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Texas Instruments LM2597MX-3.3/NOPB
- Part No.:
- LM2597MX-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM2597MX-3.3/NOPB.pdf
- Description:
- IC REG BUCK 3.3V 500MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,982
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Product details
Overview
LM2597MX-3.3/NOPB from Texas Instruments is a monolithic 150-kHz nonsynchronous step-down (buck) DC-DC converter delivering 0.5-A output current with fixed 3.3-V output, ±4% output voltage tolerance over line/load/temperature, 4.5–40-V input range, and integrated soft-start/shutdown control - used in industrial power supplies and embedded system point-of-load regulation.
For engineers reviewing the LM2597MX-3.3/NOPB datasheet, LM2597MX-3.3/NOPB pinout, LM2597MX-3.3/NOPB application, or LM2597MX-3.3/NOPB equivalent, key selection criteria include its 3.3-V fixed output accuracy, 85-μA standby quiescent current, SOIC-8 package thermal performance (RθJA = 95°C/W), and bias supply (VBS) pin capability for efficiency optimization at high input voltages.
Technical Context
The LM2597MX-3.3/NOPB implements a fixed-frequency (150 kHz) current-mode buck topology with internal oscillator, two-stage current limiting, and thermal shutdown. Its feedback loop uses a precision 1.23-V reference and senses output via dedicated FB pin, enabling stable regulation across 4.5–40 V input and –40°C to +125°C ambient.
It integrates dual-function Shutdown/Soft-Start (SD/SS) pin for logic-level enable/disable and controlled output ramp-up via external capacitor, plus open-collector Error_Flag with 5% dropout detection and programmable delay via external capacitor on Delay pin - all coordinated without external compensation components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±4% over full line/load/temperature range - ensures reliable microcontroller core rail compliance. |
| Max Output Current | 0.5 A DC - supports moderate-power digital loads without external current boosting. |
| Input Voltage Range | 4.5 V to 40 V - accommodates 5-V, 12-V, 24-V, and 36-V industrial bus inputs. |
| Switching Frequency | 150 kHz (±15%) - enables use of low-cost, standard off-the-shelf inductors and reduces EMI filtering burden. |
| Standby Quiescent Current | 85 μA typical - minimizes battery drain in always-on systems during sleep mode. |
| Efficiency | 80% typical at 12-VIN/3.3-VOUT/0.5-A - reduces thermal load and eliminates need for heatsinks on PCB copper traces. |
| Oscillator Accuracy | ±15% over temperature - sufficient for non-critical timing applications where precise frequency isn't required. |
Pinout & Package
LM2597MX-3.3/NOPB is housed in an 8-pin SOIC (D package), 4.90 mm × 3.91 mm body size, with exposed pad not present - compatible with standard surface-mount reflow profiles and manual soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Error_Flag | Open-collector fault indicator | Asserts low when output drops >5% below 3.3 V; used as microprocessor reset signal after delay. |
| 2 - Delay | Capacitor-programmable flag delay | Controls time between VOUT reaching 95% and Error_Flag going high - prevents false resets during startup. |
| 3 - Bias_Supply (VBS) | Internal circuitry power source | Accepts regulated 3.3-V output (not applicable here - requires ≥4 V; thus left open per datasheet guidance). |
| 4 - Feedback (FB) | Voltage sense input | Internally referenced to 1.23 V; unused in fixed-output version but must be connected to GND per datasheet. |
| 5 - Shutdown/Soft-Start (SD/SS) | Enable and ramp control | Pull low to shut down (IQ ≈ 85 μA); add capacitor for soft-start - limits inrush current to ~160 mA. |
| 6 - Ground (GND) | Power and signal reference | Common return for internal switch, control logic, and external components - requires low-impedance PCB plane. |
| 7 - +VIN | Main power input | Accepts 4.5–40 V; requires local 100-nF ceramic bypass capacitor to suppress switching transients. |
| 8 - Output (SW) | Internal NPN switch collector | Drives external catch diode and inductor; swings between (VIN − VSAT) and ~−0.5 V - minimize trace area to reduce EMI. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Soft-Start | Reduces peak inrush current from 700 mA to 160 mA using external capacitor - protects input source and avoids brownouts. |
| Out-of-Regulation Flag with Delay | Provides clean, debounced reset signal to microcontrollers after configurable delay - eliminates need for external supervisor IC. |
| Thermal Shutdown & Two-Stage Current Limit | Prevents damage under overload or high ambient; first stage limits peak switch current to 0.8 A, second stage reduces fSW under severe overload. |
| Low Standby IQ (85 μA) | Enables battery-backed operation for >1 year in low-duty-cycle IoT sensors - measured with SD/SS pin grounded. |
| Fixed-Frequency Operation | 150-kHz switching simplifies EMI filter design and allows use of compact, low-DCR shielded inductors (e.g., 68–100 μH). |
Applications
| Industrial PLC I/O Power | Embedded Microcontroller Core Rail |
|---|---|
Use Scenario: Providing isolated 3.3-V supply for digital I/O modules in programmable logic controllers operating from 24-V DC field bus. IC Role / Device Role / Timing Role: Primary step-down regulator converting 24-V bus to stable 3.3-V logic rail with fault reporting via Error_Flag. Use Value: ±4% output tolerance ensures reliable FPGA and MCU operation; 85-μA standby current extends backup battery life during mains failure. |
Use Scenario: Generating core voltage for ARM Cortex-M4 microcontrollers in portable medical devices powered by Li-ion batteries. IC Role / Device Role / Timing Role: Buck converter supplying 3.3-V core rail with soft-start to prevent processor lockup during cold boot. Use Value: Soft-start limits inrush to 160 mA - avoids triggering battery protection circuitry; 150-kHz fSW enables small 68-μH inductor footprint. |
| Automotive Body Control Module | Point-of-Load for FPGA Peripherals |
Use Scenario: Regulating 3.3-V supply for CAN transceivers and EEPROM in automotive BCMs fed from 12-V battery (with load dump protection). IC Role / Device Role / Timing Role: Pre-regulator stepping down 12-V nominal (up to 40-V transient) to 3.3-V for noise-sensitive analog/digital interfaces. Use Value: 40-V absolute max input rating withstands ISO 7637-2 pulse 5a; Error_Flag provides diagnostics for CAN bus fault isolation. |
Use Scenario: Local 3.3-V supply for FPGA configuration memory, ADC drivers, and level-shifters in test equipment with multi-rail power architecture. IC Role / Device Role / Timing Role: Secondary buck regulator delivering low-noise 3.3-V rail adjacent to FPGA BGA package. Use Value: Fixed 3.3-V output eliminates external resistor divider; SOIC-8 package allows placement near FPGA for minimal trace inductance. |
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 | Lower max input (40 V same), but lower switching frequency (150 kHz vs. LM2596's 150 kHz - identical), higher dropout (1.5 V vs. LM2597's 1.2 V), no VBS pin. | Lacks bias supply pin and error flag delay - requires external reset IC for supervised startup. | Choose LM2596-3.3 only if cost sensitivity outweighs need for integrated fault signaling and soft-start flexibility. |
| TPS54302DDCR | Higher efficiency (92% vs. 80%), smaller 6-pin SOT-23 package, 2.5–18-V input, but no integrated error flag or delay function. | Requires external supervisor for reset generation; unsuitable for >18-V input or 40-V transient environments. | Select TPS54302DDCR for space-constrained, high-efficiency 12-V bus apps where fault signaling is handled elsewhere. |
Compared with LM2596-3.3 and TPS54302DDCR, LM2597MX-3.3/NOPB uniquely combines 40-V input tolerance, integrated error flag with programmable delay, and soft-start - making it optimal for industrial and automotive pre-regulator roles where reliability and diagnostic capability are prioritized over minimal footprint or peak efficiency.
Availability
LM2597MX-3.3/NOPB is available at Aetrix Electronics and suitable for industrial PLC power supplies, embedded microcontroller core rails, and automotive body control modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM2597MX-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, serving industrial, automotive, and communications markets since 1930.
The LM2597MX-3.3/NOPB belongs to TI's SIMPLE SWITCHER® family - designed specifically for robust, easy-to-implement DC-DC conversion in harsh environments where reliability, wide input range, and integrated supervision features are critical.
FAQ
What is the maximum input voltage rating for LM2597MX-3.3/NOPB?
The LM2597MX-3.3/NOPB has a maximum input voltage rating of 40 V, with recommended operating range from 4.5 V to 40 V. This makes it suitable for 24-V industrial buses and automotive 12-V systems with load dump transients. Exceeding 40 V risks permanent damage per Absolute Maximum Ratings table in the datasheet.
Can the LM2597MX-3.3/NOPB be used in an inverting (positive-to-negative) configuration?
Yes, the LM2597MX-3.3/NOPB can be configured as a positive-to-negative converter by bootstrapping its ground pin to the negative output. The datasheet confirms this topology in Figure 24, though output current capability depends on input/output voltage ratio and must keep total regulator voltage ≤40 V. Note that the fixed 3.3-V version produces –3.3 V in this mode.
Is the Bias Supply (VBS) pin usable with the LM2597MX-3.3/NOPB?
No - the VBS pin requires a minimum of ~4 V to operate, as specified in Section 8.3.1. Since the LM2597MX-3.3/NOPB delivers only 3.3 V output, the VBS pin cannot be connected to VOUT and must be left open. Internal circuitry is then powered from VIN, per datasheet guidance.
What is the purpose of the Delay pin on LM2597MX-3.3/NOPB?
The Delay pin on LM2597MX-3.3/NOPB accepts an external capacitor to set the time interval between when VOUT reaches 95% of 3.3 V and when the Error_Flag pin transitions high. This prevents premature system reset during startup and is essential for reliable microprocessor power sequencing in LM2597MX-3.3/NOPB-based designs.
Does LM2597MX-3.3/NOPB require external compensation components?
No - the LM2597MX-3.3/NOPB includes internal frequency compensation and requires no external compensation network. Its fixed-frequency current-mode architecture and optimized internal loop ensure stability with standard external components (inductor, catch diode, input/output capacitors), as validated in the Typical Application circuits of the datasheet.
LM2597MX-3.3/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):
- 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
LM2597MX-3.3/NOPB FAQ
1.How can I place an order for LM2597MX-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2597MX-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 LM2597MX-3.3/NOPB reliable?
The price and inventory of LM2597MX-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 LM2597MX-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LM2597MX-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2597MX-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2597MX-3.3/NOPB?
LM2597MX-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2597MX-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 LM2597MX-3.3/NOPB?
For technical support, including LM2597MX-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2597MX-3.3/NOPB requirements.
6.How does Aetrix verify that LM2597MX-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2597MX-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 LM2597MX-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LM2597MX-3.3/NOPB?
All LM2597MX-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2597MX-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 LM2597MX-3.3/NOPB part is unused and in its original packaging.
Return procedure for LM2597MX-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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