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Texas Instruments LMR14203XMKX/NOPB
- Part No.:
- LMR14203XMKX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SOT-23-6 Thin, TSOT-23-6
- Datasheet:
-
LMR14203XMKX/NOPB.pdf
- Description:
- IC REG BUCK ADJ 300MA SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:703
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Product details
Overview
LMR14203XMKX/NOPB from Texas Instruments is a PWM synchronous buck DC/DC regulator optimized for 0.3A load current, operating from 4.5V to 42V input and delivering adjustable output voltages from 0.765V to 34V with 0.765V feedback reference. It integrates a 0.9Ω typical RDSON internal MOSFET switch, operates at fixed 1.25 MHz switching frequency, and delivers up to 85% typical efficiency at 1.2V/3.3V outputs-ideal for point-of-load conversion in industrial power meters and portable instrumentation.
For engineers reviewing the LMR14203XMKX/NOPB datasheet, LMR14203XMKX/NOPB pinout, LMR14203XMKX/NOPB application, or LMR14203XMKX/NOPB equivalent, key selection considerations include its SOT-23-6 thin package footprint, 16 µA shutdown quiescent current, internal compensation, soft-start via SHDN pin, and thermal/UVLO protection-critical for space-constrained, battery-powered, and distributed power systems requiring stable low-noise regulation.
Technical Context
The LMR14203XMKX/NOPB implements current-mode PWM control with an integrated high-side N-channel MOSFET and internal gate driver. Its error amplifier compares FB voltage against a precise 0.765V bandgap reference, while the oscillator sets a fixed 1.25 MHz switching frequency to minimize external component size and output ripple.
Protection architecture includes thermal shutdown (engages at ~175°C), input UVLO (4.4V turn-on, 3.5V turn-off), CB under-voltage lockout, and cycle-by-cycle current limiting (525 mA typical). Soft-start is implemented externally via RC network on the SHDN pin, modulating current limit from 0 to full scale during startup.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 42V - supports direct regulation from 5V, 12V, 24V, and 36V rails without pre-regulation. |
| Output Current | Up to 0.3A - sufficient for powering microcontrollers, sensors, and analog front-ends in compact systems. |
| Switching Frequency | 1.25 MHz (typical) - enables use of small 10–22 µH inductors and ceramic capacitors for minimal board area. |
| Feedback Reference | 0.765V ±1.8% - allows precise output setting (e.g., 3.3V with 3.4kΩ/1.02kΩ divider) with low resistor-current error. |
| RDS(ON) | 0.9Ω (typical) - reduces conduction loss and improves efficiency, especially at higher input voltages. |
| Shutdown Quiescent Current | 16 µA (typical) - extends battery life in always-on or low-power wake-up applications. |
| Operating Junction Temp | −40°C to +125°C - qualified for industrial and metering environments with wide ambient ranges. |
Pinout & Package
LMR14203XMKX/NOPB is housed in a 6-pin SOT-23-THIN (DDC0006A) package measuring 2.97 × 1.65 × 1.0 mm, optimized for high-density PCB layouts and automated assembly. The thermally enhanced leadframe supports junction-to-ambient thermal resistance of 121°C/W under JEDEC-standard 4-layer board conditions.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CB | Bootstrap capacitor connection | Provides gate drive bias for internal high-side FET; requires 0.15 µF ceramic cap between CB and SW. |
| GND | Power and signal ground reference | Must be connected directly to system ground plane at single-point near COUT to minimize noise coupling. |
| FB | Feedback voltage sense input | Monitors output via resistor divider; 0.765V reference enables accurate VOUT = 0.765V × (1 + R1/R2). |
| SHDN | Logic-level enable/disable control | Pull ≥2.3V to enable; ≤0.9V to disable; supports RC soft-start by modulating current limit during ramp-up. |
| VIN | Main power input | Accepts 4.5–42V; requires local 2.2–10 µF low-ESR ceramic bypass capacitor placed adjacent to pin. |
| SW | Switch node output | Drives external inductor and Schottky diode; connects to CBOOT and must be routed short/low-inductance. |
Key Features
| Feature | Design Value |
|---|---|
| Internally compensated | Eliminates need for external compensation network-reduces BOM count and design iteration time. |
| Short-circuit protected | Includes cycle-by-cycle current limiting (525 mA typ.) and thermal shutdown to prevent damage during overload. |
| Low-profile SOT-23-6 | 1.0 mm max height enables stacking in ultra-thin enclosures and compatibility with standard pick-and-place equipment. |
| WEBENCH® enabled | Fully supported in TI's WEBENCH Power Designer for automated schematic generation, efficiency simulation, and BOM export. |
| Soft-start programmable | RC network on SHDN pin tailors startup dV/dt to prevent inrush-induced rail collapse or sensor reset. |
Applications
| Industrial Power Meters | Battery-Powered Handheld Instruments |
|---|---|
|
Use Scenario: Regulating 3.3V or 5V rails from 12–24V battery or auxiliary supply in smart electricity meters with isolation barriers and metrology ADCs. IC Role / Device Role / Timing Role: Primary step-down regulator supplying precision analog circuitry, microcontroller core, and communication interfaces (RS-485, PLC). Use Value: 85% typical efficiency at 200 mA load minimizes self-heating in sealed enclosures; 125°C max junction rating ensures reliability over 10+ year field life. |
Use Scenario: Powering portable multimeters, thermal imagers, or gas detectors with Li-ion or alkaline battery inputs (4.5–12V). IC Role / Device Role / Timing Role: Main DC/DC converter enabling dynamic voltage scaling and low-quiescent sleep modes. Use Value: 16 µA shutdown current extends battery runtime in standby; 1.25 MHz operation avoids audible noise and simplifies EMI filtering. |
| Point-of-Load Conversion in Distributed Systems | Space-Constrained Industrial Controllers |
|
Use Scenario: Generating localized 1.2V, 1.8V, or 3.3V supplies for FPGA I/O banks or isolated MCU peripherals in modular PLC backplanes. IC Role / Device Role / Timing Role: Compact, self-contained buck regulator eliminating need for external controller + MOSFET + driver combos. Use Value: SOT-23-6 footprint occupies <10 mm² PCB area; internal 0.9Ω FET eliminates layout sensitivity of discrete solutions. |
Use Scenario: Replacing linear regulators in DIN-rail mounted controllers where thermal dissipation and board real estate are critical constraints. IC Role / Device Role / Timing Role: High-efficiency drop-in replacement for inefficient 78xx-style regulators feeding 3.3V logic rails. Use Value: Delivers >80% efficiency at 300 mA (vs. <30% for linear regulators at 12V→3.3V), reducing heatsink requirements and system temperature rise. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMR14003XMKX/NOPB | Wider 40V max input (vs. 42V), same 0.3A rating and SOT-23-6 package; 0.765V FB reference and 1.25 MHz switching identical. | Rated for 40V input only; not recommended for 42V transient-tolerant designs such as automotive load-dump scenarios. | Select LMR14003XMKX/NOPB only if input never exceeds 40V and RoHS-compliant SN finish is required. |
| TPS562201DDFR | Higher 2A output capability, 6-pin SOT-23 package, but 3.3–17V input range (not 4.5–42V); uses different 0.6V FB reference. | Not suitable for 24V/36V industrial rails; requires redesign of feedback divider and input capacitance due to lower VIN range. | Choose TPS562201DDFR only when >0.3A output is needed and input is limited to ≤17V-e.g., USB-powered test equipment. |
Compared with LMR14203XMKX/NOPB, LMR14003XMKX/NOPB offers identical functionality at marginally reduced input voltage tolerance, while TPS562201DDFR trades wide-input capability for higher current and lower FB reference-making neither a drop-in replacement, but viable alternatives when input range or output current requirements shift.
Availability
LMR14203XMKX/NOPB is available at Aetrix Electronics and suitable for industrial power meters, battery-powered handheld instruments, and space-constrained distributed power applications requiring stable component supply across multi-year production cycles.
Supply support for LMR14203XMKX/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 LMR14203XMKX/NOPB belongs to TI's SIMPLE SWITCHER® family-designed specifically for ease-of-use, minimal external components, and robust operation in industrial, metering, and portable applications where board space and thermal performance are critical.
FAQ
What is the maximum input voltage rating for LMR14203XMKX/NOPB?
The absolute maximum input voltage for LMR14203XMKX/NOPB is +45V, but the recommended operating range is 4.5V to 42V per the datasheet. Operation above 42V risks exceeding safe SOA limits and may trigger UVLO or thermal shutdown. For sustained 42V operation, ensure adequate PCB copper area and airflow to maintain junction temperature below 125°C.
Can LMR14203XMKX/NOPB regulate output voltages below 0.765V?
No-LMR14203XMKX/NOPB cannot regulate below its internal 0.765V feedback reference voltage. The minimum output is set by VFB × (1 + R1/R2), so with R1 = 0 (shorted), VOUT = VFB = 0.765V. To achieve lower outputs, an external reference or different regulator topology is required.
Is LMR14203XMKX/NOPB pin-compatible with other SOT-23-6 buck regulators?
LMR14203XMKX/NOPB has a unique pinout (CB/GND/FB/SHDN/VIN/SW) not shared with common SOT-23-6 buck regulators like the TPS562201 or MP1471. Direct pin-for-pin replacement is not possible without PCB redesign due to differing terminal functions-especially CB vs. BST or COMP pins.
Does LMR14203XMKX/NOPB require an external bootstrap capacitor?
Yes-LMR14203XMKX/NOPB requires a 0.15 µF or larger ceramic capacitor connected between CB and SW pins to provide gate drive voltage for the internal high-side MOSFET. Omitting CBOOT causes failure to start or erratic switching due to insufficient gate bias.
What is the thermal shutdown threshold for LMR14203XMKX/NOPB?
The thermal shutdown circuit in LMR14203XMKX/NOPB activates at approximately 175°C (typical) junction temperature and releases at ~155°C (typical). This hysteresis prevents oscillation during thermal stress. The device's 121°C/W θJA rating means 300 mA loads at 24V input require careful thermal layout to avoid repeated shutdown.
LMR14203XMKX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- 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:
- 300mA
- Frequency - Switching:
- 1.25MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-THIN
LMR14203XMKX/NOPB FAQ
1.How can I place an order for LMR14203XMKX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LMR14203XMKX/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 LMR14203XMKX/NOPB reliable?
The price and inventory of LMR14203XMKX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMR14203XMKX/NOPB is usually 5 days.
3.What payment methods are accepted for LMR14203XMKX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMR14203XMKX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMR14203XMKX/NOPB?
LMR14203XMKX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMR14203XMKX/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 LMR14203XMKX/NOPB?
For technical support, including LMR14203XMKX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMR14203XMKX/NOPB requirements.
6.How does Aetrix verify that LMR14203XMKX/NOPB is sourced from the original manufacturer or authorized distributors?
All LMR14203XMKX/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 LMR14203XMKX/NOPB meets industry standards.
7.What is the process for return or replacement of LMR14203XMKX/NOPB?
All LMR14203XMKX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LMR14203XMKX/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 LMR14203XMKX/NOPB part is unused and in its original packaging.
Return procedure for LMR14203XMKX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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