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Texas Instruments LM2738XMY/NOPB
- Part No.:
- LM2738XMY/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-PowerTSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LM2738XMY/NOPB.pdf
- Description:
- IC REG BUCK ADJ 1.5A 8HVSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:527
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Product details
Overview
LM2738XMY/NOPB from Texas Instruments is a monolithic 1.6-MHz, 1.5-A synchronous step-down DC-DC switching regulator in an 8-pin WSON (3.0 mm × 3.0 mm) package with PowerPAD™ thermal enhancement. It integrates a 250-mΩ NMOS switch, internal soft-start, current-mode PWM control, and 0.8-V ±2% reference to deliver precise local point-of-load regulation for space-constrained USB-powered devices and set-top boxes.
For engineers reviewing the LM2738XMY/NOPB datasheet, LM2738XMY/NOPB pinout, LM2738XMY/NOPB application, or LM2738XMY/NOPB equivalent, key selection criteria include its fixed 1.6-MHz switching frequency, 3–20-V input range, 0.8–18-V adjustable output, 400-nA shutdown current, and thermal shutdown protection - all validated for industrial-grade operation up to +125°C junction temperature.
Technical Context
The LM2738XMY/NOPB implements constant-frequency current-mode PWM control with internal compensation, enabling stable regulation across wide load and line variations without external loop components. Its architecture uses cycle-by-cycle current limiting (2.9-A typical), undervoltage lockout (2.7-V rising threshold), and output overvoltage protection (16% above VREF) to ensure robust system-level fault tolerance.
Switching is driven by an internal oscillator fixed at 1.6 MHz (±20%), supporting ceramic output capacitors and sub-3-mm inductors. The BOOST pin supplies gate drive via external bootstrap capacitor and diode, requiring VBOOST–VSW between 2.5 V and 5.5 V for optimal NMOS conduction and efficiency up to 90% at 12-VIN/3.3-VOUT.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 1.6 MHz (fixed); enables use of ≤2.2-µH inductors and 10–22-µF ceramic output caps in compact layouts |
| Output Current | 1.5 A continuous; supports core power for HDDs and high-current USB peripherals without external MOSFETs |
| Input Voltage Range | 3 V to 20 V; accommodates 5-V/12-V rails and wide-input industrial supplies |
| Output Voltage Range | 0.8 V to 18 V (adjustable via FB resistor divider); covers 1.5-V, 1.8-V, 3.3-V, and 5-V logic domains |
| NMOS RDS(ON) | 250 mΩ (typical); minimizes conduction loss and thermal rise at full load |
| Shutdown Current | 400 nA (typical); extends battery life in always-on USB devices during sleep mode |
| Reference Voltage | 0.800 V ±2%; ensures ±2% output accuracy over temperature and line/load conditions |
Pinout & Package
LM2738XMY/NOPB is housed in an 8-pin WSON package (3.0 mm × 3.0 mm) with exposed thermal pad (DAP) for enhanced PCB heat dissipation. Pin 1 is BOOST; pins 5 and 7 are GND; pin 8 is SW. The DAP must be soldered to a dedicated ground plane with ≥4 thermal vias for thermal compliance per JEDEC standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BOOST | Bootstrap supply input | Drives NMOS gate; requires external 0.1-µF X7R capacitor to SW to sustain >2.5-V gate drive swing |
| VIN | Main power input | Supplies power stage; must be bypassed with ≥10-µF ceramic cap near pin; tied internally to VCC |
| EN | Enable control | Logic-high (>1.4 V) enables regulation; logic-low (<0.4 V) enters 400-nA shutdown; must not float |
| SW | Switch node | Connects to inductor and catch diode; swings from ~0 V to VIN – ILOAD×RDS(ON); critical for EMI layout |
| FB | Feedback input | Senses output voltage via resistor divider; 0.8-V reference sets VOUT = 0.8×(1+R1/R2) |
| GND (pins 5,7) | Signal & power ground | Return path for feedback network and power stage; place bottom FB resistor adjacent to these pins |
| DAP (exposed pad) | Thermal & electrical ground | Mandatory connection to PCB ground plane; primary thermal path; improves θJA to 45.9°C/W |
Key Features
| Feature | Design Value |
|---|---|
| Internal soft-start | Ramps reference from 0 V to 0.8 V over ~600 µs to limit in-rush current during power-up |
| Current-mode PWM control | Enables fast transient response and inherent cycle-by-cycle current limiting without external slope compensation |
| Output overvoltage protection | Disables SW when FB exceeds 0.928 V (16% above 0.8-V reference), preventing downstream IC damage |
| Thermal shutdown | Halts switching at 165°C junction temperature; resumes at ~150°C to protect against sustained overload |
| Undervoltage lockout | Prevents startup until VIN ≥2.7 V; hysteresis (400 mV) avoids oscillation during brownout recovery |
Applications
| USB-Powered Devices | Set-Top Boxes |
|---|---|
Use Scenario: Regulating 5-V USB input to 1.5-V or 3.3-V for SoC cores and memory interfaces in portable media players. IC Role / Device Role / Timing Role: Primary buck converter delivering 1.5-A continuous current with tight output accuracy and low quiescent draw. Use Value: 400-nA shutdown current extends battery runtime; 1.6-MHz operation allows miniaturized 2.2-µH inductors and eliminates bulk electrolytics. | Use Scenario: Generating 3.3-V and 5-V rails from 12-V main supply in digital video broadcast receivers with multiple tuners and demodulators. IC Role / Device Role / Timing Role: Local point-of-load regulator for FPGA I/O banks and audio DACs requiring low-noise, fast-transient response. Use Value: Current-mode control delivers <50-µs load-step recovery; 250-mΩ RDS(ON) maintains >88% efficiency at full load. |
| HDD Core Power | Battery-Powered Devices |
Use Scenario: Supplying 1.2-V core voltage to 2.5-inch SATA hard disk drive controllers under dynamic read/write workloads. IC Role / Device Role / Timing Role: High-efficiency step-down regulator handling 1.5-A peak currents with minimal thermal derating on small PCB areas. Use Value: WSON PowerPAD™ package achieves 45.9°C/W θJA, enabling operation at 125°C ambient without heatsinks. | Use Scenario: Powering ARM Cortex-M microcontrollers and sensors in handheld test equipment powered by Li-ion batteries (3.3–4.2 V). IC Role / Device Role / Timing Role: Main system regulator supporting wide input range (3–20 V) and seamless transition from battery to wall adapter. Use Value: 3-V minimum input enables operation down to single-cell Li-ion depletion; UVLO hysteresis prevents erratic restarts during voltage sag. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2738YMY/NOPB | Fixed 550-kHz switching frequency; higher max duty cycle (95% vs. 92%); lower boost current (2.5 mA vs. 4.5 mA) | Better suited for high-VIN/low-VOUT ratios where lower frequency improves efficiency and reduces EMI | Select LM2738YMY/NOPB when board area is less constrained and lower EMI is prioritized over component miniaturization. |
| TPS62130ARGTR | 3-MHz fixed frequency; integrated synchronous rectifier; 95% efficiency at light loads; no external BOOST diode required | Superior light-load efficiency and smaller solution size but lacks OVP and has narrower input range (3–17 V) | Choose TPS62130ARGTR for ultra-compact designs needing >90% efficiency down to 1-mA load, accepting trade-offs in fault protection and input headroom. |
Compared with LM2738YMY/NOPB, the LM2738XMY/NOPB trades lower EMI and higher duty-cycle headroom for smaller magnetics and faster transient response; versus TPS62130ARGTR, it offers stronger fault protection and wider input range at the cost of external diode dependency and lower light-load efficiency.
Availability
LM2738XMY/NOPB is available at Aetrix Electronics and suitable for USB-powered devices, set-top boxes, and battery-powered instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM2738XMY/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 ICs, with decades of expertise in high-reliability DC-DC conversion solutions.
The LM2738XMY/NOPB belongs to TI's high-frequency buck regulator product line, engineered specifically for space-constrained consumer and industrial applications demanding high power density, fast transient response, and robust thermal performance without external compensation.
FAQ
What is the exact switching frequency tolerance of the LM2738XMY/NOPB?
The LM2738XMY/NOPB has a nominal switching frequency of 1.6 MHz with a guaranteed range of 1.28 MHz to 1.92 MHz across temperature and process variation. This ±20% tolerance is specified in the Electrical Characteristics table (FSW parameter) and reflects factory-trimmed oscillator accuracy without external adjustment.
Can the LM2738XMY/NOPB operate with an input voltage below 3 V?
No - the LM2738XMY/NOPB has a minimum recommended input voltage of 3 V per the Recommended Operating Conditions table. Below this, undervoltage lockout engages, and the device remains disabled. Absolute maximum ratings allow down to –0.5 V, but functional operation is not assured below 3 V.
Does the LM2738XMY/NOPB require an external catch diode?
Yes, the LM2738XMY/NOPB requires an external Schottky catch diode (e.g., BAT54WS) connected between SW and GND. It is not a synchronous buck regulator; the internal NMOS switch operates in conjunction with this external diode to complete the inductor current path during off-time.
How is thermal performance affected if the DAP (exposed pad) is not soldered to PCB ground?
If the DAP of the LM2738XMY/NOPB is left unconnected or poorly soldered, junction-to-ambient thermal resistance increases from 45.9°C/W to >80°C/W, risking thermal shutdown at loads above 0.8 A. TI mandates DAP connection to a solid ground plane with ≥4 thermal vias for rated 1.5-A operation.
What is the purpose of the BOOST pin, and what happens if it's left floating?
The BOOST pin supplies gate drive voltage to the internal NMOS switch via an external bootstrap capacitor. If left floating, the switch cannot turn on fully, causing excessive RDS(ON), thermal runaway, and immediate failure. A 0.1-µF X7R capacitor must connect BOOST to SW, and BOOST must be biased from VIN or VOUT through a diode per Figure 26 in the datasheet.
LM2738XMY/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-PowerTSSOP, 8-MSOP (0.118", 3.00mm 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):
- 3V
- Voltage - Input (Max):
- 20V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 18V
- Current - Output:
- 1.5A
- Frequency - Switching:
- 1.6MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-HVSSOP
LM2738XMY/NOPB FAQ
1.How can I place an order for LM2738XMY/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2738XMY/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 LM2738XMY/NOPB reliable?
The price and inventory of LM2738XMY/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2738XMY/NOPB is usually 5 days.
3.What payment methods are accepted for LM2738XMY/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2738XMY/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2738XMY/NOPB?
LM2738XMY/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2738XMY/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 LM2738XMY/NOPB?
For technical support, including LM2738XMY/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2738XMY/NOPB requirements.
6.How does Aetrix verify that LM2738XMY/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2738XMY/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 LM2738XMY/NOPB meets industry standards.
7.What is the process for return or replacement of LM2738XMY/NOPB?
All LM2738XMY/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2738XMY/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 LM2738XMY/NOPB part is unused and in its original packaging.
Return procedure for LM2738XMY/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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