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LM2676 SIMPLE SWITCHER
®
High Efficiency 3A Step-Down Voltage Regulator
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1FEATURES DESCRIPTION
The LM2676 series of regulators are monolithic
2• Efficiency Up to 94% integrated circuits which provide all of the active
• Simple and Easy to Design with (Using Off- functions for a step-down (buck) switching regulator
The-Shelf External Components) capable of driving up to 3A loads with excellent line
• 150 mΩDMOS Output Switch and load regulation characteristics. High efficiency
(>90%) is obtained through the use of a low ON-
• 3.3V, 5V and 12V Fixed Output and Adjustable resistance DMOS power switch. The series consists
(1.2V to 37V) Versions of fixed output voltages of 3.3V, 5V and 12V and an
• 50μA Standby Current When Switched OFF adjustable output version.
• ±2% Maximum Output Tolerance Over Full The SIMPLE SWITCHER concept provides for a
Line and Load Conditions complete design using a minimum number of external
• Wide Input Voltage Range: 8V to 40V components. A high fixed frequency oscillator
(260KHz) allows the use of physically smaller sized
• 260 KHz Fixed Frequency Internal Oscillator components. A family of standard inductors for use
•−40 to +125°C Operating Junction Temperature with the LM2676 are available from several
Range manufacturers to greatly simplify the design process.
The LM2676 series also has built in thermal
APPLICATIONS shutdown, current limiting and an ON/OFF control
• Simple to Design, High Efficiency (>90%) Step- input that can power down the regulator to a low
Down Switching Regulators 50μA quiescent current standby condition. The output
voltage is ensured to a ±2% tolerance. The clock
• Efficient System Pre-Regulator for Linear frequency is controlled to within a ±11% tolerance.
Voltage Regulators
• Battery Chargers
Typical Application
1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2SIMPLE SWITCHER, Switchers Made Simple are registered trademarks of Texas Instruments.
PRODUCTION DATA information is current as of publication date. Copyright © 2000–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
1
2
3
4
7
9
10
VSW
CB
*
VIN
5
6
11
12
13
14
VSW
GND
ON/OFF
*
*
*
FB 8
VIN VSW
DAP**
*No Connections
** Connect to Pin 9 on PCB
*
LM2676
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Connection Diagrams
Figure 1. DDPAK Package (Top View) Figure 2. TO-220 Package (Top View)
See Package Number KTW0007B See Package Number NDZ0007B
Figure 3. VSON-14 (Top View)
See Package Number NHM0014A
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.
Absolute Maximum Ratings(1)(2)
Input Supply Voltage 45V
ON/OFF Pin Voltage −0.1V to 6V
Switch Voltage to Ground(3) −1V to VIN
Boost Pin Voltage VSW + 8V
Feedback Pin Voltage −0.3V to 14V
Power Dissipation Internally Limited
ESD(4) 2 kV
Storage Temperature Range −65°C to 150°C
Soldering Temperature Wave 4 sec, 260°C
Infrared 10 sec, 240°C
Vapor Phase 75 sec, 219°C
(1) Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings indicate conditions under
which of the device is ensured. Operating Ratings do not imply ensured performance limits. For ensured performance limits and
associated test condition, see the Electrical Characteristics tables.
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and
specifications.
(3) The absolute maximum specification of the 'Switch Voltage to Ground' applies to DC voltage. An extended negative voltage limit of -8V
applies to a pulse of up to 20 ns, -6V of 60 ns and -3V of up to 100 ns.
(4) ESD was applied using the human-body model, a 100pF capacitor discharged through a 1.5 kΩresistor into each pin.
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Operating Ratings
Supply Voltage 8V to 40V
Junction Temperature Range (TJ)−40°C to 125°C
Electrical Characteristics
LM2676-3.3
Limits appearing in bold type face apply over the entire junction temperature range of operation, −40°C to 125°C.
Specifications appearing in normal type apply for TA= TJ= 25°C.
Symbol Parameter Conditions Typ(1) Min(2) Max(2) Units
VOUT Output Voltage VIN = 8V to 40V, 100mA ≤IOUT ≤3A 3.3 3.234/3.201 3.366/3.399 V
ηEfficiency VIN = 12V, ILOAD = 3A 86 %
(1) Typical values are determined with TA= TJ= 25°C and represent the most likely norm.
(2) All limits are ensured at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature
limits are 100% tested during production with TA= TJ= 25°C. All limits at temperature extremes are ensured via correlation using
standard Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
LM2676-5.0
Symbol Parameter Conditions Typ(1) Min(2) Max(2) Units
VOUT Output Voltage VIN = 8V to 40V, 100mA ≤IOUT ≤3A 5.0 4.900/4.850 5.100/5.150 V
ηEfficiency VIN = 12V, ILOAD = 3A 88 %
(1) Typical values are determined with TA= TJ= 25°C and represent the most likely norm.
(2) All limits are ensured at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature
limits are 100% tested during production with TA= TJ= 25°C. All limits at temperature extremes are ensured via correlation using
standard Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
LM2676-12
Symbol Parameter Conditions Typ(1) Min(2) Max(2) Units
VOUT Output Voltage VIN = 15V to 40V, 100mA ≤IOUT ≤3A 12 11.76/11.64 12.24/12.36 V
ηEfficiency VIN = 24V, ILOAD = 3A 94 %
(1) Typical values are determined with TA= TJ= 25°C and represent the most likely norm.
(2) All limits are ensured at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature
limits are 100% tested during production with TA= TJ= 25°C. All limits at temperature extremes are ensured via correlation using
standard Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
LM2676-ADJ
Symbol Parameter Conditions Typ(1) Min(2) Max(2) Units
VFB Feedback Voltage VIN = 8V to 40V, 100mA ≤IOUT ≤3A 1.21 1.186/1.174 1.234/1.246 V
VOUT Programmed for 5V
ηEfficiency VIN = 12V, ILOAD = 3A 88 %
(1) Typical values are determined with TA= TJ= 25°C and represent the most likely norm.
(2) All limits are ensured at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature
limits are 100% tested during production with TA= TJ= 25°C. All limits at temperature extremes are ensured via correlation using
standard Quality Control (SQC) methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
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All Output Voltage Versions
Electrical Characteristics
Limits appearing in bold type face apply over the entire junction temperature range of operation, −40°C to 125°C.
Specifications appearing in normal type apply for TA= TJ= 25°C. Unless otherwise specified VIN=12V for the 3.3V, 5V and
Adjustable versions and VIN=24V for the 12V version.
Symbol Parameter Conditions Typ Min Max Units
DEVICE PARAMETERS
IQQuiescent Current VFEEDBACK = 8V 4.2 6 mA
For 3.3V, 5.0V, and ADJ Versions
VFEEDBACK = 15V
For 12V Versions
ISTBY Standby Quiescent ON/OFF Pin = 0V 50 100/150 μA
Current
ICL Current Limit 4.5 3.8/3.6 5.25/5.4 A
ILOutput Leakage VIN = 40V, ON/OFF Pin = 0V μA
Current VSWITCH = 0V 200 mA
VSWITCH =−1V 16 15
RDS(ON) Switch On- ISWITCH = 3A 0.15 0.17/0.29 Ω
Resistance
fOOscillator Measured at Switch Pin 260 225 280 kHz
Frequency
D Duty Cycle Maximum Duty Cycle 91 %
Minimum Duty Cycle 0 %
IBIAS Feedback Bias VFEEDBACK = 1.3V 85 nA
Current ADJ Version Only
VON/OFF ON/OFF Threshold 1.4 0.8 2.0 V
Voltage
ION/OFF ON/OFF Input ON/OFF Input = 0V 20 45 μA
Current
θJA Thermal NDZ Package, Junction to Ambient(1) 65
Resistance
θJA NDZ Package, Junction to Ambient(2) 45
θJC NDZ Package, Junction to Case 2
θJA KTW Package, Junction to Ambient(3) 56 °C/W
θJA KTW Package, Junction to Ambient(4) 35
θJA KTW Package, Junction to Ambient(5) 26
θJC KTW Package, Junction to Case 2 ++
θJA NHM Package, Junction to Ambient(6) 55 °C/W
θJA NHM Package, Junction to Ambient(7) 29
(1) Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with ½ inch leads in a
socket, or on a PC board with minimum copper area.
(2) Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with ½ inch leads
soldered to a PC board containing approximately 4 square inches of (1 oz.) copper area surrounding the leads.
(3) Junction to ambient thermal resistance for the 7 lead DDPAK mounted horizontally against a PC board area of 0.136 square inches (the
same size as the DDPAK package) of 1 oz. (0.0014 in. thick) copper.
(4) Junction to ambient thermal resistance for the 7 lead DDPAK mounted horizontally against a PC board area of 0.4896 square inches
(3.6 times the area of the DDPAK package) of 1 oz. (0.0014 in. thick) copper.
(5) Junction to ambient thermal resistance for the 7 lead DDPAK mounted horizontally against a PC board copper area of 1.0064 square
inches (7.4 times the area of the DDPAK package) of 1 oz. (0.0014 in. thick) copper. Additional copper area will reduce thermal
resistance further. See the thermal model in Switchers Made Simple®software.
(6) Junction to ambient thermal resistance for the 14-lead VSON mounted on a PC board copper area equal to the die attach paddle.
(7) Junction to ambient thermal resistance for the 14-lead VSON mounted on a PC board copper area using 12 vias to a second layer of
copper equal to die attach paddle. Additional copper area will reduce thermal resistance further. For layout recommendations, refer to
Application Note AN-1187 at www.ti.com/lsds/ti/analog/powermanagement/power_portal.page.
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Typical Performance Characteristics
Normalized Output Voltage Line Regulation
Figure 4. Figure 5.
Efficiency vs Input Voltage Efficiency vs ILOAD
Figure 6. Figure 7.
Switch Current Limit Operating Quiescent Current
Figure 8. Figure 9.
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Typical Performance Characteristics (continued)
Standby Quiescent Current ON/OFF Threshold Voltage
Figure 10. Figure 11.
ON/OFF Pin Current (Sourcing) Switching Frequency
Figure 12. Figure 13.
Continuous Mode Switching Waveforms
VIN = 20V, VOUT = 5V, ILOAD = 3A
Feedback Pin Bias Current L = 33 μH, COUT = 200 μF, COUTESR = 26 mΩ
A: VSW Pin Voltage, 10 V/div.
B: Inductor Current, 1 A/div
C: Output Ripple Voltage, 20 mV/div AC-Coupled
Figure 14. Figure 15. Horizontal Time Base: 1 μs/div
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Typical Performance Characteristics (continued)
Discontinuous Mode Switching Waveforms Load Transient Response for Continuous Mode
VIN = 20V, VOUT = 5V, ILOAD = 500 mA VIN = 20V, VOUT = 5V
L = 10 μH, COUT = 400 μF, COUTESR = 13 mΩL = 33 μH, COUT = 200 μF, COUTESR = 26 mΩ
A: Output Voltage, 100 mV//div, AC-Coupled.
A: VSW Pin Voltage, 10 V/div. B: Load Current: 500 mA to 3A Load Pulse
B: Inductor Current, 1 A/div
C: Output Ripple Voltage, 20 mV/div AC-Coupled
Figure 16. Horizontal Time Base: 1 μs//iv Figure 17. Horizontal Time Base: 100 μs/div
Load Transient Response for Discontinuous Mode
VIN = 20V, VOUT = 5V,
L = 10 μH, COUT = 400 μF, COUTESR = 13 mΩ
A: Output Voltage, 100 mV/div, AC-Coupled.
B: Load Current: 200 mA to 3A Load Pulse Figure 18. Horizontal Time Base: 200 μs/div
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APPLICATION HINTS
The LM2676 provides all of the active functions required for a step-down (buck) switching regulator. The internal
power switch is a DMOS power MOSFET to provide power supply designs with high current capability, up to 3A,
and highly efficient operation.
The LM2676 is part of the SIMPLE SWITCHER family of power converters. A complete design uses a minimum
number of external components, which have been pre-determined from a variety of manufacturers. Using either
this data sheet or a design software program called LM267X Made Simple (version 2.0) a complete switching
power supply can be designed quickly. The software is provided free of charge and can be downloaded from
Texas Instrument's Internet site located at www.ti.com
SWITCH OUTPUT
This is the output of a power MOSFET switch connected directly to the input voltage. The switch provides energy
to an inductor, an output capacitor and the load circuitry under control of an internal pulse-width-modulator
(PWM). The PWM controller is internally clocked by a fixed 260KHz oscillator. In a standard step-down
application the duty cycle (Time ON/Time OFF) of the power switch is proportional to the ratio of the power
supply output voltage to the input voltage. The voltage on pin 1 switches between Vin (switch ON) and below
ground by the voltage drop of the external Schottky diode (switch OFF).
INPUT
The input voltage for the power supply is connected to pin 2. In addition to providing energy to the load the input
voltage also provides bias for the internal circuitry of the LM2676. For ensured performance the input voltage
must be in the range of 8V to 40V. For best performance of the power supply the input pin should always be
bypassed with an input capacitor located close to pin 2.
C BOOST
A capacitor must be connected from pin 3 to the switch output, pin 1. This capacitor boosts the gate drive to the
internal MOSFET above Vin to fully turn it ON. This minimizes conduction losses in the power switch to maintain
high efficiency. The recommended value for C Boost is 0.01μF.
GROUND
This is the ground reference connection for all components in the power supply. In fast-switching, high-current
applications such as those implemented with the LM2676, it is recommended that a broad ground plane be used
to minimize signal coupling throughout the circuit
FEEDBACK
This is the input to a two-stage high gain amplifier, which drives the PWM controller. It is necessary to connect
pin 6 to the actual output of the power supply to set the dc output voltage. For the fixed output devices (3.3V, 5V
and 12V outputs), a direct wire connection to the output is all that is required as internal gain setting resistors are
provided inside the LM2676. For the adjustable output version two external resistors are required to set the dc
output voltage. For stable operation of the power supply it is important to prevent coupling of any inductor flux to
the feedback input.
ON/OFF
This input provides an electrical ON/OFF control of the power supply. Connecting this pin to ground or to any
voltage less than 0.8V will completely turn OFF the regulator. The current drain from the input supply when OFF
is only 50μA. Pin 7 has an internal pull-up current source of approximately 20μA and a protection clamp zener
diode of 7V to ground. When electrically driving the ON/OFF pin the high voltage level for the ON condition
should not exceed the 6V absolute maximum limit. When ON/OFF control is not required pin 7 should be left
open circuited.
DAP (VSON PACKAGE)
The Die Attach Pad (DAP) can and should be connected to PCB Ground plane/island. For CAD and assembly
guidelines refer to Application Note AN-1187 at www.ti.com/lsds/ti/analog/powermanagement/power_portal.page.
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DESIGN CONSIDERATIONS
Figure 19. Basic Circuit for Fixed Output Voltage Applications.
Figure 20. Basic Circuit for Adjustable Output Voltage Applications
Power supply design using the LM2676 is greatly simplified by using recommended external components. A wide
range of inductors, capacitors and Schottky diodes from several manufacturers have been evaluated for use in
designs that cover the full range of capabilities (input voltage, output voltage and load current) of the LM2676. A
simple design procedure using nomographs and component tables provided in this data sheet leads to a working
design with very little effort. Alternatively, the design software, LM267X Made Simple (version 6.0), can also be
used to provide instant component selection, circuit performance calculations for evaluation, a bill of materials
component list and a circuit schematic.
The individual components from the various manufacturers called out for use are still just a small sample of the
vast array of components available in the industry. While these components are recommended, they are not
exclusively the only components for use in a design. After a close comparison of component specifications,
equivalent devices from other manufacturers could be substituted for use in an application.
Important considerations for each external component and an explanation of how the nomographs and selection
tables were developed follows.
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INDUCTOR
The inductor is the key component in a switching regulator. For efficiency the inductor stores energy during the
switch ON time and then transfers energy to the load while the switch is OFF.
Nomographs are used to select the inductance value required for a given set of operating conditions. The
nomographs assume that the circuit is operating in continuous mode (the current flowing through the inductor
never falls to zero). The magnitude of inductance is selected to maintain a maximum ripple current of 30% of the
maximum load current. If the ripple current exceeds this 30% limit the next larger value is selected.
The inductors offered have been specifically manufactured to provide proper operation under all operating
conditions of input and output voltage and load current. Several part types are offered for a given amount of
inductance. Both surface mount and through-hole devices are available. The inductors from each of the three
manufacturers have unique characteristics.
Renco: ferrite stick core inductors; benefits are typically lowest cost and can withstand ripple and transient peak
currents above the rated value. These inductors have an external magnetic field, which may generate EMI.
Pulse Engineering: powdered iron toroid core inductors; these also can withstand higher than rated currents and,
being toroid inductors, will have low EMI.
Coilcraft: ferrite drum core inductors; these are the smallest physical size inductors and are available only as
surface mount components. These inductors also generate EMI but less than stick inductors.
OUTPUT CAPACITOR
The output capacitor acts to smooth the dc output voltage and also provides energy storage. Selection of an
output capacitor, with an associated equivalent series resistance (ESR), impacts both the amount of output ripple
voltage and stability of the control loop.
The output ripple voltage of the power supply is the product of the capacitor ESR and the inductor ripple current.
The capacitor types recommended in the tables were selected for having low ESR ratings.
In addition, both surface mount tantalum capacitors and through-hole aluminum electrolytic capacitors are offered
as solutions.
Impacting frequency stability of the overall control loop, the output capacitance, in conjunction with the inductor,
creates a double pole inside the feedback loop. In addition the capacitance and the ESR value create a zero.
These frequency response effects together with the internal frequency compensation circuitry of the LM2676
modify the gain and phase shift of the closed loop system.
As a general rule for stable switching regulator circuits it is desired to have the unity gain bandwidth of the circuit
to be limited to no more than one-sixth of the controller switching frequency. With the fixed 260KHz switching
frequency of the LM2676, the output capacitor is selected to provide a unity gain bandwidth of 40KHz maximum.
Each recommended capacitor value has been chosen to achieve this result.
In some cases multiple capacitors are required either to reduce the ESR of the output capacitor, to minimize
output ripple (a ripple voltage of 1% of Vout or less is the assumed performance condition), or to increase the
output capacitance to reduce the closed loop unity gain bandwidth (to less than 40KHz). When parallel
combinations of capacitors are required it has been assumed that each capacitor is the exact same part type.
The RMS current and working voltage (WV) ratings of the output capacitor are also important considerations. In a
typical step-down switching regulator, the inductor ripple current (set to be no more than 30% of the maximum
load current by the inductor selection) is the current that flows through the output capacitor. The capacitor RMS
current rating must be greater than this ripple current. The voltage rating of the output capacitor should be
greater than 1.3 times the maximum output voltage of the power supply. If operation of the system at elevated
temperatures is required, the capacitor voltage rating may be de-rated to less than the nominal room temperature
rating. Careful inspection of the manufacturer's specification for de-rating of working voltage with temperature is
important.
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INPUT CAPACITOR
Fast changing currents in high current switching regulators place a significant dynamic load on the unregulated
power source. An input capacitor helps to provide additional current to the power supply as well as smooth out
input voltage variations.
Like the output capacitor, the key specifications for the input capacitor are RMS current rating and working
voltage. The RMS current flowing through the input capacitor is equal to one-half of the maximum dc load current
so the capacitor should be rated to handle this. Paralleling multiple capacitors proportionally increases the
current rating of the total capacitance. The voltage rating should also be selected to be 1.3 times the maximum
input voltage. Depending on the unregulated input power source, under light load conditions the maximum input
voltage could be significantly higher than normal operation and should be considered when selecting an input
capacitor.
The input capacitor should be placed very close to the input pin of the LM2676. Due to relative high current
operation with fast transient changes, the series inductance of input connecting wires or PCB traces can create
ringing signals at the input terminal which could possibly propagate to the output or other parts of the circuitry. It
may be necessary in some designs to add a small valued (0.1μF to 0.47μF) ceramic type capacitor in parallel
with the input capacitor to prevent or minimize any ringing.
CATCH DIODE
When the power switch in the LM2676 turns OFF, the current through the inductor continues to flow. The path for
this current is through the diode connected between the switch output and ground. This forward biased diode
clamps the switch output to a voltage less than ground. This negative voltage must be greater than −1V so a low
voltage drop (particularly at high current levels) Schottky diode is recommended. Total efficiency of the entire
power supply is significantly impacted by the power lost in the output catch diode. The average current through
the catch diode is dependent on the switch duty cycle (D) and is equal to the load current times (1-D). Use of a
diode rated for much higher current than is required by the actual application helps to minimize the voltage drop
and power loss in the diode.
During the switch ON time the diode will be reversed biased by the input voltage. The reverse voltage rating of
the diode should be at least 1.3 times greater than the maximum input voltage.
BOOST CAPACITOR
The boost capacitor creates a voltage used to overdrive the gate of the internal power MOSFET. This improves
efficiency by minimizing the on resistance of the switch and associated power loss. For all applications it is
recommended to use a 0.01μF/50V ceramic capacitor.
ADDITIONAL APPLICATION INFORMATION
When the output voltage is greater than approximately 6V, and the duty cycle at minimum input voltage is greater
than approximately 50%, the designer should exercise caution in selection of the output filter components. When
an application designed to these specific operating conditions is subjected to a current limit fault condition, it may
be possible to observe a large hysteresis in the current limit. This can affect the output voltage of the device until
the load current is reduced sufficiently to allow the current limit protection circuit to reset itself.
Under current limiting conditions, the LM267x is designed to respond in the following manner:
1. At the moment when the inductor current reaches the current limit threshold, the ON-pulse is immediately
terminated. This happens for any application condition.
2. However, the current limit block is also designed to momentarily reduce the duty cycle to below 50% to avoid
subharmonic oscillations, which could cause the inductor to saturate.
3. Thereafter, once the inductor current falls below the current limit threshold, there is a small relaxation time
during which the duty cycle progressively rises back above 50% to the value required to achieve regulation.
If the output capacitance is sufficiently ‘large’, it may be possible that as the output tries to recover, the output
capacitor charging current is large enough to repeatedly re-trigger the current limit circuit before the output has
fully settled. This condition is exacerbated with higher output voltage settings because the energy requirement of
the output capacitor varies as the square of the output voltage (½CV2), thus requiring an increased charging
current.
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A simple test to determine if this condition might exist for a suspect application is to apply a short circuit across
the output of the converter, and then remove the shorted output condition. In an application with properly
selected external components, the output will recover smoothly.
Practical values of external components that have been experimentally found to work well under these specific
operating conditions are COUT = 47µF, L = 22µH. It should be noted that even with these components, for a
device’s current limit of ICLIM, the maximum load current under which the possibility of the large current limit
hysteresis can be minimized is ICLIM/2. For example, if the input is 24V and the set output voltage is 18V, then for
a desired maximum current of 1.5A, the current limit of the chosen switcher must be confirmed to be at least 3A.
Under extreme over-current or short circuit conditions, the LM267X employs frequency foldback in addition to the
current limit. If the cycle-by-cycle inductor current increases above the current limit threshold (due to short circuit
or inductor saturation for example) the switching frequency will be automatically reduced to protect the IC.
Frequency below 100 KHz is typical for an extreme short circuit condition.
SIMPLE DESIGN PROCEDURE
Using the nomographs and tables in this data sheet (or use the available design software at www.ti.com) a
complete step-down regulator can be designed in a few simple steps.
Step 1: Define the power supply operating conditions:
Required output voltage
Maximum DC input voltage
Maximum output load current
Step 2: Set the output voltage by selecting a fixed output LM2676 (3.3V, 5V or 12V applications) or determine
the required feedback resistors for use with the adjustable LM2676−ADJ
Step 3: Determine the inductor required by using one of the four nomographs, Figure 21 through Figure 24.
Table 1 provides a specific manufacturer and part number for the inductor.
Step 4: Using Table 6 and Table 7 (fixed output voltage) or Table 12 and Table 13 (adjustable output voltage),
determine the output capacitance required for stable operation. Table 3 and Table 4 provide the specific
capacitor type from the manufacturer of choice.
Step 5: Determine an input capacitor from Table 8 or Table 9 for fixed output voltage applications. Use Table 3
or Table 4 to find the specific capacitor type. For adjustable output circuits select a capacitor from Table 3 or
Table 4 with a sufficient working voltage (WV) rating greater than Vin max, and an rms current rating greater than
one-half the maximum load current (2 or more capacitors in parallel may be required).
Step 6: Select a diode from Table 10. The current rating of the diode must be greater than I load max and the
Reverse Voltage rating must be greater than Vin max.
Step 7: Include a 0.01μF/50V capacitor for Cboost in the design.
FIXED OUTPUT VOLTAGE DESIGN EXAMPLE
A system logic power supply bus of 3.3V is to be generated from a wall adapter which provides an unregulated
DC voltage of 13V to 16V. The maximum load current is 2.5A. Through-hole components are preferred.
Step 1: Operating conditions are:
Vout = 3.3V
Vin max = 16V
Iload max = 2.5A
Step 2: Select an LM2676T-3.3. The output voltage will have a tolerance of
±2% at room temperature and ±3% over the full operating temperature range.
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Step 3: Use the nomograph for the 3.3V device, Figure 21. The intersection of the 16V horizontal line (Vin max)
and the 2.5A vertical line (Iload max) indicates that L33, a 22μH inductor, is required.
From Table 1, L33 in a through-hole component is available from Renco with part number RL-1283-22-43 or part
number PE-53933 from Pulse Engineering.
Step 4: Use Table 6 or Table 7 to determine an output capacitor. With a 3.3V output and a 22μH inductor there
are four through-hole output capacitor solutions with the number of same type capacitors to be paralleled and an
identifying capacitor code given. Table 3 or Table 4 provide the actual capacitor characteristics. Any of the
following choices will work in the circuit:
1 x 220μF/10V Sanyo OS-CON (code C5)
1 x 1000μF/35V Sanyo MV-GX (code C10)
1 x 2200μF/10V Nichicon PL (code C5)
1 x 1000μF/35V Panasonic HFQ (code C7)
Step 5: Use Table 8 or Table 9 to select an input capacitor. With 3.3V output and 22μH there are three through-
hole solutions. These capacitors provide a sufficient voltage rating and an rms current rating greater than 1.25A
(1/2 Iload max). Again using Table 3 or Table 4 for specific component characteristics the following choices are
suitable:
1 x 1000μF/63V Sanyo MV-GX (code C14)
1 x 820μF/63V Nichicon PL (code C24)
1 x 560μF/50V Panasonic HFQ (code C13)
Step 6: From Table 10 a 3A Schottky diode must be selected. For through-hole components 20V rated diodes
are sufficient and 2 part types are suitable:
1N5820
SR302
Step 7: A 0.01μF capacitor will be used for Cboost.
ADJUSTABLE OUTPUT DESIGN EXAMPLE
In this example it is desired to convert the voltage from a two battery automotive power supply (voltage range of
20V to 28V, typical in large truck applications) to the 14.8VDC alternator supply typically used to power electronic
equipment from single battery 12V vehicle systems. The load current required is 2A maximum. It is also desired
to implement the power supply with all surface mount components.
Step 1: Operating conditions are:
Vout = 14.8V
Vin max = 28V
Iload max = 2A
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Step 2: Select an LM2676S-ADJ. To set the output voltage to 14.9V two resistors need to be chosen (R1 and R2
in Figure 20). For the adjustable device the output voltage is set by the following relationship:
where
• VFB is the feedback voltage of typically 1.21V (1)
A recommended value to use for R1 is 1K. In this example then R2 is determined to be:
(2)
R2 = 11.23KΩ
The closest standard 1% tolerance value to use is 11.3KΩ
This will set the nominal output voltage to 14.88V which is within 0.5% of the target value.
Step 3: To use the nomograph for the adjustable device, Figure 24, requires a calculation of the inductor
Volt•microsecond constant (E•T expressed in V•μS) from the following formula:
where
• VSAT is the voltage drop across the internal power switch which is Rds(ON) times Iload (3)
In this example this would be typically 0.15Ωx 2A or 0.3V and VDis the voltage drop across the forward biased
Schottky diode, typically 0.5V. The switching frequency of 260KHz is the nominal value to use to estimate the
ON time of the switch during which energy is stored in the inductor.
For this example E•T is found to be:
(4)
(5)
Using Figure 24, the intersection of 27V•μS horizontally and the 2A vertical line (Iload max) indicates that L38 , a
68μH inductor, should be used.
From Table 1, L38 in a surface mount component is available from Pulse Engineering with part number PE-
54038S.
Step 4: Use Table 12 or Table 13 to determine an output capacitor. With a 14.8V output the 12.5 to 15V row is
used and with a 68μH inductor there are three surface mount output capacitor solutions. Table 3 or Table 4
provide the actual capacitor characteristics based on the C Code number. Any of the following choices can be
used:
1 x 33μF/20V AVX TPS (code C6)
1 x 47μF/20V Sprague 594 (code C8)
1 x 47μF/20V Kemet T495 (code C8)
NOTE
When using the adjustable device in low voltage applications (less than 3V output), if the
nomograph, Figure 24, selects an inductance of 22μH or less, Table 12 and Table 13 do
not provide an output capacitor solution. With these conditions the number of output
capacitors required for stable operation becomes impractical. It is recommended to use
either a 33μH or 47μH inductor and the output capacitors from Table 12 or Table 13.
Step 5: An input capacitor for this example will require at least a 35V WV rating with an rms current rating of 1A
(1/2 Iout max). From Table 3 or Table 4 it can be seen that C12, a 33μF/35V capacitor from Sprague, has the
required voltage/current rating of the surface mount components.
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Step 6: From Table 10 a 3A Schottky diode must be selected. For surface mount diodes with a margin of safety
on the voltage rating one of five diodes can be used:
SK34
30BQ040
30WQ04F
MBRS340
MBRD340
Step 7: A 0.01μF capacitor will be used for Cboost.
VSON PACKAGE DEVICES
The LM2676 is offered in the 14 lead VSON surface mount package to allow for a significantly decreased
footprint with equivalent power dissipation compared to the DDPAK. For details on mounting and soldering
specifications, refer to Application Note AN-1187 at
www.ti.com/lsds/ti/analog/powermanagement/power_portal.page.
Inductor Selection Guides
For Continuous Mode Operation
Figure 21. LM2676-3.3 Figure 22. LM2676-5.0
Figure 23. LM2676-12 Figure 24. LM2676-ADJ
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Table 1. Inductor Manufacturer Part Numbers
Inductor Renco Pulse Engineering Coilcraft
Inductance Current
Reference Through Hole Surface Mount Through Hole Surface Mount Surface Mount
(µH) (A)
Number
L23 33 1.35 RL-5471-7 RL1500-33 PE-53823 PE-53823S DO3316-333
L24 22 1.65 RL-1283-22-43 RL1500-22 PE-53824 PE-53824S DO3316-223
L25 15 2.00 RL-1283-15-43 RL1500-15 PE-53825 PE-53825S DO3316-153
L29 100 1.41 RL-5471-4 RL-6050-100 PE-53829 PE-53829S DO5022P-104
L30 68 1.71 RL-5471-5 RL6050-68 PE-53830 PE-53830S DO5022P-683
L31 47 2.06 RL-5471-6 RL6050-47 PE-53831 PE-53831S DO5022P-473
L32 33 2.46 RL-5471-7 RL6050-33 PE-53932 PE-53932S DO5022P-333
L33 22 3.02 RL-1283-22-43 RL6050-22 PE-53933 PE-53933S DO5022P-223
L34 15 3.65 RL-1283-15-43 — PE-53934 PE-53934S DO5022P-153
L38 68 2.97 RL-5472-2 — PE-54038 PE-54038S —
L39 47 3.57 RL-5472-3 — PE-54039 PE-54039S —
L40 33 4.26 RL-1283-33-43 — PE-54040 PE-54040S —
L41 22 5.22 RL-1283-22-43 — PE-54041 P0841 —
L44 68 3.45 RL-5473-3 — PE-54044 — —
L45 10 4.47 RL-1283-10-43 — — P0845 DO5022P-103HC
Table 2. Inductor Manufacturer Contact Numbers
Coilcraft Phone (800) 322-2645
FAX (708) 639-1469
Coilcraft, Europe Phone +44 1236 730 595
FAX +44 1236 730 627
Pulse Engineering Phone (619) 674-8100
FAX (619) 674-8262
Pulse Engineering, Europe Phone +353 93 24 107
FAX +353 93 24 459
Renco Electronics Phone (800) 645-5828
FAX (516) 586-5562
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Capacitor Selection Guides
Table 3. Input and Output Capacitor Codes—Surface Mount
Surface Mount
Capacitor AVX TPS Series Sprague 594D Series Kemet T495 Series
Reference Code C (µF) WV (V) Irms (A) C (µF) WV (V) Irms (A) C (µF) WV (V) Irms (A)
C1 330 6.3 1.15 120 6.3 1.1 100 6.3 0.82
C2 100 10 1.1 220 6.3 1.4 220 6.3 1.1
C3 220 10 1.15 68 10 1.05 330 6.3 1.1
C4 47 16 0.89 150 10 1.35 100 10 1.1
C5 100 16 1.15 47 16 1 150 10 1.1
C6 33 20 0.77 100 16 1.3 220 10 1.1
C7 68 20 0.94 180 16 1.95 33 20 0.78
C8 22 25 0.77 47 20 1.15 47 20 0.94
C9 10 35 0.63 33 25 1.05 68 20 0.94
C10 22 35 0.66 68 25 1.6 10 35 0.63
C11 15 35 0.75 22 35 0.63
C12 33 35 1 4.7 50 0.66
C13 15 50 0.9
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Table 4. Input and Output Capacitor Codes—Through Hole
Through Hole
Capacitor Sanyo OS-CON SA Series Sanyo MV-GX Series Nichicon PL Series Panasonic HFQ Series
Reference C (µF) WV (V) Irms C (µF) WV (V) Irms C (µF) WV (V) Irms C (µF) WV (V) Irms
Code (A) (A) (A) (A)
C1 47 6.3 1 1000 6.3 0.8 680 10 0.8 82 35 0.4
C2 150 6.3 1.95 270 16 0.6 820 10 0.98 120 35 0.44
C3 330 6.3 2.45 470 16 0.75 1000 10 1.06 220 35 0.76
C4 100 10 1.87 560 16 0.95 1200 10 1.28 330 35 1.01
C5 220 10 2.36 820 16 1.25 2200 10 1.71 560 35 1.4
C6 33 16 0.96 1000 16 1.3 3300 10 2.18 820 35 1.62
C7 100 16 1.92 150 35 0.65 3900 10 2.36 1000 35 1.73
C8 150 16 2.28 470 35 1.3 6800 10 2.68 2200 35 2.8
C9 100 20 2.25 680 35 1.4 180 16 0.41 56 50 0.36
C10 47 25 2.09 1000 35 1.7 270 16 0.55 100 50 0.5
C11 220 63 0.76 470 16 0.77 220 50 0.92
C12 470 63 1.2 680 16 1.02 470 50 1.44
C13 680 63 1.5 820 16 1.22 560 50 1.68
C14 1000 63 1.75 1800 16 1.88 1200 50 2.22
C15 220 25 0.63 330 63 1.42
C16 220 35 0.79 1500 63 2.51
C17 560 35 1.43
C18 2200 35 2.68
C19 150 50 0.82
C20 220 50 1.04
C21 330 50 1.3
C22 100 63 0.75
C23 390 63 1.62
C24 820 63 2.22
C25 1200 63 2.51
Table 5. Capacitor Manufacturer Contact Numbers
Nichicon Phone (847) 843-7500
FAX (847) 843-2798
Panasonic Phone (714) 373-7857
FAX (714) 373-7102
AVX Phone (845) 448-9411
FAX (845) 448-1943
Sprague/Vishay Phone (207) 324-4140
FAX (207) 324-7223
Sanyo Phone (619) 661-6322
FAX (619) 661-1055
Kemet Phone (864) 963-6300
FAX (864) 963-6521
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Table 6. Output Capacitors for Fixed Output Voltage Application—Surface Mount(1)(2)
Surface Mount
Output Voltage Inductance (µH) AVX TPS Series Sprague 594D Series Kemet T495 Series
(V) No. C Code No. C Code No. C Code
10 4 C2 3 C1 4 C4
15 4 C2 3 C1 4 C4
3.3 22 3 C2 2 C7 3 C4
33 2 C2 2 C6 2 C4
10 4 C2 4 C6 4 C4
15 3 C2 2 C7 3 C4
522 3 C2 2 C7 3 C4
33 2 C2 2 C3 2 C4
47 2 C2 1 C7 2 C4
10 4 C5 3 C6 5 C9
15 3 C5 2 C7 4 C8
22 2 C5 2 C6 3 C8
12 33 2 C5 1 C7 2 C8
47 2 C4 1 C6 2 C8
68 1 C5 1 C5 2 C7
100 1 C4 1 C5 1 C8
(1) No. represents the number of identical capacitor types to be connected in parallel
(2) C Code indicates the Capacitor Reference number in Table 3 and Table 4 for identifying the specific component from the manufacturer.
Table 7. Output Capacitors for Fixed Output Voltage Application—Through Hole(1)(2)
Through Hole
Output Inductance Sanyo OS-CON SA Sanyo MV-GX Series Nichicon PL Series Panasonic HFQ Series
Voltage (V) (µH) Series
No. C Code No. C Code No. C Code No. C Code
10 1 C3 1 C10 1 C6 2 C6
15 1 C3 1 C10 1 C6 2 C5
3.3 22 1 C5 1 C10 1 C5 1 C7
33 1 C2 1 C10 1 C13 1 C5
10 2 C4 1 C10 1 C6 2 C5
15 1 C5 1 C10 1 C5 1 C6
522 1 C5 1 C5 1 C5 1 C5
33 1 C4 1 C5 1 C13 1 C5
47 1 C4 1 C4 1 C13 2 C3
10 2 C7 1 C5 1 C18 2 C5
15 1 C8 1 C5 1 C17 1 C5
22 1 C7 1 C5 1 C13 1 C5
12 33 1 C7 1 C3 1 C11 1 C4
47 1 C7 1 C3 1 C10 1 C3
68 1 C7 1 C2 1 C10 1 C3
100 1 C7 1 C2 1 C9 1 C1
(1) No. represents the number of identical capacitor types to be connected in parallel
(2) C Code indicates the Capacitor Reference number in Table 3 and Table 4 for identifying the specific component from the manufacturer.
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Table 8. Input Capacitors for Fixed Output Voltage Application—Surface Mount(1)(2)(3)
Surface Mount
Output Voltage Inductance (µH) AVX TPS Series Sprague 594D Series Kemet T495 Series
(V) No. C Code No. C Code No. C Code
10 2 C5 1 C7 2 C8
15 3 C9 1 C10 3 C10
3.3 22 See(4) See(4) 2 C13 3 C12
33 See(4) See(4) 2 C13 2 C12
10 2 C5 1 C7 2 C8
15 2 C5 1 C7 2 C8
522 3 C10 2 C12 3 C11
33 See(4) See(4) 2 C13 3 C12
47 See(4) See(4) 1 C13 2 C12
10 2 C7 2 C10 2 C7
15 2 C7 2 C10 2 C7
22 3 C10 2 C12 3 C10
12 33 3 C10 2 C12 3 C10
47 See(4) See(4) 2 C13 3 C12
68 See(4) See(4) 2 C13 2 C12
100 See(4) See(4) 1 C13 2 C12
(1) Assumes worst case maximum input voltage and load current for a given inductance value
(2) No. represents the number of identical capacitor types to be connected in parallel
(3) C Code indicates the Capacitor Reference number in Table 3 and Table 4 for identifying the specific component from the manufacturer.
(4) Check voltage rating of capacitors to be greater than application input voltage.
Table 9. Input Capacitors for Fixed Output Voltage Application—Through Hole(1)(2)(3)
Through Hole
Output Inductance Sanyo OS-CON SA Sanyo MV-GX Series Nichicon PL Series Panasonic HFQ Series
Voltage (V) (µH) Series
No. C Code No. C Code No. C Code No. C Code
10 1 C7 2 C4 1 C5 1 C6
15 1 C10 1 C10 1 C18 1 C6
3.3 22 See(4) See(4) 1 C14 1 C24 1 C13
33 See(4) See(4) 1 C12 1 C20 1 C12
10 1 C7 2 C4 1 C14 1 C6
15 1 C7 2 C4 1 C14 1 C6
522 See(4) See(4) 1 C10 1 C18 1 C13
33 See(4) See(4) 1 C14 1 C23 1 C13
47 See(4) See(4) 1 C12 1 C20 1 C12
10 1 C9 1 C10 1 C18 1 C6
15 1 C10 1 C10 1 C18 1 C6
22 1 C10 1 C10 1 C18 1 C6
12 33 See(4) See(4) 1 C10 1 C18 1 C6
47 See(4) See(4) 1 C13 1 C23 1 C13
68 See(4) See(4) 1 C12 1 C21 1 C12
100 See(4) See(4) 1 C11 1 C22 1 C11
(1) Assumes worst case maximum input voltage and load current for a given inductance value
(2) No. represents the number of identical capacitor types to be connected in parallel
(3) C Code indicates the Capacitor Reference number in Table 3 and Table 4 for identifying the specific component from the manufacturer.
(4) Check voltage rating of capacitors to be greater than application input voltage.
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Table 10. Schottky Diode Selection Table
Reverse Surface Mount Through Hole
Voltage (V) 3A 5A or More 3A 5A or More
20V SK32 1N5820
SR302
30V SK33 MBRD835L 1N5821
30WQ03F 31DQ03
40V SK34 MBRB1545CT 1N5822
30BQ040 6TQ045S MBR340 MBR745
30WQ04F 31DQ04 80SQ045
MBRS340 SR403 6TQ045
MBRD340
50V or More SK35 MBR350
30WQ05F 31DQ05
SR305
Table 11. Diode Manufacturer Contact Numbers
International Rectifier Phone (310) 322-3331
FAX (310) 322-3332
Motorola Phone (800) 521-6274
FAX (602) 244-6609
General Semiconductor Phone (516) 847-3000
FAX (516) 847-3236
Diodes, Inc. Phone (805) 446-4800
FAX (805) 446-4850
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Table 12. Output Capacitors for Adjustable Output Voltage Applications—Surface Mount(1)(2)
Surface Mount
Output Voltage (V) Inductance (µH) AVX TPS Series Sprague 594D Series Kemet T495 Series
No. C Code No. C Code No. C Code
33(3) 7 C1 6 C2 7 C3
1.21 to 2.50 47(3) 5 C1 4 C2 5 C3
33(3) 4 C1 3 C2 4 C3
2.5 to 3.75 47(3) 3 C1 2 C2 3 C3
22 4 C1 3 C2 4 C3
3.75 to 5 33 3 C1 2 C2 3 C3
47 2 C1 2 C2 2 C3
22 3 C2 3 C3 3 C4
33 2 C2 2 C3 2 C4
5 to 6.25 47 2 C2 2 C3 2 C4
68 1 C2 1 C3 1 C4
22 3 C2 1 C4 3 C4
33 2 C2 1 C3 2 C4
6.25 to 7.5 47 1 C3 1 C4 1 C6
68 1 C2 1 C3 1 C4
33 2 C5 1 C6 2 C8
47 1 C5 1 C6 2 C8
7.5 to 10 68 1 C5 1 C6 1 C8
100 1 C4 1 C5 1 C8
33 1 C5 1 C6 2 C8
47 1 C5 1 C6 2 C8
10 to 12.5 68 1 C5 1 C6 1 C8
100 1 C5 1 C6 1 C8
33 1 C6 1 C8 1 C8
47 1 C6 1 C8 1 C8
12.5 to 15 68 1 C6 1 C8 1 C8
100 1 C6 1 C8 1 C8
33 1 C8 1 C10 2 C10
47 1 C8 1 C9 2 C10
15 to 20 68 1 C8 1 C9 2 C10
100 1 C8 1 C9 1 C10
33 2 C9 2 C11 2 C11
47 1 C10 1 C12 1 C11
20 to 30 68 1 C9 1 C12 1 C11
100 1 C9 1 C12 1 C11
10 4 C13 8 C12
15 3 C13 5 C12
22 2 C13 4 C12
30 to 37 No Values Available
33 1 C13 3 C12
47 1 C13 2 C12
68 1 C13 2 C12
(1) No. represents the number of identical capacitor types to be connected in parallel
(2) C Code indicates the Capacitor Reference number in Table 3 and Table 4 for identifying the specific component from the manufacturer.
(3) Set to a higher value for a practical design solution. See Application Hints section
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Table 13. Output Capacitors for Adjustable Output Voltage Applications—Through Hole(1)(2)
Through Hole
Inductance Sanyo OS-CON SA
Output Voltage (V) Sanyo MV-GX Series Nichicon PL Series Panasonic HFQ Series
(µH) Series
No. C Code No. C Code No. C Code No. C Code
33(3) 2 C3 5 C1 5 C3 3 C
1.21 to 2.50 47(3) 2 C2 4 C1 3 C3 2 C5
33(3) 1 C3 3 C1 3 C1 2 C5
2.5 to 3.75 47(3) 1 C2 2 C1 2 C3 1 C5
22 1 C3 3 C1 3 C1 2 C5
3.75 to 5 33 1 C2 2 C1 2 C1 1 C5
47 1 C2 2 C1 1 C3 1 C5
22 1 C5 2 C6 2 C3 2 C5
33 1 C4 1 C6 2 C1 1 C5
5 to 6.25 47 1 C4 1 C6 1 C3 1 C5
68 1 C4 1 C6 1 C1 1 C5
22 1 C5 1 C6 2 C1 1 C5
33 1 C4 1 C6 1 C3 1 C5
6.25 to 7.5 47 1 C4 1 C6 1 C1 1 C5
68 1 C4 1 C2 1 C1 1 C5
33 1 C7 1 C6 1 C14 1 C5
47 1 C7 1 C6 1 C14 1 C5
7.5 to 10 68 1 C7 1 C2 1 C14 1 C2
100 1 C7 1 C2 1 C14 1 C2
33 1 C7 1 C6 1 C14 1 C5
47 1 C7 1 C2 1 C14 1 C5
10 to 12.5 68 1 C7 1 C2 1 C9 1 C2
100 1 C7 1 C2 1 C9 1 C2
33 1 C9 1 C10 1 C15 1 C2
47 1 C9 1 C10 1 C15 1 C2
12.5 to 15 68 1 C9 1 C10 1 C15 1 C2
100 1 C9 1 C10 1 C15 1 C2
33 1 C10 1 C7 1 C15 1 C2
47 1 C10 1 C7 1 C15 1 C2
15 to 20 68 1 C10 1 C7 1 C15 1 C2
100 1 C10 1 C7 1 C15 1 C2
33 1 C7 1 C16 1 C2
47 1 C7 1 C16 1 C2
20 to 30 No Values Available
68 1 C7 1 C16 1 C2
100 1 C7 1 C16 1 C2
10 1 C12 1 C20 1 C10
15 1 C11 1 C20 1 C11
22 1 C11 1 C20 1 C10
30 to 37 No Values Available
33 1 C11 1 C20 1 C10
47 1 C11 1 C20 1 C10
68 1 C11 1 C20 1 C10
(1) No. represents the number of identical capacitor types to be connected in parallel
(2) C Code indicates the Capacitor Reference number in Table 3 and Table 4 for identifying the specific component from the manufacturer.
(3) Set to a higher value for a practical design solution. See Application Hints section
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REVISION HISTORY
Changes from Revision I (April 2013) to Revision J Page
• Changed layout of National Data Sheet to TI format .......................................................................................................... 24
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PACKAGE OPTION ADDENDUM
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Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead/Ball Finish
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM2676S-12 NRND DDPAK/
TO-263 KTW 7 45 TBD Call TI Call TI -40 to 125 LM2676
S-12
LM2676S-12/NOPB ACTIVE DDPAK/
TO-263 KTW 7 45 Pb-Free (RoHS
Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2676
S-12
LM2676S-3.3 NRND DDPAK/
TO-263 KTW 7 45 TBD Call TI Call TI -40 to 125 LM2676
S-3.3
LM2676S-3.3/NOPB ACTIVE DDPAK/
TO-263 KTW 7 45 Pb-Free (RoHS
Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2676
S-3.3
LM2676S-5.0 NRND DDPAK/
TO-263 KTW 7 45 TBD Call TI Call TI -40 to 125 LM2676
S-5.0
LM2676S-5.0/NOPB ACTIVE DDPAK/
TO-263 KTW 7 45 Pb-Free (RoHS
Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2676
S-5.0
LM2676S-ADJ NRND DDPAK/
TO-263 KTW 7 45 TBD Call TI Call TI -40 to 125 LM2676
S-ADJ
LM2676S-ADJ/NOPB ACTIVE DDPAK/
TO-263 KTW 7 45 Pb-Free (RoHS
Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2676
S-ADJ
LM2676SD-12/NOPB ACTIVE VSON NHM 14 250 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 S0003LB
LM2676SD-3.3 NRND VSON NHM 14 250 TBD Call TI Call TI -40 to 125 S0003NB
LM2676SD-3.3/NOPB ACTIVE VSON NHM 14 250 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 S0003NB
LM2676SD-5.0/NOPB ACTIVE VSON NHM 14 250 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 S0003PB
LM2676SD-ADJ NRND VSON NHM 14 250 TBD Call TI Call TI -40 to 125 S0003RB
LM2676SD-ADJ/NOPB ACTIVE VSON NHM 14 250 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 S0003RB
LM2676SDX-12/NOPB ACTIVE VSON NHM 14 2500 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 S0003LB
LM2676SDX-3.3/NOPB ACTIVE VSON NHM 14 2500 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 S0003NB
LM2676SDX-5.0/NOPB ACTIVE VSON NHM 14 2500 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 S0003PB
LM2676SDX-ADJ NRND VSON NHM 14 2500 TBD Call TI Call TI -40 to 125 S0003RB
PACKAGE OPTION ADDENDUM
www.ti.com 1-Nov-2013
Addendum-Page 2
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead/Ball Finish
(6)
MSL Peak Temp
(3)
Op Temp (°C) Device Marking
(4/5)
Samples
LM2676SDX-ADJ/NOPB ACTIVE VSON NHM 14 2500 Green (RoHS
& no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 S0003RB
LM2676SX-12 NRND DDPAK/
TO-263 KTW 7 500 TBD Call TI Call TI -40 to 125 LM2676
S-12
LM2676SX-12/NOPB ACTIVE DDPAK/
TO-263 KTW 7 500 Pb-Free (RoHS
Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2676
S-12
LM2676SX-3.3/NOPB ACTIVE DDPAK/
TO-263 KTW 7 500 Pb-Free (RoHS
Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2676
S-3.3
LM2676SX-5.0 NRND DDPAK/
TO-263 KTW 7 500 TBD Call TI Call TI -40 to 125 LM2676
S-5.0
LM2676SX-5.0/NOPB ACTIVE DDPAK/
TO-263 KTW 7 500 Pb-Free (RoHS
Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2676
S-5.0
LM2676SX-ADJ NRND DDPAK/
TO-263 KTW 7 500 TBD Call TI Call TI -40 to 125 LM2676
S-ADJ
LM2676SX-ADJ/NOPB ACTIVE DDPAK/
TO-263 KTW 7 500 Pb-Free (RoHS
Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2676
S-ADJ
LM2676T-12/NOPB ACTIVE TO-220 NDZ 7 45 Green (RoHS
& no Sb/Br) CU SN Level-1-NA-UNLIM -40 to 125 LM2676
T-12
LM2676T-3.3/NOPB ACTIVE TO-220 NDZ 7 45 Green (RoHS
& no Sb/Br) CU SN Level-1-NA-UNLIM -40 to 125 LM2676
T-3.3
LM2676T-5.0 NRND TO-220 NDZ 7 45 TBD Call TI Call TI -40 to 125 LM2676
T-5.0
LM2676T-5.0/NOPB ACTIVE TO-220 NDZ 7 45 Green (RoHS
& no Sb/Br) CU SN Level-1-NA-UNLIM -40 to 125 LM2676
T-5.0
LM2676T-ADJ NRND TO-220 NDZ 7 45 TBD Call TI Call TI -40 to 125 LM2676
T-ADJ
LM2676T-ADJ/NOPB ACTIVE TO-220 NDZ 7 45 Green (RoHS
& no Sb/Br) CU SN Level-1-NA-UNLIM -40 to 125 LM2676
T-ADJ
(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.
PACKAGE OPTION ADDENDUM
www.ti.com 1-Nov-2013
Addendum-Page 3
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(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.
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
LM2676SD-12/NOPB VSON NHM 14 250 178.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SD-3.3 VSON NHM 14 250 178.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SD-3.3/NOPB VSON NHM 14 250 178.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SD-5.0/NOPB VSON NHM 14 250 178.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SD-ADJ VSON NHM 14 250 178.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SD-ADJ/NOPB VSON NHM 14 250 178.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SDX-12/NOPB VSON NHM 14 2500 330.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SDX-3.3/NOPB VSON NHM 14 2500 330.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SDX-5.0/NOPB VSON NHM 14 2500 330.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SDX-ADJ VSON NHM 14 2500 330.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SDX-ADJ/NOPB VSON NHM 14 2500 330.0 16.4 5.3 6.3 1.5 12.0 16.0 Q1
LM2676SX-12 DDPAK/
TO-263 KTW 7 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2676SX-12/NOPB DDPAK/
TO-263 KTW 7 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2676SX-3.3/NOPB DDPAK/
TO-263 KTW 7 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2676SX-5.0 DDPAK/
TO-263 KTW 7 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
PACKAGE MATERIALS INFORMATION
www.ti.com 11-Oct-2013
Pack Materials-Page 1
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
LM2676SX-5.0/NOPB DDPAK/
TO-263 KTW 7 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2676SX-ADJ DDPAK/
TO-263 KTW 7 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
LM2676SX-ADJ/NOPB DDPAK/
TO-263 KTW 7 500 330.0 24.4 10.75 14.85 5.0 16.0 24.0 Q2
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM2676SD-12/NOPB VSON NHM 14 250 210.0 185.0 35.0
LM2676SD-3.3 VSON NHM 14 250 210.0 185.0 35.0
LM2676SD-3.3/NOPB VSON NHM 14 250 210.0 185.0 35.0
LM2676SD-5.0/NOPB VSON NHM 14 250 210.0 185.0 35.0
LM2676SD-ADJ VSON NHM 14 250 210.0 185.0 35.0
LM2676SD-ADJ/NOPB VSON NHM 14 250 210.0 185.0 35.0
LM2676SDX-12/NOPB VSON NHM 14 2500 367.0 367.0 35.0
LM2676SDX-3.3/NOPB VSON NHM 14 2500 367.0 367.0 35.0
LM2676SDX-5.0/NOPB VSON NHM 14 2500 367.0 367.0 35.0
LM2676SDX-ADJ VSON NHM 14 2500 367.0 367.0 35.0
LM2676SDX-ADJ/NOPB VSON NHM 14 2500 367.0 367.0 35.0
LM2676SX-12 DDPAK/TO-263 KTW 7 500 367.0 367.0 45.0
PACKAGE MATERIALS INFORMATION
www.ti.com 11-Oct-2013
Pack Materials-Page 2
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LM2676SX-12/NOPB DDPAK/TO-263 KTW 7 500 367.0 367.0 45.0
LM2676SX-3.3/NOPB DDPAK/TO-263 KTW 7 500 367.0 367.0 45.0
LM2676SX-5.0 DDPAK/TO-263 KTW 7 500 367.0 367.0 45.0
LM2676SX-5.0/NOPB DDPAK/TO-263 KTW 7 500 367.0 367.0 45.0
LM2676SX-ADJ DDPAK/TO-263 KTW 7 500 367.0 367.0 45.0
LM2676SX-ADJ/NOPB DDPAK/TO-263 KTW 7 500 367.0 367.0 45.0
PACKAGE MATERIALS INFORMATION
www.ti.com 11-Oct-2013
Pack Materials-Page 3
MECHANICAL DATA
NDZ0007B
www.ti.com
TA07B (Rev E)
MECHANICAL DATA
NHM0014A
www.ti.com
SRC14A (Rev A)
MECHANICAL DATA
KTW0007B
www.ti.com
BOTTOM SIDE OF PACKAGE
TS7B (Rev E)
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