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Texas Instruments LM2587T-3.3
- Part No.:
- LM2587T-3.3
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-5 Formed Leads
- Datasheet:
-
LM2587T-3.3.pdf
- Description:
- IC REG BST FLYBACK 3.3V TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,910
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Product details
Overview
LM2587T-3.3 from Texas Instruments is a monolithic 5A flyback/boost regulator IC with fixed 3.3V output, integrated 5.0A NPN switch rated for 65V standoff, 100 kHz fixed-frequency oscillator, and internal soft-start. It operates across 4V–40V input, delivers ±4% system output voltage tolerance over line/load, and targets isolated DC-DC conversion in industrial power supplies and embedded systems.
For engineers reviewing the LM2587T-3.3 datasheet, LM2587T-3.3 pinout, LM2587T-3.3 application, or LM2587T-3.3 equivalent, key selection criteria include its 3.3V fixed-output architecture, TO-220-5 thermal performance (θJA = 65°C/W), current-mode control for transient rejection, and compatibility with standard flyback transformers such as Coilcraft Q4434-B and Schott 67141450.
Technical Context
The LM2587T-3.3 implements current-mode PWM control with cycle-by-cycle current limiting, using an internal 1.23V reference and error amplifier (transconductance = 1.193 mmho, gain = 260 V/V) to regulate output via feedback pin voltage. Its 100 kHz oscillator enables compact magnetics, while undervoltage lockout (3.30V threshold) and thermal shutdown protect the integrated NPN switch.
It supports three topologies: flyback (isolated, multi-output capable), boost (non-isolated step-up), and forward converter. In flyback mode, output current is internally limited; in boost mode, external current limiting is required to prevent switch damage at short-circuit conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±4% over 4V–40V input and 400 mA–1.75A load - ensures stable logic rail generation without external resistor network. |
| Switch Current Limit | 5.0A typical, 6.5A max - defines peak primary-side current handling in flyback designs and sets transformer sizing baseline. |
| Oscillator Frequency | 100 kHz (±15%) - determines minimum inductor/flyback transformer size and EMI profile; fixed frequency simplifies filter design. |
| Input Voltage Range | 4V to 40V - supports wide-range industrial inputs including 5V, 12V, 24V, and 36V bus systems with margin. |
| Thermal Resistance | θJA = 65°C/W (TO-220, minimal copper) - requires heatsink above ~1.5W dissipation at full load in ambient >50°C. |
| Reference Voltage | 3.3V at FB pin (3.242V min / 3.358V max) - directly sets regulated output; no external divider needed for 3.3V version. |
| Efficiency | 75% at VIN = 12V, ILOAD = 1A - reflects real-world conversion loss in typical flyback configuration with standard diodes and magnetics. |
Pinout & Package
LM2587T-3.3 is housed in a 5-lead TO-220 (T package) with exposed tab electrically connected to Pin 2 (Ground). The package provides vertical mounting capability and moderate thermal performance without heatsink on minimal PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Input | Power input supply connection | Accepts 4V–40V unregulated DC; requires ≥100 μF bulk capacitance near pin for stability. |
| Pin 2: Ground | Power and signal reference node | Common return for input capacitor, output capacitor, feedback network, and heatsink mounting surface. |
| Pin 3: Feedback | Output voltage sensing input | Internally compared to 3.3V reference; open or misconnected causes overvoltage failure. |
| Pin 4: Compensation | Error amplifier output compensation node | Connect RC network (e.g., 2 kΩ + 0.47 μF) to stabilize loop response and prevent oscillation. |
| Pin 5: Switch | Collector of internal NPN power transistor | Drives primary winding of flyback transformer or boost inductor; must be routed with low-inductance layout. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 5A/65V NPN switch | Eliminates external high-current transistor; reduces BOM count and layout complexity in flyback/boost designs. |
| Current-mode PWM control | Enables inherent line/load transient immunity and simplifies loop compensation versus voltage-mode controllers. |
| Internal soft-start (11 μA current source) | Gradually ramps output during startup to limit inrush current into output capacitors and avoid input droop. |
| Undervoltage lockout (3.30V threshold) | Prevents erratic operation during brownout; ensures clean start-up only when input exceeds safe regulation range. |
| Thermal shutdown protection | Disables switching at 150°C junction temperature, allowing safe cooldown before automatic recovery. |
Applications
| Industrial Power Supply | Automotive Body Control Module |
|---|---|
|
Use Scenario: Isolated 3.3V rail generation from 12V battery in harsh environment with wide temperature swing. IC Role / Device Role / Timing Role: Primary-side controller in flyback topology providing galvanic isolation and regulation. Use Value: Enables single-chip solution for safety-critical subsystems requiring reinforced insulation and ±4% output accuracy over −40°C to +125°C. |
Use Scenario: Boosting 5V microcontroller supply to 3.3V logic rail in infotainment head unit with variable input. IC Role / Device Role / Timing Role: Non-isolated step-up regulator delivering stable 3.3V under dynamic load transients. Use Value: Delivers 75% efficiency at 1A load while rejecting 12V bus ripple via current-mode control-no external MOSFET needed. |
| Medical Sensor Interface | IoT Edge Node Power |
|
Use Scenario: Generating isolated 3.3V for analog front-end and ADC in portable diagnostic device. IC Role / Device Role / Timing Role: Flyback controller driving transformer-coupled secondary with synchronous rectification option. Use Value: Supports dual-output configurations (e.g., +3.3V/−12V) using standard T1 transformer (Coilcraft Q4434-B), reducing design time. |
Use Scenario: Compact 3.3V supply for LoRaWAN node powered by 4×AA batteries (4.8V–6.4V range). IC Role / Device Role / Timing Role: Boost regulator extending battery life through fixed 100 kHz switching and low quiescent current (11 mA). Use Value: Maintains regulation down to 4V input, enabling full battery discharge utilization without external enable sequencing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar flyback/boost regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2587S-3.3 | Same electrical specs, but TO-263-5 (S package) with θJA = 26°C/W - superior thermal performance on large copper areas. | Preferred for high-power density PCBs where heatsink space is constrained and thermal management relies on board copper. | Select LM2587S-3.3 when board-level thermal resistance can be reduced below 35°C/W; LM2587T-3.3 remains optimal for vertical-mount, heatsink-equipped designs. |
| LM2577-3.3 | Lower 3A switch current, 50 kHz oscillator, no internal soft-start - smaller magnetics but slower transient response and higher peak currents. | Suitable for cost-sensitive, lower-power (<1A) applications where efficiency and EMI are less critical than BOM cost. | Choose LM2577-3.3 only if output current ≤0.8A and thermal budget allows higher losses; LM2587T-3.3 is required for 1.75A continuous flyback loads. |
Compared with LM2587S-3.3, the LM2587T-3.3 trades thermal efficiency for mechanical robustness and heatsink compatibility; versus LM2577-3.3, it delivers 67% higher switch current and 100% higher switching frequency-enabling smaller transformers and faster load-step recovery in demanding industrial systems.
Availability
LM2587T-3.3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, medical sensor interfaces, and IoT edge node designs requiring stable component supply with long lifecycle support.
Supply support for LM2587T-3.3 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 engineered specifically for cost-effective, low-component-count flyback, boost, and forward converter applications in industrial, automotive, and medical equipment-emphasizing reliability, thermal robustness, and ease of implementation.
FAQ
What is the maximum continuous output current supported by the LM2587T-3.3 in flyback configuration?
The LM2587T-3.3 supports up to 1.75A continuous output current in flyback mode under specified conditions (VIN = 4V–12V, TJ ≤125°C), as guaranteed by system-level output voltage tolerance testing. This assumes proper transformer selection (e.g., Coilcraft Q4434-B), adequate heatsinking, and adherence to the recommended layout guidelines in the TI datasheet SNVS115C.
Does the LM2587T-3.3 require external components to set the output voltage?
No, the LM2587T-3.3 has a factory-trimmed internal feedback network that fixes the output to 3.3V. Unlike the adjustable LM2587-ADJ version, it does not require external resistors R1/R2. The feedback pin (Pin 3) connects directly to the output via a small RC filter for noise immunity, per Figure 6 of the LM2587T-3.3 datasheet.
Can the LM2587T-3.3 be used in boost topology without risk of switch damage during output short-circuit?
No - in boost configuration, the LM2587T-3.3's internal current limit does not protect against output short-circuit because current bypasses the internal switch via the inductor and diode path. External current limiting (e.g., input current limiter or foldback circuit) is mandatory to prevent switch destruction. This limitation is explicitly documented in Note 2 of the Absolute Maximum Ratings section.
What is the purpose of the compensation pin (Pin 4) on the LM2587T-3.3, and what network is recommended?
The compensation pin (Pin 4) is the output of the internal error amplifier and must be connected to an RC network (e.g., 2 kΩ resistor + 0.47 μF capacitor to ground) to stabilize the control loop. This network sets dominant pole frequency and phase margin; omitting it causes instability and output oscillation. TI recommends this exact network in Figure 6 of the LM2587T-3.3 datasheet for 3.3V/5V versions.
How does the undervoltage lockout (UVLO) function in the LM2587T-3.3 affect system startup behavior?
The LM2587T-3.3 incorporates a 3.30V (typical) UVLO threshold with 0.7V hysteresis, meaning it starts switching only when input voltage rises above 3.30V and remains active until input drops below 2.6V. This prevents erratic operation during brownouts and ensures clean, monotonic startup - critical for systems powered from weak sources like batteries or unregulated wall adapters.
LM2587T-3.3 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:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- 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-3.3 FAQ
1.How can I place an order for LM2587T-3.3 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2587T-3.3 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-3.3 reliable?
The price and inventory of LM2587T-3.3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2587T-3.3 is usually 5 days.
3.What payment methods are accepted for LM2587T-3.3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2587T-3.3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2587T-3.3?
LM2587T-3.3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2587T-3.3 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-3.3?
For technical support, including LM2587T-3.3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2587T-3.3 requirements.
6.How does Aetrix verify that LM2587T-3.3 is sourced from the original manufacturer or authorized distributors?
All LM2587T-3.3 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-3.3 meets industry standards.
7.What is the process for return or replacement of LM2587T-3.3?
All LM2587T-3.3 units undergo pre-shipment inspection (PSI). If there is an issue with LM2587T-3.3, 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-3.3 part is unused and in its original packaging.
Return procedure for LM2587T-3.3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2587T-3.3 Tags
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