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Texas Instruments LM2831YSDX
- Part No.:
- LM2831YSDX
- Manufacturer:
- Texas Instruments
- Package:
- 6-WDFN Exposed Pad
- Datasheet:
-
LM2831YSDX.pdf
- Description:
- IC REG BUCK ADJ 1.5A 6WSON
- Quantity:
- Payment:
- Shipping:
Inventory:3,235
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Product details
Overview
LM2831YSDX from Texas Instruments is a monolithic, current-mode PWM step-down DC-DC regulator in 6-pin LLP package, delivering 1.5A output current with internal 150 mΩ PMOS switch, fixed 550 kHz switching frequency, and 0.6 V ±2% feedback reference voltage. It operates from 3.0 V to 5.5 V input and supports adjustable output down to 0.6 V - ideal for local core power conversion in space-constrained USB-powered devices and set-top boxes.
For engineers reviewing the LM2831YSDX datasheet, LM2831YSDX pinout, LM2831YSDX application, or LM2831YSDX equivalent, key selection criteria include its 550 kHz fixed-frequency operation, thermal shutdown at 165°C, 30 nA shutdown current, internal soft-start (≈600 µs), and compatibility with ceramic output capacitors for high-efficiency, low-ripple regulation in compact PCB layouts.
Technical Context
The LM2831YSDX employs current-mode PWM control with internal compensation and a fixed 550 kHz oscillator, enabling stable regulation across 3.0–5.5 V input and 0.6–4.5 V output ranges. Its architecture integrates a 150 mΩ PMOS switch (LLP-6 package), cycle-by-cycle current limiting (1.8–2.5 A), and overvoltage protection triggered at FB = 1.15 × VFB.
It features undervoltage lockout (UVLO) with 2.73 V turn-on threshold and 430 mV hysteresis, 0.1–0.2×IOUT inductor ripple design guidance, and thermal shutdown with 15°C hysteresis (165°C trip, ~150°C recovery). The DAP (Die Attach Pad) must be connected to system ground for thermal management but is not a primary GND path.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | Fixed 550 kHz - enables use of small surface-mount inductors (e.g., 4.7 µH) and ceramic capacitors without compromising transient response. |
| Output Current | 1.5 A continuous - supported by internal PMOS switch with 150 mΩ RDS(ON) in LLP-6 package, validated over −40°C to +125°C junction temperature range. |
| Input Voltage Range | 3.0 V to 5.5 V - compatible with single-cell Li-ion, USB 5 V, and regulated 3.3 V/5 V rails; UVLO prevents operation below 2.73 V. |
| Feedback Reference | 0.600 V ±2% - sets output voltage via external resistor divider; line regulation ≤0.02%/V ensures stability across input variation. |
| Quiescent Current | 2.8–4.5 mA (active), 30 nA (shutdown) - minimizes standby power loss in battery-powered applications like DSL modems and portable HDDs. |
| Thermal Shutdown | 165°C trip temperature with ~15°C hysteresis - protects against sustained overload or poor PCB thermal design; requires DAP-to-ground connection for effective heat dissipation. |
| Package Thermal Resistance | θJA = 80°C/W, θJC = 18°C/W (LLP-6) - mandates ≥4 thermal vias under DAP and solid ground plane for reliable 1.5 A operation at ambient up to 104°C. |
Pinout & Package
LM2831YSDX is housed in a thermally enhanced 6-pin LLP (Leadless Leadframe Package) with exposed die attach pad (DAP). The DAP must be soldered to a dedicated ground plane using ≥4 thermal vias for optimal thermal performance. Pin 1 is FB, Pin 2 is GND, Pin 3 is SW, Pin 4 is VIND, Pin 5 is VINA, and Pin 6 is EN. VIND and VINA are internally isolated power domains: VIND supplies the PMOS switch, while VINA powers control circuitry and must be tied to VIND on PCB.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (FB) | Feedback input | High-impedance node sensing output voltage via resistor divider; trace must be short and远离 noisy nodes to avoid regulation error. |
| Pin 2 (GND) | Signal & power ground | Reference for FB, EN, and internal circuits; bottom resistor of feedback network must connect here with minimal trace length. |
| Pin 3 (SW) | Switch node | Drives external inductor and catch diode; experiences fast dV/dt edges - requires tight layout coupling to minimize EMI and ringing. |
| Pin 4 (VIND) | Power input (switch side) | Supplies internal PMOS switch; requires local 22 µF ceramic input capacitor with low ESL placed adjacent to this pin. |
| Pin 5 (VINA) | Control supply | Powers bias circuitry, oscillator, and error amplifier; must be connected directly to VIND on PCB - no series impedance or filtering. |
| Pin 6 (EN) | Enable input | Logic-high active; threshold 1.8 V, max voltage VINA + 0.3 V; floating state disables regulator - pull-down recommended if unused. |
| DAP | Die attach pad | Thermal interface only - must be soldered to system ground plane with ≥4 thermal vias; not electrically connected to internal GND. |
Key Features
| Feature | Design Value |
|---|---|
| Internal soft-start | Ramps internal reference from 0 V to 0.6 V over ≈600 µs - limits inrush current during startup and prevents output overshoot in systems with large output capacitance. |
| Current-mode PWM control | Enables fast transient response and inherent cycle-by-cycle current limiting (1.8–2.5 A) - eliminates need for external current-sense resistor and simplifies loop compensation. |
| Overvoltage protection | Shuts off PMOS switch when FB exceeds 1.15 × 0.6 V (≈0.69 V) - safeguards downstream loads from fault-induced overvoltage events. |
| Ultra-low shutdown current | 30 nA typical - extends battery life in always-on USB peripherals and low-power embedded systems requiring deep sleep modes. |
| Thermal shutdown with hysteresis | Turns off switching at 165°C junction temperature and resumes at ~150°C - prevents thermal runaway while allowing safe recovery without manual reset. |
Applications
| USB-Powered Devices | Set-Top Boxes |
|---|---|
Use Scenario: Powering FPGA I/O banks or microcontroller cores from a 5 V USB port in portable media adapters. IC Role / Device Role / Timing Role: Primary step-down regulator converting 5 V USB input to 1.2 V or 1.8 V core rail with tight load-transient response. Use Value: 550 kHz switching allows compact 4.7 µH inductor and 2×22 µF X5R MLCC output stage - fits within <1 cm² footprint while maintaining >88% efficiency at 1.25 A. |
Use Scenario: Generating 3.3 V logic supply for demodulator ICs and tuners in cost-sensitive consumer STBs. IC Role / Device Role / Timing Role: Local DC/DC converter replacing linear regulators to reduce heat and improve power density on dense mainboards. Use Value: Internal 150 mΩ PMOS switch and 0.6 V reference enable ±1% output accuracy over line/load/temperature - meets STB standby power and ripple requirements (<20 mVpp). |
| HDD Core Power | DSL Modems |
Use Scenario: Supplying 1.2 V Vcore to 2.5″ SATA HDD controller ASICs in external storage enclosures. IC Role / Device Role / Timing Role: High-current buck regulator handling dynamic load steps up to 1.5 A with <10 µs recovery time. Use Value: Current-mode control and internal compensation ensure stable operation with ceramic output caps - eliminates electrolytic bulk capacitors and reduces board area by 30% vs. legacy solutions. |
Use Scenario: Providing 1.8 V or 2.5 V supply to ADSL2+ PHY and DSP processors in wall-powered broadband modems. IC Role / Device Role / Timing Role: Efficient intermediate rail generator operating from 5 V adapter input with low quiescent current during idle periods. Use Value: 30 nA shutdown current and 2.8 mA active IQ enable compliance with Energy Star Level 5 standby power limits (<300 mW system-wide). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRVR | Fixed 3 MHz switching, 0.6 V reference, 1.5 A rating, SOT-23-6 package; higher RDS(ON) (200 mΩ), no DAP. | Better suited for ultra-compact designs where board area is more critical than thermal headroom; lacks thermal pad for sustained 1.5 A loads. | Select TPS62231DRVR only when PCB real estate is constrained and peak load duration is short; LM2831YSDX preferred for continuous 1.5 A with thermal margin. |
| MP2104DQ-LF-Z | 500 kHz switching, 0.6 V reference, 1.5 A rating, QFN-6 (0.9 mm height); RDS(ON) = 180 mΩ, no integrated OVP, 1 µA shutdown current. | Lower profile (0.9 mm vs. 1.0 mm) and smaller footprint (2 mm × 2 mm vs. 3 mm × 3 mm), but lacks overvoltage protection and has higher conduction loss. | Choose MP2104DQ-LF-Z for height-sensitive applications like slim modems; LM2831YSDX remains superior where robustness (OVP, thermal shutdown hysteresis) and long-term reliability are prioritized. |
Compared with TPS62231DRVR and MP2104DQ-LF-Z, LM2831YSDX offers superior thermal performance via its exposed DAP, integrated overvoltage protection, and tighter feedback reference tolerance (±2% vs. ±3%), making it the preferred choice for industrial-grade USB-powered equipment and consumer electronics requiring extended lifetime under thermal stress.
Availability
LM2831YSDX is available at Aetrix Electronics and suitable for USB-powered devices, set-top boxes, HDD core power, DSL modems, and portable media adapters requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for LM2831YSDX 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 and embedded processing technologies, with decades of expertise in power management ICs for industrial, automotive, and consumer markets.
The LM2831YSDX belongs to TI's high-frequency buck regulator product line, designed specifically for space-constrained, efficiency-critical applications requiring simple implementation, minimal external components, and robust protection features in portable and always-on electronics.
FAQ
What is the switching frequency of the LM2831YSDX?
The LM2831YSDX has a fixed internal switching frequency of 550 kHz. This value is factory-trimmed and cannot be adjusted externally. It is optimized to balance inductor size, efficiency, and EMI performance - enabling use of standard 4.7 µH shielded inductors and ceramic output capacitors while maintaining >88% efficiency at 1.25 A output. The 550 kHz frequency is specific to the "Y" variant; other variants (X, Z) operate at 1.6 MHz and 3.0 MHz respectively.
Does the LM2831YSDX require external compensation components?
No, the LM2831YSDX uses internal compensation and is fully functional with only five external components: input capacitor, output capacitor, inductor, catch diode, and feedback resistor divider. Its current-mode control architecture and factory-tuned compensation network eliminate the need for external Type-II or Type-III compensation networks - significantly reducing design complexity and board area. This is confirmed in the "Applications Information" section of the official TI datasheet (SNVS422B).
What is the purpose of separate VIND and VINA pins on the LM2831YSDX?
VIND (Pin 4) supplies power to the internal PMOS switch, while VINA (Pin 5) powers the control circuitry (oscillator, error amplifier, logic). They are electrically isolated inside the IC to prevent switching noise from coupling into sensitive analog blocks. Per the datasheet, VINA must be connected directly to VIND on the PCB with zero series impedance - no ferrite bead or RC filter - to ensure stable operation and avoid startup failure or erratic enable behavior.
Can the LM2831YSDX drive a 1.5 A load continuously in the LLP-6 package?
Yes, the LM2831YSDX is rated for 1.5 A continuous output in the LLP-6 package, provided the PCB implements proper thermal design: the DAP must be soldered to a solid ground plane with ≥4 thermal vias, and the layout must follow TI's recommended guidelines (e.g., short high-current traces, localized input/output capacitors). Under these conditions and at 5 VIN/3.3 VOUT, junction temperature remains below 125°C at ambient ≤104°C, as verified in the thermal characterization example (page 14, SNVS422B).
What protection features does the LM2831YSDX include?
The LM2831YSDX integrates five key protections: (1) cycle-by-cycle current limiting (trip point 1.8–2.5 A), (2) thermal shutdown at 165°C with ~15°C hysteresis, (3) output overvoltage protection (trips when FB > 0.69 V), (4) undervoltage lockout (2.73 V turn-on, 2.3 V turn-off), and (5) 30 nA ultra-low shutdown current to prevent battery drain. All are implemented entirely within the IC - no external components required - and are documented in Sections 7–9 of the TI datasheet SNVS422B.
LM2831YSDX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 6-WDFN Exposed Pad
- 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):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 4.5V
- 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:
- 6-WSON (3x3)
LM2831YSDX FAQ
1.How can I place an order for LM2831YSDX through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2831YSDX 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 LM2831YSDX reliable?
The price and inventory of LM2831YSDX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2831YSDX is usually 5 days.
3.What payment methods are accepted for LM2831YSDX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2831YSDX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2831YSDX?
LM2831YSDX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2831YSDX 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 LM2831YSDX?
For technical support, including LM2831YSDX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2831YSDX requirements.
6.How does Aetrix verify that LM2831YSDX is sourced from the original manufacturer or authorized distributors?
All LM2831YSDX 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 LM2831YSDX meets industry standards.
7.What is the process for return or replacement of LM2831YSDX?
All LM2831YSDX units undergo pre-shipment inspection (PSI). If there is an issue with LM2831YSDX, 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 LM2831YSDX part is unused and in its original packaging.
Return procedure for LM2831YSDX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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