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Texas Instruments LMQ66420MA3RXBRQ1
- Part No.:
- LMQ66420MA3RXBRQ1
- Manufacturer:
- Texas Instruments
- Package:
- 14-PowerTFQFN
- Datasheet:
-
LMQ66420MA3RXBRQ1.pdf
- Description:
- IC REG BUCK ADJ/1V 2A 14VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,245
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Product details
Overview
LMQ66420MA3RXBRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous step-down DC/DC converter delivering up to 2A output current with fixed 3.3V output, 400kHz switching frequency, integrated VIN bypass and CBOOT capacitors, and operation across 3.0V–36V input range. It supports 42V load dump transients and −40°C to +150°C junction temperature, targeting radar ECU and infotainment power rails.
For engineers reviewing the LMQ66420MA3RXBRQ1 datasheet, LMQ66420MA3RXBRQ1 pinout, LMQ66420MA3RXBRQ1 application, or LMQ66420MA3RXBRQ1 equivalent, key selection considerations include its ZEN 2 switcher architecture for CISPR 25 Class 5 compliance, ultra-small 2.6mm × 2.6mm HotRod QFN package with wettable flanks, auto-mode light-load efficiency down to 1.5µA, and integrated protection features including thermal shutdown and power-good flag.
Technical Context
The LMQ66420MA3RXBRQ1 employs peak-current-mode control with frequency foldback in auto mode, enabling seamless PWM-to-PFM transition and >85% efficiency at 1mA. Its dual-random spread spectrum (DRSS) and optimized HotRod QFN pinout minimize EMI without external filters.
It integrates two 22-nF VIN bypass capacitors and a 0.1-µF bootstrap capacitor internally, eliminating external components while maintaining low switch-node ringing. The MODE/SYNC pin supports FPWM/auto mode selection or external clock synchronization up to 2.5MHz, with dedicated NC pins between high-voltage nodes for enhanced FMEA reliability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 2A continuous - supports radar sensor and head unit SoC core rail loads without derating at 125°C ambient. |
| Input Voltage Range | 3.0V–36V after start-up - withstands automotive cold-crank (3VIN) and 42V load dump transients with no external protection. |
| Switching Frequency | Fixed 400kHz - enables use of smaller magnetics than 2.2MHz variants while avoiding AM-band interference. |
| Quiescent Current | 1.5µA at 13.5V VIN, unloaded - meets ultra-low standby power requirements for always-on ADAS modules. |
| Output Voltage | Fixed 3.3V ±0.9% - eliminates external feedback resistors and ensures stable logic supply for MCU/FPGA interfaces. |
| Package | RXB (VQFN-FCRLF, 14-pin), 2.6mm × 2.6mm - wettable flanks enable automated optical inspection; corner anchor pins improve solder joint reliability. |
| Thermal Protection | Thermal shutdown at 158°C–186°C with 15°C–20°C hysteresis - prevents latch-up during sustained overload or poor airflow conditions. |
Pinout & Package
RXB package: 14-pin enhanced HotRod™ VQFN-FCRLF, 2.6mm × 2.6mm, 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 regulation when VIN ≥ 3.35V; shuts down below 2.7V; supports direct connection to VIN for simple on/off control. |
| 3 VIN | Main input supply | Internally connects to two series 22-nF bypass capacitors; accepts up to 42V transient without damage. |
| 6 PGND | Power ground return | Low-inductance path for high di/dt currents; must be routed with short, wide traces to minimize noise coupling. |
| 7 SW | Switch node | Connects to power inductor; minimized ringing due to bond-wire-free HotRod construction and internal layout optimization. |
| 8 BOOT | Bootstrap supply | Internally connected to SW via 0.1-µF capacitor; eliminates need for external boot cap and reduces layout sensitivity. |
| 10 VCC | Internal LDO output | 3.3V ±3.3% regulated supply for control circuitry; can power external logic but not recommended for >1mA loads. |
| 11 VOUT/FB | Fixed output / feedback node | Direct connection to 3.3V output; no external resistor divider required; FB function disabled in fixed-VOUT variant. |
| 13 MODE/SYNC | Mode selection / clock sync | Configures FPWM/auto mode or synchronizes to external 0.2–2.5MHz clock; eliminates beat frequencies in multi-rail systems. |
| 14 PG | Open-drain power-good flag | Asserts high after 2.5ms soft-start delay when VOUT reaches 90%; provides reset timing without external supervisor IC. |
| GND/DAP | Thermal pad / ground | Must be soldered to PCB ground plane; primary thermal path (RθJB = 26.2°C/W); improves EMI performance via low-impedance return. |
Key Features
| Feature | Design Value |
|---|---|
| ZEN 2 switcher architecture | Enables CISPR 25 Class 5 compliance via DRSS, optimized pinout, and integrated capacitors-reduces need for common-mode chokes or shielding. |
| Integrated VIN bypass & CBOOT | Two 22-nF series bypass caps and 0.1-µF boot cap inside package-eliminates 3 external MLCCs and saves >12mm² board area. |
| Auto-mode light-load efficiency | 1.5µA quiescent current at 13.5V VIN-extends battery life in always-on ADAS modules during vehicle sleep states. |
| Enhanced HotRod QFN package | 2.6mm × 2.6mm footprint with wettable flanks and corner anchors-enables AOI verification and improves mechanical reliability under thermal cycling. |
| NC pins between critical nodes | Three NC pins isolate VIN, SW, and PGND-reduces risk of field-induced failure and improves pin-level FMEA score per ISO 26262 ASIL-B requirements. |
Applications
| Radar ECU Power Supply | Infotainment Head Unit Core Rail |
|---|---|
|
Use Scenario: Powers 77GHz radar transceiver SoC in front-end module requiring stable 3.3V at ≤2A with minimal EMI impact on RF front-end. IC Role / Device Role / Timing Role: Primary buck regulator supplying digital core voltage; operates in auto mode during idle periods to reduce system standby power. Use Value: Integrated DRSS and HotRod package meet CISPR 25 Class 5 limits without ferrite beads or shielded inductors, reducing BOM cost by $0.32/unit. |
Use Scenario: Delivers 3.3V to application processor and display interface in automotive head unit with cold-crank support during engine start. IC Role / Device Role / Timing Role: Secondary power rail generator downstream of main 12V–5V conversion; maintains regulation during 3VIN events down to 3.0V input. Use Value: 42V transient tolerance and −40°C to +150°C junction rating eliminate need for external TVS or thermal derating margins. |
| eCall Module Backup Power | Body Control Module Sensor Interface |
|
Use Scenario: Provides always-on 3.3V supply to GNSS receiver and cellular modem in eCall telematics unit with ultra-low IQ during vehicle off-state. IC Role / Device Role / Timing Role: Standby power source with power-good monitoring; PG flag triggers MCU wake-up upon valid VOUT establishment. Use Value: 1.5µA shutdown current extends backup battery life beyond 12 months; integrated soft-start prevents inrush-induced brownout. |
Use Scenario: Supplies 3.3V to LIN transceivers and ambient light sensors in door module with space-constrained PCB layout. IC Role / Device Role / Timing Role: Compact point-of-load regulator replacing discrete buck + LDO solution; uses same 2.6mm × 2.6mm footprint as legacy LDOs. Use Value: 2.6mm × 2.6mm RXB package fits into legacy 3mm × 3mm footprints; wettable flanks ensure 100% solder joint inspection pass rate. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMQ66420MC3RXBRQ1 | Same 2A/3.3V rating but fixed 2.2MHz switching frequency; higher EMI risk in sensitive RF zones without additional filtering. | Preferred for space-constrained designs where smaller inductors are mandatory; less suitable for radar proximity layouts. | Select when board area is prioritized over EMI margin and layout allows tighter input filtering. |
| TPS62903RTERQ1 | 2A, 3.3V, 1.8–6.5V input; lower IQ (250nA) but no integrated bypass caps or load-dump tolerance; requires external 42V TVS. | Targeted at low-voltage domains (e.g., domain controllers); lacks automotive-grade transient robustness for direct battery connection. | Choose only for secondary rails powered from regulated 5V, not direct battery-fed systems. |
Compared with LMQ66420MC3RXBRQ1 and TPS62903RTERQ1, the LMQ66420MA3RXBRQ1 uniquely combines 400kHz operation for AM-band avoidance, integrated 42V transient handling, and zero-external-capacitor VIN bypass-making it the only option qualified for direct-battery radar ECU power without redesign.
Availability
LMQ66420MA3RXBRQ1 is available at Aetrix Electronics and suitable for advanced driver assistance systems, infotainment head units, and body electronics requiring stable component supply across automotive production lifecycles.
Supply support for LMQ66420MA3RXBRQ1 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-grade power management ICs with over 40 years of automotive qualification experience.
The LMQ664x0-Q1 product line was designed specifically for ultra-compact, low-EMI, always-on automotive power rails-including radar, camera, and telematics modules-where board space, thermal performance, and CISPR 25 compliance are critical.
FAQ
What is the maximum input voltage the LMQ66420MA3RXBRQ1 can withstand during automotive load dump?
The LMQ66420MA3RXBRQ1 supports 42V transients on the VIN pin per AEC-Q100 stress testing. This rating applies to short-duration (≤400ms) load dump events without external clamping, making it suitable for direct connection to the vehicle battery rail in ADAS and infotainment systems.
Does the LMQ66420MA3RXBRQ1 require external input bypass capacitors?
No. The LMQ66420MA3RXBRQ1 integrates two 22-nF VIN bypass capacitors internally, eliminating the need for external high-frequency ceramic capacitors. A single bulk electrolytic or polymer capacitor (≥10µF) is still recommended at the input for low-frequency energy storage.
How does the MODE/SYNC pin function on the LMQ66420MA3RXBRQ1?
The MODE/SYNC pin on the LMQ66420MA3RXBRQ1 configures three operating modes: pull low for auto (PFM/FPWM) mode, pull high for forced-PWM mode, or apply an external 0.2–2.5MHz clock signal to synchronize switching. No external pull resistors are required-the pin has internal biasing.
What is the thermal performance of the LMQ66420MA3RXBRQ1 in a standard 4-layer PCB layout?
On a JEDEC-standard 4-layer board, the LMQ66420MA3RXBRQ1 exhibits RθJA = 66.1°C/W. With the GND/DAP thermal pad fully soldered to a 250mm² copper pour, junction-to-board resistance drops to 26.2°C/W-enabling 2A continuous output at 85°C ambient without forced airflow.
Is the LMQ66420MA3RXBRQ1 pin-compatible with other members of the LMQ664x0-Q1 family?
Yes. All LMQ664x0-Q1 variants-including LMQ66410MA3RXBRQ1, LMQ66420MA3RXBRQ1, and LMQ66430MA3RXBRQ1-share identical RXB (14-pin VQFN-FCRLF) packaging, pinout, and footprint. Only output current rating and switching frequency differ; no PCB redesign is needed when scaling capacity.
LMQ66420MA3RXBRQ1 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:
- 400kHz
- 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)
LMQ66420MA3RXBRQ1 FAQ
1.How can I place an order for LMQ66420MA3RXBRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LMQ66420MA3RXBRQ1 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 LMQ66420MA3RXBRQ1 reliable?
The price and inventory of LMQ66420MA3RXBRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMQ66420MA3RXBRQ1 is usually 5 days.
3.What payment methods are accepted for LMQ66420MA3RXBRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMQ66420MA3RXBRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMQ66420MA3RXBRQ1?
LMQ66420MA3RXBRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMQ66420MA3RXBRQ1 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 LMQ66420MA3RXBRQ1?
For technical support, including LMQ66420MA3RXBRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMQ66420MA3RXBRQ1 requirements.
6.How does Aetrix verify that LMQ66420MA3RXBRQ1 is sourced from the original manufacturer or authorized distributors?
All LMQ66420MA3RXBRQ1 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 LMQ66420MA3RXBRQ1 meets industry standards.
7.What is the process for return or replacement of LMQ66420MA3RXBRQ1?
All LMQ66420MA3RXBRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LMQ66420MA3RXBRQ1, 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 LMQ66420MA3RXBRQ1 part is unused and in its original packaging.
Return procedure for LMQ66420MA3RXBRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMQ66420MA3RXBRQ1 Tags
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