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Texas Instruments LM2597M-3.3/NOPB
- Part No.:
- LM2597M-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM2597M-3.3/NOPB.pdf
- Description:
- IC REG BUCK 3.3V 500MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:101
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Product details
Overview
LM2597M-3.3/NOPB from Texas Instruments is a monolithic nonsynchronous step-down DC-DC converter delivering 3.3 V at up to 0.5 A with ±4% output voltage tolerance, 150-kHz fixed-frequency operation, and input voltage support up to 40 V. It integrates internal frequency compensation, thermal shutdown, current limiting, and bias supply (VBS) functionality for improved efficiency at high VIN/low VOUT conditions - used in industrial power supplies and embedded system point-of-load regulation.
For engineers reviewing the LM2597M-3.3/NOPB datasheet, LM2597M-3.3/NOPB pinout, LM2597M-3.3/NOPB application, or LM2597M-3.3/NOPB equivalent, key selection criteria include its 8-pin SOIC package, 85 μA standby current, ±4% output accuracy over line/load/temperature, soft-start/shutdown control, and error flag with delay timing - all critical for reliable buck regulator design in space-constrained, thermally sensitive applications.
Technical Context
The LM2597M-3.3/NOPB implements a fixed-frequency (150 kHz) PWM controller with integrated N-channel MOSFET switch, internal compensation, and voltage-mode feedback using a precision 1.23 V reference. Its architecture supports both standard buck and inverting topologies, with dedicated pins for error flag assertion (open-collector), delay timing capacitor interface, and bias supply (VBS) to power internal circuitry from VOUT instead of VIN.
It features dual-stage current limiting (peak and foldback), thermal shutdown, and undervoltage lockout via external resistor divider on the Shutdown/Soft-Start pin. The 3.3 V fixed-output version eliminates external feedback resistors, simplifying layout while maintaining ±4% regulation across –40°C to +125°C and input voltages from 4.5 V to 40 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±4% over full line, load, and temperature range - ensures stable logic rail without external feedback components. |
| Max Output Current | 0.5 A DC - sufficient for powering microcontrollers, FPGAs, and peripheral ICs in compact systems. |
| Input Voltage Range | 4.5 V to 40 V - supports wide-input industrial and automotive battery-derived supplies. |
| Switching Frequency | 150 kHz (±15%) - enables use of low-cost, standard inductors and reduces EMI compared to lower-frequency alternatives. |
| Standby Quiescent Current | 85 μA typical - minimizes battery drain during system sleep modes. |
| Efficiency | 80% typical at 12 VIN, 0.5 A load - reduces thermal stress and PCB copper area required for heat sinking. |
| Thermal Resistance θJA | 95 °C/W (SOIC-8) - allows operation up to +125°C junction temperature with minimal heatsinking. |
Pinout & Package
LM2597M-3.3/NOPB is housed in an 8-pin SOIC package (4.90 mm × 3.91 mm body size) with standard surface-mount footprint and gull-wing leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Error Flag | Open-collector output | Asserts low when VOUT drops >5% below nominal; used for microprocessor reset or fault monitoring with external pull-up. |
| 2 - Delay | Capacitor connection node | Sets time delay between VOUT reaching 95% and Error Flag deassertion - prevents false resets during startup. |
| 3 - Bias Supply (VBS) | Power input for internal circuitry | Accepts regulated VOUT (≥3.5 V) to reduce VIN current and improve efficiency - not usable with 3.3 V output due to minimum voltage requirement. |
| 4 - Feedback | Regulation sense input | Internally tied to 3.3 V reference; no external resistor network needed for fixed-output version. |
| 5 - Shutdown/Soft-Start | Dual-function digital control | Pulled low → shutdown (85 μA IQ); capacitor added → controlled VOUT ramp-up and reduced inrush current. |
| 6 - Ground | Power and signal reference | Common return path for internal switch, control logic, and feedback - requires low-impedance PCB plane connection. |
| 7 - +VIN | Main power input | Accepts 4.5–40 V; requires local ceramic bypass capacitor to handle high di/dt switching currents. |
| 8 - Output | Internal switch drain | Drives external catch diode and inductor; voltage swings between (VIN − VSAT) and ≈−0.5 V - demands minimal PCB copper area to limit EMI coupling. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 0.5-A N-channel switch | Eliminates need for external MOSFET and gate driver - reduces BOM count and layout complexity. |
| 150-kHz fixed-frequency oscillator | Enables predictable EMI filtering and consistent inductor sizing - avoids variable-frequency jitter and loop stability issues. |
| Shutdown/Soft-Start pin | Single-pin control for both ultra-low-power disable mode and programmable output voltage ramp - simplifies system power sequencing. |
| Out-of-regulation error flag with delay | Provides reliable power-good signaling with user-adjustable hold-off time - prevents premature processor wake-up during transient recovery. |
| Thermal shutdown & current limiting | Two-stage protection (peak and foldback) plus junction temperature cutoff at 150°C - ensures robust operation under overload or poor heatsinking. |
Applications
| Industrial PLC Power Supply | Embedded Microcontroller Core Rail |
|---|---|
Use Scenario: Providing isolated 3.3 V power to I/O modules and communication interfaces in programmable logic controllers operating from 24 V DC field buses. IC Role / Device Role / Timing Role: Primary step-down regulator converting unregulated 24 V bus to clean, regulated 3.3 V for logic-level peripherals and RS-485 transceivers. Use Value: ±4% output accuracy ensures reliable digital interface operation; 85 μA standby current extends uptime during brownout events. | Use Scenario: Generating core voltage for ARM Cortex-M4 microcontrollers in portable test equipment with battery backup. IC Role / Device Role / Timing Role: Point-of-load buck converter supplying 3.3 V at ≤0.5 A with soft-start to prevent inrush-induced brownouts on shared battery rails. Use Value: Soft-start reduces peak input current from 700 mA to 160 mA - avoids triggering battery protection circuits during cold start. |
| Automotive Body Control Module | POS Terminal Power Management |
Use Scenario: Regulating 12 V vehicle battery to 3.3 V for CAN transceiver and sensor interface ICs in body electronics units. IC Role / Device Role / Timing Role: High-input-voltage buck regulator handling 12–16 V nominal battery range with surge tolerance up to 40 V. Use Value: 40 V absolute maximum input rating withstands load-dump transients; thermal shutdown protects against enclosure overheating. | Use Scenario: Powering 3.3 V logic and display drivers in retail point-of-sale terminals with AC/DC adapter and backup supercapacitor. IC Role / Device Role / Timing Role: Main DC-DC converter enabling seamless switchover between adapter and backup power sources. Use Value: Error flag output provides precise power-fail detection for controlled data save and graceful shutdown before backup depletion. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2596-3.3 | Same 3.3 V fixed output, but 150-kHz frequency and 3 A rating - larger die, higher quiescent current (5 mA vs 85 μA), no VBS pin. | Better suited for higher-current loads (>0.5 A); lacks bias supply feature for efficiency optimization at light loads. | Select LM2596-3.3 only if ≥1 A output capability is required; LM2597M-3.3/NOPB preferred for low-IQ, space-constrained designs. |
| TPS54302DDCR | 3.3 V adjustable via external resistors, 2.5–6 V input, 3 A output, 2.5 MHz switching - smaller inductors, but requires feedback network and has no error flag/delay pins. | Targets ultra-compact, high-efficiency designs with tight board area constraints; lacks supervisory features for system-level power sequencing. | Choose TPS54302DDCR for miniaturized, high-frequency applications where footprint matters more than fault signaling; LM2597M-3.3/NOPB retains full diagnostic capability in legacy-compatible layouts. |
Compared with LM2596-3.3 and TPS54302DDCR, LM2597M-3.3/NOPB uniquely balances low quiescent current (85 μA), integrated error flag with programmable delay, and 40 V input tolerance - making it optimal for industrial and automotive systems requiring reliability, diagnostics, and moderate power density without sacrificing simplicity.
Availability
LM2597M-3.3/NOPB is available at Aetrix Electronics and suitable for industrial PLC power supplies, embedded microcontroller core rails, automotive body control modules, and POS terminal power management requiring stable component supply and long-term lifecycle support.
Supply support for LM2597M-3.3/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 switching regulator design.
The LM2597 series was developed as part of TI's SIMPLE SWITCHER® portfolio to deliver easy-to-use, highly integrated buck regulators for cost-sensitive, space-constrained applications requiring robust performance without complex external compensation.
FAQ
What is the maximum input voltage rating for LM2597M-3.3/NOPB?
The LM2597M-3.3/NOPB has an absolute maximum input voltage rating of 45 V and a recommended maximum operating input voltage of 40 V. This makes it suitable for 24 V industrial systems and 12 V automotive applications with transient tolerance. Exceeding 40 V during normal operation risks violating recommended conditions, though brief transients up to 45 V are within absolute maximum limits per the datasheet.
Does LM2597M-3.3/NOPB require external feedback resistors?
No, LM2597M-3.3/NOPB does not require external feedback resistors because it is a fixed 3.3 V output version. The feedback pin (Pin 4) is internally connected to the 1.23 V reference and output divider network - eliminating component count and layout sensitivity associated with adjustable regulators. This simplifies design and improves long-term stability.
Can the bias supply (VBS) pin be used with LM2597M-3.3/NOPB?
No, the bias supply (VBS) pin cannot be used with LM2597M-3.3/NOPB because the VBS feature requires a minimum of approximately 3.5 V at room temperature (4 V at –40°C) to power internal circuitry, and the 3.3 V output falls below this threshold. When VBS is left open, the device operates normally using VIN to power internal logic - confirmed in TI's datasheet Section 8.3.1.
What is the purpose of the Delay pin on LM2597M-3.3/NOPB?
On LM2597M-3.3/NOPB, the Delay pin (Pin 2) sets the time interval between when the output voltage reaches 95% of nominal (3.135 V) and when the Error Flag pin transitions high - preventing premature system wake-up during startup. A capacitor connected between this pin and ground determines the delay duration, enabling customizable power-good assertion timing for microprocessor reset sequencing.
How does the Shutdown/Soft-Start pin function on LM2597M-3.3/NOPB?
The Shutdown/Soft-Start pin (Pin 5) on LM2597M-3.3/NOPB serves two roles: pulling it low disables switching and reduces quiescent current to 85 μA (shutdown mode), while connecting a capacitor enables controlled output voltage ramp-up (soft-start mode). This dual functionality simplifies power sequencing and reduces inrush current - verified by TI's Figure 21 and Section 8.3.2.
LM2597M-3.3/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- 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):
- 3.3V
- 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
LM2597M-3.3/NOPB FAQ
1.How can I place an order for LM2597M-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2597M-3.3/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 LM2597M-3.3/NOPB reliable?
The price and inventory of LM2597M-3.3/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2597M-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LM2597M-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2597M-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2597M-3.3/NOPB?
LM2597M-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2597M-3.3/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 LM2597M-3.3/NOPB?
For technical support, including LM2597M-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2597M-3.3/NOPB requirements.
6.How does Aetrix verify that LM2597M-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2597M-3.3/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 LM2597M-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LM2597M-3.3/NOPB?
All LM2597M-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2597M-3.3/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 LM2597M-3.3/NOPB part is unused and in its original packaging.
Return procedure for LM2597M-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2597M-3.3/NOPB Tags
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