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Texas Instruments LM5574QMTX/NOPB
- Part No.:
- LM5574QMTX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM5574QMTX/NOPB.pdf
- Description:
- IC REG BUCK ADJ 500MA 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:6,033
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Product details
Overview
LM5574QMTX/NOPB from Texas Instruments is a 75V-input, 0.5A synchronous step-down DC/DC regulator with integrated 750mΩ N-channel MOSFET, emulated current-mode control, and adjustable 50–500kHz switching frequency. It delivers stable output down to 1.225V with 1.5% feedback reference accuracy and supports industrial power bus applications requiring high-voltage input tolerance and robust fault protection.
For engineers reviewing the LM5574QMTX/NOPB datasheet, LM5574QMTX/NOPB pinout, LM5574QMTX/NOPB application, or LM5574QMTX/NOPB equivalent, key selection criteria include its 6–75V input range, cycle-by-cycle current limiting, thermal shutdown, remote shutdown capability, and TSSOP-16 package compatibility with WEBENCH® Power Designer integration.
Technical Context
The LM5574QMTX/NOPB implements emulated current-mode control using an internal ramp generator and diode-current sampling via the IS pin, eliminating leading-edge spikes and enabling reliable low-duty-cycle operation at high VIN/VOUT ratios. Its dual-mode VCC regulator maintains ~7V bias for VIN > 9V and tracks VIN directly below 9V, supporting wide-input operation without external bias supplies.
Frequency is set by a single RT-to-AGND resistor (50–500kHz), and the SYNC pin enables master-slave synchronization across multiple LM5574QMTX/NOPB units or to external clocks. Protection includes cycle-by-cycle current limit (0.7A typ), thermal shutdown (165°C), and programmable undervoltage lockout on SD and VCC pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 6V to 75V - supports direct connection to industrial 24V/48V/72V buses and telecom -48V systems without pre-regulation. |
| Output Current | 0.5A continuous - sufficient for powering microcontrollers, sensors, and interface ICs in ruggedized embedded systems. |
| Feedback Reference | 1.225V ±1.5% - enables precise output regulation down to 1.225V with standard resistor-divider design. |
| Switching Frequency | 50kHz to 500kHz - adjustable via RT resistor to optimize trade-off between efficiency, size, and EMI performance. |
| Integrated MOSFET Rds(on) | 750mΩ (max 1500mΩ) - reduces external component count and conduction losses in compact designs. |
| Soft-Start Current | 10µA (7–14µA range) - sets predictable voltage ramp rate on external SS capacitor for controlled inrush management. |
| Thermal Shutdown | 165°C with 25°C hysteresis - prevents permanent damage during overload or poor heatsinking conditions. |
Pinout & Package
The LM5574QMTX/NOPB is housed in a 16-pin TSSOP (PW) package measuring 5mm × 6.4mm, optimized for thermal performance (RθJA = 95°C/W) and PCB space efficiency in industrial power modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Main input supply | Accepts 6–75V unregulated input; powers internal bias regulator and buck switch. |
| VCC | Bias regulator output | Provides ~7V internal supply; can accept external 7.5–14V auxiliary source to reduce dissipation. |
| SW | Switching node | Source of internal N-MOSFET; connects to inductor and Schottky diode anode. |
| BST | Bootstrap capacitor input | Requires 0.022µF ceramic cap to SW for high-side gate drive; enables N-MOSFET operation. |
| FB | Feedback input | Connects to resistor divider; regulates output by comparing against 1.225V internal reference. |
| COMP | Error amplifier output | Interface for type-II compensation network between COMP and FB to stabilize loop response. |
| RT | Oscillator frequency set | Single resistor to AGND sets switching frequency from 50kHz to 500kHz. |
| SS | Soft-start control | 10µA current source charges external capacitor to ramp reference voltage gradually at startup. |
| SD | Shutdown/UVLO input | 0.7V threshold disables regulator; 1.225V enables operation; open-circuit defaults to active. |
| SYNC | Oscillator sync I/O | Allows multi-device synchronization or external clock locking; supports pulldown-driven interface. |
| RAMP | Emulated current ramp | External capacitor sets slope; reconstructs inductor current without sensing noise or delay. |
| IS | Diode current sense | Measures recirculating diode current to sample DC level of emulated ramp; requires IS-to-PGND connection. |
| PRE | Pre-charge assist | Open-drain output tied to SW to boost BST capacitor charge under light-load or pre-biased conditions. |
| AGND | Analog ground | Reference for error amp, FB, RAMP, and RT; must be separated from PGND for noise immunity. |
| PGND | Power ground | Low-side return for IS sense resistor and PRE switch; ties to power path ground plane. |
| OUT | Regulated output | Direct connection point for output capacitor and load; referenced to PGND. |
Key Features
| Feature | Design Value |
|---|---|
| Emulated current-mode control | Eliminates current-sense noise and propagation delay, enabling stable regulation at <10% duty cycles in high-VIN applications. |
| Integrated 75V/750mΩ N-MOSFET | Reduces BOM count and layout complexity while maintaining 0.5A output capability without external switches. |
| Adjustable soft-start | External SS capacitor sets startup time; internal 10µA source ensures repeatable inrush current limiting. |
| Controller synchronization | SYNC pin allows deterministic phase alignment of multiple LM5574QMTX/NOPB regulators to suppress beat frequencies and EMI peaks. |
| Built-in protection suite | Includes cycle-by-cycle current limit (0.7A), thermal shutdown (165°C), VCC UVLO (5.35V), and remote shutdown via SD pin. |
| WEBENCH® Power Designer support | Enables full schematic generation, efficiency simulation, thermal analysis, and bill-of-materials export directly from TI's online tool. |
Applications
| Industrial Power Bus Converter | Telecom -48V Intermediate Supply |
|---|---|
|
Use Scenario: Converting 24V/48V/72V factory floor power rails to 3.3V/5V for PLC I/O modules and fieldbus transceivers. IC Role / Device Role / Timing Role: Primary buck regulator delivering isolated, regulated low-voltage rails with high line transient immunity. Use Value: 75V absolute max rating and 6–75V operating range eliminate need for front-end pre-regulators in variable industrial input environments. |
Use Scenario: Stepping down telecom -48V nominal (–36V to –72V) battery-backed supply to +5V or +3.3V for baseband processors and memory. IC Role / Device Role / Timing Role: High-efficiency non-isolated DC/DC converter handling wide input swings and cold-start conditions. Use Value: Dual-mode VCC regulator sustains operation down to 6V input, enabling reliable startup even after deep battery discharge. |
| Ruggedized Sensor Node Power | Automotive Off-Battery Systems |
|
Use Scenario: Powering MEMS accelerometers, temperature sensors, and wireless transceivers in oil & gas or railway monitoring equipment. IC Role / Device Role / Timing Role: Compact, thermally robust local regulator immune to load dump and reverse polarity events. Use Value: Thermal shutdown (165°C) and cycle-by-cycle current limiting ensure survivability in unventilated enclosures with ambient up to 125°C. |
Use Scenario: Supporting infotainment head units or ADAS camera modules connected to 12V/24V vehicle batteries with load-dump transients. IC Role / Device Role / Timing Role: Input-tolerant buck controller surviving ISO 7637-2 Pulse 5a (120V/100ms) when paired with TVS clamping. Use Value: 76V absolute max VIN rating provides margin against load-dump spikes, reducing need for oversized input TVS devices. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5575QMTX/NOPB | Higher 1.5A output current, same 75V input, identical pinout and feature set. | Suitable where higher load current is required; shares same layout and compensation network. | Select LM5575QMTX/NOPB when output current exceeds 0.5A but all other requirements match. |
| LM5164QWRNTRQ1 | Automotive-grade (AEC-Q100), 100V input, 0.6A, integrated FET, but uses different control architecture (constant-on-time). | Designed for automotive under-hood use; lacks SYNC and RAMP pins; no emulated current mode. | Choose LM5164QWRNTRQ1 only for AEC-Q100-compliant designs requiring >75V input or constant-on-time simplicity. |
Compared with LM5575QMTX/NOPB, the LM5574QMTX/NOPB offers lower cost and thermal footprint for ≤0.5A loads; versus LM5164QWRNTRQ1, it provides superior line/load transient response and design flexibility via emulated current-mode control and SYNC capability-critical for synchronized multi-rail systems.
Availability
LM5574QMTX/NOPB is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and ruggedized sensor node designs requiring stable component supply, long-term lifecycle assurance, and automotive-qualified alternatives.
Supply support for LM5574QMTX/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 expertise in high-reliability power conversion ICs.
The LM5574QMTX/NOPB belongs to TI's high-voltage buck regulator product line, engineered specifically for industrial and telecom applications demanding wide-input operation, integrated protection, and minimal external components.
FAQ
What is the maximum input voltage rating for the LM5574QMTX/NOPB?
The LM5574QMTX/NOPB has an absolute maximum input voltage rating of 76V, with recommended operation from 6V to 75V. Exceeding 76V-even transiently-can cause permanent damage. Layout best practices include placing high-quality input capacitors close to the VIN and PGND pins to suppress ringing during load dumps or line transients. The device's internal VCC regulator automatically transitions between direct VIN tracking (<9V) and regulated 7V output (>9V) to maintain bias stability across this full range.
Does the LM5574QMTX/NOPB require an external bootstrap capacitor?
Yes, the LM5574QMTX/NOPB requires a 0.022µF ceramic capacitor between the BST and SW pins to enable proper high-side gate drive for its internal N-channel MOSFET. This capacitor is charged through an internal diode during the switch off-time. TI specifies short, low-inductance PCB traces for this connection to minimize ringing and ensure reliable bootstrapping, especially under light-load or pre-biased output conditions where the PRE pin may assist charging.
How is the switching frequency set on the LM5574QMTX/NOPB?
The switching frequency of the LM5574QMTX/NOPB is set by a single resistor (RT) connected between the RT pin and AGND. Using Equation 1 from the datasheet (RT = (1/(F)) × 580nS − 135pF), a 32.4kΩ resistor yields ~200kHz. Frequency ranges from 50kHz to 500kHz depending on RT value, and the SYNC pin allows synchronization to external clocks or other LM5574QMTX/NOPB units-enabling deterministic multi-phase operation and EMI reduction in dense power systems.
What protection features does the LM5574QMTX/NOPB include?
The LM5574QMTX/NOPB integrates cycle-by-cycle current limiting (triggered at ~0.7A), thermal shutdown at 165°C with 25°C hysteresis, VCC undervoltage lockout (5.35V), and remote shutdown via the SD pin (0.7V threshold). It also includes forced off-time (500ns) to ensure diode current sampling and prevent runaway during overload or inductor saturation. These protections operate independently and do not require external components, making the LM5574QMTX/NOPB suitable for unattended industrial deployments.
Can the LM5574QMTX/NOPB be used with WEBENCH® Power Designer?
Yes, the LM5574QMTX/NOPB is fully supported in TI's WEBENCH® Power Designer tool. Engineers can enter input/output specifications, select LM5574QMTX/NOPB, and generate complete schematics, BOMs, efficiency plots, thermal simulations, and PCB layout recommendations-including optimized compensation networks and component footprints. The tool validates design margins against datasheet limits and exports design files directly for prototyping or production.
LM5574QMTX/NOPB 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:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 6V
- Voltage - Input (Max):
- 75V
- Voltage - Output (Min/Fixed):
- 1.225V
- Voltage - Output (Max):
- 70V
- Current - Output:
- 500mA
- Frequency - Switching:
- 50kHz ~ 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP
LM5574QMTX/NOPB FAQ
1.How can I place an order for LM5574QMTX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM5574QMTX/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 LM5574QMTX/NOPB reliable?
The price and inventory of LM5574QMTX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM5574QMTX/NOPB is usually 5 days.
3.What payment methods are accepted for LM5574QMTX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM5574QMTX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM5574QMTX/NOPB?
LM5574QMTX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM5574QMTX/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 LM5574QMTX/NOPB?
For technical support, including LM5574QMTX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM5574QMTX/NOPB requirements.
6.How does Aetrix verify that LM5574QMTX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM5574QMTX/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 LM5574QMTX/NOPB meets industry standards.
7.What is the process for return or replacement of LM5574QMTX/NOPB?
All LM5574QMTX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM5574QMTX/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 LM5574QMTX/NOPB part is unused and in its original packaging.
Return procedure for LM5574QMTX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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