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Texas Instruments LMR14203XMK/NOPB
- Part No.:
- LMR14203XMK/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- SOT-23-6 Thin, TSOT-23-6
- Datasheet:
-
LMR14203XMK/NOPB.pdf
- Description:
- IC REG BUCK ADJ 300MA SOT23
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LMR14203XMK/NOPB from Texas Instruments is a PWM synchronous step-down 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 ±2.3% feedback reference accuracy (0.765V typical). It integrates a 0.9Ω typical RDSON internal N-channel MOSFET switch, operates at a fixed 1.25 MHz switching frequency, and features internal compensation, soft-start via SHDN pin, and thermal shutdown - used in point-of-load conversion from industrial 12V/24V rails.
For engineers reviewing the LMR14203XMK/NOPB datasheet, LMR14203XMK/NOPB pinout, LMR14203XMK/NOPB application, or LMR14203XMK/NOPB equivalent, key selection criteria include input voltage range (4.5–42V), output current capability (300 mA), fixed-frequency operation (1.25 MHz), SOT-23-6 thin package footprint, and integrated soft-start functionality using external RC on SHDN.
Technical Context
The LMR14203XMK/NOPB implements a current-mode PWM buck architecture with an internal high-side N-MOSFET switch and gate driver. Its control loop uses an error amplifier comparing FB voltage against a 0.765V internal bandgap reference, with internal compensation eliminating external compensation components.
Protection functions include thermal shutdown (engages at ~175°C, disengages at ~155°C), input UVLO (turn-on at 4.4V, turn-off at 3.5V), CB under-voltage lockout, and cycle-by-cycle current limiting (525 mA typical). Shutdown mode reduces quiescent current to 16 µA typical while maintaining logic-level compatibility on SHDN (2.3V threshold).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 42V - supports direct regulation from unregulated 5V, 12V, 24V, and 36V industrial rails without pre-regulation. |
| Output Current | Up to 300 mA - sufficient for powering microcontrollers, sensors, and interface ICs in space-constrained systems. |
| Switching Frequency | 1.25 MHz (±25%) - enables use of small external inductors (e.g., 10–22 µH) and ceramic capacitors while minimizing output ripple. |
| Feedback Reference | 0.765 V ±2.3% - sets precise output voltage via resistor divider; enables stable 1.2V, 3.3V, 5V, and 12V outputs with <1% tolerance over line/load/temperature. |
| RDS(ON) | 0.9 Ω typical - minimizes conduction loss at full load, contributing to 85% typical efficiency at 3.3V/200mA with 12V input. |
| Quiescent Current | 16 µA typical in shutdown - extends battery life in portable equipment during standby or sleep modes. |
| Operating Junction Temp | −40°C to +125°C - qualified for industrial temperature environments including power meters and distributed control systems. |
Pinout & Package
LMR14203XMK/NOPB is housed in a 6-pin SOT-23-THIN (DDC0006A) package measuring 2.97 mm × 1.65 mm × 1.0 mm, with exposed pad not electrically connected. The package is RoHS-compliant, lead-finished with matte tin, and rated MSL Level-1 (unlimited floor life at ≤30°C/60% RH).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CB | Bootstrap capacitor connection | Provides gate drive voltage for internal high-side FET; requires 0.15 µF ceramic cap between CB and SW to sustain low RDS(ON) during duty cycles >50%. |
| GND | Power and signal ground reference | Common return path for internal circuitry, feedback network, and external input/output capacitors; must be tied directly to system ground plane at COUT location. |
| FB | Feedback voltage sensing node | Monitors output via resistor divider; internal 0.765V reference sets VOUT = 0.765V × (1 + R1/R2); resistors selected from 100Ω–10kΩ range to minimize bias current error. |
| SHDN | Logic-controlled enable/disable input | Pull ≥2.3V to enable; pull ≤0.9V to enter 16 µA shutdown; open or tied to VIN if unused; supports RC soft-start by modulating current limit during ramp-up. |
| VIN | Main power input | Accepts 4.5–42V DC; requires local 2.2–10 µF low-ESR ceramic bypass capacitor placed adjacent to pin to suppress transients and reduce EMI. |
| SW | Switch node output | Drives external inductor and Schottky diode; connects to CBOOT and L1; voltage swings from GND to VIN; layout must minimize trace length and loop area to reduce radiated noise. |
Key Features
| Feature | Design Value |
|---|---|
| Internally compensated control loop | Eliminates need for external compensation components, reducing BOM count and layout complexity while ensuring stability across all valid output configurations. |
| Fixed 1.25 MHz switching frequency | Enables consistent EMI profile and predictable filter design; allows use of compact 10–22 µH shielded inductors and low-ESR ceramic capacitors for minimal solution size. |
| Soft-start via SHDN pin | RC network on SHDN pin provides user-adjustable startup time (e.g., 100 kΩ + 10 nF ≈ 1 ms rise), preventing inrush current and output overshoot during power-up. |
| Thermal shutdown with hysteresis | Protects device under overload or poor PCB thermal design; shuts down at ~175°C and resumes operation only after die cools to ~155°C, avoiding oscillatory behavior. |
| Low shutdown quiescent current | 16 µA typical draw in shutdown mode preserves battery capacity in handheld instruments and remote sensors during extended idle periods. |
Applications
| Industrial Power Meters | Portable Hand-Held Instruments |
|---|---|
Use Scenario: Regulating 3.3V rail from 24V DC supply in smart electricity meters with isolated communication interfaces and real-time clock backup. IC Role / Device Role / Timing Role: Primary point-of-load DC/DC converter supplying power to metrology ADC, microcontroller, and RF transceiver subsystems. Use Value: High input voltage range (up to 42V) accommodates wide industrial bus tolerances; 125°C junction rating ensures reliability in sealed meter enclosures. | Use Scenario: Generating 1.2V core voltage for an ARM Cortex-M4 MCU and 3.3V I/O rail from a single-cell Li-ion battery (3.0–4.2V) with boost-capable front-end. IC Role / Device Role / Timing Role: Secondary buck regulator post-boost stage, delivering tightly regulated low-noise supply to precision analog front-end and digital logic. Use Value: 0.765V feedback reference enables accurate low-VOUT generation; 16 µA shutdown current extends battery runtime during measurement intervals. |
| Space-Constrained IoT Edge Nodes | Industrial Distributed Power Systems |
Use Scenario: Compact sensor node integrating temperature, humidity, and LoRaWAN radio, powered by 12V field bus with strict board area constraints (<100 mm²). IC Role / Device Role / Timing Role: Single-chip power solution replacing discrete buck controller + external MOSFET, minimizing component count and PCB footprint. Use Value: SOT-23-6 package (2.97 × 1.65 mm) plus 1.25 MHz operation allow total solution size < 50 mm²; internal compensation removes 3–4 passive components. | Use Scenario: Local 5V rail generation in PLC backplane modules where multiple LMR14203XMK/NOPB units power isolated I/O channels from shared 24V supply. IC Role / Device Role / Timing Role: Independent, fault-isolated DC/DC stage per channel, supporting hot-swap and individual enable/disable via SHDN pins. Use Value: Logic-compatible SHDN pin enables centralized power sequencing; short-circuit and thermal protection prevent cascade failures across channels. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMR14206XMK/NOPB | Higher output current (600 mA), same 4.5–42V input, identical SOT-23-6 package and pinout. | Supports higher-power loads such as dual-core MCUs or multi-channel ADCs without redesigning layout. | Select when load exceeds 300 mA but board space and thermal budget permit same footprint. |
| TPS54202HDDCR | 4.5–28V input, 2A output, 2.5V–17V adjustable output, 6-pin SOT-23 package, but requires external compensation. | Better suited for higher-current, lower-input-voltage applications; lacks 42V rating and integrated soft-start via SHDN. | Choose when 2A output is needed and design can accommodate compensation network and reduced input range. |
Compared with LMR14203XMK/NOPB, LMR14206XMK/NOPB offers double the current in identical packaging for seamless upgrade paths, while TPS54202HDDCR trades off high-voltage capability and simplicity for higher output current and flexibility - making LMR14203XMK/NOPB optimal for cost-sensitive, space-limited 300 mA industrial point-of-load designs.
Availability
LMR14203XMK/NOPB is available at Aetrix Electronics and suitable for industrial power meters, portable hand-held instruments, and space-constrained IoT edge nodes requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for LMR14203XMK/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 headquartered in Dallas, Texas, designing and manufacturing analog, embedded processing, and silicon technologies for industrial, automotive, and personal electronics markets.
The LMR14203XMK/NOPB belongs to TI's SIMPLE SWITCHER® family of easy-to-use DC/DC regulators, engineered specifically for rapid power design in industrial and instrumentation applications where input voltage variability, thermal constraints, and board space are critical.
FAQ
What is the maximum input voltage rating for LMR14203XMK/NOPB?
The absolute maximum input voltage for LMR14203XMK/NOPB is +45V, but the recommended continuous operating range is 4.5V to 42V. Exceeding 42V may trigger internal UVLO protection or cause stress beyond guaranteed specifications. The device is commonly deployed in 24V and 36V industrial systems where transient spikes remain within the 45V limit.
Can LMR14203XMK/NOPB generate a 1.2V output, and what resistor values are required?
Yes, LMR14203XMK/NOPB can generate a precise 1.2V output using its 0.765V feedback reference. With R2 = 1.02 kΩ (standard value), R1 = 5.62 kΩ yields VOUT = 0.765V × (1 + 5.62k/1.02k) ≈ 1.2V. Resistor tolerances ≤1% are recommended to maintain output accuracy within datasheet limits.
Does LMR14203XMK/NOPB require an external bootstrap capacitor, and what value is recommended?
Yes, LMR14203XMK/NOPB requires a bootstrap capacitor (CBOOT) between CB and SW pins to sustain gate drive for the internal high-side MOSFET. A 0.15 µF X7R ceramic capacitor is standard; for VIN < 2×VOUT (e.g., 5V input → 3.3V output), use 0.22–1 µF to ensure robust switching and low RDS(ON).
How does the SHDN pin implement soft-start in LMR14203XMK/NOPB?
The SHDN pin implements soft-start by modulating the internal current limit during startup: applying a rising voltage (0–2.3V) via an RC network linearly increases the switch current limit from zero to full 525 mA, controlling output voltage slew rate and suppressing inrush. A 100 kΩ resistor and 10 nF capacitor yield ~1 ms soft-start time.
Is LMR14203XMK/NOPB thermally protected, and at what temperature does it shut down?
Yes, LMR14203XMK/NOPB includes thermal shutdown protection that activates at approximately 175°C junction temperature and resets automatically when the die cools to ~155°C. This hysteresis prevents oscillation during thermal overload and protects the IC from permanent damage during sustained overloads or inadequate PCB copper area.
LMR14203XMK/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
LMR14203XMK/NOPB FAQ
1.How can I place an order for LMR14203XMK/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LMR14203XMK/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 LMR14203XMK/NOPB reliable?
The price and inventory of LMR14203XMK/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMR14203XMK/NOPB is usually 5 days.
3.What payment methods are accepted for LMR14203XMK/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMR14203XMK/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMR14203XMK/NOPB?
LMR14203XMK/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMR14203XMK/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 LMR14203XMK/NOPB?
For technical support, including LMR14203XMK/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMR14203XMK/NOPB requirements.
6.How does Aetrix verify that LMR14203XMK/NOPB is sourced from the original manufacturer or authorized distributors?
All LMR14203XMK/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 LMR14203XMK/NOPB meets industry standards.
7.What is the process for return or replacement of LMR14203XMK/NOPB?
All LMR14203XMK/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LMR14203XMK/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 LMR14203XMK/NOPB part is unused and in its original packaging.
Return procedure for LMR14203XMK/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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