinguishes
itself as a very high-accuracy output voltage micropower LDO. This includes a tight initial tolerance (typically
1.5% at 50 mA, 25°C junction temperature; also available in A grade with an accuracy of 1% under the same
conditions), extremely good line regulation (0.01%/V typical), and a very low output-voltage temperature
coefficient, making the part an ideal low-power voltage reference.
7.3.2 Low Ground Current
The LP2983 device uses a vertical PNP process which allows for quiescent currents that are considerably lower
than those associated with traditional lateral PNP regulators, typically 825 μA at 150-mA load and 75 μA at 1-mA
load.
10
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Feature Description (continued)
7.3.3 Reverse Input-Output Voltage
The internal PNP power transistor used as the pass element in the LP2983 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 (See Figure 21).
LP2983
VIN
VOUT
PNP
GND
Copyright © 2016, Texas Instruments Incorporated
Figure 21. LP2983 Reverse Current Path
However, if the input voltage is more than a VBE below the output voltage, this diode turns ON and current flows
into the regulator output. In such cases, a parasitic SCR can latch which allows a high current to flow into the VIN
pin and out the ground pin, which can damage the part.
The internal diode can also be turned on if the input voltage is abruptly stepped down to a voltage which is a VBE
below the output voltage.
In any application where the output voltage may be higher than the input voltage, an external Schottky diode
must be connected from VIN to VOUT (cathode on VIN, anode on VOUT — see Figure 22), to limit the reverse
voltage across the LP2983 to 0.3 V (see Absolute Maximum Ratings).
SCHOTTKY DIODE
LP2983
VIN
VOUT
PNP
GND
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Figure 22. Adding External Schottky Diode Protection
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Feature Description (continued)
7.3.4 ON/OFF Input Operation
The LP2983 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 must 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 turnon or turnoff voltage thresholds listed in Typical Characteristics under VON/OFF. To prevent
mis-operation, the turnon (and turnoff) 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 ensured if a slow-moving AC (or DC) signal is
applied that is in the range between the specified turn-on and turn-off voltages listed
under the electrical specification VON/OFF (see Electrical Characteristics).
7.3.5 Thermal Protection
The LP2983 contains a thermal shutdown protection circuit to turn off the output current when excessive heat is
dissipated in the LDO. The thermal time-constant of the semiconductor die is fairly short, and thus the output
cycles on and off at a high rate when thermal shutdown is reached until the power dissipation is reduced. The
internal protection circuitry of the LM2983 is designed to protect against thermal overload conditions. The
circuitry is not intended to replace proper heat sinking. Continuously running the device into thermal shutdown
degrades its reliability.
7.4 Device Functional Modes
7.4.1 Operation With VO(NOM) + 1 V ≤ VIN < 16 V
The device operates if the input voltage is equal to, or exceeds, VOUT(TARGET) + 1 V. If the previous condition is
not met, the device will not operate correctly, and the output voltage may not reach target value.
7.4.2 Operation With ON/OFF Control
If the voltage on the ON/OFF pin is less than 0.1 V at room temperature and less than 0.05 V over the full
operating temperature range, the device output is disabled, and the shutdown current (IGND) will not exceed 12
μA. Raising ON/OFF above 1.4 V at room temperature and above 1.6 V over the full operating temperature
range initiates the start-up sequence of the device.
12
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8 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The LP2983 is a linear voltage regulator operating from 2.2 V to 16 V on the input and regulates voltages
between ≤ 1.2 V with high accuracy and a 150-mA maximum output current. To achieve high efficiency, the
dropout voltage (VIN – VOUT) must be as small as possible. Successfully implementing an LDO in an application
depends on the application requirements. If the requirements are simply input voltage and output voltage,
compliance specifications (such as internal power dissipation or stability) must be verified to ensure performance.
8.2 Typical Application
VIN
IN
VOUT
OUT
1 µF
GND
2.2 µF
ON/OFF*
ON/OFF
ESR
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*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). A ceramic capacitor is required
for output (see External Capacitors).
Figure 23. LP2983 Typical Application
8.2.1 Design Requirements
For typical voltage regulator applications, use the parameters listed in Table 1:
Table 1. Design Parameters
PARAMETER
DESIGN REQUIREMENT
Input voltage
2.2 V to 16 V
Output voltage
1V or 1.2 V
Output current
0 mA to 150 mA
Output tolerance (1 mA ≤ IL ≤ 50 mA at
25°C)
±1.5% (±1% with A-grade version)
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8.2.2 Detailed Design Procedure
8.2.2.1 External Capacitors
Like any low-dropout regulator, the LP2983 requires external capacitors for regulator stability. These capacitors
must be correctly selected for good performance.
8.2.2.1.1 Input Capacitor
An input capacitor whose capacitance is ≥ 1 µF is required between the LP2983 input and ground (the amount of
capacitance 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.
NOTE
Tantalum capacitors can 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
capacitor is used at the input, it must be ensured 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 is ≥ 1 µF over the entire operating
temperature range.
8.2.2.1.2 Output Capacitors
The LP2983 is designed specifically to work with ceramic output 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
0 Ω.
The ceramic output capacitor must be connected between the OUT pin (device pin 5) and the ESR pin (device
pin 4) (see Figure 24).
Figure 24. Ceramic to ESR Pin (COUT = 2.2 µF)
The LP2983 requires a minimum of 2.2 µF on the output (output capacitor size can be increased without limit).
It is important to remember that capacitor tolerance and variation 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 operating temperature range. Note that ceramic capacitors can exhibit large changes in
capacitance with temperature (see Capacitor Characteristics).
The output capacitor must be located not more than 1 cm from the output pin and returned to a clean analog
ground via the ESR pin.
14
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8.2.2.2 Capacitor Characteristics
The LP2983 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).
One disadvantage of ceramic capacitors is that their capacitance 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 LP2983 to oscillate). 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 capacitors is X7R, which holds the capacitance within
±15%. Unfortunately, the larger values of capacitance are not offered by all manufacturers in the X7R dielectric.
8.2.2.3 Power Dissipation
Knowing the device power dissipation and proper sizing of the thermal plane connected to the tab or pad is
critical to ensuring reliable operation. Device power dissipation depends on input voltage, output voltage, and
load conditions and can be calculated with Equation 1.
PD(MAX) = (VIN(MAX) – VOUT) × IOUT
(1)
Power dissipation can be minimized, and greater efficiency can be achieved, by using the lowest available
voltage drop option that would still be greater than the dropout voltage (VDO). However, keep in mind that higher
voltage drops result in better dynamic (that is, PSRR and transient) performance.
On the SOT-23 (DBV) package, the primary conduction path for heat is through the pins to the PCB. The
maximum allowable junction temperature (TJ(MAX))determines maximum power dissipation allowed (PD(MAX)) for
the device package.
Power dissipation and junction temperature are most often related by the junction-to-ambient thermal resistance
(RθJA) of the combined PCB and device package and the temperature of the ambient air (TA), according to
Equation 2 or Equation 3:
TJ(MAX) = TA(MAX) + (RθJA × PD(MAX))
PD = TJ(MAX) – TA(MAX) / RθJA
(2)
(3)
Unfortunately, this RθJA is highly dependent on the heat-spreading capability of the particular PCB design, and
therefore varies according to the total copper area, copper weight, and location of the planes. The RθJA recorded
in Thermal Information is determined by the specific EIA/JEDEC JESD51-7 standard for PCB and copperspreading area, and is to be used only as a relative measure of package thermal performance. For a welldesigned thermal layout, RθJA is actually the sum of the package junction-to-case (bottom) thermal resistance
(RθJCbot) plus the thermal resistance contribution by the PCB copper area acting as a heat sink.
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8.2.2.4 Estimating Junction Temperature
The EIA/JEDEC standard recommends the use of psi (Ψ) thermal characteristics to estimate the junction
temperatures of surface mount devices on a typical PCB board application. These characteristics are not true
thermal resistance values, but rather package specific thermal characteristics that offer practical and relative
means of estimating junction temperatures. These psi metrics are determined to be significantly independent of
copper-spreading area. The key thermal characteristics (ΨJT and ΨJB) are given in Thermal Information and are
used in accordance with Equation 4 or Equation 5.
TJ(MAX) = TTOP + (ΨJT × PD(MAX))
where
•
•
PD(MAX) is explained in Equation 3
TTOP is the temperature measured at the center-top of the device package.
TJ(MAX) = TBOARD + (ΨJB × PD(MAX))
(4)
where
•
•
PD(MAX) is explained in Equation 3.
TBOARD is the PCB surface temperature measured 1-mm from the device package and centered on the
package edge.
(5)
For more information about the thermal characteristics ΨJT and ΨJB, see Semiconductor and IC Package
Thermal Metrics (SPRA953); for more information about measuring TTOP and TBOARD, see Using New Thermal
Metrics (SBVA025); and for more information about the EIA/JEDEC JESD51 PCB used for validating RθJA, see
Thermal Characteristics of Linear and Logic Packages Using JEDEC PCB Designs (SZZA017). These
application notes are available at www.ti.com.
8.2.3 Application Curves
Unless otherwise specified, CIN = 1 μF, COUT = 2.2 μF, VIN = VOUT(NOM) + 1, TA = 25°C, ON/OFF pin is tied to VIN..
Figure 25. Line Transient Response
Figure 26. Load Transient Response
9 Power Supply Recommendations
The LP2983 is designed to operate from an input voltage supply range between 2.2 V and 16 V. The input
voltage range provides adequate headroom for the device to have a regulated output. This input supply must be
well regulated. If the input supply is noisy, additional input capacitors with low ESR can help improve the output
noise and transient performance.
16
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10 Layout
10.1 Layout Guidelines
For best overall performance, place all circuit components on the same side of the circuit board and as near as
practical to the respective LDO pin connections. Place ground return connections to the input and output
capacitors, and to the LDO ground pin as close to each other as possible, connected by a wide, component-side,
copper surface. The use of vias and long traces to create LDO circuit connections is strongly discouraged and
negatively affects system performance. This grounding and layout scheme minimizes inductive parasitics, and
thereby reduces load-current transients, minimizes noise, and increases circuit stability. TI also recommends a
ground reference plane, either embedded in the PCB itself or located on the bottom side of the PCB opposite the
components. This reference plane serves to assure accuracy of the output voltage, shield noise, and behaves
similar to a thermal plane to spread (or sink) heat from the LDO device. In most applications, this ground plane is
necessary to meet thermal requirements.
10.2 Layout Example
VIN
Input
Capacitor
VOUT
IN
GND
OUT
Output
Capacitor
Ground
ON/OFF
ON/OFF
ESR
Figure 27. LP2983 Layout Example
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11 Device and Documentation Support
11.1 Documentation Support
11.1.1 Related Documentation
For additional information, see the following:
• Semiconductor and IC Package Thermal Metrics (SPRA953)
• Using New Thermal Metrics (SBVA025)
• Thermal Characteristics of Linear and Logic Packages Using JEDEC PCB Designs (SZZA017)
11.2 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
11.3 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.4 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
11.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
18
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PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
LP2983AIM5-1.0/NOPB
LIFEBUY
SOT-23
DBV
5
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
LENA
LP2983AIM5-1.2/NOPB
LIFEBUY
SOT-23
DBV
5
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
LELA
LP2983AIM5X-1.0/NOPB
ACTIVE
SOT-23
DBV
5
3000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
LENA
Samples
LP2983AIM5X-1.2/NOPB
ACTIVE
SOT-23
DBV
5
3000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
LELA
Samples
LP2983IM5-1.0/NOPB
LIFEBUY
SOT-23
DBV
5
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
LENB
LP2983IM5-1.2/NOPB
LIFEBUY
SOT-23
DBV
5
1000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
LELB
LP2983IM5X-1.0/NOPB
LIFEBUY
SOT-23
DBV
5
3000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
LENB
LP2983IM5X-1.2/NOPB
ACTIVE
SOT-23
DBV
5
3000
RoHS & Green
SN
Level-1-260C-UNLIM
-40 to 125
LELB
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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