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Texas Instruments LM2840XMKX-ADJL/NOPB
- Part No.:
- LM2840XMKX-ADJL/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SOT-23-6 Thin, TSOT-23-6
- Datasheet:
-
LM2840XMKX-ADJL/NOPB.pdf
- Description:
- IC REG BUCK ADJ 100MA TSOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:2,586
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Product details
Overview
LM2840XMKX-ADJL/NOPB from Texas Instruments is a non-synchronous step-down DC/DC regulator in SOT-6L package, delivering up to 100 mA output current with 0.765-V feedback reference, 550-kHz fixed switching frequency, and 4.5-V to 42-V input range. It integrates a 0.9-Ω typical RDS(ON) power switch and supports adjustable output voltage via external resistor divider - used in battery-powered instrumentation requiring compact, high-input-voltage regulation.
For engineers reviewing the LM2840XMKX-ADJL/NOPB datasheet, LM2840XMKX-ADJL/NOPB pinout, LM2840XMKX-ADJL/NOPB application, or LM2840XMKX-ADJL/NOPB equivalent, key selection criteria include its 100-mA current rating, 550-kHz switching frequency, internal soft-start via SHDN pin, thermal shutdown protection, and compatibility with low-ESR ceramic output capacitors in space-constrained industrial and portable designs.
Technical Context
The LM2840XMKX-ADJL/NOPB implements current-mode PWM control with fixed 550-kHz oscillator, enabling stable regulation across 4.5–42 V input while maintaining <±2% output voltage accuracy via 0.765-V precision feedback reference. Its integrated 0.9-Ω high-side MOSFET and gate-drive bias (CB) pin support efficient operation without external driver circuitry.
Protection features include thermal shutdown (engages at 175°C), input undervoltage lockout (UVLO turns on at 3.7 V), gate-drive UVLO, and cycle-by-cycle current limiting (525 mA typical). Shutdown mode reduces quiescent current to 16 µA, and soft-start is implemented externally via RC network on SHDN pin.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5 V to 42 V - supports wide-range unregulated sources like automotive batteries or industrial rails. |
| Output Current Capability | Up to 100 mA - optimized for low-power embedded systems and sensor nodes. |
| Switching Frequency | 550 kHz - enables use of small external inductors (e.g., 10–15 µH) and low-ripple ceramic output capacitors. |
| Feedback Reference Voltage | 0.765 V ±1.5% - sets precise output voltage via external resistor divider (e.g., 3.3 V with R1=3.4 kΩ, R2=1.02 kΩ). |
| Quiescent Current (Shutdown) | 16 µA typical - minimizes battery drain in always-on standby applications. |
| Internal Switch RDS(ON) | 0.9 Ω typical - ensures >85% typical efficiency at 12-V input / 3.3-V output / 100-mA load. |
| Minimum ON-Time | 100 ns - supports high step-down ratios (e.g., 42 V → 3.3 V) without pulse-skipping instability. |
Pinout & Package
LM2840XMKX-ADJL/NOPB is housed in a 6-pin SOT-6L (DDC) package measuring 1.60 mm × 2.90 mm, optimized for thermal performance and PCB layout simplicity in high-density applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - CB | Bootstrap bias supply | Connects external 0.15-µF ceramic capacitor to SW; provides gate drive voltage for internal high-side MOSFET. |
| 2 - GND | Power and signal ground | Common return path for internal circuitry, feedback network, and external components; requires low-impedance PCB connection. |
| 3 - FB | Feedback input | Senses output voltage via resistor divider; regulates VOUT = 0.765 V × (1 + R1/R2); input bias current ≤1 µA avoids divider error. |
| 4 - SHDN | Logic-level enable/disable | Pull ≥2.3 V to enable; ≤0.3 V to enter 16-µA shutdown; must not float; supports RC-controlled soft-start. |
| 5 - VIN | Main power input | Accepts 4.5–42 V; supplies internal bias and high-side switch; requires local 2.2-µF ceramic bypass capacitor. |
| 6 - SW | Switch node output | Drives external inductor and Schottky diode; connects to CBOOT capacitor; peak voltage reaches VIN during operation. |
Key Features
| Feature | Design Value |
|---|---|
| Internally compensated control loop | Eliminates need for external compensation network - simplifies design and reduces BOM count. |
| Thermal shutdown with hysteresis | Shuts down at 175°C (typical), restarts at 155°C (typical) - prevents permanent damage during overload or poor heatsinking. |
| Short-circuit protected | Current-limited to 525 mA (typical) - sustains safe operation during output fault without latch-up. |
| Soft-start via SHDN pin | RC-controlled ramp-up of current limit - suppresses inrush current and output overshoot during startup. |
| Low-RDS(ON) integrated switch | 0.9 Ω typical - reduces conduction loss and improves efficiency at light-to-moderate loads. |
Applications
| Battery-Powered Instrumentation | Industrial Distributed Power |
|---|---|
|
Use Scenario: Portable handheld multimeter powered by 9-V alkaline or Li-ion battery pack (6–42 V range). IC Role / Device Role / Timing Role: Primary step-down regulator converting variable battery voltage to stable 3.3-V rail for MCU, ADC, and display driver. Use Value: Enables single-battery operation across full discharge curve; 16-µA shutdown current extends shelf life; SOT-6L footprint saves board space. |
Use Scenario: Remote sensor node in factory automation system powered from 24-V DC bus with transient spikes. IC Role / Device Role / Timing Role: Local point-of-load regulator generating 5-V supply for analog front-end and RS-485 transceiver. Use Value: 42-V absolute max input withstands load-dump transients; UVLO prevents erratic behavior during brownouts; thermal shutdown ensures reliability under enclosure heat buildup. |
| Portable Media Players | Medical Diagnostic Handhelds |
|
Use Scenario: Flash-based audio player using dual-cell Li-ion (6–8.4 V) with requirement for clean 1.8-V core and 3.3-V I/O rails. IC Role / Device Role / Timing Role: Secondary buck converter deriving 3.3-V supply from main battery rail, feeding USB interface and SD card controller. Use Value: 550-kHz switching allows compact 10-µH inductor and 22-µF ceramic output cap; low EMI due to fixed-frequency operation aids EMC compliance. |
Use Scenario: Battery-operated ultrasound probe with strict low-noise, low-power requirements and safety-critical uptime. IC Role / Device Role / Timing Role: Isolated auxiliary supply generating 5-V rail for analog signal conditioning and microcontroller peripherals. Use Value: Internal soft-start prevents voltage droop on shared battery; short-circuit protection avoids fault propagation; 0.765-V reference enables accurate calibration of analog stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2841XMKX-ADJL/NOPB | 300-mA output capability; identical pinout, feedback voltage, and 550-kHz frequency. | Supports higher-current loads (e.g., multi-sensor modules) without changing PCB layout. | Select when load exceeds 100 mA but remains ≤300 mA and board space is constrained. |
| TPS62840DRVR | 200-mA output; 1.8–6.5-V input; 1.8-MHz switching; 25-nA shutdown IQ; WSON-6 package. | Optimized for ultra-low-power coin-cell applications; incompatible input voltage range and pinout. | Choose only for sub-100-µA standby systems with ≤6.5-V input; requires full redesign due to different pin assignment and control scheme. |
Compared with LM2840XMKX-ADJL/NOPB, LM2841XMKX-ADJL/NOPB offers higher current headroom in same footprint, while TPS62840DRVR delivers vastly lower quiescent current but sacrifices high-input-voltage capability and introduces layout incompatibility - making LM2840XMKX-ADJL/NOPB optimal for cost-sensitive, 4.5–42-V, ≤100-mA industrial and portable applications.
Availability
LM2840XMKX-ADJL/NOPB is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial distributed power, and portable media players requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for LM2840XMKX-ADJL/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 LM284x family was designed for simple, robust DC/DC conversion in harsh environments - targeting industrial, automotive, and portable equipment where wide input range, thermal resilience, and minimal external components are critical.
FAQ
What is the maximum input voltage rating for LM2840XMKX-ADJL/NOPB?
The LM2840XMKX-ADJL/NOPB has an absolute maximum input voltage rating of 45 V, with recommended operating range from 4.5 V to 42 V. Operation above 42 V risks exceeding thermal limits or triggering UVLO shutdown; sustained exposure beyond 45 V may cause permanent damage per Absolute Maximum Ratings table in the datasheet.
Can LM2840XMKX-ADJL/NOPB be used to generate a 0.8-V output?
Yes, LM2840XMKX-ADJL/NOPB supports 0.8-V output using the adjustable feedback configuration: set R2 = 787 Ω and R1 = 30.9 Ω to achieve VOUT = 0.765 V × (1 + 30.9/787) ≈ 0.8 V. The 0.765-V reference and low FB bias current (<1 µA) ensure accuracy even at low output voltages.
Does LM2840XMKX-ADJL/NOPB require an external bootstrap capacitor?
Yes, LM2840XMKX-ADJL/NOPB requires a minimum 0.15-µF ceramic capacitor between CB and SW pins to sustain gate drive for the internal high-side MOSFET. For input voltages less than twice the output voltage, a larger value (up to 1 µF) is recommended to maintain low RDS(ON) and prevent dropout.
How does the SHDN pin implement soft-start in LM2840XMKX-ADJL/NOPB?
In LM2840XMKX-ADJL/NOPB, soft-start is achieved by applying a controlled RC-ramped voltage to the SHDN pin: as SHDN voltage rises from 0 V to 2.3 V, the internal current limit increases linearly from 0 mA to 525 mA, thereby limiting inrush current and controlling output voltage rise time without external circuitry beyond the RC network.
Is LM2840XMKX-ADJL/NOPB RoHS-compliant and lead-free?
Yes, LM2840XMKX-ADJL/NOPB is RoHS-compliant and lead-free, as indicated by the "/NOPB" suffix in the part number per Texas Instruments' packaging nomenclature. It meets JEDEC J-STD-020 moisture sensitivity level 1 and is qualified for lead-free reflow soldering processes.
LM2840XMKX-ADJL/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- SOT-23-6 Thin, TSOT-23-6
- 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):
- 4.5V
- Voltage - Input (Max):
- 42V
- Voltage - Output (Min/Fixed):
- 0.765V
- Voltage - Output (Max):
- 34V
- Current - Output:
- 100mA
- Frequency - Switching:
- 550kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-6
LM2840XMKX-ADJL/NOPB FAQ
1.How can I place an order for LM2840XMKX-ADJL/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2840XMKX-ADJL/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 LM2840XMKX-ADJL/NOPB reliable?
The price and inventory of LM2840XMKX-ADJL/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2840XMKX-ADJL/NOPB is usually 5 days.
3.What payment methods are accepted for LM2840XMKX-ADJL/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2840XMKX-ADJL/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2840XMKX-ADJL/NOPB?
LM2840XMKX-ADJL/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2840XMKX-ADJL/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 LM2840XMKX-ADJL/NOPB?
For technical support, including LM2840XMKX-ADJL/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2840XMKX-ADJL/NOPB requirements.
6.How does Aetrix verify that LM2840XMKX-ADJL/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2840XMKX-ADJL/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 LM2840XMKX-ADJL/NOPB meets industry standards.
7.What is the process for return or replacement of LM2840XMKX-ADJL/NOPB?
All LM2840XMKX-ADJL/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2840XMKX-ADJL/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 LM2840XMKX-ADJL/NOPB part is unused and in its original packaging.
Return procedure for LM2840XMKX-ADJL/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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