My Inquiry
My Account
Texas Instruments LM2574MX-3.3/NOPB
- Part No.:
- LM2574MX-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 14-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
LM2574MX-3.3/NOPB.pdf
- Description:
- IC REG BUCK 3.3V 500MA 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,162
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2574MX-3.3/NOPB from Texas Instruments (formerly National Semiconductor) is a monolithic 0.5A step-down (buck) switching voltage regulator with fixed 3.3V output, 52 kHz internal oscillator, and integrated switch. It delivers ±4% output voltage accuracy over line/load/temperature, supports 4.75–40V input, and requires only four external components for operation in industrial power supplies.
For engineers reviewing the LM2574MX-3.3/NOPB datasheet, LM2574MX-3.3/NOPB pinout, LM2574MX-3.3/NOPB application, or LM2574MX-3.3/NOPB equivalent, key selection considerations include its 0.5A continuous output current capability, thermal shutdown and cycle-by-cycle current limiting, TTL-compatible shutdown control, and compatibility with standard off-the-shelf inductors optimized for 52 kHz operation.
Technical Context
The LM2574MX-3.3/NOPB implements a fixed-frequency, current-mode buck topology with an integrated NPN power switch and internal frequency compensation. Its 52 kHz oscillator enables predictable EMI behavior and simplifies filter design using low-cost, high-saturation-current inductors.
It operates in continuous conduction mode across typical loads (≥0.1A), delivering stable 3.3V regulation with ≤3.432V maximum and ≥3.168V minimum output under full temperature and load range (−40°C to +125°C, 0.1–0.5A). Standby current is 50 µA typical when the ON/OFF pin is pulled high.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±4% over −40°C to +125°C, 0.1–0.5A load, 4.75–40V input |
| Max Output Current | 0.5A continuous - sufficient for powering microcontrollers, FPGAs, and logic rails without external heatsinking |
| Input Voltage Range | 4.75V to 40V - supports wide-input industrial and automotive battery-supplied systems |
| Oscillator Frequency | 52 kHz fixed - enables use of low-cost, high-current inductors and reduces core loss vs. higher-frequency alternatives |
| Efficiency | 72% at VIN = 12V, IOUT = 0.5A - significantly higher than linear regulators, minimizing board-level heat dissipation |
| Shutdown Current | 50 µA typical - enables low-power sleep modes in battery-powered applications |
| Thermal Protection | Internal thermal shutdown - prevents damage during overload or poor PCB copper layout |
Pinout & Package
LM2574MX-3.3/NOPB is housed in a 14-pin SOIC (Small Outline Integrated Circuit) package, designated NS package code M14B. The exposed pad is not electrically connected but should be soldered to PCB copper for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Input Supply | Accepts 4.75–40V DC; requires local 22 µF electrolytic bypass capacitor |
| 2 (GND) | Power Ground | Common return for input/output capacitors, inductor, and catch diode |
| 3 (OUT) | Switch Node | Drives external catch diode anode and inductor; carries pulsed 0.5A peak current |
| 4 (FEEDBACK) | Regulation Sense | Not used in fixed-output versions - internally tied to output divider |
| 5 (ON/OFF) | Enable Control | TTL-compatible shutdown: <1.0V = ON, >2.2V = OFF; draws ≤30 µA in standby |
| 6–14 | No Connect / Exposed Pad | Pins 6–13 are NC; Pin 14 is thermal pad - must be soldered to PCB copper for θJA = 78°C/W |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3V output | Eliminates external feedback resistors - reduces BOM count and layout sensitivity |
| Integrated NPN switch | Removes need for external MOSFET driver and gate resistor - simplifies bill-of-materials |
| Cycle-by-cycle current limit | Protects against short-circuit and inductor saturation - limits peak switch current to 1.0A typ |
| Internal frequency compensation | Enables stable operation with only 4 external parts - no loop compensation design required |
| Standard inductor compatibility | Works with off-the-shelf 330 µH inductors (e.g., Pulse PE-52627) - accelerates prototyping |
Applications
| Industrial Power Rails | Embedded Microcontroller Supplies |
|---|---|
Use Scenario: Providing clean 3.3V power to PLC I/O modules operating from 24V DC bus with variable load transients. IC Role / Device Role / Timing Role: Primary buck regulator converting unregulated 24V to regulated 3.3V for digital logic and communication interfaces. Use Value: Delivers 0.5A with 72% efficiency at 12V input, reducing thermal stress on PCB copper traces versus linear regulators. | Use Scenario: Powering ARM Cortex-M4-based edge sensor nodes powered by 9–18V Li-ion packs. IC Role / Device Role / Timing Role: Main system regulator supplying 3.3V to MCU, ADC, and wireless transceiver under dynamic load conditions. Use Value: 50 µA standby current enables multi-week battery life in sleep mode; thermal shutdown prevents fault propagation. |
| On-Card DC-DC Conversion | Pre-Regulator for Linear LDOs |
Use Scenario: Generating local 3.3V rail on dense FPGA carrier boards where space prohibits discrete buck controllers. IC Role / Device Role / Timing Role: Compact, self-contained buck stage placed adjacent to FPGA core voltage domain. Use Value: 14-pin SOIC footprint and 4-component requirement minimize board area and routing complexity. | Use Scenario: Reducing 12V supply to ~4V before feeding low-noise LDOs for analog sensor front-ends. IC Role / Device Role / Timing Role: High-efficiency pre-regulator lowering dropout voltage and power dissipation of downstream LDOs. Use Value: 88% efficiency at 15V→12V (LM2574-12 variant) demonstrates capability to reduce thermal load on final regulation stage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575-3.3 | 0.5A output, same pinout, but 57 kHz oscillator and higher quiescent current (11 mA vs. 5 mA) | Lacks ON/OFF pin - no external enable control; less suitable for battery sleep modes | Choose if existing layout uses LM2575 footprint and enable control is unnecessary |
| TPS54202DR | 2A output, 4.5–28V input, 500 kHz switching, integrated MOSFETs, requires external compensation | Higher integration and efficiency, but demands more complex layout and design validation | Choose for higher current or smaller solution size where design resources support synchronous buck optimization |
Compared with LM2575-3.3, LM2574MX-3.3/NOPB offers TTL shutdown and lower quiescent current; compared with TPS54202DR, it trades higher current and frequency for simplicity, fewer external parts, and proven robustness in industrial environments.
Availability
LM2574MX-3.3/NOPB is available at Aetrix Electronics and suitable for industrial automation, embedded computing, and sensor node power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM2574MX-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 acquired National Semiconductor in 2011 and maintains the SIMPLE SWITCHER™ portfolio, known for rugged, easy-to-use DC-DC regulators targeting cost-sensitive and reliability-critical applications.
The LM2574MX-3.3/NOPB belongs to the LM2574 series - a family of monolithic buck regulators designed for industrial, automotive, and telecom power systems where minimal external components, thermal resilience, and long-lifecycle availability are essential.
FAQ
What is the maximum input voltage rating for LM2574MX-3.3/NOPB?
The absolute maximum input voltage for LM2574MX-3.3/NOPB is 45V, with recommended operating input voltage up to 40V. Exceeding 40V risks violating the guaranteed output voltage tolerance and may trigger internal protection circuits. This rating applies specifically to the standard-voltage LM2574 series; the HV variant (LM2574HV) supports up to 60V operating input.
Does LM2574MX-3.3/NOPB require an external feedback resistor network?
No, LM2574MX-3.3/NOPB does not require external feedback resistors. As a fixed-output version, its 3.3V regulation is implemented internally - the FEEDBACK pin is pre-connected to an internal resistor divider. External resistors are only needed for the adjustable LM2574-ADJ variant.
Can LM2574MX-3.3/NOPB be used in discontinuous conduction mode?
Yes, LM2574MX-3.3/NOPB operates reliably in both continuous and discontinuous conduction modes. At light loads (<0.1A), inductor current naturally drops to zero each cycle. The device's 52 kHz oscillator and current-limit architecture maintain regulation and stability without external intervention.
What is the thermal resistance (θJA) of LM2574MX-3.3/NOPB in its SOIC package?
LM2574MX-3.3/NOPB in the 14-pin SOIC (M14B) package has a junction-to-ambient thermal resistance of 102°C/W with ~1 in² of PCB copper, and 78°C/W with ~4 in² of 1 oz copper. These values assume the exposed thermal pad (Pin 14) is soldered to the PCB ground plane - omitting this connection degrades thermal performance significantly.
Is LM2574MX-3.3/NOPB pin-compatible with LM2574N-3.3?
No, LM2574MX-3.3/NOPB is not pin-compatible with LM2574N-3.3. The former uses a 14-pin SOIC (M14B) package, while the latter uses an 8-pin DIP (N08A). Although both share identical electrical functionality and pin functions, their physical layouts, pin counts, and thermal pad configurations differ - requiring separate PCB footprints.
LM2574MX-3.3/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 14-SOIC (0.295", 7.50mm 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):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 500mA
- Frequency - Switching:
- 52kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SOIC
LM2574MX-3.3/NOPB FAQ
1.How can I place an order for LM2574MX-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2574MX-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 LM2574MX-3.3/NOPB reliable?
The price and inventory of LM2574MX-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 LM2574MX-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LM2574MX-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2574MX-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2574MX-3.3/NOPB?
LM2574MX-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2574MX-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 LM2574MX-3.3/NOPB?
For technical support, including LM2574MX-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2574MX-3.3/NOPB requirements.
6.How does Aetrix verify that LM2574MX-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2574MX-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 LM2574MX-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LM2574MX-3.3/NOPB?
All LM2574MX-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2574MX-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 LM2574MX-3.3/NOPB part is unused and in its original packaging.
Return procedure for LM2574MX-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2574MX-3.3/NOPB Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
