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Texas Instruments LMQ66420MA5RXBRQ1
- Part No.:
- LMQ66420MA5RXBRQ1
- Manufacturer:
- Texas Instruments
- Package:
- 14-PowerTFQFN
- Datasheet:
-
LMQ66420MA5RXBRQ1.pdf
- Description:
- IC REG BUCK ADJ/1V 2A 14VQFN
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LMQ66420MA5RXBRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous step-down DC/DC converter delivering up to 2A output current at fixed 5V output, operating from 3.0V to 36V input with 42V load dump 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 in radar ECU power rails.
For engineers reviewing the LMQ66420MA5RXBRQ1 datasheet, LMQ66420MA5RXBRQ1 pinout, LMQ66420MA5RXBRQ1 application, or LMQ66420MA5RXBRQ1 equivalent, key selection criteria include its 400 kHz fixed switching frequency, integrated capacitors reducing external BOM count, ultra-small 2.6mm × 2.6mm HotRod QFN package with wettable flanks, and functional safety documentation support for ASIL-B system integration.
Technical Context
The LMQ66420MA5RXBRQ1 implements peak-current-mode control with auto mode enabling frequency foldback below 1mA load, achieving 1.5µA quiescent current at 13.5VIN. 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 ringing via enhanced HotRod QFN construction.
It supports FPWM and PFM operation via MODE/SYNC pin configuration, includes precision enable with 0.7V wake threshold and 1.23V VOUT turn-on threshold, and provides open-drain power-good flag with 2.5ms activation delay and 40µs deglitch filtering - all optimized for always-on automotive subsystems requiring low standby power and robust transient immunity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 2 A continuous DC output - supports radar sensor modules and infotainment SoCs without external current boosting. |
| Input Voltage Range | 3.0 V to 36 V after startup; withstands 42 V load dump transients - meets ISO 7637-2 Pulse 5a requirements for 12 V automotive systems. |
| Output Voltage | Fixed 5 V ±1.2% accuracy over –40°C to +150°C - eliminates need for external feedback resistors and simplifies layout. |
| Switching Frequency | Fixed 400 kHz - enables use of smaller inductors while avoiding AM band interference and easing EMI filter design. |
| Quiescent Current | 1.5 µA at 13.5 VIN, no load, Auto mode - sustains >10-year battery life in always-on vehicle modules. |
| Thermal Shutdown | 168°C trip with 20°C hysteresis - protects against sustained overload in enclosed ECUs without derating. |
| Package | RXB (VQFN-FCRLF, 14-pin), 2.6 mm × 2.6 mm with wettable flanks - supports automated optical inspection and high-reliability solder joints in automotive reflow profiles. |
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 | Wakes at 0.7 V, turns on regulator at 1.23 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 bulk capacitance only for low-frequency ripple. |
| 6 PGND | Power ground return | Low-inductance path for high di/dt switch currents; must be routed with short, wide copper to minimize noise coupling. |
| 7 SW | Switch node | Connects to power inductor; minimized ring due to bond-wire-free HotRod construction and internal DRSS modulation. |
| 8 BOOT | Bootstrap supply | Internally connects 0.1-µF capacitor to SW; eliminates external boot cap and routing loop. |
| 10 VCC | Internal LDO output | 3.3 V ±3% regulated supply for control circuitry; decoupled with 1-µF ceramic to GND; usable as logic rail for PG. |
| 11 VOUT/FB | Fixed 5 V output / feedback node | Direct connection to output for fixed-VOUT operation; no resistor divider needed - reduces component count and layout sensitivity. |
| 13 MODE/SYNC | Mode selection / clock sync input | Selects Auto (PFM), FPWM, or external sync; accepts 0.2–2.5 MHz clock; enables deterministic multi-rail timing in ADAS domains. |
| 14 PG | Open-drain power-good flag | Asserts high after 2.5 ms soft-start; includes 40 µs deglitch and 2.4% hysteresis - replaces discrete reset supervisor ICs. |
| 2,4,5,9,12 NC | No-connect terminals | Isolate critical high-voltage pins (VIN, SW, BOOT); improve pin-level FMEA score and reduce field failure risk. |
Key Features
| Feature | Design Value |
|---|---|
| ZEN 2 switcher architecture | Integrates two 22-nF VIN bypass caps and one 0.1-µF CBOOT capacitor - reduces external component count by ≥3 and shrinks total solution size by 30%. |
| Dual-random spread spectrum (DRSS) | Reduces peak EMI emissions by >10 dB across 150 kHz–108 MHz - enables CISPR 25 Class 5 compliance without common-mode chokes. |
| Enhanced HotRod QFN package | Bond-wire-free construction with wettable flanks and corner anchor pins - improves solder joint reliability and enables AOI verification per IPC-A-610. |
| Auto mode with frequency foldback | Switches from 400 kHz to sub-100 kHz below 1 mA load - maintains >85% efficiency down to 1 mA while drawing only 1.5 µA IQ. |
| NC pins between high-voltage nodes | Eliminates creepage/clearance violations between VIN, SW, and BOOT - achieves best-in-class pin-level FMEA rating for automotive safety-critical designs. |
Applications
| Radar ECU Power Supply | Infotainment Head Unit Core Rail |
|---|---|
Use Scenario: Powers 77 GHz radar transceiver SoC in front bumper module with strict EMI limits and cold-crank operation. IC Role / Device Role / Timing Role: Primary 5 V buck regulator supplying digital core, ADC reference, and PLL VCO bias rails. Use Value: DRSS + HotRod package ensures CISPR 25 Class 5 pass without shielding; 42 V load dump tolerance prevents brownout during alternator surge. |
Use Scenario: Supplies 5 V rail to application processor and display interface in central infotainment head unit. IC Role / Device Role / Timing Role: Always-on system power rail supporting fast wake-from-sleep and audio DSP real-time processing. Use Value: 1.5 µA quiescent current extends battery reserve time; fixed 5 V output eliminates calibration drift in touch controller and audio codec references. |
| eCall Telematics Module | Body Control Module (BCM) Sensor Hub |
Use Scenario: Powers GSM/LTE modem and GNSS receiver in crash-response eCall module with backup battery operation. IC Role / Device Role / Timing Role: Main 5 V supply enabling GPS acquisition and cellular handshake within 2 s of crash detection. Use Value: 3.0 V minimum input supports 3 V cold-crank condition; PG flag triggers MCU watchdog reset if VOUT drops below 4.77 V. |
Use Scenario: Supplies 5 V to LIN transceivers, ambient light sensors, and door handle proximity ICs in BCM distributed architecture. IC Role / Device Role / Timing Role: Secondary regulated rail derived from 12 V battery, isolated from main ECU power domain. Use Value: NC pin isolation prevents latch-up during LIN bus fault events; wettable flanks ensure solder joint integrity in high-vibration door modules. |
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 | Same 2 A / 5 V output but fixed 2.2 MHz switching frequency - higher frequency enables smaller inductors but increases switching loss above 500 mA. | Preferred for space-constrained infotainment displays where board area is more critical than light-load efficiency. | Select when EMI filtering bandwidth allows >2 MHz operation and thermal margin supports higher AC losses. |
| TPS62932RQWRQ1 | 2 A, 5 V fixed output, 2.2 MHz, but no integrated bypass/boot capacitors - requires external 22 nF VIN bypass and 0.1 µF CBOOT. | Suitable for cost-sensitive body electronics where BOM count is less critical than total solution cost. | Choose when design already includes robust input filtering and layout constraints allow extra capacitor placement near SW node. |
Compared with LMQ66420MC5RXBRQ1, the LMQ66420MA5RXBRQ1 trades higher light-load efficiency and lower EMI at 400 kHz for larger magnetics; versus TPS62932RQWRQ1, it delivers superior EMI performance and reduced layout sensitivity due to on-die capacitors - making it optimal for radar and telematics where regulatory compliance is non-negotiable.
Availability
LMQ66420MA5RXBRQ1 is available at Aetrix Electronics and suitable for advanced driver assistance systems (radar ECU), infotainment head units, eCall telematics modules, and body control module sensor hubs requiring stable component supply across automotive production lifecycles.
Supply support for LMQ66420MA5RXBRQ1 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 analog and embedded processing chips for industrial, automotive, and consumer markets since 1930.
The LMQ664x0-Q1 product line was developed specifically for automotive power management in ASIL-B systems, emphasizing ultra-low quiescent current, integrated EMI mitigation, and AEC-Q100 reliability - targeting radar, infotainment, and always-on telematics subsystems.
FAQ
What is the maximum input voltage the LMQ66420MA5RXBRQ1 can withstand during automotive load dump events?
The LMQ66420MA5RXBRQ1 supports 42 V absolute maximum input voltage per its Absolute Maximum Ratings table, enabling reliable operation during ISO 7637-2 Pulse 5a load dump transients in 12 V automotive systems. This rating is validated across the full –40°C to +150°C junction temperature range and does not require external clamping circuitry when used within recommended operating conditions.
Does the LMQ66420MA5RXBRQ1 require external input bypass capacitors despite its integrated VIN capacitors?
Yes - while the LMQ66420MA5RXBRQ1 integrates two 22-nF series-connected VIN bypass capacitors internally, it still requires an external high-quality bulk capacitor (e.g., 10 µF X5R ceramic) placed close to the VIN and PGND pins to handle low-frequency ripple and transient energy from the battery or alternator. The internal capacitors target high-frequency noise suppression only.
Can the LMQ66420MA5RXBRQ1 operate with input voltage as low as 3.0 V, and what happens during cold-crank conditions?
Yes - the LMQ66420MA5RXBRQ1 operates down to 3.0 V after startup and supports 3 V cold-crank conditions per its Recommended Operating Conditions. During cold-crank, it maintains regulation using frequency foldback and extended duty cycle (up to 98%), ensuring uninterrupted power to critical ADAS sensors even when battery voltage dips below 6 V for up to 15 ms.
How does the MODE/SYNC pin function on the LMQ66420MA5RXBRQ1, and what modes does it support?
The MODE/SYNC pin on the LMQ66420MA5RXBRQ1 configures three operational modes: Auto (PFM at light loads), FPWM (forced PWM across full load range), or external synchronization to a 0.2–2.5 MHz clock source. In SYNC mode, the internal oscillator locks to the external signal's rising edge, enabling deterministic multi-rail timing in radar and camera fusion systems without phase jitter.
What is the purpose of the NC pins on the LMQ66420MA5RXBRQ1, and how do they improve reliability?
The LMQ66420MA5RXBRQ1 includes five NC pins (pins 2, 4, 5, 9, 12) positioned between high-voltage nodes (VIN, SW, BOOT) to increase creepage and clearance distances. This physical isolation reduces risk of surface contamination-induced leakage or arcing, directly improving pin-level FMEA scores and meeting stringent automotive reliability requirements for long-term field operation in humid or contaminated environments.
LMQ66420MA5RXBRQ1 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):
- -
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 1V
- Voltage - Output (Max):
- 5V
- Current - Output:
- 2A
- Frequency - Switching:
- 400kHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 14-VQFN (2.6x2.6)
LMQ66420MA5RXBRQ1 FAQ
1.How can I place an order for LMQ66420MA5RXBRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LMQ66420MA5RXBRQ1 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 LMQ66420MA5RXBRQ1 reliable?
The price and inventory of LMQ66420MA5RXBRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMQ66420MA5RXBRQ1 is usually 5 days.
3.What payment methods are accepted for LMQ66420MA5RXBRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMQ66420MA5RXBRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMQ66420MA5RXBRQ1?
LMQ66420MA5RXBRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMQ66420MA5RXBRQ1 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 LMQ66420MA5RXBRQ1?
For technical support, including LMQ66420MA5RXBRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMQ66420MA5RXBRQ1 requirements.
6.How does Aetrix verify that LMQ66420MA5RXBRQ1 is sourced from the original manufacturer or authorized distributors?
All LMQ66420MA5RXBRQ1 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 LMQ66420MA5RXBRQ1 meets industry standards.
7.What is the process for return or replacement of LMQ66420MA5RXBRQ1?
All LMQ66420MA5RXBRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LMQ66420MA5RXBRQ1, 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 LMQ66420MA5RXBRQ1 part is unused and in its original packaging.
Return procedure for LMQ66420MA5RXBRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMQ66420MA5RXBRQ1 Tags
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