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Texas Instruments LMQ66420MC3RXBRQ1
- Part No.:
- LMQ66420MC3RXBRQ1
- Manufacturer:
- Texas Instruments
- Package:
- 14-PowerTFQFN
- Datasheet:
-
LMQ66420MC3RXBRQ1.pdf
- Description:
- IC REG BUCK ADJ/1V 2A 14VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,433
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Product details
Overview
LMQ66420MC3RXBRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous step-down DC/DC converter delivering up to 2A output current at a fixed 3.3V output, operating from 3.0V to 36V input with 42V transient tolerance. It integrates VIN bypass and CBOOT capacitors, uses peak-current-mode control, and features dual-random spread spectrum (DRSS) for CISPR 25 Class 5 EMI compliance - deployed in radar ECUs and infotainment head units.
For engineers reviewing the LMQ66420MC3RXBRQ1 datasheet, LMQ66420MC3RXBRQ1 pinout, LMQ66420MC3RXBRQ1 application, or LMQ66420MC3RXBRQ1 equivalent, key selection criteria include its 2.2MHz fixed switching frequency, integrated capacitors reducing external BOM count, ultra-low 1.5µA no-load quiescent current, and enhanced HotRod QFN-14 package with wettable flanks for automotive-grade reliability and optical inspection.
Technical Context
The LMQ66420MC3RXBRQ1 employs peak-current-mode control with auto mode enabling frequency foldback below ~10mA load, sustaining >85% efficiency at 1mA while maintaining regulation. Its ZEN 2 switcher architecture integrates two 22-nF VIN bypass capacitors and a 0.1-µF bootstrap capacitor internally, eliminating associated external components and minimizing high-frequency loop area.
EMI suppression is achieved via DRSS dithering, optimized pinout with NC pins isolating critical high-voltage nodes (VIN, SW), and an enhanced HotRod QFN-14 package that eliminates bond wires to suppress switch-node ringing. The MODE/SYNC pin supports FPWM/PFM selection or external clock synchronization from 200kHz to 2.5MHz without disrupting regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 2 A continuous - supports radar sensor power rails and infotainment SoC core supplies without external current boosting. |
| Input Voltage Range | 3.0 V to 36 V - covers full automotive battery range including cold-crank (3V) and load-dump transients (42V). |
| Output Voltage | Fixed 3.3 V ±0.9% - eliminates feedback resistor network, simplifies layout, and ensures stable MCU/ASIC interface voltage. |
| Switching Frequency | 2.2 MHz fixed - enables use of small 1.0 µH inductors and avoids AM-band interference in vehicle RF systems. |
| Quiescent Current | 1.5 µA at 13.5 VIN, no load - meets ISO 26262 ASIL-B standby power requirements for always-on ADAS modules. |
| Package | RXB (VQFN-FCRLF, 14-pin) - 2.6 mm × 2.6 mm with wettable flanks for automated optical inspection and robust thermal performance (RθJA = 66.1°C/W). |
| EMI Features | Dual-random spread spectrum + enhanced HotRod QFN + integrated bypass/boot caps - achieves CISPR 25 Class 5 without common-mode chokes or shielding. |
Pinout & Package
RXB package: 14-pin enhanced HotRod™ VQFN-FCRLF, 2.6 mm × 2.6 mm, with exposed thermal pad (GND/DAP) requiring solder connection to PCB ground plane for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 EN/UVLO | Enable input with precision UVLO | Starts regulator when VIN ≥ 3.35 V; shuts down at ≤2.7 V; supports direct connection to VIN for simple enable logic. |
| 3 VIN | Main power input | Internally connects to two series 22-nF bypass capacitors; requires external high-quality ceramic cap for low-impedance path to PGND. |
| 6 PGND | Power ground return | Low-inductance return path for high di/dt switch currents; must be connected to system ground with short, wide traces. |
| 7 SW | Switch node | Connects to inductor; high dv/dt node - minimized ringing via bond-wire-free HotRod package and optimized pin placement. |
| 8 BOOT | Bootstrap supply | Internally connects 0.1-µF cap to SW; supplies gate drive for high-side MOSFET - no external boot cap required. |
| 10 VCC | Internal LDO output | 3.3 V ±3.3% regulated supply for control circuitry; can power external logic or PG pull-up; requires 1-µF decoupling to GND. |
| 11 VOUT/FB | Output voltage sense / feedback | Fixed 3.3 V output - connect directly to output rail; no external resistors needed; pin must not float. |
| 13 MODE/SYNC | Mode selection / clock sync | Selects PFM (auto) or FPWM mode; accepts external 200 kHz–2.5 MHz clock for synchronized multi-rail systems. |
| 14 PG | Open-drain power-good flag | Asserts high after soft-start completes (tPG_ACT ≈ 2.5 ms); includes 40 µs deglitch and 2.4% hysteresis for reliable system reset signaling. |
| GND/DAP | Thermal pad / ground | Exposed copper pad - must be soldered to solid GND plane for thermal dissipation (RθJB = 26.2°C/W) and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated VIN bypass & CBOOT capacitors | Reduces external component count by 3–4 passive parts, shrinks input filter footprint, and eliminates placement-sensitive high-frequency paths. |
| ZEN 2 switcher architecture | Combines DRSS, optimized pinout with NC isolation between VIN/SW, and bond-wire-free HotRod packaging to meet CISPR 25 Class 5 without shielding. |
| Auto mode with frequency foldback | Enables seamless PWM-to-PFM transition; maintains >85% efficiency at 1 mA while drawing only 1.5 µA quiescent current for always-on ADAS modules. |
| AEC-Q100 Grade 1 qualification | Rated for –40°C to +125°C ambient (–40°C to +150°C junction), supporting under-hood and cockpit applications with validated FMEA pin layout. |
| Enhanced HotRod QFN with wettable flanks | Enables automated optical inspection of solder joints and improves board-level reliability via corner anchor pins and low-profile thermal pad attachment. |
Applications
| Radar ECU Power Supply | Infotainment Head Unit Core Rail |
|---|---|
|
Use Scenario: Powers 77-GHz radar transceiver SoCs requiring clean, low-noise 3.3V at up to 2A with strict EMI limits in compact front-bumper modules. IC Role / Device Role / Timing Role: Primary buck regulator providing regulated 3.3V rail; delivers precise voltage with <±0.9% accuracy across temperature and load for analog front-end stability. Use Value: Integrated bypass/boot caps and DRSS eliminate need for external EMI filters, reducing solution size by 35% versus discrete alternatives while meeting CISPR 25 Class 5. |
Use Scenario: Supplies core logic voltage to multimedia SoCs in automotive head units, operating continuously during vehicle ignition cycles with cold-crank support. IC Role / Device Role / Timing Role: Always-on step-down converter with ultra-low IQ (1.5 µA); manages power sequencing via EN and PG signals for safe boot/reset coordination. Use Value: 3.0–36V input range and 42V transient tolerance ensure uninterrupted operation during load dump; PG flag replaces external supervisor IC. |
| ADAS Camera Module Power | eCall Telematics System Rail |
|
Use Scenario: Powers image signal processors and MIPI interfaces in surround-view camera modules mounted in door mirrors and bumpers. IC Role / Device Role / Timing Role: Compact 2.6 mm × 2.6 mm buck converter delivering stable 3.3V at 1.5A; supports rapid start-up (<4 ms soft-start) for wake-on-event functionality. Use Value: Wettable-flank QFN enables AOI verification in high-volume SMT lines; NC pins between VIN/SW reduce field failure risk per pin FMEA analysis. |
Use Scenario: Provides backup power rail for eCall cellular modems and GNSS receivers in telematics control units, requiring long-term reliability and low standby drain. IC Role / Device Role / Timing Role: Automotive-qualified DC/DC with AEC-Q100 Grade 1 rating and 150°C max junction temperature for under-dash mounting environments. Use Value: 2A capability supports modem burst transmission; integrated capacitors reduce bill-of-materials cost and improve supply-chain resilience. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMQ66420MC5RXBRQ1 | Fixed 5V output instead of 3.3V; identical package, current rating, and feature set. | Suitable for SoC I/O rails or USB PHY supplies where 5V is required instead of 3.3V logic voltage. | Select when system requires 5V output - no layout change needed, but feedback network and output capacitor may differ. |
| TPS62933QRNRRQ1 | 3A rated, 2.5V–18V input, 3.3V fixed output; uses different control architecture (D-CAP3) and lacks integrated bypass caps. | Better suited for space-constrained non-automotive industrial applications where 42V transients are not required. | Choose if higher current headroom is needed and external EMI filtering is acceptable; not drop-in due to different pinout and no integrated capacitors. |
Compared with LMQ66420MC3RXBRQ1, the LMQ66420MC5RXBRQ1 offers identical form-factor and automotive qualification but targets 5V loads, whereas the TPS62933QRNRRQ1 provides higher current and wider input range but requires external bypass capacitors and does not meet CISPR 25 Class 5 out-of-box.
Availability
LMQ66420MC3RXBRQ1 is available at Aetrix Electronics and suitable for advanced driver assistance systems (radar ECUs), infotainment head units, body electronics modules, and telematics systems requiring stable component supply with automotive-grade traceability and lifecycle continuity.
Supply support for LMQ66420MC3RXBRQ1 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 automotive ICs, with decades of automotive qualification expertise and functional safety documentation support.
The LMQ664x0-Q1 product line was designed specifically for ultra-compact, low-EMI automotive power rails - targeting radar, camera, and infotainment subsystems where board space, EMI compliance, and AEC-Q100 reliability are non-negotiable.
FAQ
What is the maximum input voltage transient the LMQ66420MC3RXBRQ1 can withstand?
The LMQ66420MC3RXBRQ1 supports 42V automotive load-dump transients per AEC-Q100 requirements. Its absolute maximum VIN rating is 42V, and it maintains regulation during these events without latch-off or damage when properly implemented with appropriate input capacitance and layout. This capability is verified across the full –40°C to +125°C ambient temperature range.
Does the LMQ66420MC3RXBRQ1 require external input bypass capacitors?
Yes - although the LMQ66420MC3RXBRQ1 integrates two 22-nF VIN bypass capacitors internally, an external high-quality ceramic capacitor (e.g., 10 µF X7R, 0805) must still be placed close to the VIN and PGND pins to handle bulk energy and high-frequency ripple. The internal capacitors reduce but do not eliminate the need for external input filtering.
How does the MODE/SYNC pin function on the LMQ66420MC3RXBRQ1?
The MODE/SYNC pin on the LMQ66420MC3RXBRQ1 serves three roles: (1) logic-high selects FPWM mode, (2) logic-low enables Auto (PFM) mode, and (3) AC-coupled external clock input (200 kHz–2.5 MHz) synchronizes switching to avoid beat frequencies. It uses an internal PLL for glitch-free locking and remains in FPWM during sync operation.
What is the purpose of the NC pins on the LMQ66420MC3RXBRQ1 package?
The LMQ66420MC3RXBRQ1 includes multiple NC (no-connect) pins strategically placed between high-voltage nodes like VIN and SW to improve pin-level FMEA reliability. These pins act as creepage/clearance barriers, reducing risk of field-induced arcing or contamination-related failures - a design requirement validated for AEC-Q100 Grade 1 automotive deployment.
Can the LMQ66420MC3RXBRQ1 operate during automotive cold-crank conditions?
Yes - the LMQ66420MC3RXBRQ1 supports 3V minimum input voltage after startup, meeting automotive cold-crank requirements. Its EN pin UVLO threshold drops to 2.7V (typical) once operating, allowing continuous regulation down to 3.0V input while delivering full 2A output current at 3.3V with maintained efficiency and stability.
LMQ66420MC3RXBRQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 14-PowerTFQFN
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable (Fixed)
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 1V (3.3V)
- Voltage - Output (Max):
- 18V
- Current - Output:
- 2A
- Frequency - Switching:
- 2.2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 14-VQFN (2.6x2.6)
LMQ66420MC3RXBRQ1 FAQ
1.How can I place an order for LMQ66420MC3RXBRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LMQ66420MC3RXBRQ1 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 LMQ66420MC3RXBRQ1 reliable?
The price and inventory of LMQ66420MC3RXBRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMQ66420MC3RXBRQ1 is usually 5 days.
3.What payment methods are accepted for LMQ66420MC3RXBRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMQ66420MC3RXBRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMQ66420MC3RXBRQ1?
LMQ66420MC3RXBRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMQ66420MC3RXBRQ1 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 LMQ66420MC3RXBRQ1?
For technical support, including LMQ66420MC3RXBRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMQ66420MC3RXBRQ1 requirements.
6.How does Aetrix verify that LMQ66420MC3RXBRQ1 is sourced from the original manufacturer or authorized distributors?
All LMQ66420MC3RXBRQ1 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 LMQ66420MC3RXBRQ1 meets industry standards.
7.What is the process for return or replacement of LMQ66420MC3RXBRQ1?
All LMQ66420MC3RXBRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LMQ66420MC3RXBRQ1, 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 LMQ66420MC3RXBRQ1 part is unused and in its original packaging.
Return procedure for LMQ66420MC3RXBRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMQ66420MC3RXBRQ1 Tags
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AZ34063UMTR-G1
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MC34063EBD-TR
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