My Inquiry
My Account
Texas Instruments LMR33630BRNXT
- Part No.:
- LMR33630BRNXT
- Manufacturer:
- Texas Instruments
- Package:
- 12-PowerVFQFN
- Datasheet:
-
LMR33630BRNXT.pdf
- Description:
- IC REG BUCK ADJ 3A 12VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:511
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LMR33630BRNXT 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 1.4 MHz switching frequency - deployed in motor drive systems, PLC CPU supplies, and HVAC control units.
For engineers reviewing the LMR33630BRNXT datasheet, LMR33630BRNXT pinout, LMR33630BRNXT application, or LMR33630BRNXT equivalent, key selection considerations include its 12-pin VQFN (3 mm × 2 mm) HotRod™ package, integrated 75-mΩ/50-mΩ MOSFETs, precision enable threshold (1.231 V typ), power-good flag with glitch filtering (60–170 µs), and thermal shutdown at 165°C.
Technical Context
The LMR33630BRNXT implements peak-current-mode control with automatic PFM/PWM mode transition to maintain high light-load efficiency, supported by internal loop compensation and a 68 ns minimum on-time enabling regulation down to 3.8 V input at 3.3 V output. Its architecture integrates cycle-by-cycle current limiting, hiccup-mode short-circuit protection, and thermal shutdown with 148°C recovery.
Designed for low EMI, it uses symmetrical VIN/PGND pin placement and parallel input current paths in the VQFN package, while the BOOT-to-SW bootstrap circuit relies on a 100-nF capacitor and supports operation with SW connected to NC on PCB per TI's layout guidance for simplified routing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.8 V to 36 V - supports wide-VIN industrial rails including 12 V, 24 V, and 36 V battery/supply inputs without external pre-regulation. |
| Output Current | 3 A continuous - sustains full load under worst-case thermal conditions (TJ ≤ 125°C) with proper PCB copper area and airflow. |
| Switching Frequency | 1.4 MHz (fixed) - enables compact magnetics and reduces output ripple; avoids AM radio band and simplifies EMI filtering. |
| Efficiency (Typ.) | >95% at mid-load - minimizes thermal stress and power loss in space-constrained enclosures such as servo drives and PLC modules. |
| Quiescent Current | 25 µA (non-switching) - extends battery life in always-on monitoring nodes and low-power wake-up circuits. |
| Feedback Reference | 1.0 V ±1.5% - provides tight output regulation accuracy over temperature and line/load variations for sensitive analog or MCU supply rails. |
| Thermal Shutdown | 165°C activation / 148°C recovery - protects against sustained overload or poor heatsinking while allowing automatic recovery after cooling. |
Pinout & Package
The LMR33630BRNXT is housed in a 12-pin VQFN package (3.00 mm × 2.00 mm × 0.85 mm) with wettable flanks and exposed thermal pad (AGND). This HotRod™ package minimizes parasitic inductance, suppresses switch-node ringing, and improves thermal performance via direct PCB copper connection to the bottom-side thermal pad.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 11 | PGND | Power ground return for high-current paths; must be tied directly to system ground plane and bypassed with low-ESR capacitors near VIN. |
| 2, 10 | VIN | Main input supply (3.8–36 V); requires local ceramic decoupling (≥10 µF) between VIN and PGND to stabilize switching transients. |
| 9 | EN | Enable input with precision thresholds (1.231 V typ ON, 1.131 V typ OFF); supports external UVLO via resistor divider or direct tie to VIN. |
| 8 | PG | Open-drain power-good flag; asserts high when VOUT is within ±5% of target (after soft-start delay); requires external pull-up (e.g., to VCC or VOUT). |
| 7 | FB | Feedback node for adjustable output; connects to resistor divider (RFBT/RFBB) setting VOUT = 1.0 V × (1 + RFBT/RFBB); must not float or short. |
| 5 | VCC | Internal 5-V LDO output; powers internal logic; requires 1-µF ceramic capacitor to AGND; not for external loading. |
| 4 | BOOT | Bootstrap supply for high-side gate driver; requires 100-nF ceramic capacitor between BOOT and SW; SW must connect to NC on PCB per TI layout rules. |
| 12 | SW | Switch node connecting to power inductor; carries high di/dt; must route with minimal loop area and avoid sensitive analog traces. |
| 6 | AGND | Analog ground reference for feedback, error amplifier, and internal references; must be solidly connected to system ground and thermal pad. |
| 3 | NC | No internal connection; left unconnected on PCB; used only to simplify CBOOT-to-SW routing in VQFN layout. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated High/Low-Side MOSFETs | 75 mΩ HS / 50 mΩ LS RDS(on) in VQFN - eliminates external FETs and drivers, reducing BOM count and layout complexity. |
| Automatic PFM/PWM Transition | Enables >90% efficiency at 1 mA load - critical for battery-backed sensors and standby subsystems without manual mode control. |
| Low EMI HotRod™ Layout | Symmetrical VIN/PGND pins and minimized bond-wire inductance - achieves CISPR-22 Class B compliance with simple 2-layer PCB design. |
| Integrated Compensation Network | Eliminates external Type-II/III compensation components - reduces design time and validation effort for stable 3-A buck operation. |
| Power-Good Flag with Glitch Filter | 60–170 µs filter window prevents false resets during transient load steps - ensures reliable microprocessor sequencing in industrial controllers. |
Applications
| Motor Drive Systems | Factory Automation |
|---|---|
Use Scenario: Powering gate drivers and logic in drone ESCs and AC inverter control boards requiring clean, regulated 5 V or 3.3 V from 12–24 V battery inputs. IC Role / Device Role / Timing Role: Primary synchronous buck regulator supplying isolated gate-driver bias and MCU core voltage with fast transient response. Use Value: 1.4 MHz switching enables small 1.5 µH inductors and <100 µF output capacitance, reducing board area by >35% vs. lower-frequency alternatives. | Use Scenario: Providing stable 3.3 V or 5 V supply to PLC CPU modules operating in harsh factory environments with wide ambient temperature swings (–40°C to +85°C). IC Role / Device Role / Timing Role: Main point-of-load regulator delivering 3 A with ±1.5% output accuracy and thermal fault protection. Use Value: Junction temperature rating up to +125°C and integrated thermal shutdown ensure uninterrupted operation during cabinet overheating events. |
| HVAC Control Units | Elevator Control Systems |
Use Scenario: Regulating auxiliary 12 V or 15 V rail for fan controllers, valve actuators, and communication interfaces in building management systems. IC Role / Device Role / Timing Role: Wide-input buck converter supporting both 24 V DC and rectified 24 V AC inputs with dropout capability down to 3.8 V. Use Value: 68 ns minimum on-time allows regulation at ultra-low input differentials, maintaining output during brownout conditions common in aging HVAC wiring. | Use Scenario: Supplying safety-critical 5 V logic rail to elevator door controllers and position-sensing circuits where functional safety compliance is required. IC Role / Device Role / Timing Role: Functional safety-capable DC/DC with documented failure modes, power-good signaling, and hiccup-mode short-circuit protection. Use Value: Power-good flag synchronized to output regulation status enables safe system reset and diagnostics per IEC 61508 SIL-2 requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMR33630BDDA | Same electrical specs but in 8-pin HSOIC (5 mm × 4 mm); higher RDS(on) (95/66 mΩ); 1.4 MHz frequency; no wettable flanks. | Better suited for through-hole prototyping or legacy layouts; less optimal for high-density, low-EMI designs. | Select when mechanical compatibility with existing HSOIC footprints is required and thermal/EMI margins allow. |
| TPSM53603 | Pin-compatible module integrating inductor; same 1.4 MHz frequency; 3-A rating; larger footprint (7.5 mm × 6.5 mm); higher cost. | Reduces design risk and layout effort; eliminates inductor selection and EMI tuning; ideal for rapid prototyping. | Choose when time-to-market outweighs BOM cost and board area constraints, especially for first-pass designs. |
Compared with LMR33630BDDA, the LMR33630BRNXT offers superior thermal performance (72.5°C/W vs. 42.9°C/W RθJA), lower MOSFET losses, and better EMI behavior - making it preferred for compact, convection-cooled industrial PCBs. Against TPSM53603, it trades integration for size and cost efficiency, requiring careful inductor selection but enabling tighter layout control.
Availability
LMR33630BRNXT is available at Aetrix Electronics and suitable for motor drive systems, factory automation controllers, and HVAC control units requiring stable component supply, long-term lifecycle support, and AEC-Q100-qualified variants for safety-critical deployments.
Supply support for LMR33630BRNXT 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 industrial and automotive power solutions.
The LMR33630BRNXT belongs to TI's SIMPLE SWITCHER® family - engineered specifically for rugged, wide-input industrial DC/DC conversion where reliability, ease of use, and low EMI are mandatory.
FAQ
What is the recommended input capacitor configuration for LMR33630BRNXT?
TI recommends ≥10 µF total ceramic input capacitance placed as close as possible between VIN and PGND pins, using multiple X7R/X5R 0603 or 0805 capacitors (e.g., one 4.7 µF + two 2.2 µF) to minimize impedance across 100 kHz–10 MHz. The LMR33630BRNXT datasheet specifies this configuration to suppress high-frequency switching noise and prevent input rail collapse during load transients. Layout must avoid vias in the VIN-PGND path to preserve low-inductance routing.
Does LMR33630BRNXT support adjustable soft-start time?
No, the LMR33630BRNXT features a fixed internal soft-start time of 2.9–6 ms (typ. 4 ms), which controls output voltage ramp rate to prevent inrush current and overshoot. Unlike some programmable regulators, it does not accept external capacitor-based soft-start adjustment. This fixed timing is verified in the LMR33630BRNXT datasheet Section 7.5 and ensures consistent startup behavior across temperature and unit variance without added BOM cost.
Can LMR33630BRNXT operate with an output voltage below 1 V?
No, the LMR33630BRNXT has a fixed 1.0 V internal feedback reference; the minimum output voltage is 1 V (set by FB = 1.0 V × [1 + RFBT/RFBB]). Output voltages below 1 V are not supported. Attempting to force lower outputs via external circuitry violates absolute maximum ratings and invalidates regulation accuracy. For sub-1-V applications, consider TI's TPS62864 or similar dedicated low-VOUT converters.
What is the maximum allowable PCB trace length between BOOT and SW pins on LMR33630BRNXT?
TI specifies that the trace between BOOT and SW pins on the LMR33630BRNXT must be as short as physically possible - ideally ≤2 mm - and routed as a wide, low-inductance copper pour. Longer traces increase bootstrap loop inductance, causing gate-drive instability and reduced efficiency. The LMR33630BRNXT datasheet Figure 10-2 shows best-practice layout with direct 100-nF capacitor placement adjacent to both pins, confirming this constraint is critical for reliable 1.4 MHz operation.
Is LMR33630BRNXT qualified for automotive applications?
The LMR33630BRNXT itself is not AEC-Q100 qualified; however, Texas Instruments offers a separate AEC-Q100-qualified variant (LMR33630QRNXT) with identical electrical specs and enhanced reliability testing. Engineers requiring automotive-grade qualification must specify the "Q" version. The LMR33630BRNXT remains suitable for industrial applications meeting –40°C to +125°C junction temperature requirements, but lacks the extended test scope required for automotive deployment.
LMR33630BRNXT 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:
- 1.4MHz
- 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)
LMR33630BRNXT FAQ
1.How can I place an order for LMR33630BRNXT through Aetrix?
Please submit a Request for Quotation (RFQ) for LMR33630BRNXT 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 LMR33630BRNXT reliable?
The price and inventory of LMR33630BRNXT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMR33630BRNXT is usually 5 days.
3.What payment methods are accepted for LMR33630BRNXT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMR33630BRNXT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMR33630BRNXT?
LMR33630BRNXT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMR33630BRNXT 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 LMR33630BRNXT?
For technical support, including LMR33630BRNXT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMR33630BRNXT requirements.
6.How does Aetrix verify that LMR33630BRNXT is sourced from the original manufacturer or authorized distributors?
All LMR33630BRNXT 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 LMR33630BRNXT meets industry standards.
7.What is the process for return or replacement of LMR33630BRNXT?
All LMR33630BRNXT units undergo pre-shipment inspection (PSI). If there is an issue with LMR33630BRNXT, 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 LMR33630BRNXT part is unused and in its original packaging.
Return procedure for LMR33630BRNXT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMR33630BRNXT Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
