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Texas Instruments LM2596SX-12
- Part No.:
- LM2596SX-12
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LM2596SX-12.pdf
- Description:
- IC REG BUCK 12V 3A TO263
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LM2596SX-12 from Texas Instruments is a monolithic 150-kHz nonsynchronous buck DC-DC converter delivering up to 3 A output current with fixed 12-V output, ±4% output voltage tolerance over line and load, input voltage range up to 40 V, and integrated thermal shutdown and current-limit protection - used in industrial power supplies and embedded system rails.
For engineers reviewing the LM2596SX-12 datasheet, LM2596SX-12 pinout, LM2596SX-12 application, or LM2596SX-12 equivalent, key selection criteria include fixed 12-V output accuracy, TO-263-5 (KTT) surface-mount package compatibility, 150-kHz switching frequency for compact filter design, and TTL-compatible ON/OFF control with 80-μA standby current.
Technical Context
The LM2596SX-12 implements a fixed-frequency (150 kHz) current-mode PWM control architecture with internal compensation, enabling stable regulation using only four external components. Its nonsynchronous topology uses an internal NPN power switch and requires an external catch diode.
Operation includes TTL-compatible ON/OFF pin control (1.3-V threshold), two-stage current limiting (peak limit ~4.5 A at 25°C), and thermal shutdown at ~150°C junction temperature. Feedback is taken directly from the output via the internal 1.23-V reference and resistive divider network.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V ±4% over full line/load/temperature range - ensures stable rail for microcontrollers and analog circuitry without external feedback resistors. |
| Max Output Current | 3 A DC continuous - supports mid-power applications such as motor drivers and display backlights without external current boosting. |
| Input Voltage Range | 4.5 V to 40 V - accommodates wide-input industrial supplies, automotive battery variations (12 V nominal), and unregulated AC/DC adapters. |
| Switching Frequency | 150 kHz ±15% - enables use of low-cost, high-saturation-current inductors (e.g., 47–100 μH) and reduces EMI compared to higher-frequency alternatives. |
| Quiescent Current | 80 μA in shutdown (ISTBY) - minimizes standby power loss in battery-backed or energy-sensitive systems. |
| Thermal Protection | Internal junction temperature shutdown at ~150°C - prevents catastrophic failure during overload or poor heatsinking conditions. |
| Efficiency | 90% typical at VIN = 25 V, IOUT = 3 A - reduces thermal load and improves power density in enclosed enclosures. |
Pinout & Package
LM2596SX-12 is housed in a 5-pin TO-263 (KTT) surface-mount package with exposed thermal pad (10.10 mm × 8.89 mm body size), optimized for PCB heat dissipation via tab soldering to copper area.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Positive input supply | Accepts 4.5–40 V DC; requires local 100-μF low-ESR input capacitor to handle high di/dt switching currents and suppress transients. |
| 2 - OUTPUT | Internal switch node | Drives external catch diode and LC filter; voltage swings between ~VIN–1.4 V (ON) and ~–0.5 V (OFF); minimal PCB copper area required to reduce EMI coupling. |
| 3 - GND | Circuit ground reference | Common return for internal logic, feedback, and power stage; must be connected to low-impedance ground plane adjacent to thermal pad. |
| 4 - FEEDBACK | Voltage sense input | Internally referenced to 1.23 V; unused in fixed-output version - left open or grounded per datasheet guidance for stability. |
| 5 - ON/OFF | Logic-controlled enable | TTL-compatible shutdown: <1.3 V = ON, >1.3 V = OFF; draws ≤200 μA in shutdown; can be tied to GND for always-on operation. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12-V output | Eliminates external feedback resistor network, reducing BOM count and layout sensitivity while guaranteeing ±4% regulation across –40°C to +125°C. |
| TO-263-5 thermal package | Exposed tab enables direct thermal conduction to PCB copper; achieves RθJA ≈ 20°C/W with 3 in² double-sided 1-oz copper - suitable for convection-cooled industrial designs. |
| 150-kHz fixed oscillator | Enables use of standard off-the-shelf shielded power inductors (e.g., 47–100 μH, 4–5 A saturation) without custom magnetics or EMI filtering complexity. |
| TTL shutdown with 80-μA IQ | Allows clean system-level power sequencing and ultra-low standby consumption - critical for remote sensors and battery-buffered controllers. |
| Integrated protection | Combines peak current limiting (~4.5 A) and thermal shutdown to prevent damage during short-circuit, startup surge, or inadequate heatsinking - no external fault management needed. |
Applications
| Industrial Power Supply | Embedded Control Rail |
|---|---|
Use Scenario: Providing regulated 12-V DC for PLC I/O modules operating from 24-V industrial bus with transient surges and wide ambient temperature range. IC Role / Device Role / Timing Role: Primary step-down regulator converting unregulated 24-V bus to stable 12-V rail for digital logic, analog sensors, and relay drivers. Use Value: Delivers 3-A continuous current with ±4% output accuracy and thermal shutdown - maintains functional safety during sustained overloads without external supervision. | Use Scenario: Generating 12-V bias for FPGA configuration circuitry and peripheral interfaces in edge-computing gateways with strict power-up sequencing. IC Role / Device Role / Timing Role: Fixed-output buck converter supplying auxiliary rail; enabled via system controller through ON/OFF pin for controlled power sequencing. Use Value: 80-μA shutdown current and TTL-compatible enable allow precise coordination with host processor reset timing - avoids brown-out during boot. |
| Automotive Aftermarket Display | Home Theater Amplifier Bias |
Use Scenario: Converting vehicle battery (9–16 V) to stable 12-V for LCD backlight driver and MCU in dashboard infotainment displays. IC Role / Device Role / Timing Role: Input-transient-tolerant buck regulator handling cold-crank (6.5 V) and load-dump (40 V) events per ISO 7637-2. Use Value: 40-V absolute max input rating and internal current limiting protect against automotive transients - eliminates need for upstream TVS or active clamping. | Use Scenario: Delivering clean 12-V bias to op-amp stages and audio DACs in multi-channel AV receivers where ripple and noise affect dynamic range. IC Role / Device Role / Timing Role: Secondary regulation stage following bulk 15-V supply; filters switching noise via LC output filter and low-ESR capacitors. Use Value: 150-kHz switching allows effective post-filtering with small ferrite beads and ceramic caps - achieves <5-mVpp output ripple at full load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2596T-12 | TO-220-5 (NDH) through-hole package; identical electrical specs and pinout; higher RθJA (50°C/W) without heatsink. | Suitable for prototyping, low-volume assemblies, or legacy through-hole boards - not recommended for high-density SMT production. | Select LM2596T-12 only when manual assembly or socket-based testing is required; LM2596SX-12 preferred for automated SMT and thermal performance. |
| MP1584EN-LF-Z | 40-V input, 3-A synchronous buck; 1.5-MHz switching; smaller solution size; no external diode needed; different pinout and control interface. | Better suited for space-constrained designs requiring higher efficiency at light loads and lower output ripple - but requires full schematic/layout redesign. | Choose MP1584EN-LF-Z only when board re-spin is acceptable and 1.5-MHz operation aligns with system EMI requirements; not drop-in compatible. |
Compared with LM2596T-12, LM2596SX-12 offers superior thermal performance in SMT layouts; compared with MP1584EN-LF-Z, it provides proven reliability and simpler external component count at the cost of larger magnetics and lower light-load efficiency.
Availability
LM2596SX-12 is available at Aetrix Electronics and suitable for industrial power supplies, embedded control rails, and automotive aftermarket electronics requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2596SX-12 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 ICs, with decades of expertise in high-reliability power conversion solutions.
The LM2596 series belongs to TI's SIMPLE SWITCHER® portfolio - designed specifically for cost-sensitive, robust DC-DC conversion in industrial, automotive, and consumer applications where ease of use and minimal external components are critical.
FAQ
What is the maximum input voltage rating for LM2596SX-12?
The LM2596SX-12 has an absolute maximum input voltage rating of 45 V, with recommended operating range from 4.5 V to 40 V. Exceeding 40 V continuously risks exceeding internal transistor breakdown limits and triggering thermal shutdown. The device is commonly used in automotive environments where load-dump transients reach 40 V, and its robust design tolerates these events without latch-up or degradation when properly decoupled.
Does LM2596SX-12 require external feedback resistors?
No, LM2596SX-12 does not require external feedback resistors. As a fixed 12-V output variant, the feedback divider is fully internalized. Pin 4 (FEEDBACK) is unused and should be left open or grounded per TI's datasheet guidance to ensure loop stability and avoid noise injection. This simplifies layout and eliminates resistor tolerance errors affecting output accuracy.
What package type is used by LM2596SX-12?
LM2596SX-12 uses the TO-263-5 (KTT) surface-mount package with an exposed thermal pad measuring 10.10 mm × 8.89 mm. This thermally enhanced package requires soldering the tab to a minimum 2.5 in² single-sided or 3 in² double-sided 1-oz copper area on the PCB to achieve optimal thermal resistance (RθJA ≈ 20–30°C/W). It is not pin-compatible with the through-hole LM2596T-12 variant.
Can LM2596SX-12 be synchronized to an external clock?
No, LM2596SX-12 cannot be synchronized to an external clock. It features a fixed internal 150-kHz oscillator with ±15% tolerance and no synchronization input pin. Frequency adjustment or phase-locking is not supported. For synchronizable alternatives, consider TI's LM5115 or MPQ4312, which provide SYNC pins for EMI reduction in multi-rail systems.
What protection features are built into LM2596SX-12?
LM2596SX-12 integrates thermal shutdown (triggering at ~150°C junction temperature) and two-stage current limiting (peak limit ~4.5 A at 25°C). It also includes under-voltage lockout (UVLO) that disables operation below ~3.5 V input. These protections operate autonomously without external components, safeguarding the IC and downstream circuitry during overload, short-circuit, or overheating conditions - eliminating need for discrete fault monitoring circuits.
LM2596SX-12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 12V
- Voltage - Output (Max):
- -
- Current - Output:
- 3A
- Frequency - Switching:
- 150kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263 (DDPAK-5)
LM2596SX-12 FAQ
1.How can I place an order for LM2596SX-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2596SX-12 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 LM2596SX-12 reliable?
The price and inventory of LM2596SX-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2596SX-12 is usually 5 days.
3.What payment methods are accepted for LM2596SX-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2596SX-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2596SX-12?
LM2596SX-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2596SX-12 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 LM2596SX-12?
For technical support, including LM2596SX-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2596SX-12 requirements.
6.How does Aetrix verify that LM2596SX-12 is sourced from the original manufacturer or authorized distributors?
All LM2596SX-12 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 LM2596SX-12 meets industry standards.
7.What is the process for return or replacement of LM2596SX-12?
All LM2596SX-12 units undergo pre-shipment inspection (PSI). If there is an issue with LM2596SX-12, 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 LM2596SX-12 part is unused and in its original packaging.
Return procedure for LM2596SX-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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