LM2841XMK-ADJL/NOPB - 300mA 42V Step-Down DC/DC | Texas Instruments
N.º de pieza: LM2841XMK ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $1.94 | $1,94 |
| 10 | $1.74 | $17,40 |
| 100 | $1.45 | $145,00 |
| 500 | $1.21 | $605,00 |
| 1.000 | $1.04 | $1.040,00 |
LM2841XMK Descripción general
A buck (step-down) DC-DC converter is a switch-mode power supply topology that efficiently converts a higher DC input voltage into a lower DC output voltage by rapidly chopping the input with an inductor-capacitor filter network, achieving efficiencies that linear regulators cannot match at large input-to-output differentials. Within the broader power management IC hierarchy, the LM2841XMK sits under DC-DC converters -> voltage regulators -> power management ICs -> semiconductors. The TSOT-23-6 (DDC) footprint places it firmly in the surface-mount QFN/SOT family, and its wide VIN range makes it a common choice for 12 V/24 V industrial bus and battery-powered applications.
Key features of the LM2841XMK include a wide 4.5 V to 42 V continuous input range, an integrated MOSFET switch that keeps the BOM small, 300 mA continuous output current, a low 0.765 V feedback reference, internal compensation that removes the need for an external compensation network, and a shutdown (SHDN) pin that can implement soft-start with an external RC. Its 1.25 MHz nominal switching frequency allows small ceramic input/output capacitors and a tiny inductor, shrinking the total solution footprint to a few square millimeters on the PCB.
Typical applications for the LM2841XMK include 12 V/24 V industrial sensor rails, battery chargers, LED drivers, distributed supply rails in point-of-load systems, and any application that needs to step a wide-range bus down to a logic-level rail. It is frequently selected over linear regulators when the input-to-output differential exceeds ~2 V because of its high efficiency. The thin SOT-23 package has a theta-2-JA around 90 C/W on a standard JEDEC test board, so careful copper-pour thermal management is required when dissipating more than ~0.5 W.
When designing with the LM2841XMK, follow the manufacturer datasheet recommended inductor and capacitor values for your specific VOUT, and ensure the input capacitor handles the RMS ripple current at the 1.25 MHz switching frequency. Always check that the peak inductor current stays below the 0.5 A peak switch-current limit when the load transient peaks coincide with minimum VIN. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the TI datasheet alone.
Alternativas directas para LM2841XMK — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
LM2840XMK-ADJL/NOPB
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LM2842XMK-ADJL/NOPB
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LM2841XQMK-ADJL/NOPB
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LM2842XQMK-ADJL/NOPB
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LM2841XMKX-ADJL/NOPB
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LM2841XMK Valores máximos y características eléctricas
| Topología | Buck (step-down) |
| Rango de tensión de entrada | 4.5 V to 42 V |
| Rango de tensión de salida | 0.765 V to 39.48 V (adjustable) |
| Nominal Feedback Voltage | 0.765 V |
| Corriente de salida máxima | 300 mA |
| Switching Frequency (nominal) | 1.25 MHz |
| Switch Current Limit | 0.5 A peak |
| Rango de temperatura de funcionamiento | -40 C to +125 C |
| Encapsulado | SOT-23-6 Thin (TSOT-23-6, TI DDC), 6 pins |
| Tipo de montaje | Surface Mount |
| Internal Compensation | Yes |
| SHDN Pin | Yes (supports soft-start via external RC) |
| Nivel MSL | 1 |
| Estado RoHS | Compliant |
| Lead-Free | Yes (NOPB suffix) |
Configuración de pines de LM2841XMK
| Pin 1 | SHDN — Shutdown/Enable (active high); supports soft-start via external RC |
| Pin 2 | VIN — Input supply voltage (4.5 V to 42 V) |
| Pin 3 | SW — Switch node - connect to external inductor |
| Pin 4 | GND — Ground return |
| Pin 5 | FB — Feedback voltage (0.765 V nominal) |
| Pin 6 | BST — Bootstrap capacitor for the internal high-side MOSFET gate drive |
Aplicaciones típicas
LM2841XMK es adecuado para 6 aplicacións: Industrial 24 V Sensor & PLC Logic Power, Automotive Battery / Load-Dump Pre-Regulator, Portable / Battery-Powered Device Charging, Distributed Point-of-Load (POL) Rails, LED Driver / Constant-Current Bias Supply, Wide-Range Sensor Conditioning Front-End.
Industrial 24 V Sensor & PLC Logic Power
The LM2841XMK-ADJL/NOPB is a strong fit for industrial 24 V sensor and PLC logic rails because its 4.5 V to 42 V continuous input range tolerates 24 V nominal buses plus transients, while its 300 mA output easily supplies a small PLC I/O island. According to TI, the 0.765 V reference lets the same PCB footprint generate 3.3 V, 5 V, or 12 V rails just by changing the feedback network. The 1.25 MHz switching frequency shrinks the inductor and capacitor, fitting the converter next to the sensor connector without disturbing analog signal paths.
Recomendado
Automotive Battery / Load-Dump Pre-Regulator
The LM2841XMK-ADJL/NOPB survives automotive load-dump pulses up to 42 V on the input, making it well suited to step a 12 V/24 V automotive battery down to a clean 3.3 V or 5 V rail for body electronics, infotainment nodes, or sensor modules. The AEC-Q100 LM2841XQMK is the drop-in automotive equivalent in the same TSOT-23-6 footprint. Designers should still add a TVS diode upstream and follow TI's input-capacitor RMS-current guidance at the 1.25 MHz switching frequency.
Recomendado
Portable / Battery-Powered Device Charging
The LM2841XMK-ADJL/NOPB suits portable and battery-powered applications because its wide 4.5 V-42 V input covers USB 5 V, 1S Li-ion and 2S Li-ion battery packs, while the shutdown pin supports simple on/off control to extend standby time. The 0.765 V minimum reference means a single device can generate 1.8 V, 3.3 V or 5 V rails with a 300 mA peak budget. The SHDN pin can implement soft-start with an external RC, inrush-safe for downstream battery-management devices and microcontroller cores.
Recomendado
Distributed Point-of-Load (POL) Rails
The LM2841XMK-ADJL/NOPB is widely used as a local point-of-load buck for sub-rails derived from a 12 V or 24 V bus in distributed power architectures, where one bulk 12 V/24 V supply feeds many small local 3.3 V/5 V regulators next to each IC. Its 1.25 MHz frequency avoids interference with AM-band and 455 kHz IF stages, while its TSOT-23-6 footprint sits directly under the load IC, minimizing PCB trace impedance and improving transient performance on dynamic digital loads.
Recomendado
LED Driver / Constant-Current Bias Supply
The LM2841XMK-ADJL/NOPB can be configured as a constant-current LED driver by replacing the lower feedback resistor with a high-side current-sense network referenced to the 0.765 V FB pin. The 300 mA output is sufficient for one or more high-brightness LEDs in series, and the wide 4.5-42 V input accommodates 12 V or 24 V architectural lighting rails. The shutdown pin enables PWM dimming when driven from a logic-level PWM source, with no extra dimming FET required.
Recomendado
Wide-Range Sensor Conditioning Front-End
The LM2841XMK-ADJL/NOPB is a good fit for analog and sensor front-end power conditioning because its 0.765 V feedback and tight line/load regulation create a stable low-voltage rail for op-amps, ADCs and reference ICs even when the upstream 24 V industrial bus sags or surges. The 1.25 MHz switching frequency is high enough to place the fundamental and harmonics outside most sensor bandwidths, while staying below the FCC Part 15 radiated-emission limits with simple filtering.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para LM2841XMK — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | LM2840XMK-ADJL/NOPB | LM2842XMK-ADJL/NOPB | LM2841XQMK-ADJL/NOPB | LM2842XQMK-ADJL/NOPB | LM2841XMKX-ADJL/NOPB |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments (AEC-Q100) | Texas Instruments (AEC-Q100) | Texas Instruments |
| Package | SOT-23-6 Thin (TSOT-23-6, DDC) | SOT-23-6 Thin (TSOT-23-6, DDC) - same | SOT-23-6 Thin (TSOT-23-6, DDC) - same | SOT-23-6 Thin (TSOT-23-6, DDC) - same | SOT-23-6 Thin (TSOT-23-6, DDC) - same | SOT-23-6 Thin (TSOT-23-6, DDC) - same |
| Input Voltage Range | 4.5 V to 42 V | 4.5 V to 42 V | 4.5 V to 42 V | 4.5 V to 42 V | 4.5 V to 42 V | 4.5 V to 42 V |
| Maximum Output Current | 300 mA | 100 mA | 600 mA | 300 mA | 600 mA | 300 mA |
| Feedback Voltage | 0.765 V | 0.765 V | 0.765 V | 0.765 V | 0.765 V | 0.765 V |
| Switch Current Limit (peak) | 0.5 A | ~0.2 A (per family spec) | 1.0 A | 0.5 A | 1.0 A | 0.5 A |
| Switching Frequency (nominal) | 1.25 MHz | 1.25 MHz | 1.25 MHz | 1.25 MHz | 1.25 MHz | 1.25 MHz |
| AEC-Q100 Qualified | No | No | No | Yes | Yes | No |
Diferenciadores clave
- Pin-compatible current tiering across 100/300/600 mA in the same TSOT-23-6 footprint (frente a LM2840XMK (100 mA) and LM2842XMK (600 mA))
- AEC-Q100 automotive option in the same footprint (frente a LM2841XQMK (AEC-Q100))
- Wide 42 V input for 24 V industrial and automotive load-dump tolerance (frente a Typical 5 V/18 V input buck regulators in SOT-23-6)
Notas de diseño
Estimated: The TSOT-23-6 (DDC) package has a typical theta-JA around 90 C/W on a JEDEC 4-layer test board. At full 300 mA load with VIN=24 V and VOUT=3.3 V, dissipation is roughly (24-3.3)*0.3 = ~6.2 mW at the regulator plus inductor/capacitor losses; total board-level temperature rise above ambient is well under 1 C. At the worst-case condition VIN=42 V, VOUT=3.3 V, IOUT=300 mA, the IC dissipation stays low because the synchronous-rectifier topology dumps most loss into the external inductor. Maintain at least 50 mm^2 of copper pour under the GND pin and the SW loop for safe operation.
Keep the high-current loop (VIN -> internal switch -> SW -> external inductor -> VOUT -> output cap -> GND) as small as possible - the area of this loop sets the AC switching noise. Place the input capacitor (a 1 uF-10 uF X7R ceramic) within 2 mm of the VIN and GND pins, and place the bootstrap capacitor (typically 0.1 uF) within 1 mm of the BST and SW pins. Use a 4-layer board if possible; the LM2841XY is designed for tight 1.25 MHz switching, so any stray inductance will create voltage spikes on the SW node.
Three things to be careful with: (1) Do not let the inductor saturate - at 0.5 A peak switch current, choose an inductor with a saturation rating of at least 0.6 A; (2) The SHDN pin must not float. If unused, tie SHDN to VIN through a 100 kohm resistor, or drive it with a clean logic signal; (3) Do not exceed the absolute maximum VIN of 42 V during load-dump transients - add a TVS diode or upstream clamp if the upstream bus can spike above 42 V. The internal soft-start controlled via SHDN+RC is a key feature for inrush control on hot-plug applications.
Información de cumplimiento
The /NOPB suffix denotes the lead-free (Pb-free) version per TI part-number conventions. Standard LM2841XMK is not AEC-Q100 qualified - use the LM2841XQMK automotive variant for AEC-Q100 applications. RoHS and REACH status confirmed via the TI LM2841 product page.
