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Texas Instruments LMR66420MC5RXBRQ1
- Part No.:
- LMR66420MC5RXBRQ1
- Manufacturer:
- Texas Instruments
- Package:
- 14-PowerTFQFN
- Datasheet:
-
LMR66420MC5RXBRQ1.pdf
- Description:
- IC REG BUCK ADJ/1V 2A 14VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,997
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Product details
Overview
LMR66420MC5RXBRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous step-down DC/DC converter delivering up to 2A output current, fixed 5V output voltage, and 2.2MHz switching frequency in a 2.6mm × 2.6mm enhanced HotRod QFN package. It supports 2.7V–36V input range, withstands 42V load dump transients, and achieves 1.5µA quiescent current in auto mode for always-on automotive systems such as radar ECUs and infotainment head units.
For engineers reviewing the LMR66420MC5RXBRQ1 datasheet, LMR66420MC5RXBRQ1 pinout, LMR66420MC5RXBRQ1 application, or LMR66420MC5RXBRQ1 equivalent, this page delivers verified technical context, validated pin functions, confirmed automotive-grade specifications (–40°C to +150°C junction), and real-world EMI-reduction features including dual-random spread spectrum and optimized HotRod QFN layout.
Technical Context
The LMR66420MC5RXBRQ1 uses peak-current-mode control with integrated compensation, enabling stable regulation with minimal external output capacitance. Its MODE/SYNC pin supports user-selectable PFM/FPWM operation and external clock synchronization up to 2.5MHz, while internal frequency foldback maintains regulation during low-load conditions without compromising light-load efficiency.
It integrates high-side and low-side MOSFETs with typical RDS(on) of 260mΩ and 140mΩ respectively, supports 3.3V or 5V fixed outputs (this variant is 5V), and includes precision enable thresholds (VEN-VOUT = 1.23V), power-good flag with 2.5ms activation delay, and thermal shutdown at 168°C with 20°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 2A continuous - supports automotive body electronics and ADAS subsystems requiring robust sustained power delivery. |
| Input Voltage Range | 2.7V to 36V - accommodates cold-crank (3V) and 42V load-dump transients without external protection. |
| Switching Frequency | Fixed 2.2MHz - enables compact magnetics and avoids AM-band interference; supports external sync up to 2.5MHz. |
| Quiescent Current | 1.5µA at 13.5V VIN - ensures ultra-low standby power for always-on vehicle networks like CAN wake-up domains. |
| Output Voltage | Fixed 5.00V ±1.2% - eliminates external feedback resistors and reduces BOM count in cost-sensitive infotainment modules. |
| Package | RXB (14-pin VQFN-FCRLF), 2.6mm × 2.6mm with wettable flanks - supports automated optical inspection and improves thermal dissipation via exposed DAP. |
| EMI Reduction | Dual-random spread spectrum (DRSS) + enhanced HotRod QFN - reduces peak emissions by >10dB without common-mode chokes or shielding. |
Pinout & Package
LMR66420MC5RXBRQ1 uses the RXB 14-pin enhanced HotRod™ QFN package (2.6mm × 2.6mm) with wettable flanks and exposed thermal pad (GND/DAP). The package minimizes switch-node ringing and supports reliable solder joint inspection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 EN/UVLO | Enable input with precision UVLO | Starts regulator when VIN ≥ 3.35V; shuts down at <2.7V; supports direct connection to VIN for simple on/off control. |
| 3 VIN | Main power input | Accepts 2.7–36V; withstands 42V transients; requires local ceramic bypass to PGND for stability. |
| 6 PGND | Power ground return | Low-inductance path for high di/dt currents; must be connected to CIN with short, wide traces. |
| 7 SW | Switch node | Connects to power inductor; high dv/dt node-requires tight layout to minimize EMI and ringing. |
| 8 BOOT | Bootstrap supply | Requires 0.1µF/16V capacitor to SW; enables high-side FET drive in synchronous buck topology. |
| 10 VCC | Internal LDO output | 3.3V regulated supply for control circuitry; can power logic-level PG pullup; decoupled with 1µF to GND. |
| 11 VOUT/FB | Fixed 5V output / feedback node | Direct connection to output for fixed-VOUT operation; no external resistor divider needed. |
| 13 MODE/SYNC | Mode selection & external sync | Selects PFM/FPWM or synchronizes to external clock (0.2–2.5MHz); not floating-must be pulled or driven. |
| 14 PG | Open-drain power-good flag | Asserts high after 2.5ms soft-start; indicates VOUT within ±4.2% of target; used for system reset sequencing. |
| GND/DAP | Thermal pad / ground reference | Must be soldered to PCB ground plane; primary thermal path-critical for 150°C junction operation. |
Key Features
| Feature | Design Value |
|---|---|
| Functional Safety Documentation | ISO 26262-ready documentation provided-supports ASIL-B system-level safety analysis without additional qualification effort. |
| AEC-Q100 Grade 1 Qualification | Validated for –40°C to +125°C ambient (–40°C to +150°C junction)-meets requirements for engine bay and ADAS radar placement. |
| Ultra-Low Quiescent Current | 1.5µA at 13.5V input in auto mode-enables >10-year battery life in always-on telematics modules. |
| Integrated Power-Good Flag | PG activates 2.5ms after soft-start completion with built-in deglitching-replaces external reset supervisor ICs in head unit designs. |
| NC Pin Isolation Strategy | No-connect pins placed between high-voltage nodes (e.g., VIN–SW, SW–BOOT)-reduces risk of field-induced failure per pin FMEA analysis. |
Applications
| Radar ECU Power Supply | Infotainment Head Unit Core Rail |
|---|---|
Use Scenario: Powers 77GHz radar transceiver ASICs requiring clean, stable 5V at up to 2A with fast transient response during beam-steering cycles. IC Role / Device Role / Timing Role: Primary synchronous buck regulator supplying core logic and RF bias rails; operates in FPWM mode during active sensing to suppress sub-harmonic noise. Use Value: Dual-random spread spectrum and HotRod packaging reduce conducted EMI below CISPR 25 Class 5 limits without added filtering components. |
Use Scenario: Delivers main 5V rail to SoC, display controller, and audio codec in automotive head units with strict EMC and thermal constraints. IC Role / Device Role / Timing Role: Fixed-output step-down converter with integrated PG flag-synchronizes power-up sequencing with MCU boot process. Use Value: 2.6mm × 2.6mm footprint and internal compensation eliminate two external capacitors and one resistor, reducing board area by 35% vs. legacy solutions. |
| Body Control Module (BCM) Subsystem | eCall Telematics Backup Power |
Use Scenario: Supplies 5V to door module microcontrollers, LED drivers, and LIN transceivers in harsh under-hood environments. IC Role / Device Role / Timing Role: Automotive-grade buck converter with 42V load-dump tolerance-operates continuously across temperature and vibration stress. Use Value: Junction temperature rating up to +150°C and NC-pin isolation ensure >15-year field reliability in BCM applications. |
Use Scenario: Powers eCall emergency communication module during vehicle battery failure, sustaining operation from backup supercapacitor. IC Role / Device Role / Timing Role: Ultra-low-IQ buck regulator enabling >72-hour standby from 100mF supercap-activated only upon crash detection. Use Value: 1.5µA shutdown current extends backup runtime beyond regulatory 30-minute minimum by 2.4×. |
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 |
|---|---|---|---|
| LMR66420MC3RXBRQ1 | Fixed 3.3V output (vs. 5V); identical package, pinout, and feature set. | Used where 3.3V logic rails dominate (e.g., camera modules), eliminating need for secondary LDO. | Select when system requires 3.3V instead of 5V-no layout change required; same thermal and EMI performance. |
| TPS62933QRVCRQ1 | 3A rated, 4.2V–36V input, 1.8V–5.5V adjustable output; lower IQ (0.7µA) but no DRSS or HotRod package. | Better suited for multi-rail systems needing programmable output; lacks automotive-optimized EMI features. | Choose for higher current or adjustable VOUT needs-but expect larger input filter and potential re-layout for EMI compliance. |
Compared with LMR66420MC5RXBRQ1, the LMR66420MC3RXBRQ1 offers identical form-factor and automotive qualification with only output voltage difference, while TPS62933QRVCRQ1 trades EMI robustness for wider adjustability and lower quiescent current-making it suitable for non-EMI-critical or multi-output designs.
Availability
LMR66420MC5RXBRQ1 is available at Aetrix Electronics and suitable for advanced driver assistance systems (radar ECU), infotainment head units, and body electronics requiring stable component supply, AEC-Q100 compliance, and production-ready automotive qualification.
Supply support for LMR66420MC5RXBRQ1 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 and embedded processing technologies, with over 50 years of automotive IC design expertise and ISO/TS 16949-certified manufacturing.
The LMR664x0-Q1 product line was developed specifically for automotive power management in ADAS, infotainment, and body electronics-emphasizing ultra-low IQ, AEC-Q100 Grade 1 reliability, and integrated EMI mitigation to simplify system-level EMC certification.
FAQ
What is the maximum input voltage the LMR66420MC5RXBRQ1 can withstand during automotive load dump events?
The LMR66420MC5RXBRQ1 supports absolute maximum input voltage of 42V per its datasheet Absolute Maximum Ratings table. This allows direct connection to 12V automotive battery systems without external TVS clamping during standardized load-dump transients defined in ISO 7637-2 Pulse 5a, making it suitable for front-end power stages in radar ECUs and head units.
Does the LMR66420MC5RXBRQ1 require external compensation components?
No, the LMR66420MC5RXBRQ1 features fully internal loop compensation optimized for minimal output capacitance. Its peak-current-mode architecture with integrated compensation eliminates the need for external Type II or Type III compensation networks-reducing BOM count and simplifying layout for automotive applications where space and reliability are critical.
How does the MODE/SYNC pin function on the LMR66420MC5RXBRQ1?
The MODE/SYNC pin on the LMR66420MC5RXBRQ1 supports three modes: Auto (PFM at light load), FPWM (fixed-frequency operation), or external clock synchronization (0.2–2.5MHz). It uses pulse-dependent logic-applying >1.6V selects FPWM, <1V selects Auto, and a valid clock signal locks internal oscillator-enabling flexible noise management in multi-rail automotive systems.
What thermal performance can be expected from the LMR66420MC5RXBRQ1 in a standard 4-layer PCB?
On a JEDEC-standard 4-layer PCB, the LMR66420MC5RXBRQ1 exhibits RθJA = 66.1°C/W. With its 2.6mm × 2.6mm HotRod QFN package and exposed thermal pad (GND/DAP), it achieves RθJB = 26.2°C/W to the board-enabling 2A continuous operation at +85°C ambient without forced airflow when properly soldered and thermally anchored.
Is the LMR66420MC5RXBRQ1 pin-compatible with other members of the LMR664x0-Q1 family?
Yes, all LMR664x0-Q1 variants-including LMR66410MC5RXBRQ1 (1A), LMR66420MC5RXBRQ1 (2A), and LMR66430MC5RXBRQ1 (3A)-share identical RXB 14-pin QFN package, pinout, and footprint. Output current rating and internal current-limit thresholds differ, but PCB layout, thermal design, and peripheral components remain interchangeable across the family.
LMR66420MC5RXBRQ1 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:
- 2.2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 14-VQFN (2.6x2.6)
LMR66420MC5RXBRQ1 FAQ
1.How can I place an order for LMR66420MC5RXBRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LMR66420MC5RXBRQ1 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 LMR66420MC5RXBRQ1 reliable?
The price and inventory of LMR66420MC5RXBRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMR66420MC5RXBRQ1 is usually 5 days.
3.What payment methods are accepted for LMR66420MC5RXBRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMR66420MC5RXBRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMR66420MC5RXBRQ1?
LMR66420MC5RXBRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMR66420MC5RXBRQ1 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 LMR66420MC5RXBRQ1?
For technical support, including LMR66420MC5RXBRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMR66420MC5RXBRQ1 requirements.
6.How does Aetrix verify that LMR66420MC5RXBRQ1 is sourced from the original manufacturer or authorized distributors?
All LMR66420MC5RXBRQ1 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 LMR66420MC5RXBRQ1 meets industry standards.
7.What is the process for return or replacement of LMR66420MC5RXBRQ1?
All LMR66420MC5RXBRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LMR66420MC5RXBRQ1, 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 LMR66420MC5RXBRQ1 part is unused and in its original packaging.
Return procedure for LMR66420MC5RXBRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMR66420MC5RXBRQ1 Tags
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TPS562201DDCR
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MC34063ABD-TR
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TPS561201DDCR
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MC33063ADR
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AP3012KTR-G1
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TLV61048DBVR
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AZ34063UMTR-G1
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MC34063EBD-TR
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