Texas Instruments LM2831YSD/NOPB

Overview

LM2831YSD/NOPB from Texas Instruments is a monolithic, current-mode PWM step-down DC-DC regulator IC in a 6-pin WSON package, delivering up to 1.5-A output current with 0.55-MHz fixed switching frequency, 0.6-V internal reference (±2%), and 130-mΩ PMOS switch. It operates from 3 V to 5.5 V input and supports adjustable output voltages from 0.6 V to 4.5 V, commonly used in USB-powered devices and set-top box core power rails.

For engineers reviewing the LM2831YSD/NOPB datasheet, LM2831YSD/NOPB pinout, LM2831YSD/NOPB application, or LM2831YSD/NOPB equivalent, key selection criteria include its 0.55-MHz switching frequency for low EMI and moderate inductor sizing, thermal shutdown at 165°C, undervoltage lockout with 430-mV hysteresis, and ultra-low 30-nA shutdown current-critical for battery-backed and always-on embedded systems.

Technical Context

The LM2831YSD/NOPB implements constant-frequency current-mode control with internal compensation, enabling stable regulation across wide load and line variations without external loop components. Its 30-ns minimum on-time supports high duty-cycle operation down to 0.6-V output while maintaining 0.55-MHz switching across –40°C to 125°C.

It integrates pulse-by-pulse current limiting (2.5-A typical), soft-start (600-µs ramp), overvoltage protection (15% above VREF), and separate VINA/VIND power inputs for improved noise immunity. The WSON package features an exposed die attach pad (DAP) tied to GND for enhanced thermal performance (R_θJC(bot) = 9.2°C/W).

Key Specifications

Pinout & Package

LM2831YSD/NOPB uses a 6-pin WSON (NGG) package, 3.00 mm × 3.00 mm, with exposed die attach pad (DAP) for thermal conduction to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with TPS62231DRVR and MP2101DJ-LF-Z, the LM2831YSD/NOPB offers superior low-output-voltage flexibility (0.6 V min), dedicated noise-isolated power inputs, and proven thermal robustness in industrial ambient conditions-making it preferred for USB-C PD adapters and legacy DSL hardware where reference accuracy and EMI control are prioritized over minimal footprint.

Availability

LM2831YSD/NOPB is available at Aetrix Electronics and suitable for USB-powered devices, set-top boxes, HDD core power, and DSL modems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LM2831YSD/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-efficiency DC-DC conversion.

The LM2831YSD/NOPB belongs to TI's high-frequency buck regulator product line, designed specifically for space-constrained, medium-current applications where simplicity, thermal reliability, and low-noise operation are essential-such as consumer electronics and broadband infrastructure.

FAQ

What is the switching frequency of the LM2831YSD/NOPB and how does it affect inductor selection?

The LM2831YSD/NOPB has a fixed switching frequency of 0.55 MHz. This allows use of compact 2.2–4.7-µH shielded ferrite inductors rated for ≥2.2-A saturation current, balancing size, cost, and output ripple. Lower frequencies would require larger inductors; higher frequencies increase switching losses and EMI filtering complexity. The 0.55-MHz point was selected to optimize efficiency and component count for 1.5-A loads in consumer-grade PCBs.

Can the LM2831YSD/NOPB operate with a 3.3-V input to generate 1.2-V output at 1.5 A?

Yes, the LM2831YSD/NOPB supports input voltages from 3 V to 5.5 V and delivers 1.5-A continuous output across its full input range. At VIN = 3.3 V and VOUT = 1.2 V, the calculated duty cycle is ~36%, well within the 2–90% operational range. Efficiency remains >92% under these conditions, and thermal performance is verified per R_θJA = 54.9°C/W (WSON package) with standard 2-oz copper layout.

Does the LM2831YSD/NOPB require external compensation components?

No, the LM2831YSD/NOPB uses internally compensated current-mode control, eliminating the need for external compensation networks. This simplifies design, reduces BOM count, and ensures stability across all recommended operating conditions-including input voltage from 3 V to 5.5 V, output voltage from 0.6 V to 4.5 V, and load current from 0 A to 1.5 A-without tuning.

How does the EN pin function on the LM2831YSD/NOPB and what is its threshold voltage?

The EN pin on the LM2831YSD/NOPB is a logic-level enable input with a typical threshold of 1.8 V (rising) and 0.4 V (falling). A voltage ≥1.8 V enables regulation; ≤0.4 V places the device in ultra-low-power shutdown (30 nA). The pin draws only 100 nA, allowing direct connection to microcontroller GPIO or open-drain logic without pull-up resistors in most cases.

What thermal protection mechanisms are built into the LM2831YSD/NOPB?

The LM2831YSD/NOPB includes thermal shutdown that activates at 165°C junction temperature and recovers at ~150°C. It also features thermal derating via R_θJA = 54.9°C/W (WSON) and R_θJC(bot) = 9.2°C/W, enabling effective heat transfer through the exposed DAP to the PCB ground plane. No external thermal monitoring or intervention is required for safe operation within datasheet limits.