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Texas Instruments LM2587T-ADJ/LF03
- Part No.:
- LM2587T-ADJ/LF03
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-5 Formed Leads
- Datasheet:
-
LM2587T-ADJ/LF03.pdf
- Description:
- IC REG BST FLYBCK ADJ 5A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,449
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Product details
Overview
LM2587T-ADJ/LF03 from Texas Instruments is a monolithic 5A NPN-switch flyback/boost regulator IC with adjustable output voltage, 100 kHz fixed-frequency operation, internal soft-start, and integrated current-limit/thermal-shutdown/UVLO protection. It operates from 4V to 40V input and delivers regulated output up to 60V in flyback topology-used in industrial power supplies requiring isolated multi-output DC-DC conversion.
For engineers reviewing the LM2587T-ADJ/LF03 datasheet, LM2587T-ADJ/LF03 pinout, LM2587T-ADJ/LF03 application, or LM2587T-ADJ/LF03 equivalent, this page provides verified technical context, exact pin functions, real-world design meaning of key specs, confirmed alternative parts, and supply support for production-grade embedded power designs.
Technical Context
The LM2587T-ADJ/LF03 implements current-mode control with cycle-by-cycle peak-current limiting and a 100 kHz oscillator driving an internal 5.0A/65V NPN switch. Its error amplifier features 1.230 V reference (±1.5 mV line regulation), 670 V/V gain, and 3.2 mmho transconductance-enabling precise feedback loop compensation for flyback and boost topologies.
It supports adjustable output via external resistor divider (VOUT = 1.23 × (1 + R1/R2)), with guaranteed ±4% system output tolerance over line/load/temperature. The device enters soft-start at power-up by linearly ramping the error amp output current (11 μA typical) to limit in-rush current during startup.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Switch | 5.0A NPN transistor with 65V blocking capability-supports high-power flyback/boost stages without external switch |
| Input Voltage Range | 4V to 40V-enables direct operation from 5V, 12V, 24V, or 36V industrial rails without pre-regulation |
| Switching Frequency | 100 kHz (±15 kHz)-permits use of compact magnetics while maintaining EMI compliance in most industrial bands |
| Reference Voltage | 1.230 V ±1.5 mV over 4V–40V input-sets accurate, stable output voltage across wide input range |
| Thermal Protection | Internal thermal shutdown at 150°C junction-prevents damage under sustained overload or poor heatsinking |
| Undervoltage Lockout | 3.30 V ±0.35 V turn-on threshold-ensures reliable start-up only when input rail is sufficiently stable |
| Efficiency | 90% typical at 10V input / 1A load (flyback config)-reduces thermal load and improves power density |
Pinout & Package
LM2587T-ADJ/LF03 is housed in a 5-lead TO-220 (T package) with vertical mounting and bent staggered leads. Thermal resistance is 65°C/W (no copper) or 45°C/W (4 in² copper area), requiring heatsink for >2W dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Input | Power input to internal bias circuitry | Supplies IC core logic; must be decoupled near pin with ≥100 μF electrolytic + 0.1 μF ceramic |
| Pin 2: Ground | Power and signal reference node | Must connect to low-impedance ground plane; separates power return from feedback ground to avoid noise coupling |
| Pin 3: Feedback | Inverting input of error amplifier | Accepts resistor-divider voltage; regulates output by comparing to 1.230 V internal reference |
| Pin 4: Compensation | Error amplifier output for loop compensation | Connect RC network here to stabilize feedback loop-critical for flyback transformer phase margin |
| Pin 5: Switch | Collector of internal NPN power switch | Drives primary winding of flyback transformer or boost inductor; requires snubber for voltage spike suppression |
Key Features
| Feature | Design Value |
|---|---|
| Current-mode control | Enables fast transient response and inherent cycle-by-cycle current limiting-eliminates need for external current-sense resistor in most designs |
| Internal soft-start | 11 μA typical soft-start current ramps error amp output-limits in-rush current and prevents output overshoot during startup |
| Integrated protection | Combined UVLO (3.3 V), thermal shutdown (150°C), and current limit (6.5 A typical)-reduces BOM count and improves system reliability |
| Adjustable output | 1.230 V reference enables output programming from ~1.25 V to >60 V using two precision resistors-supports custom voltage rails without redesign |
| Fixed 100 kHz frequency | Allows consistent magnetic design across variants-simplifies EMI filter selection and reduces layout iterations |
Applications
| Industrial Flyback Power Supply | Automotive Boost Converter |
|---|---|
Use Scenario: Isolated 12 V/1.2 A output from 24 V vehicle battery with reverse-polarity and load-dump protection. IC Role / Device Role / Timing Role: Primary-side controller regulating flyback transformer; 100 kHz switching defines transformer size and EMI profile. Use Value: Enables single-chip solution for isolated auxiliary supply-replaces discrete transistor+controller designs and reduces footprint by >40%. |
Use Scenario: Generating 48 V from 24 V battery for LED lighting or sensor bias in commercial vehicles. IC Role / Device Role / Timing Role: Boost regulator controller with internal 5 A switch; fixed 100 kHz frequency ensures predictable inductor sizing and ripple behavior. Use Value: Delivers 90% efficiency at full load without external MOSFET-cuts thermal management complexity and supports convection-cooled enclosures. |
| Multi-Output Telecom Adapter | Programmable Lab Power Module |
Use Scenario: Triple-output (±12 V, +5 V) wall adapter for test equipment with tight cross-regulation requirements. IC Role / Device Role / Timing Role: Flyback controller managing coupled secondary windings; current-mode control improves load transient rejection across outputs. Use Value: Achieves ±4% output tolerance across all rails with no post-regulation-lowers cost vs. triple-LDO or multiple converters. |
Use Scenario: Bench power supply with digitally adjustable 3–30 V output, 2 A max, using DAC-controlled feedback divider. IC Role / Device Role / Timing Role: Adjustable regulator core; 1.230 V reference enables precise DAC interface with <10 mV step resolution. Use Value: Supports software-defined voltage setting without hardware changes-enables reconfigurable test platforms with minimal component variation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar flyback/boost regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2588T-ADJ | Higher 65V switch rating, 150 kHz frequency, improved efficiency (92%) but larger die size and higher quiescent current (15.5 mA vs. 11 mA) | Better suited for high-input-voltage (>36 V) boost designs where switching loss dominates; less optimal for space-constrained 24 V flyback | Select LM2588T-ADJ when input exceeds 40 V or efficiency above 90% is required at light loads |
| UCC38C43D | Current-mode PWM controller only-requires external MOSFET, gate driver, and protection circuits; no integrated switch or UVLO | Offers greater flexibility in switch selection and thermal layout but increases BOM count and design effort for basic flyback | Choose UCC38C43D only when custom high-voltage/high-frequency switching or discrete thermal management is mandatory |
Compared with LM2587T-ADJ/LF03, LM2588T-ADJ offers higher voltage headroom and efficiency at the cost of increased layout area and idle consumption, while UCC38C43D trades integration for design flexibility-making LM2587T-ADJ/LF03 optimal for cost-sensitive, medium-power flyback/boost applications needing rapid time-to-market.
Availability
LM2587T-ADJ/LF03 is available at Aetrix Electronics and suitable for industrial power supplies, automotive DC-DC converters, telecom adapters, and programmable lab equipment requiring stable component supply and long-term manufacturability.
Supply support for LM2587T-ADJ/LF03 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management solutions, with decades of expertise in switching regulator design and manufacturing.
The LM2587 series was developed as part of TI's SIMPLE SWITCHER® portfolio to deliver robust, easy-to-use DC-DC conversion for industrial, automotive, and telecom applications-emphasizing minimal external components and proven reliability in harsh environments.
FAQ
What is the maximum output voltage achievable with LM2587T-ADJ/LF03 in flyback configuration?
The LM2587T-ADJ/LF03 supports output voltages up to 60 V in flyback topology, limited by the 65 V switch breakdown rating and transformer insulation. Output voltage is set by the feedback resistor divider (VOUT = 1.23 × (1 + R1/R2)), and practical designs maintain ≥5 V margin below 65 V to accommodate voltage spikes and derating. Real-world implementations documented in TI's Application Report SNVA224 achieve stable 48 V outputs with appropriate snubbing and transformer selection.
Does LM2587T-ADJ/LF03 require an external MOSFET for boost operation?
No, LM2587T-ADJ/LF03 integrates a 5.0 A NPN power switch rated for 65 V, eliminating the need for an external MOSFET in both boost and flyback configurations. In boost mode, the internal switch connects between ground and the inductor's grounded end, enabling direct implementation with only diode, inductor, input/output capacitors, and feedback resistors-verified in Figure 35 of the SNVS115C datasheet.
How does the soft-start function operate in LM2587T-ADJ/LF03?
The LM2587T-ADJ/LF03 implements soft-start by sourcing a constant 11 μA (typical) current into the compensation pin (Pin 4) at startup, linearly ramping the error amplifier output voltage. This gradually increases the duty cycle, limiting in-rush current and preventing output overshoot. The soft-start duration is determined by the RC time constant at Pin 4 and ends when the feedback voltage reaches regulation-fully detailed in Section 8.3.4 of the datasheet.
Can LM2587T-ADJ/LF03 be used in forward converter topology?
Yes, LM2587T-ADJ/LF03 is explicitly qualified for forward converter applications per its datasheet description and "Typical Applications" list. Its current-mode architecture, 100 kHz fixed frequency, and 5 A/65 V switch support standard forward designs with external reset winding or active clamp. However, unlike dedicated forward controllers, it lacks built-in synchronous rectification or reset timing logic-requiring careful transformer design and external reset circuitry.
What is the thermal resistance (θJA) of LM2587T-ADJ/LF03 in TO-220 package?
LM2587T-ADJ/LF03 in the 5-lead TO-220 (T) package has θJA = 65°C/W with minimal copper (½-inch leads in socket), and 45°C/W with ~4 in² of 1 oz. copper on the PCB. These values assume vertical mounting and define maximum power dissipation limits: at 25°C ambient, 65°C/W allows ≤1.15 W continuous dissipation before reaching 150°C junction temperature-necessitating heatsinking for >2 W applications.
LM2587T-ADJ/LF03 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-220-5 Formed Leads
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Boost, Flyback, Forward Converter
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.23V
- Voltage - Output (Max):
- 60V
- Current - Output:
- 5A (Switch)
- Frequency - Switching:
- 100kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-5
LM2587T-ADJ/LF03 FAQ
1.How can I place an order for LM2587T-ADJ/LF03 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2587T-ADJ/LF03 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM2587T-ADJ/LF03 reliable?
The price and inventory of LM2587T-ADJ/LF03 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2587T-ADJ/LF03 is usually 5 days.
3.What payment methods are accepted for LM2587T-ADJ/LF03?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2587T-ADJ/LF03 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2587T-ADJ/LF03?
LM2587T-ADJ/LF03 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2587T-ADJ/LF03 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM2587T-ADJ/LF03?
For technical support, including LM2587T-ADJ/LF03 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2587T-ADJ/LF03 requirements.
6.How does Aetrix verify that LM2587T-ADJ/LF03 is sourced from the original manufacturer or authorized distributors?
All LM2587T-ADJ/LF03 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM2587T-ADJ/LF03 meets industry standards.
7.What is the process for return or replacement of LM2587T-ADJ/LF03?
All LM2587T-ADJ/LF03 units undergo pre-shipment inspection (PSI). If there is an issue with LM2587T-ADJ/LF03, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM2587T-ADJ/LF03 part is unused and in its original packaging.
Return procedure for LM2587T-ADJ/LF03:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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