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Texas Instruments LM2597MX-12/NOPB
- Part No.:
- LM2597MX-12/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM2597MX-12/NOPB.pdf
- Description:
- IC REG BUCK 12V 500MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,875
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Product details
Overview
LM2597MX-12/NOPB from Texas Instruments is a monolithic 150-kHz nonsynchronous step-down (buck) DC-DC converter delivering 0.5-A output current with fixed 12-V output, ±4% output voltage tolerance over line/load/temperature, 4.5–40-V input voltage range, and integrated soft-start/shutdown/error flag functions - used in industrial power supplies and embedded system point-of-load regulation.
For engineers reviewing the LM2597MX-12/NOPB datasheet, LM2597MX-12/NOPB pinout, LM2597MX-12/NOPB application, or LM2597MX-12/NOPB equivalent, key selection criteria include its 12-V fixed output, SOIC-8 package compatibility, 85-μA standby current, bias supply (VBS) pin for efficiency optimization at high VIN/low VOUT, and error flag with programmable delay for microprocessor reset sequencing.
Technical Context
The LM2597MX-12/NOPB implements a fixed-frequency (150 kHz) current-mode control architecture with internal compensation, enabling stable operation with standard off-the-shelf inductors and minimal external components. Its nonsynchronous buck topology uses an internal NPN switch with 1.1-V typical saturation voltage at 0.5-A load.
It integrates supervisory features including a dedicated open-collector Error_Flag output activated when VOUT drops below 95% of nominal, a Delay pin for timing the flag assertion, and a Bias_Supply (VBS) pin that powers internal circuitry from VOUT instead of VIN - improving efficiency by up to 5% at high input voltages (e.g., 24 V → 12 V) and light loads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12 V ±4% over full line, load, and temperature range - ensures stable rail for logic, analog, or interface ICs without external feedback resistors. |
| Max Output Current | 0.5 A DC - supports moderate-power subsystems such as microcontroller cores, sensors, or communication interfaces. |
| Input Voltage Range | 4.5 V to 40 V - accommodates wide-input industrial, automotive (non-start-stop), and telecom power rails. |
| Switching Frequency | 150 kHz (±15%) - enables use of compact, low-cost 100–220 μH inductors and reduces EMI compared to lower-frequency alternatives. |
| Standby Quiescent Current | 85 μA typical - minimizes battery drain in always-on or low-power monitoring systems during shutdown mode. |
| Efficiency | 88% typical at VIN = 25 V, VOUT = 12 V, IOUT = 0.5 A - reduces thermal stress and eliminates need for heatsinks on PCB copper traces. |
| Oscillator Accuracy | ±15% over temperature - sufficient for non-critical timing applications where precise frequency stability is not required. |
Pinout & Package
LM2597MX-12/NOPB is housed in an 8-pin SOIC (D) package measuring 4.90 mm × 3.91 mm, optimized for surface-mount assembly and thermal performance (RθJA = 95°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Error_Flag) | Open-collector fault indicator | Asserts low when VOUT falls below 95% of 12 V; used for MCU reset or system fault signaling - requires external pull-up resistor. |
| 2 (Delay) | Capacitor-based timing node | Controls delay between VOUT reaching regulation and Error_Flag deassertion - sets power-good timing window for downstream logic. |
| 3 (Bias_Supply) | Internal circuit power source | Accepts VOUT (≥4 V) to reduce VIN current draw and improve efficiency - not usable with 3.3-V variants but fully supported for 12-V output. |
| 4 (Feedback) | Regulation reference input | Internally tied to 12-V divider - unused and left floating; no external resistor network required for fixed-output operation. |
| 5 (Shutdown/Soft-Start) | Dual-function control input | Pulled low disables switching (85-μA standby); capacitor added enables controlled VOUT ramp-up to limit inrush current. |
| 6 (Ground) | Power and signal reference | Main return path for internal switch, error amplifier, and oscillator - must connect to low-impedance PCB ground plane. |
| 7 (+VIN) | Main power input | Accepts 4.5–40 V DC; requires local 100-nF ceramic bypass capacitor to suppress switching transients. |
| 8 (Output) | Internal NPN switch collector | Switches between (VIN − VSAT) and ≈−0.5 V at 150 kHz; connects to catch diode anode and inductor - minimize trace area to reduce EMI. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 12-V output with ±4% tolerance | Eliminates external feedback resistors and calibration, reducing BOM count and layout complexity for dedicated 12-V rail generation. |
| Bias Supply (VBS) pin support | Enables powering internal circuitry from regulated 12-V output - cuts VIN supply current by ~4 mA and improves efficiency by 3–5% at VIN ≥ 24 V. |
| Integrated soft-start with external capacitor | Allows user-defined output voltage ramp rate (e.g., 10–100 ms) to prevent inrush current spikes into capacitive loads or downstream regulators. |
| Error_Flag with programmable delay | Provides synchronized power-good signal for microcontrollers or FPGAs - delay set via capacitor on Pin 2 avoids false resets during transient load steps. |
| Thermal shutdown + peak current limiting | Protects against sustained overload or ambient overheating - latches off until thermal recovery, preventing damage in enclosed or high-temp environments. |
Applications
| Industrial Power Supply | Embedded System Point-of-Load |
|---|---|
|
Use Scenario: Converting 24-V factory bus to stable 12-V rail for PLC I/O modules, motor drivers, or sensor signal conditioning circuits. IC Role / Device Role / Timing Role: Primary step-down regulator providing isolated, regulated 12-V supply with built-in fault signaling and thermal protection. Use Value: Eliminates need for discrete transistor/diode/inductor designs - achieves >85% efficiency at full load with only 4 external components (diode, inductor, input/output caps). |
Use Scenario: Generating clean 12-V supply for FPGA configuration, Ethernet PHYs, or USB hub controllers on compact embedded boards. IC Role / Device Role / Timing Role: Compact, SOIC-packaged buck controller delivering precise 12-V rail with soft-start to avoid brownout during boot sequence. Use Value: Soft-start limits inrush to <200 mA, preventing voltage droop on shared 24-V input; Error_Flag synchronizes FPGA configuration reset after power stabilization. |
| Positive-to-Negative Converter | Preregulator for Linear Regulators |
|
Use Scenario: Generating –12-V rail from +24-V input for op-amp dual-supply circuits or analog front-ends in test equipment. IC Role / Device Role / Timing Role: Inverting buck-derived topology using LM2597MX-12/NOPB's internal switch and ground-referenced feedback - configured per Figure 24 in datasheet. Use Value: Delivers up to 200 mA at –12 V with standard 100-μH inductor and Schottky diode - avoids cost/complexity of dedicated inverting controllers. |
Use Scenario: Reducing 36-V industrial input to 15-V intermediate rail before LDO regulation to 5-V/3.3-V for sensitive analog or RF sections. IC Role / Device Role / Timing Role: High-efficiency preregulator lowering power dissipation in downstream linear regulators - VBS pin further optimizes efficiency at high VIN. Use Value: Cuts total system heat by >60% vs. direct LDO conversion; 150-kHz switching allows small filter size while maintaining low noise for analog stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2597HVMX-12/NOPB | Supports 4.5–60-V input (vs. 4.5–40 V); identical 12-V output, pinout, and features. | Required for >40-V input applications (e.g., 48-V telecom, battery stacks); otherwise electrically interchangeable. | Select LM2597HVMX-12/NOPB if input may exceed 40 V; otherwise LM2597MX-12/NOPB offers same performance at lower cost. |
| LM2596-12 | Same 12-V fixed output, 0.5-A rating, and SOIC-8 package; 150-kHz frequency; lacks VBS pin and error flag/delay functionality. | Suitable for cost-sensitive, non-fault-tolerant applications; no power-good signaling or bias supply efficiency boost. | Choose LM2596-12 only when soft-start, error flag, or VBS-driven efficiency gains are unnecessary - fewer features, lower price. |
Compared with LM2597HVMX-12/NOPB, the LM2597MX-12/NOPB trades 20-V input headroom for cost savings in ≤40-V systems; versus LM2596-12, it adds critical reliability features (error flag, VBS, soft-start) without increasing board area or component count.
Availability
LM2597MX-12/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, embedded system point-of-load regulation, and positive-to-negative converter designs requiring stable component supply, long-term lifecycle support, and TI-qualified manufacturing traceability.
Supply support for LM2597MX-12/NOPB 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 technologies, with decades of expertise in high-reliability DC-DC conversion solutions.
The LM2597 series belongs to TI's SIMPLE SWITCHER® portfolio - designed specifically for ease-of-use in cost-sensitive, space-constrained industrial and embedded applications where minimal external components and robust protection features are essential.
FAQ
What is the maximum input voltage rating for LM2597MX-12/NOPB?
The LM2597MX-12/NOPB has a maximum input voltage rating of 40 V, as specified in the Absolute Maximum Ratings table. Operation above this voltage risks permanent damage. For applications requiring up to 60 V input, the pin-compatible LM2597HVMX-12/NOPB variant must be used instead. The LM2597MX-12/NOPB datasheet explicitly defines VIN(max) = 40 V under Recommended Operating Conditions.
Does LM2597MX-12/NOPB require external feedback resistors?
No, LM2597MX-12/NOPB does not require external feedback resistors because it is a fixed-output version with internal resistor divider set to 12 V. Pin 4 (Feedback) is internally connected and must be left unconnected (floating) in standard operation. Adding external resistors would disrupt regulation and is neither recommended nor supported per the datasheet's Fixed Output Voltage Versions schematic.
Can the Bias_Supply (VBS) pin be used with LM2597MX-12/NOPB?
Yes, the Bias_Supply (VBS) pin on LM2597MX-12/NOPB can be connected directly to the 12-V output to power internal circuitry, reducing VIN current draw and improving efficiency - especially beneficial at high input voltages (e.g., 24–40 V). The datasheet confirms VBS operation for all fixed-output versions except 3.3 V, and specifies minimum VBS voltage as 4 V, which is satisfied by the 12-V output.
What is the purpose of the Delay pin (Pin 2) on LM2597MX-12/NOPB?
The Delay pin (Pin 2) on LM2597MX-12/NOPB sets the time interval between when the output reaches 95% of 12 V and when the Error_Flag (Pin 1) transitions high - providing a programmable power-good assertion delay. A capacitor (typically 10–100 nF) from Pin 2 to ground determines this delay, enabling synchronization with downstream device startup sequences and avoiding false resets during transient conditions.
Is LM2597MX-12/NOPB RoHS-compliant and lead-free?
Yes, LM2597MX-12/NOPB is RoHS-compliant and lead-free, as indicated by the "/NOPB" suffix in the part number (TI's designation for "No Lead Plating – RoHS Compliant"). The device meets JEDEC J-STD-020 moisture sensitivity level 3 and is qualified for lead-free reflow soldering per IPC/JEDEC J-STD-020 standards, with peak reflow temperature up to 260°C.
LM2597MX-12/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 500mA
- Frequency - Switching:
- 150kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
LM2597MX-12/NOPB FAQ
1.How can I place an order for LM2597MX-12/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2597MX-12/NOPB 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 LM2597MX-12/NOPB reliable?
The price and inventory of LM2597MX-12/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2597MX-12/NOPB is usually 5 days.
3.What payment methods are accepted for LM2597MX-12/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2597MX-12/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2597MX-12/NOPB?
LM2597MX-12/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2597MX-12/NOPB 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 LM2597MX-12/NOPB?
For technical support, including LM2597MX-12/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2597MX-12/NOPB requirements.
6.How does Aetrix verify that LM2597MX-12/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2597MX-12/NOPB 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 LM2597MX-12/NOPB meets industry standards.
7.What is the process for return or replacement of LM2597MX-12/NOPB?
All LM2597MX-12/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2597MX-12/NOPB, 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 LM2597MX-12/NOPB part is unused and in its original packaging.
Return procedure for LM2597MX-12/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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