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Texas Instruments LMS3655AQRNLTQ1
- Part No.:
- LMS3655AQRNLTQ1
- Manufacturer:
- Texas Instruments
- Package:
- 22-PowerVFQFN
- Datasheet:
-
LMS3655AQRNLTQ1.pdf
- Description:
- IC REG BUCK ADJ 5.5A 22VQFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,420
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Product details
Overview
LMS3655AQRNLTQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive synchronous buck converter delivering up to 5.5 A output current, 36-V max input, 400-kHz fixed switching frequency, ±1.5% reference voltage tolerance, and 18-µA quiescent current at 3.3 VOUT with no load-designed for USB charging and driver monitoring ECUs.
For engineers reviewing the LMS3655AQRNLTQ1 datasheet, LMS3655AQRNLTQ1 pinout, LMS3655AQRNLTQ1 application, or LMS3655AQRNLTQ1 equivalent, this page delivers verified technical context, validated pin functions, confirmed automotive-grade thermal and EMI performance, and real-world selection guidance for high-reliability 12-V/24-V automotive power rails.
Technical Context
The LMS3655AQRNLTQ1 implements peak-current-mode control with integrated high-side (60–130 mΩ) and low-side (40–80 mΩ) MOSFETs, enabling stable regulation from 3.5 V to 36 V input down to adjustable 1–20 V output. Its frequency foldback architecture sustains regulation even at VIN = 3.5 V for 3.3-V output.
It features a true open-drain RESET output with 3-ms release timer and internal glitch filtering, plus FPWM mode control, external SYNC input (250–500 kHz), and built-in soft-start (2.5–5 ms), eliminating need for external supervisors or timing components in automotive ECU designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 5.5 A continuous - supports high-power USB PD and surround-view camera modules without external current boosting |
| Input Voltage Range | 3.5 V to 36 V - accommodates cold-crank (3.5 V) and load-dump (42 V transient) conditions per ISO 7637-2 |
| Switching Frequency | 400 kHz ±10% - enables compact 2.2-µH inductors and reduces EMI filter size in space-constrained ECUs |
| Quiescent Current | 18 µA at 3.3 VOUT, no load - meets automotive standby power requirements (e.g., < 100 µA for always-on modules) |
| Reference Voltage Tolerance | ±1.5% - ensures tight output regulation across –40°C to +125°C ambient for safety-critical ADAS sensors |
| Junction Temperature Range | –40°C to +150°C - qualified for under-hood deployment in engine control and LIDAR systems |
| RESET Output Delay | 3-ms release time - provides clean, debounced system reset signal without external RC network |
Pinout & Package
Package: 22-pin VQFN (RNL), 4.0 mm × 5.0 mm, wettable flanks - supports automated optical inspection (AOI) of solder joints per IPC-A-610.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VCC | Internal 3.1-V LDO output | Power source for internal control logic; requires 4.7-µF ceramic capacitor to AGND for stability |
| 2 CBOOT | Bootstrap capacitor node | Drives high-side gate; connects via 470-nF capacitor to SW for reliable 100% duty-cycle capability |
| 3 SYNC | External clock synchronization input | Accepts 250–500 kHz system clock; eliminates beat frequencies in multi-rail automotive domains |
| 4,14 PVIN1/PVIN2 | Main power input terminals | Dual high-current paths reduce PCB trace resistance and thermal stress; must be shorted on board |
| 5,10 PGND1/PGND2 | Power ground return | Low-inductance return for internal MOSFETs; tied directly to AGND and system ground plane |
| 9 SW | Switch node | Connects to power inductor; low ringing due to flip-chip packaging minimizes conducted EMI |
| 15 AVIN | Analog input supply | Bias source for error amplifier; connected to PVIN net for noise immunity in precision feedback path |
| 16 FPWM | Forced PWM mode control | Logic-high disables light-load PFM; ensures constant frequency for EMI-sensitive radar subsystems |
| 18 EN | Enable input | Active-high; 1.7–2.0 V threshold with 0.45–0.55 V hysteresis prevents false turn-on during supply ramp |
| 19 RESET | Open-drain fault indicator | Asserts low on UVLO, overtemperature, or output fault; 3-ms release timer avoids chatter during transients |
| 21 FB | Feedback input | Resistor-divider input for adjustable output; 1-V reference enables 1–20 V programming with ±1.5% accuracy |
| 22 BIAS | Auxiliary bias regulator input | Connected to output for improved efficiency; grounded or externally powered above 15 V output |
Key Features
| Feature | Design Value |
|---|---|
| Integrated compensation | Eliminates external Type-II/III compensation network - reduces BOM count and layout sensitivity |
| Automatic light-load PFM mode | Boosts efficiency to >90% at 10-mA loads - extends battery life in always-on vehicle-to-vehicle communication nodes |
| Low EMI switch-node waveform | Minimized overshoot/ringing via flip-chip packaging and magnetic field cancellation - eases CISPR 25 Class 5 compliance |
| Wettable flank VQFN package | Enables AOI-based solder joint verification - critical for zero-defect automotive manufacturing (IATF 16949) |
| Reset output with internal filter | 3-ms release + 24-µs glitch filter replaces discrete supervisor IC - saves 3 mm² board area and one component |
Applications
| Automotive USB Charge | Driver Monitoring System |
|---|---|
Use Scenario: Powering dual-port USB-C modules in center console with 5-V/3-A and 9-V/2-A PD profiles. IC Role / Device Role / Timing Role: Primary 12-V-to-5-V/3.3-V buck regulator with forced-PWM mode enabled for consistent EMI profile during video streaming. Use Value: 96% peak efficiency at 12-V→5-V conversion reduces thermal load in confined console enclosures. |
Use Scenario: Supplying image sensor, IR illuminator, and SoC in cabin-facing driver attention camera module. IC Role / Device Role / Timing Role: Main 12-V-to-3.3-V power rail with RESET signal used for SoC watchdog reset and sensor initialization sequencing. Use Value: 18-µA IQ_VIN enables <100-µA system standby current - meets OEM sleep-mode leakage budgets. |
| Surround View System ECU | Mechanically Scanning LIDAR |
Use Scenario: Powering four 12-MP image processors and FPGA in 360° camera fusion controller. IC Role / Device Role / Timing Role: High-current 12-V-to-1.2-V/5.5-A intermediate rail feeding point-of-load converters; SYNC input locked to system master clock. Use Value: 5.5-A output and 36-V input withstand surge events during vehicle start-stop cycles without dropout. |
Use Scenario: Generating stable 5-V rail for MEMS mirror drivers and laser diode bias in long-range scanning LIDAR. IC Role / Device Role / Timing Role: Primary 24-V-to-5-V regulator operating in FPWM mode to avoid frequency interference with time-of-flight measurement. Use Value: 400-kHz fixed frequency simplifies EMI filter design while maintaining >92% efficiency at 200-mA partial load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM61480QRNXTQ1 | 8-A output, 2.5-V min input, 2.1-MHz switching - higher frequency but lower VIN min and no frequency foldback | Better suited for space-constrained infotainment head units; not viable for 3.5-V cold-crank operation | Select LMS3655AQRNLTQ1 when cold-crank robustness below 3.9 V is required; LM61480Q requires external pre-buck stage |
| TPS54560QDGQRQ1 | 5.5-A, 3.5–60-V input, 100-kHz–2.5-MHz adjustable frequency - no integrated RESET, higher IQ (43 µA) | Used in body control modules where wide VIN range matters more than integrated supervision | Choose LMS3655AQRNLTQ1 when RESET integration, 18-µA IQ, and AEC-Q100 Grade 1 junction temp (150°C) are mandatory |
Compared with LM61480QRNXTQ1 and TPS54560QDGQRQ1, the LMS3655AQRNLTQ1 uniquely combines cold-crank operation (3.5 V), integrated RESET with filtering, and 150°C junction rating - making it the only option qualified for under-hood LIDAR and high-temp ECU deployments without derating.
Availability
LMS3655AQRNLTQ1 is available at Aetrix Electronics and suitable for automotive USB charge, driver monitoring, surround view system ECU, and mechanically scanning LIDAR applications requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.
Supply support for LMS3655AQRNLTQ1 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 deep expertise in automotive-grade power management ICs and functional safety design.
The LMS3655AQRNLTQ1 belongs to TI's LMS36x5-Q1 family of AEC-Q100 Grade 1 synchronous buck converters, engineered specifically for high-reliability automotive power rails where cold-crank resilience, low EMI, and integrated supervision are critical.
FAQ
What is the minimum input voltage required for LMS3655AQRNLTQ1 to regulate a 3.3-V output at full 5.5-A load?
The LMS3655AQRNLTQ1 maintains regulation at 3.3 V and 5.5 A with a minimum input voltage of 3.8 V after startup, per Section 7.7 of the datasheet. This enables operation during automotive cold-crank events where battery voltage dips to ~3.5 V, supported by the device's frequency foldback architecture that sustains control loop stability below nominal input.
Does LMS3655AQRNLTQ1 support external synchronization, and what is the valid frequency range?
Yes, LMS3655AQRNLTQ1 supports external synchronization via the SYNC pin, accepting a system clock in the 250 kHz to 500 kHz range with 25%–75% duty cycle. This allows precise alignment of switching edges across multiple rails in ADAS domain controllers, reducing beat-frequency EMI and simplifying EMC filter design for automotive compliance.
How does the RESET output of LMS3655AQRNLTQ1 behave during startup and fault conditions?
The LMS3655AQRNLTQ1 RESET output is open-drain and asserts low during EN deactivation, UVLO, thermal shutdown, or output undervoltage. It releases high 3 ms after regulation is established, with internal 24-µs glitch filtering. This eliminates need for external RC timing networks and provides a clean, debounced system reset signal compatible with automotive microcontrollers.
What package type and mounting features does LMS3655AQRNLTQ1 use for automotive reliability?
LMS3655AQRNLTQ1 uses a 22-pin VQFN (RNL) package measuring 4.0 mm × 5.0 mm with wettable flanks. This enables automated optical inspection (AOI) of solder joints without x-ray, meeting IATF 16949 zero-defect requirements. The flip-chip construction also minimizes parasitic inductance, reducing switch-node ringing and improving EMI performance in dense automotive PCB layouts.
Can LMS3655AQRNLTQ1 operate with an adjustable output voltage, and what is the supported range?
Yes, LMS3655AQRNLTQ1 supports adjustable output from 1 V to 20 V using the FB pin and external resistor divider. The internal 1.0-V reference has ±1.5% tolerance, and operation above 15 V requires grounding or externally powering the BIAS pin. For outputs between 1 V and 6 V, standard application circuitry applies; extended ranges may require layout adjustments and factory consultation.
LMS3655AQRNLTQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 22-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):
- 3.9V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 1V
- Voltage - Output (Max):
- 15V
- Current - Output:
- 5.5A
- Frequency - Switching:
- 250kHz ~ 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 22-VQFN-HR (5x4)
LMS3655AQRNLTQ1 FAQ
1.How can I place an order for LMS3655AQRNLTQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LMS3655AQRNLTQ1 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 LMS3655AQRNLTQ1 reliable?
The price and inventory of LMS3655AQRNLTQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMS3655AQRNLTQ1 is usually 5 days.
3.What payment methods are accepted for LMS3655AQRNLTQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMS3655AQRNLTQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMS3655AQRNLTQ1?
LMS3655AQRNLTQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMS3655AQRNLTQ1 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 LMS3655AQRNLTQ1?
For technical support, including LMS3655AQRNLTQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMS3655AQRNLTQ1 requirements.
6.How does Aetrix verify that LMS3655AQRNLTQ1 is sourced from the original manufacturer or authorized distributors?
All LMS3655AQRNLTQ1 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 LMS3655AQRNLTQ1 meets industry standards.
7.What is the process for return or replacement of LMS3655AQRNLTQ1?
All LMS3655AQRNLTQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LMS3655AQRNLTQ1, 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 LMS3655AQRNLTQ1 part is unused and in its original packaging.
Return procedure for LMS3655AQRNLTQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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