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Texas Instruments LM2831YMFX/NOPB
- Part No.:
- LM2831YMFX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LM2831YMFX/NOPB.pdf
- Description:
- IC REG BUCK ADJ 1.5A SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,826
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Product details
Overview
LM2831YMFX/NOPB from Texas Instruments is a monolithic, current-mode PWM step-down DC-DC regulator IC in a 5-pin SOT-23 package, delivering up to 1.5 A output current with 0.55 MHz fixed switching frequency, 0.6 V ±2% internal reference, and 130 mΩ PMOS switch. It operates from 3 V to 5.5 V input and regulates output voltages from 0.6 V to 4.5 V - used in USB-powered devices and HDD core power supplies.
For engineers reviewing the LM2831YMFX/NOPB datasheet, LM2831YMFX/NOPB pinout, LM2831YMFX/NOPB application, or LM2831YMFX/NOPB equivalent, key selection criteria include its 0.55 MHz switching frequency for compact magnetics, thermal shutdown at 165°C, 30 nA shutdown current, 2.73 V enable threshold, and internal soft-start for controlled ramp-up of 3.3 V @ 1.5 A rails.
Technical Context
The LM2831YMFX/NOPB implements constant-frequency current-mode control with an internal 0.6 V reference, pulse-by-pulse current limiting (2.5 A typical), and undervoltage lockout (2.73 V rising, 2.3 V falling, 430 mV hysteresis). Its 0.55 MHz oscillator enables use of small ceramic capacitors and low-profile inductors while maintaining >90% efficiency across 0.25–1.5 A loads at 3.3 V output.
It integrates a 130 mΩ PMOS high-side switch, internal soft-start (~600 µs ramp), overvoltage protection (15% above VREF), and thermal shutdown with 15°C hysteresis. The device requires no external compensation due to internal loop compensation and supports adjustable output via resistive feedback divider connected to FB pin.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 0.55 MHz - enables use of ≤4.7 µH inductors and 22 µF ceramic output caps without compromising transient response. |
| Output Current | 1.5 A continuous - sufficient for CPU core, FPGA I/O, or USB peripheral power rails with margin for peak load. |
| Input Voltage Range | 3 V to 5.5 V - compatible with single-cell Li-ion, USB 5 V, or regulated 3.3 V/5 V system rails. |
| Feedback Reference | 0.6 V ±2% - sets minimum output voltage and defines accuracy of resistor-divider-based output programming. |
| PMOS Switch RDS(on) | 130 mΩ (TJ = 25°C) - limits conduction loss to <100 mW at 1 A, supporting >93% peak efficiency at 3.3 V/1.5 A. |
| Quiescent Current | 2.8 mA (switching), 30 nA (shutdown) - enables ultra-low standby power in battery-backed or always-on systems. |
| Enable Threshold | 2.73 V (rising), 2.3 V (falling) - provides clean start-up and brownout recovery with 430 mV hysteresis. |
Pinout & Package
LM2831YMFX/NOPB uses the 5-pin SOT-23 (DBV) package (1.60 mm × 2.90 mm), optimized for space-constrained PCB layouts. Thermal performance is characterized by RθJA = 163.4°C/W on a standard 4-layer board.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power input | Primary supply connection (3–5.5 V); must be decoupled with ≥22 µF ceramic capacitor near pin. |
| SW | Switch node | Drives external inductor and catch diode; carries high di/dt; requires tight layout to minimize EMI and ringing. |
| EN | Enable control | Logic-high active input; 2.73 V threshold ensures reliable turn-on from 3.3 V GPIO; floating prohibited. |
| FB | Feedback input | Senses output voltage via resistor divider; 0.1 nA bias current enables high-impedance dividers (e.g., 15 kΩ/15 kΩ). |
| GND | Signal & power ground | Reference for FB, EN, and internal circuitry; must connect to low-impedance ground plane near FB resistor bottom leg. |
Key Features
| Feature | Design Value |
|---|---|
| Internal soft-start | ~600 µs reference ramp - limits inrush current during startup, preventing input rail collapse and output overshoot. |
| Current-mode PWM control | Single-loop stability with no external compensation - simplifies design and improves transient response to load steps. |
| Overvoltage protection | Triggers at FB = 1.15 × 0.6 V = 0.69 V - disables switch to protect downstream logic if feedback fails open. |
| Thermal shutdown | Activates at 165°C junction temperature, latches off until TJ drops to ~150°C - prevents permanent damage under overload or poor heatsinking. |
| Pulse-by-pulse current limit | 2.5 A typical switch current limit - protects internal PMOS during short-circuit or startup into large capacitive loads. |
Applications
| USB-Powered Devices | HDD Core Power |
|---|---|
Use Scenario: Portable USB hubs, external SSD enclosures, and bus-powered peripherals requiring regulated 3.3 V or 1.2 V from 5 V USB source. IC Role / Device Role: Primary step-down regulator converting 5 V USB input to stable 3.3 V/1.5 A or 1.2 V/1.5 A core rail. Use Value: 0.55 MHz switching allows compact 3.3 µH inductor and 2×22 µF X5R output caps; 30 nA shutdown extends battery life. |
Use Scenario: 2.5-inch HDDs with dual-rail requirements (e.g., 3.3 V motor + 1.2 V controller) powered from 5 V host supply. IC Role / Device Role: Dedicated core voltage regulator for HDD controller ASIC, replacing discrete buck solutions. Use Value: 1.5 A capability and 96% efficiency at 1.2 V/1.5 A reduce thermal load; internal soft-start prevents spin-up current surges. |
| Set-Top Boxes | DSL Modems |
Use Scenario: Low-power STB SoC subsystems needing clean, efficient 1.8 V or 3.3 V rails from 5 V main supply. IC Role / Device Role: Local point-of-load regulator for video decoder, tuner, or memory interface blocks. Use Value: 0.6 V reference enables precise low-voltage outputs; current-mode control maintains regulation during bursty video processing loads. |
Use Scenario: DSL line cards requiring isolated, low-noise 3.3 V digital supply for PHY and MAC layers. IC Role / Device Role: Main DC-DC converter powering Ethernet PHY, microcontroller, and flash memory. Use Value: 130 mΩ RDS(on) and ceramic-capable design minimize heat and ripple; 30 nA shutdown supports remote management wake-on-ring. |
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 | 0.65 MHz switching, 0.6 V reference, 1.5 A, 2.05 V–6.5 V input, 12 µA quiescent current (active) | Wider input range and lower active IQ suit battery-fed designs; lacks OVP and thermal shutdown latch | Prefer for longer battery runtime where input may dip below 3 V; verify external OVP if required. |
| MP1471GJ-Z | 1.3 MHz switching, 0.8 V reference, 2 A, 4.5–16 V input, 250 mΩ RDS(on), no internal soft-start | Higher input range and current rating; higher RDS(on) reduces efficiency at 1.5 A; requires external soft-start RC | Choose only if input exceeds 5.5 V or >1.5 A is needed; add 100 nF + 100 kΩ to EN for soft-start. |
Compared with LM2831YMFX/NOPB, TPS62231DRVR offers better light-load efficiency but less protection integration, while MP1471GJ-Z trades higher voltage capability for reduced efficiency and added external components - LM2831YMFX/NOPB remains optimal for 3–5.5 V, 1.5 A, space-constrained applications requiring full protection and simplicity.
Availability
LM2831YMFX/NOPB is available at Aetrix Electronics and suitable for USB-powered devices, HDD core power supplies, set-top boxes, and DSL modems requiring stable component supply, long-term production continuity, and RoHS-compliant packaging.
Supply support for LM2831YMFX/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 company specializing in analog, embedded processing, and power management ICs, with leadership in high-efficiency DC-DC conversion and automotive-grade reliability.
The LM2831YMFX/NOPB belongs to TI's LM28xx family of high-frequency, monolithic buck regulators designed for space-constrained, cost-sensitive consumer and computing applications requiring fast transient response and minimal external components.
FAQ
What is the switching frequency of the LM2831YMFX/NOPB?
The LM2831YMFX/NOPB has a fixed switching frequency of 0.55 MHz, optimized for use with small surface-mount inductors (e.g., 3.3 µH) and ceramic capacitors. This frequency balances efficiency, size, and EMI performance across its 3–5.5 V input range and supports >90% efficiency at 3.3 V/1.5 A output. Frequency tolerance is ±25% over temperature and input voltage.
Does the LM2831YMFX/NOPB require external compensation components?
No, the LM2831YMFX/NOPB features fully internal compensation and requires no external compensation network. Its current-mode architecture with integrated error amplifier and PWM comparator enables stable operation with only five external components: input cap, output cap, inductor, catch diode, and feedback divider - simplifying layout and reducing BOM count.
What is the maximum output voltage that can be set with the LM2831YMFX/NOPB?
The LM2831YMFX/NOPB supports output voltages from 0.6 V to 4.5 V, set by an external resistor divider connected to the FB pin. With its 0.6 V internal reference, a 15 kΩ top resistor and 15 kΩ bottom resistor yields 1.2 V output; scaling the divider allows any value in the specified range, limited only by resistor tolerance and FB pin bias current (0.1 nA).
How does the LM2831YMFX/NOPB handle thermal overload conditions?
The LM2831YMFX/NOPB incorporates thermal shutdown that activates at 165°C junction temperature, disabling the internal PMOS switch until the die cools to approximately 150°C. This hysteresis prevents cycling and protects against permanent damage. Thermal performance is characterized with RθJA = 163.4°C/W for the SOT-23 package on a standard 4-layer board.
Can the LM2831YMFX/NOPB be used with ceramic output capacitors?
Yes, the LM2831YMFX/NOPB is fully compatible with ceramic output capacitors, including X5R and X7R MLCCs. Its internal compensation and current-mode control ensure stability with low-ESR ceramics. Recommended minimum output capacitance is 22 µF (e.g., two 10 µF or one 22 µF 0805 X5R), enabling low ripple and excellent transient response without additional damping components.
LM2831YMFX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- 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):
- 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:
- SOT-23-5
LM2831YMFX/NOPB FAQ
1.How can I place an order for LM2831YMFX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2831YMFX/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 LM2831YMFX/NOPB reliable?
The price and inventory of LM2831YMFX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2831YMFX/NOPB is usually 5 days.
3.What payment methods are accepted for LM2831YMFX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2831YMFX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2831YMFX/NOPB?
LM2831YMFX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2831YMFX/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 LM2831YMFX/NOPB?
For technical support, including LM2831YMFX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2831YMFX/NOPB requirements.
6.How does Aetrix verify that LM2831YMFX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2831YMFX/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 LM2831YMFX/NOPB meets industry standards.
7.What is the process for return or replacement of LM2831YMFX/NOPB?
All LM2831YMFX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2831YMFX/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 LM2831YMFX/NOPB part is unused and in its original packaging.
Return procedure for LM2831YMFX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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