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Texas Instruments LM2598T-3.3/NOPB
- Part No.:
- LM2598T-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-7 Formed Leads
- Datasheet:
-
LM2598T-3.3/NOPB.pdf
- Description:
- IC REG BUCK 3.3V 1A TO220-7
- Quantity:
- Payment:
- Shipping:
Inventory:172
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Product details
Overview
LM2598T-3.3/NOPB from Texas Instruments is a monolithic 1-A nonsynchronous step-down (buck) DC-DC switching regulator with fixed 3.3-V output, 150-kHz internal oscillator, 4.5–40-V input range, and integrated thermal shutdown/current limit protection. It delivers ±4% output voltage accuracy over line and load, supports soft-start/shutdown control, and is used in embedded power supplies for microcontrollers and FPGAs.
For engineers reviewing the LM2598T-3.3/NOPB datasheet, LM2598T-3.3/NOPB pinout, LM2598T-3.3/NOPB application, or LM2598T-3.3/NOPB equivalent, key selection criteria include output current capability, input voltage headroom, thermal performance in TO-220 packaging, and compatibility with standard off-the-shelf inductors and catch diodes.
Technical Context
The LM2598T-3.3/NOPB implements a fixed-frequency, pulse-width modulation (PWM) buck topology with internal 150-kHz oscillator and nonsynchronous rectification using an external catch diode. Its feedback loop regulates output via a precision 1.23-V reference and resistor divider connected to the Feedback pin.
It integrates dual-function Shutdown/Soft-start control (logic-level enable + RC-controlled ramp), open-collector Error Flag with 5% dropout detection and programmable delay, and two-stage current limiting with thermal shutdown-enabling robust operation across industrial temperature ranges without external protection circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±4% over full line/load/temperature range - ensures stable core logic supply for 3.3-V digital ICs. |
| Max Output Current | 1 A DC - supports single-rail power for mid-power microcontrollers, sensors, and interface ICs. |
| Input Voltage Range | 4.5 V to 40 V - accommodates 5-V, 12-V, 24-V, and 36-V industrial bus inputs with margin. |
| Switching Frequency | 150 kHz (±15%) - enables use of compact, low-cost through-hole or surface-mount inductors (e.g., 68–100 µH). |
| Efficiency | 78% at VIN = 12 V, IOUT = 1 A - reduces thermal load vs. linear regulators in medium-power applications. |
| Quiescent Current | 85 µA in shutdown - minimizes standby power in battery-backed or energy-conscious systems. |
| Thermal Protection | Internal thermal shutdown at TJ ≥ 150°C - prevents damage during overload or poor heatsinking. |
Pinout & Package
LM2598T-3.3/NOPB is supplied in a 7-pin TO-220 (NDZ) package with vertical lead bend, 14.986 mm × 10.16 mm body size, and electrically isolated tab (connected to Pin 4 Ground). Thermal resistance RθJA is 50°C/W with no heatsink on standard PCB layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (OUT) | Switch Node | Drives external catch diode and inductor; swings between ~VIN–1.2 V and –0.5 V - requires minimal copper area to reduce EMI. |
| 2 (+VIN) | Power Input | Accepts 4.5–40 V DC; requires local 100-µF low-ESR input capacitor to handle high di/dt switching currents. |
| 3 (FLAG) | Error Flag Output | Open-collector signal pulled low when VOUT drops >5%; used for µP reset or system fault indication. |
| 4 (GND) | Ground Reference | Common return for power, feedback, and control circuits; tab is electrically tied to this pin. |
| 5 (DELAY) | Flag Delay Control | RC-timed delay between VOUT reaching 95% and FLAG going high - prevents false resets during startup. |
| 6 (FB) | Feedback Input | Monitors output via resistor divider; not used in fixed 3.3-V version (internally connected to reference). |
| 7 (SD/SS) | Shutdown/Soft-start | Logic-low disables regulator (IQ ≈ 85 µA); capacitor adds controlled VOUT ramp to limit inrush current. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3-V Output | Eliminates external feedback resistors - simplifies design, improves production consistency, and reduces BOM count. |
| Integrated Soft-start | Reduces peak input current at startup by controlling output voltage slew rate - avoids tripping upstream current limits or brownouts. |
| Out-of-Regulation Flag | Provides system-level fault signaling with built-in 5% tolerance and programmable delay - enables reliable power sequencing in multi-rail systems. |
| Thermal & Current Limit Protection | Self-contained safety features prevent destruction under short-circuit, overload, or inadequate heatsinking - no external sensing components required. |
| Standard Inductor Compatibility | Optimized for widely available 68–100 µH, 1.5-A+ saturation current inductors - accelerates design and procurement. |
Applications
| Industrial PLC I/O Module Power | Automotive Body Control Unit (BCU) |
|---|---|
Use Scenario: Powers 3.3-V CAN transceivers, GPIO expanders, and ADCs in DIN-rail mounted PLC modules operating from 24-V DC bus. IC Role / Device Role / Timing Role: Primary step-down regulator converting 24-V rail to clean, regulated 3.3-V supply with fault flagging for diagnostics. Use Value: Delivers 1-A continuous current with 78% efficiency and thermal shutdown - eliminates need for heatsink below 50°C ambient. | Use Scenario: Supplies 3.3-V logic rails for microcontrollers and LIN transceivers in automotive door modules powered from 12-V battery (with load dump protection). IC Role / Device Role / Timing Role: Nonsynchronous buck converter providing isolated, regulated 3.3-V output with shutdown control synchronized to vehicle ignition state. Use Value: Withstands 40-V max input and operates down to –25°C - meets automotive cold-crank and transient requirements without derating. |
| Medical Point-of-Care Device | Test & Measurement Instrumentation |
Use Scenario: Generates 3.3-V supply for ARM-based patient monitor processors and analog front-end ICs from a 12-V wall adapter. IC Role / Device Role / Timing Role: Main DC-DC converter enabling low-noise, stable power with soft-start to avoid disrupting sensitive analog measurements during power-up. Use Value: 85-µA shutdown current and ±4% output accuracy support battery backup and regulatory compliance (IEC 60601-1). | Use Scenario: Powers FPGA configuration memory, ADC drivers, and serial interface ICs in portable multimeters and oscilloscope front-ends. IC Role / Device Role / Timing Role: Compact, self-contained buck regulator delivering precise 3.3-V rail with error flag for system health monitoring. Use Value: TO-220 package allows direct mounting to metal chassis for passive cooling - avoids fan noise and improves EMC in precision instruments. |
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-3.3/NOPB | Same family, 150-kHz frequency, but lower 3-A current rating and different pinout (6-pin TO-220); no Delay pin. | Higher current capacity suits larger loads; lacks programmable flag delay - less suitable for precise power sequencing. | Select when >1-A output is needed and flag timing flexibility is not required. |
| TPS5430DDAR | 3-A synchronous buck with 500-kHz switching, integrated high-side MOSFET, and smaller 8-pin SO PowerPAD package. | Higher efficiency (≥88%), reduced external component count, but requires careful layout for thermal management. | Select for space-constrained designs needing higher efficiency and no external diode. |
Compared with LM2596T-3.3/NOPB, LM2598T-3.3/NOPB offers dedicated flag delay control and optimized thermal behavior in 7-pin TO-220; versus TPS5430DDAR, it trades synchronous efficiency and integration for simplicity, cost, and proven reliability in legacy industrial systems.
Availability
LM2598T-3.3/NOPB is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical device applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing from authorized channels.
Supply support for LM2598T-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 experience in high-reliability power conversion ICs.
The LM2598 series belongs to TI's SIMPLE SWITCHER® portfolio - designed specifically for ease-of-use, minimal external component count, and robust operation in industrial, automotive, and medical power supply applications.
FAQ
What is the maximum input voltage rating for the LM2598T-3.3/NOPB?
The LM2598T-3.3/NOPB 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 thermal limits or triggering internal protection; operation at 40 V is validated for full temperature range per datasheet Section 7.3.
Does the LM2598T-3.3/NOPB require an external catch diode, and what type is recommended?
Yes, the LM2598T-3.3/NOPB requires an external catch diode due to its nonsynchronous buck architecture. A Schottky diode rated for ≥1.5 A average current and ≥45 V PIV (e.g., SB540, MBR1545CT) is recommended to minimize conduction loss and improve efficiency - especially critical at low output voltages like 3.3 V.
Can the LM2598T-3.3/NOPB be used in a negative-output inverting configuration?
Yes, the LM2598T-3.3/NOPB can be configured as an inverting regulator to generate –3.3 V from a positive input, as documented in TI's LM2598 datasheet Figure 21. This requires re-referencing GND and FB pins, adding an isolation diode, and selecting appropriate inductor/capacitor values - but the 3.3-V fixed version remains valid for this topology.
What is the purpose of the DELAY pin on the LM2598T-3.3/NOPB, and how is it implemented?
On the LM2598T-3.3/NOPB, the DELAY pin sets the time interval between when VOUT reaches 95% of nominal and when the open-collector FLAG pin transitions high. It is implemented by connecting a capacitor (typically 0.1–1 µF) from DELAY to GND; the delay time is proportional to capacitance and internal current source (~3–6 µA).
Is a heatsink required for the LM2598T-3.3/NOPB operating at 1 A output current?
A heatsink is typically not required for the LM2598T-3.3/NOPB at 1 A if ambient temperature stays below 50°C and PCB copper area around the tab is ≥1 in². At higher loads or temperatures, thermal performance must be verified using RθJA = 50°C/W (TO-220, no heatsink) and junction temperature limits (TJ ≤ 150°C) per datasheet Section 7.4.
LM2598T-3.3/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-220-7 Formed Leads
- 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:
- 1A
- Frequency - Switching:
- 150kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-7
LM2598T-3.3/NOPB FAQ
1.How can I place an order for LM2598T-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2598T-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 LM2598T-3.3/NOPB reliable?
The price and inventory of LM2598T-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 LM2598T-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LM2598T-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2598T-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2598T-3.3/NOPB?
LM2598T-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2598T-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 LM2598T-3.3/NOPB?
For technical support, including LM2598T-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2598T-3.3/NOPB requirements.
6.How does Aetrix verify that LM2598T-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2598T-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 LM2598T-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LM2598T-3.3/NOPB?
All LM2598T-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2598T-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 LM2598T-3.3/NOPB part is unused and in its original packaging.
Return procedure for LM2598T-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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