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Texas Instruments LMR33630CRNXR
- Part No.:
- LMR33630CRNXR
- Manufacturer:
- Texas Instruments
- Package:
- 12-PowerVFQFN
- Datasheet:
-
LMR33630CRNXR.pdf
- Description:
- IC REG BUCK ADJ 3A 12VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:8,798
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Product details
Overview
LMR33630CRNXR from Texas Instruments is a synchronous step-down DC/DC converter optimized for rugged industrial power conversion, delivering up to 3 A output current across an input range of 3.8 V to 36 V, with adjustable output voltage from 1 V to 24 V, peak efficiency >95%, and fixed 2.1 MHz switching frequency in the 12-pin VQFN (RNX) package. It serves as a primary voltage regulator in motor drive inverters, PLC CPU supplies, and HVAC control systems.
For engineers reviewing the LMR33630CRNXR datasheet, LMR33630CRNXR pinout, LMR33630CRNXR application, or LMR33630CRNXR equivalent, key selection considerations include its 2.1 MHz operation enabling compact filter design, integrated compensation network reducing external component count, precision enable threshold (1.231 V typ), power-good flag with glitch filtering (60–170 µs), and thermal shutdown at 165°C - all validated for –40°C to +125°C junction operation.
Technical Context
The LMR33630CRNXR employs peak-current-mode control with automatic PFM/PWM mode transition to maintain high light-load efficiency (>25 µA quiescent current), while its 68 ns minimum on-time supports high VIN-to-VOUT step-down ratios (e.g., 36 V → 3.3 V at 2.1 MHz). The device integrates 75 mΩ high-side and 50 mΩ low-side MOSFETs in a HotRod™-enhanced VQFN package with wettable flanks and symmetrical VIN/PGND layout to minimize parasitic inductance and EMI.
Protection architecture includes cycle-by-cycle current limiting (ISC = 4.5 A typ), hiccup-mode short-circuit response (94 ms burst interval), thermal shutdown (165°C trip, 148°C recovery), input UVLO, and internal soft-start (4 ms typical). The feedback reference is tightly regulated at 1.000 V ±15 mV over temperature, enabling ±1.5% output voltage accuracy under full load and line variation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.8 V to 36 V - supports wide-input industrial rails including 24 V nominal and 36 V transients. |
| Output Current | 3 A continuous - sufficient for powering microcontrollers, gate drivers, and sensor interfaces in motor drives. |
| Switching Frequency | 2.1 MHz (RNX package) - enables use of small 1–2.2 µH inductors and 10–22 µF ceramic output capacitors. |
| Feedback Reference | 1.000 V ±15 mV - ensures ≤±1.5% output regulation accuracy across line, load, and temperature. |
| Quiescent Current | 25 µA - maintains high efficiency at light loads (e.g., standby modes in building automation). |
| Min On-Time | 68 ns - allows direct 36 V → 3.3 V conversion at 2.1 MHz without requiring external pre-regulation. |
| Thermal Shutdown | 165°C trip / 148°C recovery - provides robust overtemperature protection with hysteresis for stable recovery. |
| Power-Good Delay | ~4 ms startup delay - ensures system reset timing aligns with stable output before releasing processor reset. |
Pinout & Package
The LMR33630CRNXR is housed in a 12-pin, 3.0 mm × 2.0 mm × 0.85 mm VQFN package with wettable flanks and an exposed thermal pad (AGND). This RoHS-compliant, lead-free package supports automated optical inspection (AOI) and delivers superior thermal performance (RθJB = 23.3°C/W) and low EMI via symmetrical high-current path routing.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 11 | PGND | Power ground return for high-current paths; must be connected to PCB ground plane with low-inductance layout. |
| 2, 10 | VIN | Main input supply (3.8–36 V); requires local 10–22 µF ceramic capacitor directly to PGND. |
| 9 | EN | Precision enable input (1.231 V threshold); supports external UVLO via resistor divider; must not float. |
| 8 | PG | Open-drain power-good flag; pulls low during startup, fault, or EN deassertion; requires external pull-up. |
| 7 | FB | Feedback node for adjustable output; connects to resistor divider; reference = 1.000 V ±15 mV. |
| 5 | VCC | Internal 5-V LDO output; powers internal circuitry; bypass with 1 µF capacitor to AGND. |
| 4 | BOOT | Bootstrap supply for high-side driver; requires 100 nF capacitor to SW pin. |
| 12 | SW | Switch node; connects to power inductor; routed to NC pad on PCB per TI layout guidance. |
| 6 | AGND | Analog ground reference; connects to thermal pad and system ground; critical for noise-sensitive feedback. |
| 3 | NC | No internal connection; used only for PCB routing simplification of CBOOT-to-SW path. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated Compensation Network | Eliminates need for external Type-II/III compensation components, reducing BOM count and layout complexity. |
| HotRod™ VQFN with Wettable Flanks | Enables AOI inspection and improves thermal dissipation (RθJB = 23.3°C/W) while minimizing switch-node ringing. |
| Peak-Current-Mode Control with PFM/PWM Auto-Transition | Maintains >90% efficiency down to 1 mA load via diode-emulation discontinuous conduction mode. |
| Short Minimum On-Time (68 ns) | Supports high-frequency, high-ratio buck conversion (e.g., 36 V → 3.3 V @ 2.1 MHz) without external pre-regulator. |
| Power-Good Flag with Glitch Filtering | 60–170 µs filter window rejects transient excursions, ensuring reliable system reset signaling during line/load steps. |
| Functional Safety Documentation Support | TI provides FIT rate data, FMEA reports, and safety analysis documentation for ISO 26262 and IEC 61508 compliance efforts. |
Applications
| Motor Drive Power Supply | PLC CPU Core Supply |
|---|---|
Use Scenario: Powers FPGA, ARM Cortex-M7, or dual-core RISC-V processors in servo drive controllers requiring clean, stable 1.2 V or 3.3 V rails. IC Role / Device Role / Timing Role: Primary buck regulator delivering 3 A at 1.2 V or 3.3 V with <±1.5% regulation and fast transient response (<10 µs recovery). Use Value: 2.1 MHz operation minimizes inductor size and enables tight layout around sensitive analog signal paths in motion control PCBs. | Use Scenario: Supplies 5 V or adjustable 3.3 V to programmable logic controller (PLC) main CPU, I/O interface ASICs, and real-time Ethernet PHYs. IC Role / Device Role / Timing Role: Main system power rail regulator with power-good flag synchronized to CPU reset assertion and watchdog timeout. Use Value: Precision enable (1.231 V threshold) and UVLO hysteresis allow custom brown-out detection for deterministic system shutdown during AC line sag. |
| HVAC Control Unit | Elevator Controller Power |
Use Scenario: Provides isolated 5 V and 3.3 V rails for environmental sensors, fan motor drivers, and CAN transceivers in commercial HVAC panels. IC Role / Device Role / Timing Role: Wide-VIN buck converter operating from 24 V DC bus with immunity to automotive-grade load dump transients (up to 36 V). Use Value: Integrated 75 mΩ/50 mΩ MOSFETs and low EMI layout reduce need for shielding and filtering components in space-constrained wall-mounted enclosures. | Use Scenario: Powers elevator door control logic, position encoder interfaces, and safety relay monitoring circuits in lift machine rooms. IC Role / Device Role / Timing Role: Industrial-grade DC/DC regulator supporting extended temperature operation (–40°C to +125°C) and functional safety documentation. Use Value: Thermal shutdown with 17°C hysteresis (165°C/148°C) prevents latch-up during prolonged high-ambient operation in enclosed machinery spaces. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMR33630BRNX | Same RNX package and 3 A rating, but 1.4 MHz switching frequency - higher inductor DCR loss, larger magnetics required. | Better suited for noise-sensitive audio or RF subsystems where 1.4 MHz avoids critical bands vs. 2.1 MHz. | Select LMR33630BRNX if EMI filtering constraints favor lower fundamental frequency or if legacy layout uses 1.4 MHz-optimized magnetics. |
| TPSM53603 | Pin-compatible module integrating LMR33630 + inductor + passives in 3.8 mm × 3.0 mm × 1.8 mm QFN; no external magnetics needed. | Reduces design cycle time and layout risk for rapid prototyping or low-volume production where board area is secondary to time-to-market. | Choose TPSM53603 when minimizing engineering effort outweighs cost-per-watt optimization and board-space savings are acceptable. |
Compared with LMR33630BRNX and TPSM53603, the LMR33630CRNXR offers the highest switching frequency (2.1 MHz) for smallest passive footprint, while retaining full external component flexibility and lowest bill-of-materials cost in high-volume industrial designs.
Availability
LMR33630CRNXR is available at Aetrix Electronics and suitable for motor drive systems, factory automation PLCs, and HVAC control units requiring stable component supply, long-term industrial lifecycle support, and AEC-Q100-aligned reliability validation.
Supply support for LMR33630CRNXR 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 industrial-grade product development and manufacturing excellence.
The LMR33630 belongs to TI's SIMPLE SWITCHER® family of easy-to-use DC/DC regulators, engineered specifically for rugged industrial environments demanding wide input range, high reliability, and minimal external component count.
FAQ
What is the switching frequency of the LMR33630CRNXR?
The LMR33630CRNXR operates at a fixed 2.1 MHz switching frequency, as specified for the "C" version in the RNX (VQFN) package. This frequency enables compact magnetic design with standard 1–2.2 µH shielded inductors and low-ESR ceramic output capacitors, and is validated across the full –40°C to +125°C junction temperature range per Section 7.5 of the datasheet.
Does the LMR33630CRNXR require external compensation components?
No, the LMR33630CRNXR integrates a complete Type-II compensation network internally. This eliminates the need for external resistors and capacitors on the COMP or FB pins, reducing design complexity, BOM count, and PCB area - a key differentiator from externally compensated buck controllers.
What is the purpose of the NC pin on the LMR33630CRNXR VQFN package?
The NC pin (Pin 3) on the LMR33630CRNXR has no internal connection. Its sole function is to simplify PCB routing by providing a dedicated pad for connecting the BOOT capacitor's return path to the SW node - a layout optimization recommended in TI's datasheet Figure 6-2 and Section 10.2.
How does the power-good (PG) flag behave during startup of the LMR33630CRNXR?
During startup, the LMR33630CRNXR asserts the open-drain PG flag high approximately 4 ms after EN is pulled above 1.231 V, following completion of internal soft-start. The flag remains high only when output voltage is within ±7% of target (93–107% of FB reference), and pulls low during faults, EN deassertion, or output undervoltage.
Can the LMR33630CRNXR operate with an input voltage as low as 3.8 V while delivering 3.3 V output?
Yes, the LMR33630CRNXR supports dropout operation down to 3.8 V input for a 3.3 V output, enabled by its 68 ns minimum on-time and adaptive frequency foldback. At light loads, it automatically reduces switching frequency to extend duty cycle beyond 98%, maintaining regulation without external assistance.
LMR33630CRNXR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 12-PowerVFQFN
- 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):
- 3.8V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 1V
- Voltage - Output (Max):
- 24V
- Current - Output:
- 3A
- Frequency - Switching:
- 2.1MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 12-VQFN-HR (3x2)
LMR33630CRNXR FAQ
1.How can I place an order for LMR33630CRNXR through Aetrix?
Please submit a Request for Quotation (RFQ) for LMR33630CRNXR 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 LMR33630CRNXR reliable?
The price and inventory of LMR33630CRNXR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMR33630CRNXR is usually 5 days.
3.What payment methods are accepted for LMR33630CRNXR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMR33630CRNXR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMR33630CRNXR?
LMR33630CRNXR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMR33630CRNXR 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 LMR33630CRNXR?
For technical support, including LMR33630CRNXR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMR33630CRNXR requirements.
6.How does Aetrix verify that LMR33630CRNXR is sourced from the original manufacturer or authorized distributors?
All LMR33630CRNXR 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 LMR33630CRNXR meets industry standards.
7.What is the process for return or replacement of LMR33630CRNXR?
All LMR33630CRNXR units undergo pre-shipment inspection (PSI). If there is an issue with LMR33630CRNXR, 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 LMR33630CRNXR part is unused and in its original packaging.
Return procedure for LMR33630CRNXR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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