TI1 LM1086-ADJMDC 1.5-a low dropout positive voltage regulator Datasheet

Product
Folder
Order
Now
Support &
Community
Tools &
Software
Technical
Documents
LM1086-MIL
SNVSAX4 – JUNE 2017
LM1086-MIL 1.5-A Low Dropout Positive Voltage Regulator
1 Features
3 Description
•
The LM1086-MIL is a regulator with a maximum
dropout of 1.5 V at 1.5 A of load current. The device
has the same pin-out as TI's industry standard
LM317.
1
•
•
•
•
•
•
•
•
•
•
Available in Fixed 1.8-V, 2.5-V, 3.3-V, 5-V
Versions
Available in Adjustable Version
Current Limiting and Thermal Protection
2% Output Accuracy
Output Current 1.5 A
Line Regulation 0.015% (Typical)
Load Regulation 0.1% (Typical)
Maximum Input Voltage up to 29 V
Minimum Adjustable Output Voltage
Down to 1.25 V
Stable with Ceramic Output Capacitor with ESR
Temperature Range : –40°C to +125°C
2 Applications
•
•
•
•
•
•
•
High-Efficiency Linear Regulators
Battery Chargers
Post Regulation for Switching Supplies
Constant Current Regulators
Microprocessor Supplies
Audio Amplifiers Supplies
Fire Alarm Control
Two resistors are required to set the output voltage of
the adjustable output voltage version of the LM1086MIL. Fixed output voltage versions integrate the
adjust resistors. Typically, no input capacitor is
needed unless the device is situated more than 6
inches from the input filter capacitors. Output
capacitor can be replaced with ceramic and
appropriate ESR.
The LM1086-MIL circuit includes a zener trimmed
bandgap reference, current limiting, and thermal
shutdown. Because the LM1086-MIL regulator is
floating and detects only the input-to-output
differential voltage, supplies of several hundred volts
can be regulated as long as the maximum input-tooutput differential is not exceeded. Exceeding the
maximum input-to-output deferential will result in
short-circuiting the output. By connecting a fixed
resistor between the adjustment pin and output, the
LM1086-MIL can be also used as a precision current
regulator.
For applications requiring greater output current, refer
to LM1084 for the 5-A version, and the LM1085 for
the 3-A version.
Device Information(1)
PART NUMBER PACKAGE
LM1086-MIL
BODY SIZE (NOM)
WSON (8)
4.00 mm × 4.00 mm
DDPAK/TO-263 (3)
10.18 mm × 8.41 mm
TO-220 (3)
14.986 mm × 10.16 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application
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.
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
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
7
Absolute Maximum Ratings ......................................
ESD Ratings ............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
8
8.1 Application Information............................................ 13
8.2 Typical Applications ................................................ 13
8.3 Other Applications................................................... 14
9 Power Supply Recommendations...................... 18
10 Layout................................................................... 18
10.1 Layout Guidelines ................................................. 18
10.2 Layout Example .................................................... 18
10.3 Thermal Considerations ........................................ 19
11 Device and Documentation Support ................. 21
11.1
11.2
11.3
11.4
11.5
11.6
Detailed Description .............................................. 9
7.1
7.2
7.3
7.4
Application and Implementation ........................ 13
Overview ................................................................... 9
Functional Block Diagram ......................................... 9
Feature Description................................................. 10
Device Functional Modes........................................ 11
Documentation Support ........................................
Receiving Notification of Documentation Updates
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
21
21
21
21
21
21
12 Mechanical, Packaging, and Orderable
Information ........................................................... 21
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
2
DATE
REVISION
NOTES
June 2017
*
Initial release
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
5 Pin Configuration and Functions
NGN Package
8-Pin WSON
Top View
ADJ/GND
1
VIN
2
8
VOUT
7
VOUT
VOUT
N/C
3
6
VOUT
N/C
4
5
N/C
NDE Package
3-Pin TO-220
Top View
KTT Package
3-Pin DDPAK/TO-263
Top View
Pin Functions
PIN
NAME
ADJ/GND
VIN
VOUT
N/C
NUMBER
I/O
KTT/NDE
NGN
1
1
––
DESCRIPTION
Adjust pin for the adjustable output voltage version. Ground pin for the fixed
output voltage versions.
3
2
I
Input voltage pin for the regulator.
2, TAB
6, 7, 8, PAD
O
Output voltage pin for the regulator.
3, 4, 5
––
No connection
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
3
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)
(1) (2)
MIN
Maximum input-to-output voltage differential
MAX
UNIT
LM1086-MIL-ADJ
29
V
LM1086-MIL-1.8
27
V
LM1086-MIL-2.5
27
V
LM1086-MIL-3.3
27
V
25
V
150
°C
150
°C
LM1086-MIL-5
Power dissipation (3)
Internally Limited
Junction temperature (TJ) (4)
Storage temperature, Tstg
(1)
–65
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 Military/Aerospace specified devices are required, contact the Texas Instruments Sales Office/Distributors for availability and
specifications.
Power dissipation is kept in a safe range by current limiting circuitry. Refer to Overload Recovery in Application and Implementation. The
value RθJA for the WSON package is specifically dependent on PCB trace area, trace material, and the number of thermal vias. For
improved thermal resistance and power dissipation for the WSON package, refer to AN-1187 Leadless Leadframe Package (LLP)
The maximum power dissipation is a function of TJ(MAX) , RθJA, and TA. The maximum allowable power dissipation at any ambient
temperature is PD = (TJ(MAX) – T A) / RθJA. All numbers apply for packages soldered directly into a PC board. Refer to Thermal
Considerations.
(2)
(3)
(4)
6.2 ESD Ratings
V(ESD)
(1)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001
(1)
VALUE
UNIT
±2000
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
MIN
MAX
UNIT
0
125
°C
Output section
0
150
°C
Control section
−40
125
°C
Output section
−40
150
°C
JUNCTION TEMPERATURE RANGE (TJ) (1)
C grade
I grade
(1)
Control section
The maximum power dissipation is a function of TJ(MAX) , RθJA, and TA. The maximum allowable power dissipation at any ambient
temperature is PD = (TJ(MAX) – T A) / RθJA. All numbers apply for packages soldered directly into a PC board. Refer to Thermal
Considerations.
6.4 Thermal Information
LM1086-MIL
THERMAL METRIC (1)
KTT
NDE
NGN
UNIT
3 PINS
3 PINS
8 PINS
RθJA
Junction-to-ambient thermal resistance
40.8
23.0
35.9
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
42.3
16.1
24.2
°C/W
RθJB
Junction-to-board thermal resistance
23.3
4.5
13.2
°C/W
ψJT
Junction-to-top characterization parameter
10.2
2.4
0.2
°C/W
ψJB
Junction-to-board characterization parameter
22.3
2.5
13.3
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance: control
section/output section
1.5/4
1.5/4
2.9
°C/W
(1)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
6.5 Electrical Characteristics
Typicals and limits appearing in normal type apply for TJ = 25°C unless specified otherwise.
PARAMETER
VREF
VOUT
Reference
voltage
Output
voltage (3)
TEST CONDITIONS
(1)
(2)
(3)
(4)
Line
regulation (4)
MIN
(1)
TYP
(2)
MAX
UNIT
(1)
MIN
TYP
MAX
LM1086-MIL-ADJ, IOUT = 10 mA,
VIN − VOUT = 3 V, 10 mA ≤ IOUT ≤
IFULL LOAD, 1.5 V ≤ VIN − VOUT ≤
15 V (3)
1.238
1.25
1.262
1.225
1.250
1.27
V
LM1086-MIL-1.8, IOUT = 0 mA,
VIN = 5 V, 0 ≤ IOUT ≤ IFULL LOAD,
3.3 V ≤ VIN ≤ 18 V
1.782
1.8
1.818
1.764
1.8
1.836
V
LM1086-MIL-2.5, IOUT = 0 mA,
VIN = 5 V, 0 ≤ IOUT ≤ IFULL LOAD,
4.0 V ≤ VIN ≤ 18 V
2.475
2.5
2.525
2.450
2.5
2.55
V
LM1086-MIL-3.3, IOUT = 0 mA,
VIN = 5 V, 0 ≤ IOUT ≤ IFULL LOAD,
4.75 V ≤ VIN ≤ 18 V
3.267
3.3
3.333
3.235
3.3
3.365
V
LM1086-MIL-5, IOUT = 0 mA, VIN
= 8 V, 0 ≤ IOUT ≤ IFULL LOAD, 6.5 V
≤ VIN ≤ 20 V
4.950
5
5.05
4.9
5
5.1
V
0.015%
0.2%
0.035%
0.2%
LM1086-MIL-1.8, IOUT = 0 mA,
3.3 V ≤ VIN ≤ 18 V
0.3
6
0.6
6
mV
LM1086-MIL-2.5, IOUT = 0 mA,
4.0 V ≤ VIN ≤ 18 V
0.3
6
0.6
6
mV
LM1086-MIL-3.3, IOUT = 0 mA,
4.5 V ≤ VIN ≤ 18 V
0.5
10
1
10
mV
LM1086-MIL-5, IOUT = 0 mA, 6.5
V ≤ VIN ≤ 20 V
0.5
10
1
10
mV
LM1086-MIL-ADJ, IOUT =10 mA,
1.5 V ≤ (VIN - VOUT) ≤ 15 V
ΔVOUT
TJ over the entire range for
operation (see Recommended
Operating Conditions)
TJ = 25°C
All limits are specified by testing or statistical analysis.
Typical values represent the most likely parametric norm.
IFULL LOAD is defined in the current limit curves. The IFULL LOAD Curve defines current limit as a function of input-to-output voltage. Note
that 15 W power dissipation for the LM1086-MIL is only achievable over a limited range of input-to-output voltage.
Load and line regulation are measured at constant junction temperature, and are specified up to the maximum power dissipation of 15
W. Power dissipation is determined by the input/output differential and the output current. Ensured maximum power dissipation will not
be available over the full input/output range.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
5
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
Electrical Characteristics (continued)
Typicals and limits appearing in normal type apply for TJ = 25°C unless specified otherwise.
PARAMETER
TEST CONDITIONS
MIN
ΔVOUT
Dropout
voltage (5)
Current limit
Minimum load
current (6)
Quiescent
current
Thermal
regulation
0.3%
0.2%
0.4%
LM1086-MIL-1.8, 2.5, VIN = 5 V, 0
≤ IOUT ≤ IFULL LOAD
3
12
6
20
mV
LM1086-MIL-3.3, VIN = 5 V, 0 ≤
IOUT ≤ IFULL LOAD
3
15
7
25
mV
LM1086-MIL-5, VIN = 8 V, 0 ≤
IOUT ≤ IFULL LOAD
5
20
10
35
mV
1.3
1.5
V
1.5
2.7
0.05
0.15
LM1086-MIL-1.8,2.5, 3.3, VIN = 8
V
1.5
2.7
A
LM1086-MIL-5, VIN = 10 V
1.5
2.7
A
5
10
mA
LM1086-MIL-1.8, 2.5, VIN ≤ 18 V
5
10
mA
LM1086-MIL-3.3, VIN ≤ 18 V
5
10
mA
LM1086-MIL-5, VIN ≤ 20 V
5
10
mA
TA = 25°C, 30-ms pulse
0.008
0.04
6
%/W
60
75
dB
LM1086-MIL-1.8, 2.5, VIN = 6 V
60
72
dB
LM1086-MIL-3.3, VIN= 6.3 V
60
72
dB
LM1086-MIL-5 VIN = 8 V
60
68
dB
LM1086-MIL-ADJ, CADJ = 25 µF,
(VIN− VO) = 3 V
Adjust pin
current
LM1086-MIL
55
Adjust pin
current change
10 mA ≤ IOUT ≤ IFULL LOAD, 1.5 V
≤ (VIN − VOUT) ≤ 15 V
0.2
Temperature
stability
(5)
(6)
A
LM1086-MIL-ADJ, VIN −VOUT =
25 V
fRIPPLE = 120 Hz, COUT = 25 µF
Tantalum, IOUT = 1.5 A
Ripple rejection
MAX
UNIT
(1)
0.1%
LM1086-MIL-ADJ, 1.8, 2.5, 3.3, 5,
ΔVREF, ΔVOUT = 1%, IOUT = 1.5 A
TYP
(2)
MAX
LM1086-MIL-ADJ, VIN − VOUT = 5
V, VIN − VOUT = 25 V
ILIMIT
MIN
(1)
TYP
LM1086-MIL-ADJ, (VIN-V OUT ) =
3 V, 10 mA ≤ IOUT ≤ IFULL LOAD
Load
regulation (4)
TJ over the entire range for
operation (see Recommended
Operating Conditions)
TJ = 25°C
120
µA
5
µA
0.5%
Long-term
stability
TA = 125°C, 1000 Hrs
RMS Noise
(% of VOUT)
10 Hz ≤ f≤ 10 kHz
0.3%
1%
0.003%
Dropout voltage is specified over the full output current range of the device.
The minimum output current required to maintain regulation.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
6.6 Typical Characteristics
Figure 1. Dropout Voltage vs Output Current
Figure 2. Short-Circuit Current vs Input/Output Difference
Figure 3. Load Regulation vs Temperature
Figure 4. Percent Change in Output Voltage vs Temperature
Figure 5. Adjust Pin Current vs Temperature
Figure 6. Maximum Power Dissipation vs Temperature
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
7
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
Typical Characteristics (continued)
8
Figure 7. Ripple Rejection vs Frequency
(LM1086-MIL-ADJ)
Figure 8. Ripple Rejection vs Output Current
(LM1086-MIL-ADJ)
Figure 9. Ripple Rejection vs Frequency
(LM1086-MIL-5)
Figure 10. Ripple Rejection vs Output Current
(LM1086-MIL-5)
Figure 11. Line Transient Response
Figure 12. Load Transient Response
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
7 Detailed Description
7.1 Overview
A basic functional diagram for the LM1086-MIL-ADJ (excluding protection circuitry) is shown in Figure 13. The
topology is basically that of the LM317 except for the pass transistor. Instead of a Darlingtion NPN with its two
diode voltage drop, the LM1086-MIL uses a single NPN. This results in a lower dropout voltage. The structure of
the pass transistor is also known as a quasi LDO. The advantage of a quasi LDO over a PNP LDO is its
inherently lower quiescent current. The LM1086-MIL is specified to provide a minimum dropout voltage of 1.5 V
over temperature, at full load.
Figure 13. Basic Functional Block Diagram
7.2 Functional Block Diagram
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
9
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
7.3 Feature Description
7.3.1 Ripple Rejection
Ripple rejection is a function of the open loop gain within the feedback loop (refer to Figure 13 and Figure 16).
The LM1086-MIL exhibits 75 dB of ripple rejection (typical). When adjusted for voltages higher than VREF, the
ripple rejection decreases as function of adjustment gain: (1 + R1 / R2) or VO / VREF. Therefore, a 5-V adjustment
decreases ripple rejection by a factor of four (−12 dB); output ripple increases as adjustment voltage increases.
However, the adjustable version allows this degradation of ripple rejection to be compensated. The adjust
terminal can be bypassed to ground with a capacitor (CADJ). The impedance of the CADJ must be equal to or less
than R1 at the desired ripple frequency. This bypass capacitor prevents ripple from being amplified as the output
voltage is increased.
1 / (2π × fRIPPLE × CADJ) ≤ R1
(1)
7.3.2 Load Regulation
The LM1086-MIL regulates the voltage that appears between its output and ground pins, or between its output
and adjust pins. In some cases, line resistances can introduce errors to the voltage across the load. To obtain
the best load regulation, a few precautions are needed.
Figure 14 shows a typical application using a fixed output regulator. Rt1 and Rt2 are the line resistances. VLOAD
is less than the VOUT by the sum of the voltage drops along the line resistances. In this case, the load regulation
seen at the RLOAD would be degraded from the data sheet specification. To improve this, the load should be tied
directly to the output terminal on the positive side and directly tied to the ground terminal on the negative side.
Figure 14. Typical Application Using Fixed Output Regulator
When the adjustable regulator is used (Figure 15), the best performance is obtained with the positive side of the
resistor R1 tied directly to the output terminal of the regulator rather than near the load. This eliminates line drops
from appearing effectively in series with the reference and degrading regulation. For example, a 5-V regulator
with 0.05-Ω resistance between the regulator and load has a load regulation due to line resistance of 0.05 Ω × IL.
If R1 (= 125 Ω) is connected near the load the effective line resistance will be 0.05 Ω (1 + R2 / R1) or in this
case, it is 4 times worse. In addition, the ground side of the resistor R2 can be returned near the ground of the
load to provide remote ground sensing and improve load regulation.
Figure 15. Best Load Regulation Using Adjustable Output Regulator
10
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
Feature Description (continued)
7.3.3 Overload Recovery
Overload recovery refers to the ability of the regulator to recover from a short-circuited output. A key factor in the
recovery process is the current limiting used to protect the output from drawing too much power. The currentlimiting circuit reduces the output current as the input-to-output differential increases. Refer to short-circuit curve
in Typical Characteristics.
During normal start-up, the input-to-output differential is small because the output follows the input. But, if the
output is shorted, then the recovery involves a large input to output differential. Sometimes during this condition
the current limiting circuit is slow in recovering. If the limited current is too low to develop a voltage at the output,
the voltage will stabilize at a lower level. Under these conditions it may be necessary to recycle the power of the
regulator in order to get the smaller differential voltage and thus adequate start up conditions. Refer to Typical
Characteristics for the short circuit current vs input differential voltage.
7.4 Device Functional Modes
7.4.1 Output Voltage
The LM1086-MIL adjustable version develops a 1.25-V reference voltage, (VREF), between the output and the
ADJ pin. As shown in Figure 16, this voltage is applied across resistor R1 to generate a constant current I1. This
constant current then flows through R2. The resulting voltage drop across R2 adds to the reference voltage to
sets the desired output voltage.
The current IADJ from the adjustment terminal introduces an output error . But since it is small (120 µA
maximum), it becomes negligible when R1 is in the 100-Ω range.
For fixed voltage devices, R1 and R2 are integrated inside the devices.
Figure 16. Basic Adjustable Regulator
7.4.2 Stability Consideration
Stability consideration primarily concerns the phase response of the feedback loop. In order for stable operation,
the loop must maintain negative feedback. The LM1086-MIL requires a certain amount series resistance with
capacitive loads. This series resistance introduces a zero within the loop to increase phase margin and thus
increase stability. The equivalent series resistance (ESR) of solid tantalum or aluminum electrolytic capacitors is
used to provide the appropriate zero (approximately 500 kHz).
Aluminum electrolytics are less expensive than tantalum capacitors, but their ESR varies exponentially at cold
temperatures requiring close examination when choosing the desired transient response over temperature.
Tantalums are a convenient choice because their ESR varies less than 2:1 over temperature.
The recommended load/decoupling capacitance is a 10-µF tantalum or a 50-µF aluminum. These values assure
stability for the majority of applications.
The adjustable versions allows an additional capacitor to be used at the ADJ pin to increase ripple rejection. If
this is done increate the output capacitor to 22 µF for tantalum or to 150 µF for aluminum.
Capacitors other than tantalum or aluminum can be used at the adjust pin and the input pin. A 10-µF capacitor is
a reasonable value at the input. See Ripple Rejection regarding the value for the ADJ pin capacitor.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
11
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
Device Functional Modes (continued)
Large output capacitance is desirable for applications that entail large changes in load current (microprocessors,
for example). The higher the capacitance, the larger the available charge per demand. It is also desirable to
provide low ESR to reduce the change in output voltage:
ΔV = ΔI × ESR
(2)
It is common practice to use several tantalum and ceramic capacitors in parallel to reduce this change in the
output voltage by reducing the overall ESR.
Output capacitance can be increased indefinitely to improve transient response and stability.
7.4.3 Protection Diodes
Under normal operation, the LM1086-MIL regulator does not need any protection diode. With the adjustable
device, the internal resistance between the adjustment and output terminals limits the current. No diode is
needed to divert the current around the regulator even with a capacitor on the ADJ pin. The ADJ pin can take a
transient signal of ±25 V with respect to the output voltage without damaging the device.
When an output capacitor is connected to a regulator and the input is shorted, the output capacitor discharges
into the output of the regulator. The discharge current depends on the value of the capacitor, the output voltage
of the regulator, and rate of decrease of VIN. In the LM1086-MIL regulator, the internal diode between the output
and input pins can withstand microsecond surge currents of 10 A to 20 A. With an extremely large output
capacitor (≥ 1000 µf), and with input instantaneously shorted to ground, the regulator could be damaged. In this
case, an external diode is recommended between the output and input pins to protect the regulator, shown in
Figure 17.
Figure 17. Regulator with Protection Diode
12
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
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 LM1086-MIL is versatile in its applications, including uses in programmable output regulation and local oncard regulation. By connecting a fixed resistor between the ADJ and OUTPUT terminals, the LM1086-MIL can
function as a precision current regulator. An optional output capacitor can be added to improve transient
response. The ADJ pin can be bypassed to achieve very high ripple-rejection ratios, which are difficult to achieve
with standard three-terminal regulators. Note that, in the following applications if ADJ is mentioned, it makes use
of the adjustable version of the part, however, if GND is mentioned, it is the fixed-voltage version of the part.
8.2 Typical Applications
8.2.1 1.2-V to 15-V Adjustable Regulator
This part can be used as a simple low drop out regulator to enable a variety of output voltages needed for
demanding applications. By using an adjustable R2 resistor a variety of output voltages can be made possible as
shown in Figure 18 based on the LM1086-MIL-ADJ.
Figure 18. 1.2-V to 15-V Adjustable Regulator
8.2.1.1 Design Requirements
The device component count is very minimal, employing two resistors as part of a voltage divider circuit and an
output capacitor for load regulation.
8.2.1.2 Detailed Design Procedure
The voltage divider for this part is set based Figure 18, where R1 is the upper feedback resistor R2 is the lower
feedback resistor.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
13
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
Typical Applications (continued)
8.2.1.3 Application Curve
8.3 Other Applications
8.3.1 Adjustable at 5 V
The application shown in Figure 19 outlines a simple 5-V output application made possible by the LM1086-MILADJ. This application can provide 1.5 A at high efficiencies and very low dropout.
Figure 19. Adjustable at 5 V
8.3.2 5-V Regulator with Shutdown
A variation of the 5-V output regulator application with shutdown control is shown in Figure 20 based on the
LM1086-MIL-ADJ. It uses a simple NPN transistor on the ADJ pin to block or sink the current on the ADJ pin. If
the TTL logic is pulled high, the NPN transistor is activated and the device is disabled, outputting approximately
1.25 V. If the TTL logic is pulled low, the NPN transistor is unbiased and the regulator functions normally.
Figure 20. 5-V Regulator with Shutdown
14
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
Other Applications (continued)
8.3.3 Battery Charger
The LM1086-MIL-ADJ can be used as a battery charger to regulate the charging current required by the battery
bank as shown in Figure 21. In this application the LM1086-MIL acts as a constant voltage, constant current part
by sensing the voltage potential across the battery and compensating it to the current voltage. To maintain this
voltage, the regulator delivers the maximum charging current required to charge the battery. As the battery
approaches the fully charged state, the potential drop across the sense resistor, RS reduces and the regulator
throttles back the current to maintain the float voltage of the battery.
Figure 21. Battery Charger
8.3.4 Adjustable Fixed Regulator
A simple adjustable, fixed-range-output regulator can be made possible by placing a variable resistor on the
ground of the device as shown in Figure 22 based on the fixed output voltage LM1086-MIL-5. The GND pin has
a small quiescent current of 5 mA typical. Increasing the resistance on the GND pin increases the voltage
potential across the resistor. This potential is then mirrored on to the output to increase the total output voltage
by the potential drop across the GND resistor.
Figure 22. Adjustable Fixed Regulator
8.3.5 Regulator With Reference
A fixed output voltage version of the LM1086-MIL-5 can be employed to provide an output rail and a reference
rail at the same time as shown in Figure 23. This simple application makes use of a reference diode, the LM1365, to regulate the GND voltage to a fixed 5 V based on the quiescent current generated by the GND pin. This
voltage is then added onto the output to generate a total of 10 V out.
Figure 23. Regulator With Reference
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
15
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
Other Applications (continued)
8.3.6 High-Current Lamp-Driver Protection
A simple constant-current source with protection can be designed by controlling the impedance between the
lamp and ground. The LM1086-MIL-ADJ shown in Figure 24 makes use of an external TTL or CMOS input to
drive the NPN transistor. This pulls the output of the regulator to a few tenths of a volt and puts the part into
current limit. Releasing the logic will reduce the current flow across the lamp into the normal operating current
thereby protecting the lamp during start-up.
Figure 24. High Current Lamp Driver Protection
8.3.7 Battery-Backup-Regulated Supply
A regulated battery-backup supply can be generated by using two fixed output voltage versions of the part as
shown in Figure 25. The top regulator supplies the line voltage during normal operation, however when the input
is not available, the second regulator derives power from the battery backup and regulates it to 5 V based on the
LM1086-MIL-5. The diodes prevent the rails from back feeding into the supply and batteries.
Figure 25. Battery Backup Regulated Supply
16
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
Other Applications (continued)
8.3.8 Ripple Rejection Enhancement
A very simple ripple rejection circuit is shown in Figure 26 using the LM1086-MIL-ADJ. The capacitor C1
smooths out the ripple on the output by cleaning up the feedback path and preventing excess noise from feeding
back into the regulator. Please remember XC1 should be approximately equal to R1 at the ripple frequency.
Figure 26. Ripple Rejection Enhancement
8.3.9 Automatic Light Control
A common streetlight control or automatic light control circuit is designed in Figure 27 based on the LM1086-MILADJ. The photo transistor conducts in the presence of light and grounds the ADJ pin preventing the lamp from
turning on. However, in the absence of light, the LM1086-MIL regulates the voltage to 1.25 V between OUT and
ADJ, ensuring the lamp remains on.
Figure 27. Automatic Light Control
8.3.10 Remote Sensing
Remote sensing is a method of compensating the output voltage to a very precise degree by sensing the output
and feeding it back through the feedback. The circuit implementing this is shown in Figure 28 using the LM1086MIL-ADJ. The output of the regulator is fed into a voltage follower to avoid any loading effects and the output of
the op-amp is injected into the top of the feedback resistor network. This has the effect of modulating the voltage
to a precise degree without additional loading on the output.
Figure 28. Remote Sensing
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
17
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
9 Power Supply Recommendations
The linear regulator input supply must be well regulated and kept at a voltage level such that the maximum inputto-output voltage differential allowed by the device is not exceeded. The minimum dropout voltage (VIN – VOUT)
should be met with extra headroom when possible in order to keep the output well regulated. Pace a 10-μF or
higher capacitor at the input to bypass noise.
10 Layout
10.1 Layout Guidelines
For the best overall performance, follow these layout guidelines. Place all circuit components on the same side of
the circuit board and as near as practical to the respective linear regulator pins connections. Keep traces short
and wide to reduce the amount of parasitic elements into the system. The actual width and thickness of traces
depends on the current carrying capability and heat dissipation required by the end system. An array of plated
vias can be placed on the pad area underneath the TAB to conduct heat to any inner plane areas or to a bottomside copper plane.
10.2 Layout Example
Figure 29. Layout Example
18
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
10.3 Thermal Considerations
ICs heats up when in operation, and power consumption is one factor in how hot it gets. The other factor is how
well the heat is dissipated. Heat dissipation is predictable by knowing the thermal resistance between the IC and
ambient (RθJA). Thermal resistance has units of temperature per power (°C/W). The higher the thermal
resistance, the hotter the IC.
The LM1086-MIL specifies the thermal resistance for each package as junction to case (RθJC). In order to get the
total resistance to ambient (RθJA), two other thermal resistance must be added, one for case to heat-sink (RθCH)
and one for heatsink to ambient (RθHA). The junction temperature can be predicted as follows:
TJ = TA + PD (θJC + RθCH + RθHA) = TA + PD RθJA
where
•
•
•
TJ is junction temperature
TA is ambient temperature
PD is the power consumption of the device
(3)
Device power consumption is calculated as follows:
IIN = IL + IG
PD = (VIN−VOUT) IL + VINIG
(4)
(5)
Figure 30 shows the voltages and currents which are present in the circuit.
Figure 30. Power Dissipation Diagram
Once the devices power is determined, the maximum allowable (RθJA (max)) is calculated as:
RθJA (max) = TR(max)/PD = TJ(max) − TA(max)/PD
The LM1086-MIL has different temperature specifications for two different sections of the device: the control
section and the output section. The Thermal Information table shows the junction to case thermal resistances for
each of these sections, while the maximum junction temperatures (TJ(max)) for each section is listed in the
Absolute Maximum Ratings section of the data sheet. TJ(max) is 125°C for the control section, while TJ(max) is
150°C for the output section.
Calculate RθJA (max) separately for each section as follows:
RθJA (maximum, control section) = (125°C – TA(max))/PD
RθJA (maximum, output section) = (150°C – TA(max))/PD
(6)
(7)
The required heat sink is determined by calculating its required thermal resistance (RθHA (max)).
RθHA (max) = RθJA (max) − (RJθC + RθCH)
(RθHA
(max))
(RθHA
(RθHA
(8)
should also be calculated twice as follows:
(max))
= RθJA (maximum, control section) – (RθJC (CONTROL SECTION) + RθCH)
(max)) = RJθA(maximum, output section) - (RθJC (OUTPUT SECTION) + RθCH)
(9)
(10)
If thermal compound is used, RθCH can be estimated at 0.2°C/W. If the case is soldered to the heat sink, then a
RθCH can be estimated as 0°C/W.
After, RθHA (max) is calculated for each section, choose the lower of the two RθHA
appropriate heat sink.
(max)
values to determine the
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
19
LM1086-MIL
SNVSAX4 – JUNE 2017
www.ti.com
Thermal Considerations (continued)
If PC board copper is going to be used as a heat sink, then Figure 31 can be used to determine the appropriate
area (size) of copper foil required.
Figure 31. Heat Sink Thermal Resistance vs Area
20
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
LM1086-MIL
www.ti.com
SNVSAX4 – JUNE 2017
11 Device and Documentation Support
11.1 Documentation Support
11.1.1 Related Documentation
For related documentation see the following:
AN-1187 Leadless Leadframe Package (LLP)
11.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper
right corner, click on Alert me to register and receive a weekly digest of any product information that has
changed. For change details, review the revision history included in any revised document.
11.3 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.
11.4 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.5 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
11.6 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.
Submit Documentation Feedback
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM1086-MIL
21
PACKAGE OPTION ADDENDUM
www.ti.com
29-Jun-2017
PACKAGING INFORMATION
Orderable Device
Status
(1)
LM1086-ADJ MDC
ACTIVE
Package Type Package Pins Package
Drawing
Qty
DIESALE
Y
0
130
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Green (RoHS
& no Sb/Br)
Call TI
Level-1-NA-UNLIM
Op Temp (°C)
Device Marking
(4/5)
-40 to 85
(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 <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
Samples
IMPORTANT NOTICE
Texas Instruments Incorporated (TI) reserves the right to make corrections, enhancements, improvements and other changes to its
semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers
should obtain the latest relevant information before placing orders and should verify that such information is current and complete.
TI’s published terms of sale for semiconductor products (http://www.ti.com/sc/docs/stdterms.htm) apply to the sale of packaged integrated
circuit products that TI has qualified and released to market. Additional terms may apply to the use or sale of other types of TI products and
services.
Reproduction of significant portions of TI information in TI data sheets is permissible only if reproduction is without alteration and is
accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such reproduced
documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements
different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the
associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Buyers and others who are developing systems that incorporate TI products (collectively, “Designers”) understand and agree that Designers
remain responsible for using their independent analysis, evaluation and judgment in designing their applications and that Designers have
full and exclusive responsibility to assure the safety of Designers' applications and compliance of their applications (and of all TI products
used in or for Designers’ applications) with all applicable regulations, laws and other applicable requirements. Designer represents that, with
respect to their applications, Designer has all the necessary expertise to create and implement safeguards that (1) anticipate dangerous
consequences of failures, (2) monitor failures and their consequences, and (3) lessen the likelihood of failures that might cause harm and
take appropriate actions. Designer agrees that prior to using or distributing any applications that include TI products, Designer will
thoroughly test such applications and the functionality of such TI products as used in such applications.
TI’s provision of technical, application or other design advice, quality characterization, reliability data or other services or information,
including, but not limited to, reference designs and materials relating to evaluation modules, (collectively, “TI Resources”) are intended to
assist designers who are developing applications that incorporate TI products; by downloading, accessing or using TI Resources in any
way, Designer (individually or, if Designer is acting on behalf of a company, Designer’s company) agrees to use any particular TI Resource
solely for this purpose and subject to the terms of this Notice.
TI’s provision of TI Resources does not expand or otherwise alter TI’s applicable published warranties or warranty disclaimers for TI
products, and no additional obligations or liabilities arise from TI providing such TI Resources. TI reserves the right to make corrections,
enhancements, improvements and other changes to its TI Resources. TI has not conducted any testing other than that specifically
described in the published documentation for a particular TI Resource.
Designer is authorized to use, copy and modify any individual TI Resource only in connection with the development of applications that
include the TI product(s) identified in such TI Resource. NO OTHER LICENSE, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE
TO ANY OTHER TI INTELLECTUAL PROPERTY RIGHT, AND NO LICENSE TO ANY TECHNOLOGY OR INTELLECTUAL PROPERTY
RIGHT OF TI OR ANY THIRD PARTY IS GRANTED HEREIN, including but not limited to any patent right, copyright, mask work right, or
other intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information
regarding or referencing third-party products or services does not constitute a license to use such products or services, or a warranty or
endorsement thereof. Use of TI Resources may require a license from a third party under the patents or other intellectual property of the
third party, or a license from TI under the patents or other intellectual property of TI.
TI RESOURCES ARE PROVIDED “AS IS” AND WITH ALL FAULTS. TI DISCLAIMS ALL OTHER WARRANTIES OR
REPRESENTATIONS, EXPRESS OR IMPLIED, REGARDING RESOURCES OR USE THEREOF, INCLUDING BUT NOT LIMITED TO
ACCURACY OR COMPLETENESS, TITLE, ANY EPIDEMIC FAILURE WARRANTY AND ANY IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF ANY THIRD PARTY INTELLECTUAL
PROPERTY RIGHTS. TI SHALL NOT BE LIABLE FOR AND SHALL NOT DEFEND OR INDEMNIFY DESIGNER AGAINST ANY CLAIM,
INCLUDING BUT NOT LIMITED TO ANY INFRINGEMENT CLAIM THAT RELATES TO OR IS BASED ON ANY COMBINATION OF
PRODUCTS EVEN IF DESCRIBED IN TI RESOURCES OR OTHERWISE. IN NO EVENT SHALL TI BE LIABLE FOR ANY ACTUAL,
DIRECT, SPECIAL, COLLATERAL, INDIRECT, PUNITIVE, INCIDENTAL, CONSEQUENTIAL OR EXEMPLARY DAMAGES IN
CONNECTION WITH OR ARISING OUT OF TI RESOURCES OR USE THEREOF, AND REGARDLESS OF WHETHER TI HAS BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
Unless TI has explicitly designated an individual product as meeting the requirements of a particular industry standard (e.g., ISO/TS 16949
and ISO 26262), TI is not responsible for any failure to meet such industry standard requirements.
Where TI specifically promotes products as facilitating functional safety or as compliant with industry functional safety standards, such
products are intended to help enable customers to design and create their own applications that meet applicable functional safety standards
and requirements. Using products in an application does not by itself establish any safety features in the application. Designers must
ensure compliance with safety-related requirements and standards applicable to their applications. Designer may not use any TI products in
life-critical medical equipment unless authorized officers of the parties have executed a special contract specifically governing such use.
Life-critical medical equipment is medical equipment where failure of such equipment would cause serious bodily injury or death (e.g., life
support, pacemakers, defibrillators, heart pumps, neurostimulators, and implantables). Such equipment includes, without limitation, all
medical devices identified by the U.S. Food and Drug Administration as Class III devices and equivalent classifications outside the U.S.
TI may expressly designate certain products as completing a particular qualification (e.g., Q100, Military Grade, or Enhanced Product).
Designers agree that it has the necessary expertise to select the product with the appropriate qualification designation for their applications
and that proper product selection is at Designers’ own risk. Designers are solely responsible for compliance with all legal and regulatory
requirements in connection with such selection.
Designer will fully indemnify TI and its representatives against any damages, costs, losses, and/or liabilities arising out of Designer’s noncompliance with the terms and provisions of this Notice.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2017, Texas Instruments Incorporated