My Inquiry
My Account
Texas Instruments LM25574MTX
- Part No.:
- LM25574MTX
- Manufacturer:
- Texas Instruments
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM25574MTX.pdf
- Description:
- IC REG BUCK ADJ 500MA 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,043
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM25574MTX from Texas Instruments is a 42-V, 0.5-A synchronous step-down DC/DC switching regulator with integrated 750-mΩ N-channel MOSFET, emulated current-mode control, adjustable 50 kHz–1 MHz switching frequency, and 1.225 V feedback reference. It operates from 6 V to 42 V input and delivers regulated output for industrial power rails requiring robust high-voltage conversion.
For engineers reviewing the LM25574MTX datasheet, LM25574MTX pinout, LM25574MTX application, or LM25574MTX equivalent, key selection criteria include input voltage range (6–42 V), output current capability (0.5 A), thermal shutdown (165 °C), soft-start adjustability, and SYNC pin support for multi-regulator synchronization in noise-sensitive systems.
Technical Context
The LM25574MTX implements emulated current-mode control using a reconstructed ramp signal derived from VIN–VOUT and a diode-current sample-and-hold DC level-eliminating leading-edge spikes and enabling stable operation at low duty cycles. Its dual-mode VCC regulator maintains ~7 V bias supply above 9 V VIN while tracking VIN below that threshold.
Frequency is set via a single RT-to-AGND resistor; SYNC pin supports master/slave synchronization across up to five devices. Protection includes cycle-by-cycle current limiting (0.7 A typ), thermal shutdown (165 °C), and remote shutdown via SD pin with 0.7 V/1.225 V thresholds and 0.1 V hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 6 V to 42 V - supports wide industrial bus voltages including 12 V, 24 V, and 36 V nominal systems without external pre-regulation. |
| Output Current | 0.5 A continuous - sufficient for powering microcontrollers, sensors, and interface ICs in distributed power architectures. |
| Feedback Reference | 1.225 V ±1.5% - enables precise output regulation down to 1.225 V and scalable higher outputs via resistive divider. |
| Switching Frequency | 50 kHz to 1 MHz - adjustable via RT resistor to optimize trade-off between inductor size, efficiency, and EMI performance. |
| Integrated MOSFET RDS(on) | 750 mΩ max - reduces external component count and conduction losses in compact high-voltage buck designs. |
| Thermal Shutdown | 165 °C with 25 °C hysteresis - provides reliable overtemperature protection during overload or poor heatsinking conditions. |
| Soft-Start Current | 10 µA typ - sets rise time of internal reference with external SS capacitor, preventing inrush current and output overshoot. |
Pinout & Package
TSSOP-16 package (5.00 mm × 4.40 mm), thermally enhanced with exposed PGND pad; suitable for automated assembly and moderate-power density PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Main input supply connection | Accepts 6–42 V unregulated input; absolute max 45 V - requires local ceramic bypassing to PGND. |
| VCC | Bias regulator output | Provides internal logic and gate drive supply; self-regulates to ~7 V above 9 V VIN; accepts auxiliary 7.5–14 V supply to reduce dissipation. |
| SW | Switching node | Drives external Schottky diode and buck inductor; connects internally to source of integrated N-MOSFET. |
| BST | Bootstrap capacitor input | Charges external 0.022 µF BST–SW capacitor via internal diode during off-time to enable high-side gate drive. |
| PGND | Power ground return | Low-side reference for IS sense resistor and PRE switch; must be routed separately from AGND to minimize noise coupling. |
| AGND | Analog ground reference | Reference for FB, COMP, RAMP, RT, and error amplifier; requires star grounding near IC for stability. |
| FB | Feedback input | Connects to resistor divider from OUT; internal 1.225 V reference sets output voltage: VOUT = 1.225 × (1 + R1/R2). |
| COMP | Error amplifier output | Interface for type-II compensation network (R/C) between COMP and FB to stabilize loop response. |
| RT | Oscillator frequency set | Resistor from RT to AGND programs switching frequency per F = 1/(135 pF × RT + 580 ns); layout-critical node. |
| RAMP | Emulated current ramp input | External capacitor to AGND sets ramp slope; value selected per L × 5 µF/H to match diode-current scale factor (2 V/A). |
| IS | Diode current sense | Connects to Schottky anode; internal 250 mΩ sense resistor and sample/hold circuit provide DC level for emulated ramp. |
| SD | Shutdown control | 0.7 V threshold disables regulator; 1.225 V enables operation; internal 5 µA pull-up allows open-circuit enable. |
| SYNC | Frequency synchronization I/O | Open-drain output / input; synchronizes multiple LM25574MTX devices or accepts external clock > free-running frequency. |
| SS | Soft-start timing | 10 µA current source charges external capacitor to ramp internal reference; held low during UVLO or thermal shutdown. |
| PRE | Bootstrap pre-charge assist | Open-drain output pulsed 250 ns before each on-time to aid BST capacitor charging under light load or pre-biased output conditions. |
Key Features
| Feature | Design Value |
|---|---|
| Emulated current-mode control | Eliminates need for current-sense resistor and RC snubber; enables stable operation at <10% duty cycle in high-VIN/low-VOUT applications. |
| Adjustable soft-start | External SS capacitor sets controlled output voltage ramp time - prevents inrush current and stabilizes upstream supplies. |
| Master/slave synchronization | SINGLE SYNC pin enables deterministic phase alignment of multiple regulators - reduces input ripple and EMI peak amplitude. |
| Dual-mode VCC regulator | Tracks VIN ≤9 V and regulates to 7 V ≥9 V - minimizes internal power loss across full input range without auxiliary supply. |
| Integrated protection suite | Cycle-by-cycle current limit (0.7 A), thermal shutdown (165 °C), and programmable undervoltage lockout via SD pin ensure field reliability. |
Applications
| Industrial PLC Power Supply | Automotive Body Control Module |
|---|---|
Use Scenario: Converts 24 V vehicle battery or 36 V industrial bus to 3.3 V or 5 V for MCU, CAN transceivers, and analog sensors. IC Role / Device Role / Timing Role: Primary buck regulator providing isolated, low-noise, and thermally robust intermediate rail. Use Value: 42 V absolute max rating withstands load-dump transients; SYNC pin enables synchronized switching with other rails to suppress conducted EMI. | Use Scenario: Powers infotainment subsystems from 12 V battery with strict thermal and startup sequencing requirements. IC Role / Device Role / Timing Role: High-efficiency step-down controller delivering 0.5 A at 5 V with adjustable soft-start for controlled system boot. Use Value: Adjustable RT-based frequency avoids AM band interference; SD pin enables microcontroller-controlled power sequencing. |
| Telecom Remote Radio Unit | Factory Automation Sensor Node |
Use Scenario: Generates stable 12 V or 15 V bias from 48 V telecom rectified bus for RF amplifiers and ADCs. IC Role / Device Role / Timing Role: High-input-voltage buck converter with precision 1.225 V reference ensuring accurate output regulation under varying line conditions. Use Value: 1.5% feedback accuracy and wide VIN range maintain regulation during brownouts; TSSOP-16 package supports compact multilayer PCB layout. | Use Scenario: Supplies 3.3 V to low-power wireless sensor nodes operating from 24 V factory power lines with intermittent loads. IC Role / Device Role / Timing Role: Efficient, thermally resilient DC/DC regulator supporting long-term reliability in sealed enclosures. Use Value: Thermal shutdown (165 °C) and cycle-by-cycle current limit protect against sustained overloads in unventilated environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM25576MTX | Higher 1-A output current; identical pinout and feature set except increased RDS(on) (450 mΩ vs 750 mΩ) and higher quiescent current. | Required where >0.5 A load current or lower conduction loss is needed; same PCB layout usable. | Select LM25576MTX when output current demand exceeds 0.5 A or thermal margin is constrained. |
| LM5164QDDARQ1 | Automotive-grade (AEC-Q100); 100-V input rating; 0.6-A output; integrated high-side MOSFET; different pinout and compensation architecture. | Required for automotive safety-critical systems or >42 V transient environments; not drop-in compatible. | Choose LM5164QDDARQ1 only for AEC-Q100 qualified designs or where 100-V input capability is mandatory. |
Compared with LM25574MTX, LM25576MTX offers higher current capacity in identical packaging for seamless upgrade paths, while LM5164QDDARQ1 provides automotive qualification and extended input voltage at the cost of layout redesign and higher BOM cost.
Availability
LM25574MTX is available at Aetrix Electronics and suitable for industrial PLC power supplies, automotive body control modules, telecom remote radio units, and factory automation sensor nodes requiring stable component supply across extended temperature and voltage ranges.
Supply support for LM25574MTX 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 company specializing in analog, embedded processing, and power management ICs with broad industrial, automotive, and communications focus.
The LM25574MTX belongs to TI's high-voltage buck regulator product line, designed specifically for robust, easy-to-use DC/DC conversion in 6–42 V input systems where minimal external components and inherent protection are critical.
FAQ
What is the maximum input voltage rating for the LM25574MTX?
The LM25574MTX has an absolute maximum input voltage rating of 45 V on the VIN pin. Its recommended operating range is 6 V to 42 V. Exceeding 45 V - even momentarily during transients - risks permanent damage. Designers must use appropriate input filtering and clamping to suppress ringing and load-dump spikes, especially in automotive or industrial 24 V/36 V bus applications where the LM25574MTX is commonly deployed.
How does the LM25574MTX implement current sensing without a sense resistor?
The LM25574MTX uses an integrated diode-current sensing scheme: the IS pin connects to the Schottky diode anode, and an internal 250 mΩ sense resistor between IS and PGND generates a voltage proportional to recirculating current. This voltage is sampled and held just before each switch-on event, forming the DC level of an emulated current ramp. Combined with a VIN–VOUT–derived ramp current (IRAMP = (10 µA × (VIN – VOUT)) + 50 µA), the LM25574MTX reconstructs the inductor current waveform without external sensing components.
Can the LM25574MTX synchronize to an external clock, and what are the timing requirements?
Yes, the LM25574MTX can synchronize to an external clock via its SYNC pin. The external clock must exceed the LM25574MTX's free-running frequency (set by RT), have a minimum pulse width of 15 ns, and use an open-drain interface with pull-up. The SYNC pin features 11 kΩ source impedance and 110 Ω sink impedance, with a falling-edge threshold of 1.3 V. This capability allows precise phase alignment of multiple LM25574MTX regulators or integration into system-level clock trees.
What is the purpose of the PRE pin on the LM25574MTX, and when should it be used?
The PRE (pre-charge) pin on the LM25574MTX is an open-drain output that pulses 250 ns before each high-side switch on-time to assist bootstrap capacitor charging. It is especially useful in applications with very light loads (where SW node may not swing sufficiently) or where the output is pre-biased before startup. Connecting PRE to SW improves bootstrap reliability without adding external circuitry - a design advantage unique to the LM25574MTX among TI's high-voltage buck controllers.
Does the LM25574MTX require external compensation, and what topology is recommended?
Yes, the LM25574MTX requires external compensation via the COMP and FB pins. A standard Type-II network - typically one series RC from COMP to FB plus a shunt capacitor from FB to AGND - is recommended to place a pole at DC, a zero for phase boost, and a high-frequency pole for noise attenuation. TI's WEBENCH® Power Designer provides validated component values for specific output voltages, inductors, and capacitors. Incorrect compensation may cause instability or poor transient response, so layout of the COMP network must follow TI's guidelines for short traces and solid AGND return.
LM25574MTX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 6V
- Voltage - Input (Max):
- 42V
- Voltage - Output (Min/Fixed):
- 1.225V
- Voltage - Output (Max):
- 40V
- Current - Output:
- 500mA
- Frequency - Switching:
- 50kHz ~ 1MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP
LM25574MTX FAQ
1.How can I place an order for LM25574MTX through Aetrix?
Please submit a Request for Quotation (RFQ) for LM25574MTX 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 LM25574MTX reliable?
The price and inventory of LM25574MTX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM25574MTX is usually 5 days.
3.What payment methods are accepted for LM25574MTX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM25574MTX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM25574MTX?
LM25574MTX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM25574MTX 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 LM25574MTX?
For technical support, including LM25574MTX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM25574MTX requirements.
6.How does Aetrix verify that LM25574MTX is sourced from the original manufacturer or authorized distributors?
All LM25574MTX 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 LM25574MTX meets industry standards.
7.What is the process for return or replacement of LM25574MTX?
All LM25574MTX units undergo pre-shipment inspection (PSI). If there is an issue with LM25574MTX, 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 LM25574MTX part is unused and in its original packaging.
Return procedure for LM25574MTX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM25574MTX 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…
