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Texas Instruments LM2738YMYX/NOPB
- Part No.:
- LM2738YMYX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-PowerTSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LM2738YMYX/NOPB.pdf
- Description:
- IC REG BUCK ADJ 1.5A 8HVSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,163
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Product details
Overview
LM2738YMYX/NOPB from Texas Instruments is a monolithic 550-kHz, 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 power switch, internal soft-start, current-mode PWM control, and 0.8-V ±2% reference for precise output regulation across 0.8 V to 18 V. Used in space-constrained point-of-load applications such as USB-powered devices and set-top boxes.
For engineers reviewing the LM2738YMYX/NOPB datasheet, LM2738YMYX/NOPB pinout, LM2738YMYX/NOPB application, or LM2738YMYX/NOPB equivalent, this page delivers verified technical context, exact pin functions, real-world design meaning of key specs, validated alternatives, and supply-chain support details - all grounded in TI's SNVS556C production datasheet (Rev C, Jan 2016).
Technical Context
The LM2738YMYX/NOPB implements fixed-frequency current-mode PWM control with internal compensation, enabling stable regulation without external loop components. Its 550-kHz switching frequency (Y variant), 250-mΩ NMOS switch, and bootstrap gate-drive architecture (requiring BOOST–SW ≥ 2.5 V) support high-efficiency operation up to 90% at 12 VIN/3.3 VOUT.
It features cycle-by-cycle current limiting (2.9 A typical), thermal shutdown (165°C trip), undervoltage lockout (2.7 V rising threshold, 400 mV hysteresis), and output overvoltage protection (16% above 0.8 V reference). The EN pin enables ultralow 400-nA shutdown current and logic-level control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 550 kHz - Enables use of compact 2.2-µH inductors and ceramic capacitors; reduces board area vs lower-frequency buck regulators. |
| Max Output Current | 1.5 A - Sustained load capability with internal NMOS switch; peak switch current limit is 2.9 A (typical) for transient overload protection. |
| Input Voltage Range | 3 V to 20 V - Supports wide-input industrial, USB, and battery-powered systems; UVLO ensures clean startup above 2.7 V. |
| Output Voltage Range | 0.8 V to 18 V - Set via external resistor divider on FB pin; 0.8-V ±2% internal reference enables accurate low-voltage core rails. |
| RDS(ON) | 250 mΩ - Low conduction loss improves efficiency at 1.5-A load; measured at VBOOST–VSW = 3 V, ILOAD = 400 mA. |
| Shutdown Current | 400 nA - Enables long battery life in always-on systems; achieved via EN pin logic-low assertion. |
| Feedback Reference | 0.800 V ±2% - Tight tolerance minimizes output voltage error across temperature and line/load variations. |
Pinout & Package
LM2738YMYX/NOPB uses an 8-pin WSON package (NGQ) with 3.0 mm × 3.0 mm body and exposed thermal pad (DAP) connected to GND for enhanced thermal performance. Pin numbering follows top-view standard (pin 1 at top-left corner, counterclockwise).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - BOOST | Bootstrap supply input | Drives NMOS gate during switch-on; requires 0.1-µF ceramic capacitor between BOOST and SW; must maintain ≥2.5 V above SW for full RDS(ON) performance. |
| 2 - VIN | Main power input | Supplies power stage; connect ≥10-µF X5R ceramic bypass capacitor close to pin; tied internally to VCC in package. |
| 3 - VCC | Internal regulator input | Shares bond wire with VIN; no separate external connection required - pins 2 and 3 must be tied together externally per TI layout guidance. |
| 4 - EN | Enable control input | Logic-high (>1.4 V) enables regulation; logic-low (<0.4 V) disables switching and drops quiescent current to 400 nA; must not float or exceed VIN + 0.3 V. |
| 5, 7 - GND | Signal and power ground | Dual ground pins reduce noise coupling; feedback resistor bottom leg must connect nearest to these pins; DAP (exposed pad) must be soldered to PCB GND plane. |
| 6 - FB | Voltage feedback input | Compares divided output voltage against 0.8-V reference; bias current ≤100 nA allows high-value resistive dividers (e.g., 8.87 kΩ/10.2 kΩ for 3.3 V). |
| 8 - SW | Switch node output | Connects to inductor, catch diode cathode, and BOOST capacitor; swings from ~0 V (during off-time) to near VIN (during on-time); high dv/dt requires tight layout. |
Key Features
| Feature | Design Value |
|---|---|
| Current-mode PWM control | Enables fast transient response and inherent cycle-by-cycle current limiting without external sense resistor. |
| Internal soft-start (600 µs) | Linearly ramps reference from 0 V to 0.8 V, limiting in-rush current during startup and preventing output overshoot. |
| Output overvoltage protection | Shuts down NMOS switch if FB exceeds 0.928 V (16% above 0.8-V reference), protecting downstream loads from fault conditions. |
| Thermal shutdown (165°C) | Halts switching until junction cools to ~150°C, preventing permanent damage under sustained overload or poor heatsinking. |
| 250-mΩ NMOS switch | Reduces conduction losses at 1.5-A load; enables >90% efficiency at 12 VIN/3.3 VOUT with proper layout and component selection. |
Applications
| USB-Powered Devices | Set-Top Boxes |
|---|---|
|
Use Scenario: Powering SoC cores, memory, and peripherals from 5-V USB bus in portable media players or streaming sticks. IC Role / Device Role / Timing Role: Primary point-of-load regulator delivering stable 1.2-V or 1.8-V core voltage with fast load-step response. Use Value: 550-kHz switching enables small 2.2-µH inductors and 22-µF ceramic output caps, meeting strict size constraints while maintaining <2% output ripple. |
Use Scenario: Generating 3.3-V and 5-V rails for demodulator ICs, tuners, and HDMI interface circuitry in consumer STBs. IC Role / Device Role / Timing Role: Secondary DC-DC converter stepping down 12-V or 19-V adapter output to low-noise system rails. Use Value: 400-nA shutdown current extends standby battery life; thermal shutdown protects against enclosure overheating during extended operation. |
| HDD Core Power | Battery-Powered Devices |
|
Use Scenario: Supplying 1.2-V CPU core voltage to 2.5-inch HDD controllers in NAS enclosures or portable drives. IC Role / Device Role / Timing Role: High-current buck regulator handling dynamic 0–1.5-A load steps during spin-up and data access bursts. Use Value: Cycle-by-cycle current limiting (2.9 A typ.) prevents latch-up during motor startup surges; WSON package aids thermal dissipation on dense PCBs. |
Use Scenario: Regulating 3.3-V logic rail from single-cell Li-ion (3.0–4.2 V) or dual-cell alkaline (2.0–3.2 V) batteries in handheld test equipment. IC Role / Device Role / Timing Role: Wide-input buck converter maintaining regulated output across full battery discharge curve. Use Value: 3-V minimum input supports operation down to nearly depleted cells; 0.8-V reference enables accurate low-VOUT setting for ultra-low-power MCUs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2738XMYX/NOPB | 1.6-MHz switching frequency vs 550 kHz; identical pinout, package, and feature set. | Better suited for ultra-compact designs requiring smallest possible inductors/caps; higher switching loss reduces peak efficiency by ~2–3% at full load. | Select LM2738XMYX/NOPB only when board area is more critical than efficiency; LM2738YMYX/NOPB preferred for thermal-limited or high-current applications. |
| TPS62231DRVR | 3-MHz fixed-frequency buck; 1.8-A rated; 0.6-V reference; different pinout (6-pin WSON); no BOOST pin. | Requires external compensation; lacks OVP and thermal shutdown; optimized for sub-1-V core rails in portable apps. | Use TPS62231DRVR only for new designs targeting <1-V outputs and 3-MHz operation; LM2738YMYX/NOPB offers broader voltage range, integrated protection, and proven reliability in industrial deployments. |
Compared with LM2738XMYX/NOPB, the LM2738YMYX/NOPB trades higher efficiency and lower EMI for larger passive components; versus TPS62231DRVR, it provides superior protection features, wider input/output flexibility, and simpler layout - making it the robust choice for cost-sensitive, thermally constrained, or safety-aware designs.
Availability
LM2738YMYX/NOPB is available at Aetrix Electronics and suitable for USB-powered devices, set-top boxes, and HDD core power applications requiring stable component supply, long-term lifecycle support, and traceable sourcing from authorized channels.
Supply support for LM2738YMYX/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 power conversion solutions.
The LM2738YMYX/NOPB belongs to TI's legacy high-frequency buck regulator family, designed specifically for space-constrained, medium-current point-of-load applications where integration, thermal performance, and protection features outweigh ultra-high switching frequency demands.
FAQ
What is the switching frequency of the LM2738YMYX/NOPB?
The LM2738YMYX/NOPB operates at a fixed 550-kHz switching frequency, as confirmed in TI's SNVS556C datasheet Section 6.5 (FSW parameter). This frequency is factory-set and non-adjustable. It enables use of small surface-mount inductors (e.g., 2.2 µH) and ceramic capacitors while balancing efficiency and EMI performance - distinct from the 1.6-MHz LM2738X variant.
Does the LM2738YMYX/NOPB require an external bootstrap capacitor?
Yes, the LM2738YMYX/NOPB requires a 0.1-µF X7R ceramic capacitor (CBOOST) between the BOOST and SW pins, as specified in Figure 26 and Section 7.3.1 of the datasheet. This capacitor supplies gate drive voltage to the internal NMOS switch; omitting it causes failure to regulate due to insufficient VGS. TI recommends placing it within 2 mm of the pins with short, wide traces.
What is the maximum output current supported by the LM2738YMYX/NOPB?
The LM2738YMYX/NOPB delivers up to 1.5 A continuous output current under recommended operating conditions (TA ≤ 85°C, proper PCB thermal design). Its internal NMOS switch has a typical RDS(ON) of 250 mΩ, and cycle-by-cycle current limiting triggers at 2.9 A (typical), providing headroom for transient loads. Full 1.5-A capability assumes adequate copper area on the DAP thermal pad and ambient temperature ≤ 85°C.
How does the enable (EN) pin function on the LM2738YMYX/NOPB?
The EN pin on the LM2738YMYX/NOPB provides logic-level control: applying ≥1.4 V enables regulation, while ≤0.4 V forces shutdown with 400-nA quiescent current. The pin must never float or exceed VIN + 0.3 V. Internal pull-down ensures default-off behavior if left unconnected. This feature is critical for power sequencing in multi-rail systems and battery conservation in portable LM2738YMYX/NOPB designs.
Is the LM2738YMYX/NOPB RoHS-compliant and lead-free?
Yes, the LM2738YMYX/NOPB is RoHS-compliant and lead-free, as indicated by the "/NOPB" suffix per TI's packaging nomenclature. It meets JEDEC J-STD-020 moisture sensitivity level 2a (MSL-2a) and is compatible with standard Pb-free reflow profiles (peak 260°C). TI's official product folder and orderable addendum confirm green compliance and halogen-free construction.
LM2738YMYX/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:
- Obsolete
- 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:
- 550kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-HVSSOP
LM2738YMYX/NOPB FAQ
1.How can I place an order for LM2738YMYX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2738YMYX/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 LM2738YMYX/NOPB reliable?
The price and inventory of LM2738YMYX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2738YMYX/NOPB is usually 5 days.
3.What payment methods are accepted for LM2738YMYX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2738YMYX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2738YMYX/NOPB?
LM2738YMYX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2738YMYX/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 LM2738YMYX/NOPB?
For technical support, including LM2738YMYX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2738YMYX/NOPB requirements.
6.How does Aetrix verify that LM2738YMYX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2738YMYX/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 LM2738YMYX/NOPB meets industry standards.
7.What is the process for return or replacement of LM2738YMYX/NOPB?
All LM2738YMYX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2738YMYX/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 LM2738YMYX/NOPB part is unused and in its original packaging.
Return procedure for LM2738YMYX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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