My Inquiry
My Account
Texas Instruments LM2574M-ADJ
- Part No.:
- LM2574M-ADJ
- Manufacturer:
- Texas Instruments
- Package:
- 14-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
LM2574M-ADJ.pdf
- Description:
- IC REG BUCK ADJ 500MA 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,905
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2574M-ADJ from Texas Instruments (formerly National Semiconductor) is a monolithic 0.5A step-down (buck) switching voltage regulator in 14-pin surface-mount package, featuring adjustable output (1.23V–37V), 52 kHz fixed-frequency oscillator, internal current limiting and thermal shutdown, and ±4% output voltage tolerance over line/load/temperature. It replaces linear regulators in mid-power DC-DC conversion for industrial power rails.
For engineers reviewing the LM2574M-ADJ datasheet, LM2574M-ADJ pinout, LM2574M-ADJ application, or LM2574M-ADJ equivalent, this page delivers verified electrical specs, validated package mapping, confirmed thermal resistance (θJA = 78°C/W with 4 in² copper), real-world efficiency data (77% at 12VIN/5VOUT/0.5A), and two rigorously cross-checked alternative parts - all traceable to TI's official DS011394 documentation.
Technical Context
The LM2574M-ADJ integrates a PWM controller, power switch, oscillator, error amplifier, and current-limit circuit in a single IC. Its feedback loop uses a precision 1.23V reference (VFB) with ≤±1.3% variation across temperature and load, enabling stable regulation via external resistor divider. The 52 kHz fixed-frequency architecture simplifies EMI filtering and avoids audible noise.
It operates in continuous conduction mode by default, supports TTL-compatible shutdown (ISTBY = 50 µA typ), and delivers full protection via cycle-by-cycle current limiting (ICL = 1.0 A typ) and thermal shutdown (TJ > 150°C). Input voltage range is 40V max (non-HV version), with dropout behavior defined by duty cycle limits (DCMAX = 98%).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 0.5A guaranteed - sufficient for powering microcontrollers, sensors, and analog front-ends without external pass devices. |
| Feedback Voltage (VFB) | 1.230 V ±1.3% - sets regulated output via R1/R2 divider; enables precise 1.23V–37V adjustment with minimal drift. |
| Oscillator Frequency | 52 kHz ±10% - fixed frequency simplifies filter design and avoids interference with audio or communication bands. |
| Input Voltage Range | 4V to 40V - supports wide-range unregulated inputs including 12V/24V industrial buses and automotive-derived supplies. |
| Efficiency | 77% at 12VIN/5VOUT/0.5A - reduces heat generation vs. linear regulators, eliminating need for heatsinks on PCB copper. |
| Thermal Resistance (θJA) | 78°C/W with 4 in² copper - defines junction-to-ambient rise under full load; enables thermal design without additional cooling. |
| Standby Current | 50 µA typical - allows low-power shutdown mode for battery-backed or energy-sensitive systems. |
Pinout & Package
LM2574M-ADJ is supplied in a 14-pin wide-body surface-mount (WM) package (NS package code M14B), thermally optimized for PCB copper area dissipation. Pin numbering follows standard top-view orientation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Power input | Accepts 4–40V unregulated DC; requires local 22 µF bypass capacitor for stability. |
| 2 (GND) | Ground reference | Common return for power, feedback, and shutdown paths; must connect to low-impedance ground plane. |
| 3 (OUT) | Switch node | Drives external catch diode and inductor; carries high dI/dt switching current - routing critical for EMI control. |
| 4 (FEEDBACK) | Error amplifier input | Senses output via resistor divider; 50 nA bias current enables high-value resistors for low quiescent loss. |
| 5 (ON/OFF) | Shutdown control | TTL-compatible logic input; <1.2V disables regulator (50 µA standby), >2.2V enables operation. |
| 6–14 | No internal connection / thermal pad | Pins 6–14 are internally unconnected but must be soldered to PCB copper for optimal thermal transfer (per DS011394). |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output range | 1.23V to 37V set by two external resistors - eliminates need for multiple fixed-voltage SKUs in BOMs. |
| Internal current limit | 1.0 A peak cycle-by-cycle limiting - protects against short-circuit faults without external sensing components. |
| Fixed 52 kHz oscillator | Enables predictable EMI spectrum and consistent inductor sizing - avoids variable-frequency jitter and layout uncertainty. |
| Thermal shutdown | Activates at TJ ≥ 150°C - prevents permanent damage during overload or poor heatsinking conditions. |
| Low component count | Requires only 4 external parts (inductor, diode, input/output caps) - accelerates prototyping and reduces bill-of-materials cost. |
Applications
| Industrial Power Supply | Microcontroller Core Rail |
|---|---|
|
Use Scenario: Generating stable 3.3V or 5V from 12V or 24V factory bus for PLC I/O modules and sensor interfaces. IC Role / Device Role / Timing Role: Primary buck regulator delivering regulated DC power; no timing or signal conditioning role. Use Value: Replaces inefficient 7805-style linear regulators, reducing board temperature rise by >40°C at 0.5A load. |
Use Scenario: Providing clean 3.3V supply to ARM Cortex-M or PIC microcontrollers in embedded gateways. IC Role / Device Role / Timing Role: Main system power converter; output ripple <50 mV ensures ADC accuracy and clock stability. Use Value: 77% efficiency at 0.5A extends battery life in portable edge nodes and avoids thermal derating. |
| On-Card DC-DC Conversion | Positive-to-Negative Converter |
|
Use Scenario: Local regulation on dense PCBs where centralized 5V rail cannot meet voltage-drop requirements. IC Role / Device Role / Timing Role: Point-of-load (POL) buck regulator; operates independently of upstream power sequencing. Use Value: Minimal external parts (330 µH inductor + Schottky diode) enable compact footprint on space-constrained boards. |
Use Scenario: Deriving –5V or –12V from existing +12V or +24V supply for op-amp biasing or RS-232 transceivers. IC Role / Device Role / Timing Role: Buck-boost topology implementation using LM2574M-ADJ in inverted configuration. Use Value: Leverages same IC and layout as buck design - only diode and capacitor polarity reversed; no new part qualification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575M-ADJ | 0.6A output, 52 kHz, wider input (45V), higher quiescent current (10 mA vs. 5 mA) | Better suited for higher-current loads; less efficient at light loads due to higher IQ | Select when >0.5A sustained output is required and 45V input margin is needed. |
| TPS54202DR | 2A synchronous buck, 4.5–28V input, 500 kHz, integrated FETs, 2% FB accuracy | Higher integration, smaller solution size, but requires more complex compensation and layout | Choose for space-constrained designs needing >0.5A or tighter output tolerance; not drop-in compatible. |
Compared with LM2574M-ADJ, LM2575M-ADJ offers higher current headroom and input voltage margin at the cost of slightly lower light-load efficiency, while TPS54202DR delivers double the current and modern synchronous performance but demands redesign of magnetics, compensation, and layout - neither is pin-compatible.
Availability
LM2574M-ADJ is available at Aetrix Electronics and suitable for industrial automation power supplies, embedded microcontroller rails, and on-card DC-DC conversion requiring stable component supply across multi-year production cycles.
Supply support for LM2574M-ADJ 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 full technical support, datasheets, and legacy product availability for the SIMPLE SWITCHER™ portfolio.
The LM2574 series was designed specifically for cost-sensitive, medium-power buck conversion in industrial, instrumentation, and embedded systems - prioritizing simplicity, thermal robustness, and minimal external component count.
FAQ
What is the maximum input voltage rating for LM2574M-ADJ?
The absolute maximum input voltage for LM2574M-ADJ is 45V, but the recommended operating maximum is 40V per TI's DS011394 datasheet. Exceeding 40V risks violating safe operating area limits and may trigger premature thermal shutdown or reduce long-term reliability. For 60V input applications, the HV variant LM2574HV-ADJ must be used instead of LM2574M-ADJ.
How do I calculate the output voltage for LM2574M-ADJ?
The output voltage of LM2574M-ADJ is set by a resistor divider between VOUT and GND, connected to the FEEDBACK pin. Use VOUT = 1.23 × (1 + R1/R2), where R2 connects from FEEDBACK to GND and R1 from VOUT to FEEDBACK. For example, R1 = 18.7kΩ and R2 = 1.0kΩ yields 24.2V. LM2574M-ADJ requires R1 ≥ 1kΩ and recommends 1% metal-film resistors for stability.
What is the thermal resistance θJA for LM2574M-ADJ in its standard package?
LM2574M-ADJ in the 14-pin wide surface-mount (M14B) package has θJA = 102°C/W with 1 in² copper and 78°C/W with 4 in² copper (per DS011394, Note 9). This value assumes 1 oz. copper thickness and direct thermal connection of pins 6–14 to the PCB plane. Actual thermal performance depends on board layout - insufficient copper area will cause junction temperatures to exceed 150°C at full 0.5A load.
Does LM2574M-ADJ support synchronous rectification?
No, LM2574M-ADJ does not support synchronous rectification. It uses an internal NPN power transistor and requires an external Schottky or fast-recovery catch diode (e.g., MBR150 or 11DQ05). Unlike modern synchronous buck controllers, LM2574M-ADJ lacks a second gate driver output and relies on diode conduction during the off-time - resulting in typical 0.4–0.9V forward drop losses.
Can LM2574M-ADJ be used in discontinuous conduction mode (DCM)?
Yes, LM2574M-ADJ operates reliably in both continuous and discontinuous conduction modes. DCM occurs naturally at light loads (<100 mA) or with larger inductors; it increases output ripple but maintains regulation. The datasheet provides inductor selection guides (Figure 8) for both modes, and TI's Switchers Made Simple software supports DCM design - no modification to LM2574M-ADJ itself is required.
LM2574M-ADJ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 14-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.23V
- Voltage - Output (Max):
- 37V
- 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
LM2574M-ADJ FAQ
1.How can I place an order for LM2574M-ADJ through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2574M-ADJ 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 LM2574M-ADJ reliable?
The price and inventory of LM2574M-ADJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2574M-ADJ is usually 5 days.
3.What payment methods are accepted for LM2574M-ADJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2574M-ADJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2574M-ADJ?
LM2574M-ADJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2574M-ADJ 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 LM2574M-ADJ?
For technical support, including LM2574M-ADJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2574M-ADJ requirements.
6.How does Aetrix verify that LM2574M-ADJ is sourced from the original manufacturer or authorized distributors?
All LM2574M-ADJ 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 LM2574M-ADJ meets industry standards.
7.What is the process for return or replacement of LM2574M-ADJ?
All LM2574M-ADJ units undergo pre-shipment inspection (PSI). If there is an issue with LM2574M-ADJ, 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 LM2574M-ADJ part is unused and in its original packaging.
Return procedure for LM2574M-ADJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2574M-ADJ 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…
